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ESSENTIALSOFSMTPRACTICALKNOW-HOWMR.YOUNGBONGKANG

NotionPress5MuthuKalathyStreet,Triplicane,

Chennai-600005

FirstPublishedbyNotionPress2013

AllRightReserved.

ISBN:978-93-83185-54-2

Thisbook is sold subject tocondition that it shallnotbywayof tradeorotherwise,belent,resoldorhiredout,circulatedandnoreproductioninanyform,inwholeor inpart(except forbriefquotations in critical articlesor reviews)maybemadewithoutwrittenpermissionofthepublishers.

This book has been published in good faith that thework of the author is original.Allefforts have been taken to make the material error-free. However, the author and thepublisherdisclaimtheresponsibilityforanyinadvertenterrors.

ABOUTTHEAUTHOR

Mr.YoungBongKang

DOB-28August1970

Citizenship-SouthKorea

SMTExperience-24Years(18yearsinKorea&6YearsinIndia)

PreviousPublication-“SMTManagement”(KoreanLanguage)in2007

WorkatYBTechsolutionPvt.Ltd.

Designation-ManagingDirector

JobDescription-ConsultantprovidestotalSMTsolution.

TranslationSupport

Mr.KiyoungJin-B.A.(KoreaUniversity),Ph.D(UniversityofEdinburgh)

Ms.QuarinaShaikh-DE&Tc(CWITPune),EngineeratYBTechsolutionPvt.Ltd.

FOREWORDI feel privileged to be asked to contribute this little foreword for this wonderful bookwrittenbymygoodfriend,YoungBongKang.

IfirstmetKangwhenhecametoIndiain2007andjoinedM/sEverElectronics(oneofthemainOEMfortheKoreangiant,L.G.Electronics)asmyjuniorcolleague.Fromthebeginning,heimpressedmewithhisprofessionalismandin-depthknowledgeofworkingon theshop-floor,particularlywithSMTtechnology.Tobehonest, Iwouldbeonly toohappytoadmitthatthoughhewasreportingtome,IlearntalotfromhimabouttheSMTprocess! He has a rich experience of 24 years in SMT manufacturing, right from theselectionofmachines,layoutofmachines,processparametersandmaterialmanagement.

KanghasputallhispracticalknowledgeandwisdomassociatedwithSMTmanufacturingandpresentedallitsnuancesinaveryeasy-to-understandformatthroughthisfinebook.AfterhavingworkedwithSharpandLGElectronicsforcloseto20years,IcanvouchforthefactthatIhaveneverseenabookthatissopracticalinnature.Itmakesmerealizethatif only I had had an opportunity toworkwith such a genius duringmy apprenticeshipperiod,Iwouldhavebeenmilesahead!

I strongly recommend this book to all who wish to pursue a career in Electronics’manufacturing as SMTwill be the technology for the FUTURE…This bookwill be avaluableguidetoyoungengineersaswellasProductionmanagers.Moreoverforallthosewhoderivepleasuremerelyfromthejoyofreadingandlearning,thisbookwilldefinitelygiveimmensesatisfaction…

PuneN.Sreedharan

June9,2013AssociateVice-President,

KineticCommunicationsLimited.

PROLOGUEThisisapracticaltechnicalbookwrittenbytheauthorbasedon24yearsofexperience.Almost all SMT books, due partially to a few SMT-related books, put weight onequipment,singleprocessorparttechnologyratherthandealwithpracticalprocess.Thebookdealingwithpracticalprocessknow-howisrarelyfoundandthisisperhapsthefirstbookinwhichoverallSMTpracticalprocessesandstandardsarepresented.

After IwroteaboutSMTmanagement techniques forbeginnermanager in2007, Ihavekept on thinking towrite about overall practical processes of SMT,Nonetheless, IwasdeeplyinvolvedinothercompanyandwritingabookinEnglishwasfeltasaburdenduetomypoorEnglish,andthusmysecondbookcameoutabitlate.FortunatelyImetagoodtranslatorandthenSMTbookinEnglishcanbepresentednowtoyou.

Although now I live in India in 2013, I have experienced SMT across Korea, China,Philippines and India. Through this experience I draw my conclusion that what ishappeninginSMTissameregardlessofcountriesandthesmallercompaniesarefoundtohave the more trial-and-error and work with wrong process due to lack of correctinformationofSMT.

AlthoughauditofstandardizationcertificationorganizationlikeISOmaypointoutsomecautions,itisdifficulttoexpectSMTtechnicalsupportinaccordancewithcautions.Itisgood to use 6 sigma tool, and yet it takes a lot of time tomake statistical data for theperiod.Moreover,incaseTFTteamhasnoknowledge,theydonotfindthesolution,fordetecting thecorrect rootcausefromdefinestep isnevereasy.Eventuallyknow-howofinternalhumanresourcesisnecessary.

StandardizationofSMT,inreality,hasquiteadifficultpart.Despitethesameequipmentandsamecondition,itbecomesdifferentdependingonhumanresources.Sincecompanywise equipment investment is different, product group is different, environment isdifferent,sameworkprocesscannotbeappliedtothese.

In the area of SMT management major companies reduced error-and-trial greatly bycomputerizing quite a portion ofmanualwork and standardizingwork process, and yetthey do not know whole process structure, since they work within a parameter ofcomputerizedprocess.Incaseofsmallcompaniestheyarestillgoingthroughtheprocessoftrial-and-error.

If the process ofmajor companies intends to be applied to their vendor companies, thesameamountofinvestmentandmanpowershouldbecommitted.Incaseevenonethingislacked,itisunnaturalaswornunfitclothesandworkdoesnotproceedsmoothly.Attheendstandardandprocessmayworkseparately.

Thisbookaimstocontainalltheessentialhands-ontechniquesfrombasicSMTtoSMTmanagementonthewhole.Theauthorwishesthatthisbookcouldbealotofhelptothosewho just start SMT or struggle with lack of knowledge and standards although theyalreadystarted.

Noneedtoreadtheentirebook,justopenthechapterinwhichyouareweak.

ContentsTitle

Copyright

AboutTheAuthor

Foreword

Prologue

1.WhatisSMT?

2.GrowthinHistoryforSMT

3.IntroductiontoSMT

4.BasicsofSMTTraining

5.SMTLineMachines

6.SMTProcessManagement

7.ImprovementResult

8.Terminology

Reference

HOWMUCHDOYOUKNOWABOUTSMT?

REMEMBER

SMTWORKSBYMACHINEBUTOPERATESBYHUMAN

1WHATISSMT?

Surface Mount Technology means the technique of affixing the Surface MountComponentsautomaticallytothesurfaceofPCB(PrintedCircuitBoard).

ThecomponentusedinSMTiscalledasSurfaceMountDevices(SMD).

These components are leadless having soldering terminals at the corner of chip orhavingsolderballs(BGA)orflatsurfaceIC’s.

(a)AI(AutoInsert) (b)SMT

Figure1.1

Figure1.2BasicSMTLine

WhySMTisneeded?

Forthemassproductionofelectroniccircuitboardsrequiressometechniquetoreducethemanufacturingcost&time.InThroughHoleTechniquetheleadsneedtobeinsertedintoboardandhence theproblemswereautomaticallyencountered if the leadsarenot fittedproperly,whichslowsdownproductionrate.

Allelectronicproductsrequiremorefunction&smallsize,socircuitPCBneedstobecompact.The leads thathaveusedforconnectionactuallynotrequireforprintedcircuitboardconstruction.Thecomponentcanbe soldereddirectlyon to thepadsof thePCB,

whichsavesthecostofmakingholesinprintedcircuitboard.

As the components were mounted on the surface of the board rather than havingconnections thatwent through theholes in theboard, the technique is calledasSurfaceMountTechnologyorSMT&thedevicesusedinthisiscalledSurfaceMountDevicesorSMD.

DefinitionofSMT

“Surface Mount Technology (SMT) is a method for constructing electronic circuits inwhich the components (SMD - SurfaceMountedDevice) aremounted directly onto thesurfaceofprintedcircuitboards(PCBs)”.ElectronicdevicesmadewiththismethodarecalledsurfacemountdevicesorSMDs.

2GROWTHINHISTORYFORSMT

HISTORY:Surfacemounttechnologystartedin1950’swhensurfacemountcomponentswereappliedforthefirsttimetomilitarysupplies.In1960’sthesurfacemounttechnologygrewoutoflimited hybrid circuit products market and attached with ceramic to the surface ofmaterial.

In 1970’s Japanese electronics industry produces small portable electronic productswithwhichtheproductioncostscouldbereducedandtowhichconsumerspreferred.Asonly the solder joints hold the component to the board, the surface mounted devices(SMDs)areusuallymadesmallsize&lightweight.SMDscanbeone-quartertoone-tenthofthesizeandweight,andone-halftoone-quarterofthecostofequivalentthrough-holeparts.

ThesizeofChipcomponentsreducesfrom

3216–>2012–>1608–>1005–>0603–>0402

TheIC’sbecamemorecompactfrom

SOP–>SOJ–>QFP–>FCC–>BGA–>FlipChip

Intheearly1980’s,thelevelofintegrationoftheintegratedcircuit(IC)wasevenhigherand the electronic circuits became complicated.With this change the number of leadsgreatly increased and in many cases was more than 100. Since DIP IC for insertionrequiredmoreareathantheICforsurfacemountwhichhasnoleads,itsdemandstartedtodecrease.Untilthemid-1980s,surfacemountcomponentshadbeenusedmainlyforsmallhybridcircuits.Thereasonforthatwasthelackofhigh-speedautomaticequipmentwhichcouldbringaboutmassproductionofproducts.Inrecentyears,duetothedevelopmentofthe surfacemount related technologies, diverse components of surfacemount aremassproducedandthehigh-speedequipmentbywhichavarietyofmicro-partscanbeappliedtodensesubstratesisdevelopedsothatthesurfacemountproductsareenabletoproduceatalowercostthantheirowncompany’sexistingproduct.

Figure2.1TransitionofMountingtypes

TransitionofMountingTypes:

(1)1950-tube,thefirstgeneration,largehigh-voltagedevices.

(2)1960-Thesecondgeneration,mobileproductsparts.

(3)1970-Thethird-generationsmallmobiledevices,odd-shapedparts.

(4)1980-Thefourthgeneration,compacthigh-densitydevices,surfacemountparts.

(5) 1990- The fifth-generation ultra-compact-high-density devices, complex surface-mountcomponents,ultra-miniaturization,thinned,multiplexed,high-densitymounting,high-speedmounting.

AdvantageofSMT:

ThemainadvantagesofSMToverthethrough-holetechniqueare:

•Sophisticatedmanufacturingprocesses.•Smallsizeandlightweightcomponentsareused.•Noneedtodrilltheholesthroughboard.•Simplerautomatedassembly.•Componentplacementerrorsarecorrectedautomatically.•Bothsidesmountingarepossible.•SMTpartsgenerallycostlessthanthrough-holeparts.

DisadvantageofSMT:

•Highinitialcostandtimeofsettingupforproduction.•Difficultyinmanualhandlingduetotheverysmallsizes.• As solder paste is used itmakes repair of devices extremely difficult, and oftenuneconomical.

AskYourselfWhatisthebasicofSMT?

HowmuchdoyouknowaboutbasicsofSMT?

3INTRODUCTIONTOSMT

3.1IntroductiontoSMTMachines

1)Loader/Un-loader

Loader and un-loader is used for loading and unloading the PCB’s, an arriving PCB istakenupandtakendownbytheattachedconveyorandpushintothemagazinebypusher.Themagazine is indexes to thenextpositionand is readyfor thefollowing loadingandunloadingcycle.

Beforestartingtheline,thesetpitchdifferenceofloaderandUn-loaderistobecheckedalways.

Figure3.1Magazineloader

Figure3.2Vacuumloader

Figure3.3GateConveyer

Figure3.4MagazineUn-loader

2)ScreenPrinter:

Screenprintingisaprintingtechniquewhichisusedtoprintsolderpasteoradhesiveonthe PCB surface. The stencil has open areas to transfer the solder paste. A roller orsqueegeeismovedacrossthestencil,forcingsolderpastthroughthemeshonPCB.

Screenprintingisveryimportantbecauseit iscloselyrelatedwithproductionquality.80-90%ofthedefectsintheproductarecausedbyinappropriatescreenprinting.

Figure3.5ScreenPrinter

3)SolderPasteInspector(SPI):

ItistheequipmentintheSMTlinetodetectfaultsoccurredduringsolderpasteprintingprocess. The inspection criteria are set by the program. It is automated equipment;developedtoreducetheerrorsduetovisualhumaninspection.Inproductionlinewheresmall pitch components areused,SPI is essential as80%ofSMTdefectsdependuponpasteprinting.It isusedfordetectingprintingdefects likemissingsolder,excesssolder,nosolder,solderpasteheight,etc.

In-lineSPIisusedfor100%detectionpurposewhereasOff-lineSPIcanbeusedonlyforsamplingcheck.

OffLine

InLine

Figure3.6SPI

4)Mounter:

Thecomponentstobeplacedontheboardsareusuallydeliveredtotheproductionlineineitherpaper/plastic tapeswoundon reelsorplastic tubes.Some large integratedcircuitsaredeliveredinstatic-freetrays.Thepick-and-placemachines(Mounter)removethepartsfromthetapes,tubesortraysandplacethemonthePCB.

Machine is used for standard partmounting and dissimilar partmounting dependingupontherequirement.

(Standardcomponent like resistors, capacitors&dissimilarcomponent like IC,BGA,andConnectors,etc.)

TypesofMounter:

(1)OnebyOneMount(GantryType):

It is low speed production equipment.When PCBmoves in the loading area, the PCBstaysinfixedpositionandtheheadofmountermovesalongXandYaxis,pickupsandloadscomponentsonPCBforsmallnumberofpointsinproductionlineandformountingofLCDandRFmodules onPCBofmobile phone.One by one type is a suitable chipmounter,incaseofhighernumberofpointsinproductionline,rotarychipmounteristhemainmounterandthenmulti-mounterisused.

Figure3.7OnebyOneMount(GantryType)

(2)RotaryMount:

It isused in lesscomplexandmassproductionsystem.It isa loadingsystemwhere thePCBmovestothemountingposition;thefixedheaddrumrotatesandrepeatsthemotionand the tablewith loadedPCBmoves alongX,Yaxis. It is suitable forhighmountingpointsperPCB,sincemore than200pointsspacebetweenparts isnarrow. It isused inhighdensityproductiontypemountings.

Theareaoccupiedbyequipmentishighandtheloadingareaistoowide,lengthofthelinegetslonger,andtheweightofmainbodyissoheavythatvariousproblemsoccursuchasvibrationfrom2ndand3rdfloors,generallyitisinstalledinthe1stfloorconstructionwithreinforcements.

Figure3.8RotaryMount

(3)ModuleMount:

In themodular type equipment, the speedof eachmodule is not fast, dependingon theaddedquantityof themodule theproductioncapacity increases,and ithasadvantage inacquiring a smaller area and the lighter weight of equipment than rotary type. Foroptimizing the loadingprogram, thesupplyof requiredcomponentsneeds tobeworkedseparatelythroughmanyfeederssothatitguaranteesmaximumefficiencyasthequantityofproductionrequirementgetshigher.

Therefore, the quantity in supplying of components by manufacturer to multiplenumbersofreelunitsshouldbeefficientlymanaged.Otherwise,ifabottleneckoccursin

thesupplyofcomponent,incaseofhighernumberofcomponentrequirementinloadingmodules,itwillbeleadtoareverseeffectandtheproductioncapacityofthewholelinegetslower.

Figure3.9ModuleMountEquipment

(4)ReflowOven:

Itistheequipmentusedtohardenthesolderpasteandmakethebondingbetweenchips,solderpasteandPCBpad.

ThePCBfirstentersinapre-heatzone,wherethetemperatureoftheboardandallthecomponents are gradually, uniformly raised. The boards then enter a zone where thetemperature is high enough tomelt the solder particles in the solder paste, bonding thecomponenttothepadsonthecircuitboard.

Figure3.10ReflowOven

TypesofReflow:

(1)VaporPhaseReflow

ItwasdevelopedbyWesternElectricin1975,inthissolderingtypeahightemperatureisusedtovaporizechemicalwhichisblownonthePCBtosetthesolderpaste.

(2)IRReflow(InfraredReflow)

It isa typeofsolderingwhichusesheatgeneratedbyradiation fromquartz filamentbyappliedvoltage.

(3)LaserReflow

Itisatypeofsolderingwhichuseslaserbeam.Therearetwotypes,CO2laserandYAGlaser.

(4)HeatAirReflow(ConvectionReflow)

Itisasolderingtypethatusesheatgeneratedbythefanheatertoheattheairinacertainareabyconvection,maintaininguniformtemperature.

(5)TypeofReflowinN2(Nitrogen)Atmosphere

All materials of the general atmosphere generate oxide by reaction with oxygen andespeciallyinhigh-temperaturespeedofoxidationarefaster.However,chemicalchangeisless in the presence of Nitrogen; it could be controlled for lead soldering in nitrogenatmosphere.Theabovetypeisnitrogenatmospherereflow.In2006,thereisachangeinprocess from existing lead solder paste to lead-free (Pb-free) solder paste. From thebeginningof2000N2(nitrogen)atmosphere reflowequipmenthasbeendevelopedasasubstituteforPb-freesoldertype.

(6)AutomatedOpticalInspector(AOI):

It is theequipment in theSMT line todetect external faults inproductionbasedon theinspectioncriteriasetbytheprogram.Automatedequipmentsweredevelopedandusedtostabilize the quality of standardized tests by compensating for errors existing in visualhuman inspection, caused by manual factors, ability of inspection per person andinstabilityininspectionqualitybychangingworkers.

Thereareoff-line(deskstyle)typeandin-linetypeoftestequipmentandgenerallyin-linetypeismoreexpensivethanoff-lineasithasmanymoreoptions.

Figure3.11AOI

3.2SMTLineConfiguration

1)Bond+AILine:

GlueisusedtoholdthecomponentstothePCBduringthetotalprocess.

ProcessFlow:

Applygluebyprintingthroughstencilordispensingthroughsyringemethod.

DotheMountingofSMTcomponents.

Curetheadhesiveinreflow.(Glue)

Manuallyinsertthethrough-hole(TH)componentsonothersideofPCB.

Passtothewavesolderingm/cforsolderingofTH&PassiveSMTComponents.

Figure3.12Bond+AIlineProcessFlow

LineConfiguration:

Figure3.13Bond+AILineConfiguration

2)SMT+AI+BondLine:

InthisprocessfirstneedtodosolderprintingthenBondprocessbecausebondrequirelesscuringtemperature(150�C)thansolderpaste.

ProcessFlow:

Dothesolderpasteprintingatside-1ofPCB.

PlacetheSMTcomponentsthroughmounter.

DoSolderingbyreflowoven.

Insertauto&Manualthroughholecomponentsonside-1.

ReversethePCB;applyAdhesivetotheside-2ofPCB.

DotheMountingofSMTPassivecomponents.

Curetheadhesive.(Glue)

ReversethePCBonside-1andpassthroughwavesolderforsolderingofTH&PassiveSMT

Components.

Figure3.14SMT+AI+BondlineProcessFlow

Lineconfiguration:

Figure3.15SMT+AI+BondLineConfiguration

3)SMT+SMTLine:

ProcessFlow:

Dothesolderpasteprintingonside-1ofPCB.

PlacetheSMTcomponentsthroughmounter.

Reversetheboard&dothesolderpasteprintingonside-2ofPCB.

PlacetheSMTcomponentsonside-2

Figure3.16SMT+SMTlineProcessFlow

Lineconfiguration:

Topside:

Figure3.17SMT+SMTLineConfiguration

Bottomside:Reverse thePCB todomountingonother side and repeat theprocess as

above.

4BASICSOFSMTTRAINING

IntroductiontoSMTMaterial:

ThecomponentusedinSurfaceMountTechnologyiscalledasSurfaceMountDeviceorSMD.AnSMTcomponentisusuallysmallerthanitsthrough-holecounterpartbecauseithaseithersmallerleadornoleadatall.Itmayhaveshortpinsorleadsofvariousstyles,flat contacts, and a matrix of solder balls (BGAs), or terminals on the body of thecomponent.

ComponentName AIComponents SMTComponents

Resistor

Capacitor

Transistors

Figure4.1AIandSMTComponents

Packages:

Surface-mountcomponentsareusuallysmallerthanthroughholeandaredesignedtobehandled bymachines rather than by humans. The electronics industry has standardizedpackageshapesandsizes.

Figure4.2

ComponentSpool/reel:

Figure4.3

SpoolLabel:

Figure4.4

TypesofSpool:

Figure4.5

ICTraySupplyType:

Strip Tray Spool/Reel

Figure4.6

4.1R-L-CValueCalculation

1)Resistor:

It is used in the electronic production, it decides amount of the electric current and itshouldbeusedaccordingtovolume(orcapacity),size&tolerance.

SMDresistorsaremarkedwiththeirresistancevaluesusingthreedigits,twosignificantdigitsandamultiplierdigit.Commonlywhiteletteringonablackbackgroundisused.

Usuallytheblackorcolouredcoatingisdoneonlyononefaceofthedevice,whilethesidesandotherfacearewhiteceramicoruncoated.ThecoatedsurfacewiththemarkingonitisnormallypositionedfacingupwhenthedeviceissolderedtothePCB.

Mark:‘R’

Symbol:

Unit:‘Ω’–Ohm

Figure4.7

WayofReading:

Thebasicresistor ismarkedwith thenumberof three(3) figures in the levelofJ (5%).Initialtwo(2)figuresmarkindexandonefiguremarksmultiplier.

The details (or Precise) resistor level F (1%) ismarkedwith the number of four (4)figuresandinitialthree(3)figuresmarkindexandonefiguremarksmultiplier.

TheunitofresistorismarkedasOhm(Ω).Theunitcanbeconvertedasfollows–

1Ω=1X10°Ω=1Ω(1ohm)

1kΩ=1X103Ω=1,000Ω(1kiloohm)

1MΩ=1X106Ω=1,000,000Ω(1Megaohm)

AllowableToleranceofResistorChip

Mark AllowableTolerance Note

J �5% GeneralChipMaterial

F �1% Detail(orPrecise)chipmaterial

Figure4.8

Example:

The3digitpartnumberindicates±5%tolerance(JType).

R100=10Ω±5%

R101=100Ω±5%

R102=10X100=1000Ω=1KΩ±5%

R103=10X1000=10kΩ±5%

R0R5=0.5Ω(Rbetweenthe2digitdenotesadecimalpoint.)

The4digitpartnumberindicates±1%tolerance(FType).

R1001=100X10=1kΩ±1%

R1003=100X1000=100kΩ±1%

R1004=100X10,000=1000kΩ=1MΩ±1%

2)Capacitor:

A capacitor is a device which stores and discharges electric current, depending on thecapacity, size, character and tolerance of a dielectric which is placed in between twoconductingplateswhichcreatethecapacitance.

Nonelectrolyticcapacitorsareusuallyunmarkedandtodeterminingtheirvalueneedtoremoveitfromthecircuitandmeasureitwithacapacitancemeter(LCRmeter).

SMD (non electrolytic) capacitors exhibit the same body colour on all four facescoveredbytheendcaps.

Mark:‘C’

Symbol:

Unit:‘F’Farad.

Figure4.9

HowtoReadCapacitorCode:

Acondensercanbemarkedwitha3digitnumber,wherethefirsttwoarethe1stand2ndsignificantdigitsandthe3rdisamultipliercode.UnitofcondenserisFarad(F)–basicunitcanbemarkedaspico-farad(pF)

Theunitcanbeconvertedasfollows–

1mF=10-6(microFarad)

1nF=10-9(nanoFarad)

1pF=10-12(picoFarad)

CondenserTolerance:

Mark AllowableTolerance Note

C ±0.25% 5pF~10pFappliedvalues

D ±0.5% 5pF~10pFappliedvalues

J ±5% 10pForhigherappliedvalues

K ±10%

M ±20%

Z –0.25%~+80%

Figure4.10

Example:

C100=10pF

C101=100pF

C102=1000pF=1000x10-12=1x10-9=1nF

C103=10000pF=10000x10-12=10X10-9=10nF

C104=100000pF=100000x10-12=100X10-9=100nF=0.1μF

C105=1000000pF=1000000x10-12=1X10-6=1.0μF

C0R5=0.5pF

TheRinbetweenthedigitsdenotesadecimalpoint.

Followingmethodsareusedtoincreasethecapacityofacapacitor-

1.Usingwiderconductingplates.

2.Decreasingthedistancebetweentheplates.

3.Usinghigherdielectricconstantoftheinsulator.

Resistor&CapacitorValueCalculationMethod:

Resistor Capacitor

1Ω=100Ω=1Ω(Ohm) 1pF=10-12(picoFarad)

1kΩ=103Ω=1,000Ω(Kiloohm) 1nF=10-9(nanoFarad)

1MΩ=106Ω=1,000,000Ω(Megaohm) 1μF=10-6(microFarad)

Whilecalculatingthevaluesofcapacitor,1stcalculatethevaluebyresistorcalculatingmethodandthenconvertitintocapacitorvaluebyusingaboveconvertingmethod.

Example:

R100=10Ω C100=10pF

R101=100Ω C101=100pF

R102=1kΩ C102=1nF

R103=10kΩ C103=10nF

R104=100kΩ C104=100nF

R105=1.0MΩ C105=1μF

3)Inductor:

DuetothesmalldimensionsofSMDs,SMTinductorsareavailableinlimitedvaluesoflessthanabout1mH.Itisametalconductorloopedthroughaferritebeadwithendcaps.Theyareofdarkgreyincolour.Larger inductorsandtransformersmaybethrough-holemountedonthesameboard.

SMT inductors with larger inductance values often have turns of wire or flat straparound thebody,allowing thewireor strap tobe seen.Sometimesa ferritecore is alsopresent.

Sameas a capacitors, componentvalues and identificationarenotusuallymarkedonthecomponentitself.Itneedstoberemovedfromthecircuittodeterminingthevalues.

IncreasingthenumberofturnsofwireinthecoilwillincreasethevalueofinductorinHenry.

Mark:‘L‘

Symbol:

Unit:‘H’Henry

Figure4.11Inductors

HowtoreadInductorCode:

TheunitofinductorisHenryandthebasicunitisnanoHenry(nH).

1H=10-6(microHenry)

1nH=10-9(nanoHenry)

Example:

L471=47�101470nH

L4N7=4.7nH

ThepresenceofNinthevalueofinductorcoildenotesadecimalpoint.

4.2IntroductiontoOtherSMTComponents

1)Diode:

Mark:‘D‘

Symbol:

It’saPNfunctionalbipolarsemiconductordeviceusedinvariouscircuits.

Typesofdiodesarerectifierdiode,zenerdiodes,lightemittingdiodes(LED)etc.

Figure4.12

2)Transistor:

Mark:‘Q’OR‘TR‘

Symbol:PNPType

NPNType

Transistor is a component which amplifies the current. Various kinds of analoguecircuitsusetransistorwhilelessusedinthedigitalcircuit.Theamplificationcharacteristicoftransistormakesnodifferencetothedigitalcircuitwhichishandledby2signalsbeing‘ON’and‘OFF’.ThecircuitfunctionismostlyhandledbytheIC.

There are 2 types of transistor, PNP and NPN, depending on the placement of thesemiconductorcomponents.

Figure4.13

3)IntegratedCircuit(IC’s):

Mark:‘IC’OR‘U‘

Integrated circuit is a package of high density combination of transistors, resistors andcapacitors. IC is actually a high density printing technique of resistors, capacitors andtransistors on a silicon wafer performing the functions of transistors, resistors orcapacitors.

ICPolaritycanberecognizedbynotch/whitecolourband/dotmarkingonit.

ForSOP-PintothesideofthenotchisconsideredasFirstPin.

Figure4.14

ForQFPPintothesideofnotchinanticlockwisedirectionisconsideredasfirstpin.

Figure4.15

TypesofIC’s:

(1)SOP(SmallOutlinePackage):TheICwithleadscomingoutwardsontwosides.

Figure4.16

(2)SOJ(SmallOutlineJunction):TheICwithleadsgoinginwardsontwosides.

Figure4.17

(3)QFJ(PLCC)(QuadFlatJ-LeadPackage)orPLCC(PlasticLeadlessCarryPackage):TheICwithleadsgoinginwardsonfoursides.

Figure4.18

(4)QFP(QuadFlatPackage):TheQuadFlatPackageICwithleadscomingoutwardsonfoursides.

Figure4.19

(5)BGA (BallGridArray): It is oneof the large scale integrated circuit packages.LSIbare chip is mounted on the small quad printed circuit board. Behind the PCB, 2dimensionalarraysofhemisphericalterminalballsarearranged.

Figure4.20

(6)CSP (ChipSizePackage,ChipScalePackage):The semiconductor package has thesamesizeasthechiporlittlebigger.Collectivelyitisanultrasmall,ultrathinandlightweightsemiconductorpackage.

Figure4.21

(7)FlipChip(flipchip):ThesemiconductorwithoutleadsisbondeddirectlyonthePCB.Thepackagesizeissameasthechipsoitmakesitsmallerandlighter.Theinput/outputterminalispresentonthechipbase.

4)Filter:

Itfiltersthecapacityandfrequency.

Figure4.22

5)Connector:

ItconnectsdifferentPCBorcircuit.

Figure4.23

4.3SMTDefects

1)MissingSolder:

Cause:i)Soldernotvisible.

ii)Solderpastenotapplied.

Figure4.24

2)Short(ShortedBridge):

Cause:i)Terminalsconnectedbyextrasolder

ii)Thelandbetweentheterminalsisfilledwithsolder.

Figure4.25

3)MissingComponents:

Cause:i)Theconditionofthepartisaffixedinthewrongplace.

ii)Loststatusofpartonspecificlocation.

Figure4.26

4)ColdLeadSolder:

Cause:Badsolderduetoviolationofcorrecttemperature.

Figure4.27

5)LessSolder:

Cause: Less than the stated temperature (stated temperature violation) leading to lesssolder.

Figure4.28

6)SolderinExcess:

Cause:i)Morethanthestatedtemperatureleadingtoexcesssolderflow.

ii)Excesssupplyofsolderpasteduringpasteprinting.

Figure4.29

7)WrongComponents:

Cause:Affixingcomponentsotherthanwhatisprescribedforadesignatedarea.

Figure4.30

8)ReversePlacement:

Cause:Componentsmountedwithoppositepolarity.

Figure4.31

9)UpsideDownComponentAssembly:

Cause:Theuppersideofcomponentgetsmounteddown&downsideup.

Figure4.32

10)MissAlignment:

Cause:ChangeoftheXorYco-ordinatesoraxis.

Figure4.33

11)Twisted:

Cause:Thecaseofturningthecomponentfromitsspecificlocationwhilebeingmounted.

Figure4.34

12)BrokenandDamagedParts:

Cause:ThecaseofdamagingcomponentsandpeelingPCB.

Figure4.35

13)Tombstone:

Cause:ThecaseinwhichonesideofthecomponentgetsraisedanditselectrodemakesnocontactwiththePCB.

Figure4.36

14)SolderBalls:

Cause:i)Duetoimproperstencilcleaning.

ii)DuetowrongdesignofcomponentpadonPCB.

iii)Wrongsettingofreflowtemperatureprofile.

Figure4.37

15)Floating:

Cause:ThestateinwhichalltheleadsoftheICarenotconnectedtothePCBandonesideisraisedandisfloatingontopofthePCB.

16)Scratches:

Cause:ThestateinwhichtherearescratchesonthePCBsurface.

17)PCBBending:

Cause:ThecaseinwhichthePCBsurfaceisnotbeingflatandhasbends.

18)Overheat:

Cause:IntheeventofoccurringripplesandoverheatinthereflowovenanddamaginginthecomponentsandthePCB.

4.4IntroductiontoSMTProductParts

ThefullformofPCBisPrintedCircuitBoard.Itisusedtobuildelectronicdevices.The components are place on PCB to make a circuit. It also provides the electricalconnectionbetweenthecomponents.

Itisathin,non-conductingsheetofmaterial.Themostcommonmaterialusedisaglassfiberepoxylaminatematerial.Athinlayerofcopperisthenchemicallydepositedoneachsideofthismaterial.

Then theconnectiondiagram is“print”onto thePCB.Theconnectiondiagram is the

wiring required to connect the components. In early days these connectionswere donewith wires. This is the reason PCBs are also sometimes referred to as printed wiringboards(PWB).The“printing”isusuallydonebyphotographicallytransferringtheimagetotheboard.Thisimageis“printed”withanacidresistantmaterial.

Then, thePCBisput intoanacidbath.Theacidremoves thecopper fromtheboard,exceptfortheareasprotectedbytheresistantmaterial.Thisprocessleavesthe“printed”connectionson thePCB.Finally, aprotective coating is applied to theboard topreventcorrosionofthecoppertraces.

The above process is for doubled sided or two layer PCB. By repeating the aboveprocess it is possible to make any number of layers PCB and laminating the resultingboardsintoasinglePCB.

Figure4.38

TypesofPrintedCircuitBoards:

SingleSidedBoard

It is a simple Printed Circuit Boards with only single layer. All electrical parts andcomponentsarefixedononesideandcoppertracesaremadeontheotherside.

DoubleSidedBoard

It is amost common type of PCB inwhich parts and components are attached to bothsides.Ithasconnectingtracesonbothsides.

MultiLayeredBoard

Multi layered PCB consists of several layers of substrate separated by insulation.Mostcommonmultilayerboards are: 4 layers, 6 layers, 8 layers and10 layers.However, thetotalnumbersoflayersthatcanbemanufacturedareover42layers.Thesetypesofboardsareusedinextremelycomplexelectroniccircuits.

MaterialusedinPCB:

(1)Conductiveink

(2)Laminatematerials

•BT-Epoxy•Compositeepoxymaterial,CEM-1,5•CyanateEster•FR-2•FR-4,themostcommonPCBmaterial.

•Polyimide•PTFE,Polytetrafluoroethylene(Teflon)

PCBGuideDesignSample:

Alotofcompany’sR&Ddoesnothavestandardoffiducialmarkdesigning.R&Dpersonsdo not have SMT manufacturing knowledge; they couldn’t consider SMT productionprocess.(Fiducialmarksize,positionandshape.)

WrongPCBdesign-Nostandardsarefollowedwhiledesigning.

Figure4.39

Figure4.40 is the sampleof fiducialmarkpositionofmobilePCB.Themethodwillavoid the 180� reverse production. Inmobile PCB usually used fiducial mark size is0.8mmto1mm.Ifitssizeisbigger,thetoleranceratioalsowillincrease.

Figure4.40

2)UVBond/SMDAdhesive:

Bond is used to hold surface mounting devices in its position during the placementoperation.

•Thebond(SMTAdhesive)needstobeconductive.•Itshouldhavelongshelflife.•Smallcuretime.

•Moistureresistant.•Non-corrosive.•Freeofholes&voids.

StorageCondition:

Glue shall be ideally stored in a refrigerator, dry location in unopened containers at atemperaturebetween1�to10�C.

IQCProcedure:ProcessFlow

CheckthematerialQtyanditsdocumentsbeforereceivingfromstore.

Checkthematerialfordamage.

ChecktheMfg.&ExpiryDates.

IfnotOK,returnbacktostore.

CheckthecontentswithQualityreport.

Attachadetailedinformationtag.

Storethebottlesinrefrigeratorat1to10�C.

Figure4.41

UseProcedure:

Updatetheremovingtimein“In&OutConsumptionReport”

Keeptheglue2-3hrsatroomtemp.Makedifferentareaof‘FORAGING’and‘AFTERAGING’.

Takethegluetouseon-linefrom‘AFTERAGING’areaonly.

Figure4.42

ApplicationMethods:

(a)PinTransfer

Itusesmatrixofpinsfortransferofglue,itisfastlikestencilprinting.

(b)Dispensing/Syringing(Mostwidelyused)

Youcanapplyvaryingamountofgluedependinguponthecomponent.

Figure4.43DotFormat

LineConfiguration

Figure4.44

(c)Stencilprinting

Itissimilartopasteprinting,fasterinoperation.

Figure4.45

Sometimesduetohighheightofcomponentdispenserrequiredwithscreenprinter.

Lineconfiguration

Figure4.46

GlueCuringObjectives:

Tomaketemporarilyreliablemechanicalconnectionbetweentheprintedcircuitboardandthesurfacemountingdeviceswithoutdamagingthecomponentsandprintedboard.

CuringTemperatureProfile

Figure4.47

3)SolderPaste:

Solderpaste(orsoldercream)isusedtoconnecttheterminalofcomponentstoattachmentpoints (Pad/land) on a printed circuit board. The paste is typically applied to the landsusing a stencil. It is a graymaterial like putty. The composition of solder paste variesdependinguponitsuse.

E.g. Tin/Silver/Copper (Sn/Ag/Cu) or Tin/Lead (Sn/Pb). Flux is added to act as atemporaryadhesive,holdingthecomponentsuntil thesolderingprocessmelts thesolderandmakesastrongerphysicalconnection.

Solderpaste is typicallyused inascreenprintingprocess inwhichpaste isdepositedoverastainlesssteelmasktocreatethedesiredpatternonaprintedcircuitboard.

Figure4.48

Definition:“Solderpasteisanintermediatewhichconnectsthepartsofprintedcircuitsinsurface-mount technology.It is thepaste-typeorcream-typemadebyblendingacertainvolumeofLead,tinandspecialflux”.

ClassificationofSolderCream:

Pbsolder:

•Sn63%,Pb37%mostcommonlyused.•Sn62%,Pb36%,Ag2%PreventionofSolderLeaching.•Sn62.8%,Pb36.8%,Ag0.4%PreventionofTombstonePhenomenon.•Sn43%,Pb43%,Bi14%LowTemperatureSolder.

PbFreesolder(LeadFree):

•Sn96.5%,Ag3%,Cu0.5%(0.3%AgPbfreesolderpastearealsoavailable)

TemperatureandStirringTimeofSolderPaste:

StorageCondition:

Solder paste should be stored in an airtight container at low, but above freezing, attemperature–1to10�C.

KeepinginFridge:

Solder paste should be stored in an airtight container at low, but above freezing, attemperature–1to10�C.

SolderMixingProcedure:

Updatetheremovingtimeoninformationtagandin“Solderpastemixingreport”.

Afterremovingfromrefrigeratorkeepat‘BEFOREAGINGAREA’for2to3hrs.

Dothetimeanddateentryinchecksheet.

Mixthesolderpaste(Stirringm/c)for60to90sec.at1000rpm.Keepthejarat‘AFTERMIXINGAREA’only.Updatethetagand

report.

Figure4.49

SolderPasteStirring/MixingMachine:

Figure4.50

CheckPointforStirring:

1.Incaseofreachingtoroomtemperature,thestirringtimeneedstobereduced.

2.Thestirringtimeis3to5minutesincaseimmediatelybeingremovedfromfridge.(Themethodnotrecommended)

3.Excessivestirringbringschemicaldecompositionwiththelapseoftime.

InformationTagforsolderpastejar:

BatchNo.

OutDate

OutTime

MixingTime

Exp.Date

Figure4.51

CheckSheet:

SolderPasteMixingDetails

Date IDNo.

MixingTime

OperatorSign

VerifiedByQA Date ID

No.MixingTime

OperatorSign

VerifiedByQA

Note:1.IfopenSolderpastejarisnotusedwithin24hours,scrapthesolderpaste.

2.Keepun-usedsolderpastejarbackintorefrigerator,ifnotusedupto4Hrs.

3.Beforemixingkeepthesolderpasteatroomtemperatureforatleast2Hrs.

Figure4.52

DegreeofDifficultyOccursDuringSolderPastePrinting:

The 0.5mm CSP, 0603 chip needs inspection, due to the higher level of difficulty inprinting than 0.4mm QFP, for guaranteeing the quality print after selecting solder,designingscreen,settingupprintparameters,managingandreflowing.

StandardReflowProfileforPbSolderPaste:

Figure4.53

StandardReflowProfileforPbFreeSolderPaste:

Figure4.54

4)Under-fill:

Under-fillistheprocessofapplyingepoxytofilltheareabetweenthedieandthecarrier.It used to control the stress on the solder joints. This stress is caused by either thedifferenceinthermalexpansionbetweenthesilicondieandthecarrierorphysicalstressescausedbyvibrationordropshock.Oncecured,theunder-fillabsorbsthestress,reducingthe strain on the solder bumps and greatly increasing the life of the finished package.Under-fill is typically applied using a capillary flow process in which material isdispensednexttoabondedflipchipandallowedto“wick”underthedie.

IQCProcess:

CheckthematerialQtyanditsdocumentsbeforereceivingfromstore.

Checkthematerialfordamage.

ChecktheMfg.andExpiryDates.

IfnotOK,returnbacktostore.

CheckthecontentswithQualityreport.

Attachadetailedinformationtag.

Storethebottlesinrefrigeratorat1to10�C.FollowtheFIFO.

Figure4.55

UseProcedure:

Updatetheremovingtimein“In&OutConsumptionReport”

KeeptheU/F2-3hrsatroomtemp.MakedifferentareaofFORAGING&AFTERAGING.

TaketheU/FtouseonlinefromAFTERAGINGareaonly.

Figure4.56

DirectionforUse:

DispensingUnder-fill:

Keep the under-fill at room temperature for 2 to 3 hrs, then load into equipment fordispensing. Volumetric pump, auger, time-pressure and other dispense systemsmay beused.However,nomatterwhatmethodofdispensingisused,itisimportanttomakesurenoairismixedintomaterialpriorto,orduringuse.Whendispensing,avoidusingpatternsthatwilltrapair.

(1)Selectadispensertype:

a)Handdispenseortimepressurevalve–leastexpensive.b)Augerstylevalve–acceptable:notgivinggoodrepeatability, thusmoresuitableforlargedie.c)Linearpistonpump–recommended:highlyaccuratewhenusedforbothlarge&smalldie.

(2)Forbestresults, theapplicationsubstrateshouldbepreheatedtypically to50�Cfor20secondsormoresotoallowfastcapillaryflowandcreategoodlevelingeffect.

(3)Systempressureshouldbe:

a)Handheld/timepressurevalve–5to15psib)Augerpump–10to30psic)Pistonpump–5to15psiAtlowviscositydrippingwillbeavoided.

(4)Dispense speed shouldbemoderate (2.54 to12.7mm/sec). In addition thedispenseplatformshouldbeabletomaintaintheneedletipapproximately0.025to0.076mmoffthesubstratesurfaceand0.025to0.076mmofftheoffsetfromthechipedge.Thiswillensureoptimalflowconsistencyfortheunder-fill.

(5) The dispense pattern is typically an “I” along 1 side or “L” pattern along 2 sides,focused on the corner. The flow pattern should be designed to start at the locationfarthestawayfromthechipcenter,whichhelpsassureavoidfreefillunderneaththedie.Eachlegofthe“L”or“I”patternshouldnotexceed80%ofthelengthofeachdieedgethatisbeingdispensed.

(6) In addition, thedispensepatternmay require a2ndor3rdbeadwith timedelay forflowunderneath thechip.Typicalmulti-passpatterns require60%ofmass/volumeonthe1stpass.

RefrigeratingUnder-fill:

Under-fillmustberefrigeratingat2to10�C.

Re-refrigeratingunder-fillisnotrecommended.

CuringofUnder-fill:

1.ReflowCuringMethod:ThisisIn-linecuringprocess.

2. Chamber Curing Method: This is OFF line curing method. High temperaturemagazineracksareusedforkeepthePCB.

CuringTemperatureProfile:

Figure4.57

UnderFillCuringWorkInstruction:

Figure4.58

5)Stencil:

Astencil isa thinsheetofstainlesssteel,withadesigncutfromit,usedtoproduce thedesignonanunderlyingsurfacebyapplyingsolderpastethroughthecut-outholesinthematerial.Stencilcanbereusedrepeatedlyandproducerapidlythesamedesign.

Figure4.59

TypesandCharacteristicsofMetalMask(YoungjinAstech):

LaserMask PhotoEtching ScreenMask

Figure4.60

TypesofMetalMask:

Lasermask,Photo etching,Half etchingmask,Screenmask,Additivemask,PHmask,COBmaskandExcimermask.

(1)LaserMask:

It isamaskcorrespondingtothesmallchipmount likefinepitchQFPwithpitchwidth0.3mmto0.5mm,BGA,CSPor1005andduetothedirectprocessingusinggerberdatabylaserforaccurateandprecisedimensions,itmakespossibletogetpreciseandexcellentprintingquality,easyfallingofsolderpaste,fastprocessingandshortdeliverytimes.

•Precisedimensions,0.3mmfinepitchprocessing.•Shortdeliverytimepossibleduetothedirectprocessingbydatadesign.•Thesharpcross-sectionofopeningholebecauseofdetectingexactlocationbydataandofprecisecutting.•Excellentformofopeningholeincomparisonwithetching.•Largesizeprocessingpossible.•ExcellentholeopeningslikeBGAduetoanewyaglaserbyemployingturbo-cut.

Figure4.61LaserMetalMask

(2)PhotoEtchingMask:

PhotoetchingisgenerallyusedinmanufacturingsemiconductorICcircuits,shadowmaskforCRT, lead frame,metalmaskand superprecisioncomponents, and it is a combinedtechnologyofphotodevelopmenttechnologyandetchingtechnology.Inordertoformapatterninthephotodevelopmenttechnology,photoresististobecoatedonSUSandthedesiredportionfromtheetchingprocessistobeselectivelyprocessedaftertheexposureanddevelopment.Thisphotoetchingmaskhas thevarietyof thicknessfrom0.05mmto0.3mmanditcansignificantlyreducethediscrepancybetweenbothsidesofmetalmaskpatterncausedbycorrosionanditisrelativelycheaperthanlaser.

•ProductionpossibleonlybyPCBandfilm.•ProductionofPCBandCOBtypemetalmaskpossible.•Theprecisionoftheopeningholeisexcellent,forburrphenomenondoesnotoccur.•Halfetchingwhichchangesfreelythedepthandsizepossible.

Figure4.62EtchingMetalMask

(3)ScreenMask:

Stainless mesh as the most basic material of screen mask is primarily used to printelectronic components and polyester mesh is widely used in various industries fromgeneralprintingslikedisplayarea,PCB,BGA,MLBandfiltertoprecisionpreprint.

Screenmask is to use an appropriatemeshdependingonprint environmentof users,sizeandshapeofpattern,printthickness,usage,andotherspecificmatters.

•Applicable tovariousindustriessuchaselectronicparts,PCB,BGA,MLB,filter,andsoon.•Printfilmadjustablebycontrollingemulsionthickness.•Variousinks,conductivepaste,solderpaste,adhesives,etc.inuse.•Excellentsmoothnessofimagefilm.•Printableusingbyspecialsolventsduetotheoutstandingwaterresistanceofmetalfilm.• Excellent high-density, micro-pattern print possible due to high dimensionalaccuracy.

(4)HalfEtchingMask:

Figure4.63HalfEtchingMask:AppearanceandTypes

•Whenprocessingetching,partialetchingpossibleafterlasercutting.•Three-dimensionalprocessingpossible.•VariousrangeprocessingoffilmcorrectiononthesamePCB.

(5)HalfEtchingMask:

ItisamaskcorrespondingtothesmallchipmountsuchasfinepitchQFPwithpitchwidth0.3mm~0.5mm,BGA,CSPor1005etc.,anditisdeveloped,incontrasttoetching,byaunique manufacturing process called additive. Thus this mask has high density, easyfallingofsolderpasteandcleancross-sectionareaoftheopeninghole.

•Serviceabletosuper-precisioncomponentsbelow0.3pitch.•Preventingfromsideetchingandtheroughnessofinnerwall.•Fallingoffisverygoodsothatthefallingvolumeofaholecanbemorethan95%.•Duetoeasyfallingoff,thewidthofpatterncanbereduced.•Occurrenceofbridgecanbesignificantlyreduced.•ManufacturingCOB,COFmaskiseasy.•Becauseof longproductionperiod,gettingshortdelivery time isdifficultand thepriceishigh.

Figure4.64AdditiveMetalMask

(6)PHMask:

It is a super precisionmountmask corresponding to themicrochipmount such as finepitchQFPwith pitchwidth 0.3mm or less, BGA,CSP or 0603 and so on. It has highprocessingprecision,excellentadhesiontoPCBandfallingofsolderpasteisverygood.

•Correspondingto0.3mmfinepitchQFPpossible•Boardthicknessandmeasurementaccuracyofopeningholes�0.07mm.•Flatandsmooth-sidedformation.•Solderpastepasseswell.

(7)COBMask:

The COBmask is developed to correspond to the alreadymounted components or thecurvedsurfaceonthesubstrateanditisabletodoSMTmountingusingthesameexistingprintingmethodwithensuringexcellentprintqualitybyitsuniqueadditivemethod.

Figure4.65COBMask

•TheexistingSMTequipmentandtechnologycanbeappliedinthesamemanner.•Stablemountingqualityandcostsavingeffect•Excellentdurabilityandprintabilityduetotheintegratedproductionbytheadditiveprocess.

IQCProcess:

ReceivestencilwithMfg.Qualitydocuments.

Checkthestencilforanydamageorscratch.

Stencilframe,Metalmask,Mesh.

Ifdamaged,returnbacktostore.

CheckstencilmodelandversionasperBOMandBarePCB.

ChecktheFiducialmarkonstencilwithbarePCB.

ChecktheMetalmasktensionwithtensionguagemeter.

Dothetrialprintingandchecktheprintingundermicroscope.

IfstencilisOK,filltheOKreport.

IfitisNG,returnbacktostorewithNGReport.Storewillreturntomanufacturer.

Attachdetailedinformationtagonit.

Handoverstencilwith“StencilHistoryCard”toproduction.

Figure4.66

StencilVerificationReport(IQCReport):

Figure4.67

StencilIdentificationTag:

IdentificationNo.

Model: Side:

Thickness: Mfg.Date:

Vendor:

Figure4.68

StencilTensionMeasurementProcess:

Figure4.69

Figure4.70

1.CheckthetensiononthestencilbyTensionGaugeMeter.2.Check the tension on 4 sides of stencilmask at the distance of 20mm from theedgeofmetalmask.(SeetheFigure4.70)3.Measurethecentretensionofmetalmask.4.Thetensionrangeis0.7mm�0.1mm.5.NotedowntensiononStencilin“StencilTensionmeasurementsheet”.

MonthlyStencilTensionCheckSheet:

Figure4.71

StencilCleaningProcess:

UpdateusedStrokeQty.In“StencilMaskHistoryCard”.

1.Collectallpasteonstencil.

2.TakeIPA(cleaningsolution)oncottonandcleanthestencilfromupperandlowersides.

3.Cleanthestencilbyair.

1.Instencilcleaningm/cOR

2.Manualcleaning-DothecleaningbybrushandcleaningSolution.

1.TakeIPAoncottonandcleanthestencil.

2.Cleanthestencilbyair.

Checkfor

•BlockageofHoles

•PresenceofPaste

•PresenceofDust

WrapthestencilwithvinylcoverandKeepinstencilrackwith“StencilMaskHistoryCard”.

Figure4.72

StencilMaskHistorycard:(IssuebyQC):

Thisreportwillbekeeptogetherwithstencil.

Figure4.73

6)Squeegee:

Squeegeeisapusherthatpushessolderpastetotheboardlandsthroughtheopeningholesofmetalmask.Amongmaterialslikeurethanerubberandmetal,metalsqueegeeismainlyused.

Figure4.74SqueegeeBlade

Figure4.75

7)MagazineRack&Box:

MagazineracksareESDantistaticPCBStorageracks.Theseareusedforsafehandlingandstorageofdifferenttypeofmaterial.

ThemagazineracksarealsocalledasSSR-StaticSafetyRack.

AntistaticMagazine

RackAntistaticBox/Bin

Figure4.76

WorkInstructionforPCBHandlinginMagazineRack(SSR):

Figure4.77

4.5ESDMeasures

ESDConcept

ESDStandsfor:

E-ElectroS-StaticD-Discharge

•Itisthesuddentransfer(discharge)ofelectricityfromoneobjecttoanother.•ESDeventisthetransferofelectrostaticchargesbetweenbodiesofsurfacesthatareatdifferentelectrostaticpotential.

Figure4.78

TemperatureMonitoringSheet:

Figure4.79

OtherFactorsthatIncreaseESDDamage

•LowRelativeHumidity(dryair)•Useofsynthetics,plasticsandinsulatorsinworkareas• Bending, walking, shifting or rolling in a chair, on waxed floors or syntheticcarpets.

BasicRules:

•AssumethatallelectronicdevicesandequipmentaresusceptibletoESDdamageorfailure.•Keepyourworkareaclean.Eliminateallnon-conductors fromassemblyand testareaorneutralizestaticchargeswithionsystems.

•Handleelectronicdevicesandassembliesonlyifyouareproperlygrounded.• Store and transport ESD sensitive items in static shielding containers or faradaycages.

ESDControls:

• ESD equipment that is defective or improperly used can lead to ESD damage!Knowhowtousethem.•Testyourheelstraporfootwear.•ChecktheionizersandmakesureitisON.•InspecttheESDprotectivegroundwiring.•UseonlyapprovedESDequipment.•Promptlyreportanyproblems.

ESDControlProducts:

Aprons Whilewewalkstaticchargegenerateinourbody,ApronreducesthegenerationofStaticCharge.

Cap Dryhairgeneratesmorestaticcharge,Capreducesthegenerationofstaticcharge.

WristStrap

Wriststrapgroundthegenerated/accumulatedstaticchargeofbodythrough1Mohmofresistance&Protectthecomponentfrom

thestaticcharge.

HandGloves

Ahandglovesreducesthestaticchargesonconductivematerialswhicharebeinghandled.Protectthecomponentfromdust.

FingerCote

Fingercotereducesthestaticcharge.

Usetohandlesmallparts.

Figure4.80

ElectrostaticChargeMeasurement/ESDTools:

(1)FieldMeter:

Figure4.81

• Most convenient instrument used for diagnosing ESD problem or for auditingpurpose.•Measurestaticfieldproducedbychargedobjects.

(2)ChargePlateMonitor(CPM):

Figure4.82

Monitoringthebalanceofair ionizersandtherateofchargedecayfromafixedvoltagepoint(either+or-)toanydesiredendingpoint(usually10%)oftheoriginalcharge.

(3)FootwearChecker:

Usedtocheckaperson’sESDshoesorheelstrap.

Figure4.83

CheckSheetforHeelstraporWristBandChecking:

Figure4.84

ESDParameters:

•MatSurfaceResistance:-107to1012Ohm/sq.•ElectricalGnd&ESDGnd:-1to10MOhm•ESDGnd&MatGnd:-Lessthan1Ohm•ElectGnd&ElectNeutral:-Lessthan2Volt(<2V)•ElectPhasetoElectNeutral:-230Deg,+/-10Deg.•WristTrapResistance:-750KOhmto1MOhm

Electrical&ESDgroundingshouldbedoneseparately.

MACHINEISSENSOR

WHENEVEREACHSTEPOFMACHINEISCOMPLETED,

CHECKITBYSENSOR.

Ifthesensorisnotchecked,donotgotothenextstep.

5SMTLINEMACHINES

ProductionEquipment

5.1Loader

Loaderisafirstm/cinSMTline.ItautomaticallysuppliesPCBtoPasteprinter.

The loadercontrolled throughPLCsystem.ForunderstandingSMTm/coneneeds tostudyPLCcontrolm/c.

InSMTmanufacturing,maximumscrapcomesfromLoaderandUn-Loader.

TherearetwotypesofLoaderandUn-Loader.

1)VacuumLoader2)MagazineLoader

1) Vacuum Loader:Vacuum loader is used for loading only bare PCB (Without anyassembly).

VacuumLoader

BarePCB

Figure5.1

ProcessFlow:

WhenScreenprinterneedsPCB,itgivessignaltoloadthePCB.

ConveyergetsONtoloadthePCB.AfterloadingConveyergetsOFF.

AfterloadingPCBtoScreenPrinter,Vacuumheaddownfortaking

anotherPCB.

HeadupwithPCB.

VacuumoffanddropthePCBonconveyer.

ConveyerONandwhenPCBisonsensor,conveyerOFF.

Figure5.2

Figure5.3

2)MagazineLoader:

ItisusedforsupplyingbarePCBaswellassemifinishedPCBfromAxial&radialoronesideSMTprocessfinished.Manuallyneedtoprepare(arrange)thePCBinmagazine.

Loaderm/cMagazineBarePCBOnesidemountedPCB

Figure5.4

ProcessFlow:

(1)MagazineLoadingProcess:

Downthemagazinetounloadingpositionforunloadingtheemptymagazinerack.

UnloadingconveyerwillbeONforunloadingthemagazine.Afterun-loading,itwillgetOff.

Lift-uptoloadingpositiontoloadanewmagazinewithPCB.

LoadingconveyerwillbeONforloadingthemagazine.Afterloading,itwillbeOFF.

Liftdownthemagazineto1stPCBloadingposition.

Figure5.5

(2)PCBLoadingPosition:

ScreenprinterwillgivesignaltoloadaPCB.

PusherwillbeONtopushthePCBonconveyerandthengetOFFreturningthepusher.

Magazinewillbe1stepdowntoloadthenextPCB.

Figure5.6

OperatingProcedure:

1.PlacetheMagazineonthetopsurfaceofthemachineinput.

2.PressPOWERONbuttontoSTARTthemachine.(1)

3.ClickLOCKbuttontochangethePITCHasperrequirement.(2)

4.BESURETHATPITCHSHOULDNOTBEZERO.

5.AfterselectingthePITCH,pressLOCK,sothatitwon’tbechangeforthatprocess.(3)

6.ThereareTWOMODEStostartmachineoperation.

Magazineloadermode:AutoMode

VacuumMode:AutoMode,ManuMode.

WhenweselectAUTOMODE,machineworksautomatically.(4)

7.AfterconveysloadedPCBintheMAGAZINEtoVACUUMCONVEYOR,magazinegoesupassettledpitchandstandbyforthenextsignal.

8.OncereceivingExitSignalfromnextequipment,ittransfersPCBwhichisputdownontheCONVEYORtonextprocessingequipmentbyMOTOR.

9.ForMANUMODE,wehavetogiveinstructionsasfollows:

a)PressELEVATORUP.(5)

b)PressRACKIN-OUTbutton,sothatmagazinewillbeinsertedintothemachine.(6)

c)ClickRACKCLAMPknobsothatmagazinewillbelockedatthisposition.(7)

d)Now,PCB’swillstarttoplaceontheconveyer(toscreenprinter),asweclickPUSHbutton.(8)

Figure5.7

5.2Un-Loader:

Un-loader is used for un-loading the semi finished or finished PCB. It is available inMagazinetypeonly.

ProcessFlow:

Inconveyer,inputsensorsensesthePCB.

ConveyergetsON,PCBloadedtofrontofmagazine.OutputsensorsensesthePCBandconveyergetsOFF.

PusherwillbeONtopushthePCBintothemagazineratherthanreturnback.

Magazinewillbe1stepdownforthenextPCB.

Figure5.8

OperatingProcedure:

Figure5.9

CheckPointforInvestment:

(1)Limitsize:ThelimittotheminimumandmaximumPCBsizes.

(2)Installationcharacteristicofequipment:Afterinstallationfixedequipmentpositionsetup is required for preventing unstable movement. (Still mfg. not supportive for thissolution)

(3)Cycletimeandstability:InhighspeedofoperationthepossibilityofdamagetothesupplyofsmallorthinsizedPCB.

(4)Sparepartssupplies:Manufacturermakesspecialpartform/c,whichcouldn’tfoundinmarketanditwillbecostly.Needtoselectcommonsparepartsupply.

(5)Equipmentsafety:Safeandaccidentpreventivesystem.

5.3ScreenPrinter

Use: Solder Paste Printing on PCB by Screen Printer at chip component mountingposition.

Screen printing is very important in terms of its close relationship with productionquality.Sinceitisusedtospreadsolderpaste(adhesiveforlead)onthePCBsurface.

There are a dispense method and pin transfer method among solder paste printingmethods and yet the metal mask method is universally used. In case of low-volumeproduction,amanualprinterisalsoused.

The automatic printer has an image recognition apparatus which has the automaticfunction of width adjustment, print inspection, cleaning and absorption pin basedmachinery, along with a function of maintaining constant temperature and humidity. Itautomaticallycorrectsthesubstrateandmetalmaskanditenablesprecisionprintingandrapidchangeofprocessbytheprogramaccordingtothespecificproductionconditions.

Figure5.10PrintingMethodofScreenPrinter

Figure5.11

PrintingMethodofScreenPrinter:

Theprintingmethodistopoursolderpasteintothemetalmaskontheboardandtopushitinto theopeningholebymoving thesqueegeeso that it is toapplyandprint thesolderpasteontheboardlandsFigure5.10.

Forametalmaskusedasastencil,stainlesssteelismostlyusedconsideringabrasionresistance,chemicalresistance,andeconomics.Itisimportantforsolderpasteprintingtosupply thesameamountofsolderpastestablywithoutextraon theelectrodepad(land)andtheconsiderationshouldbegiventoviscosityofthesolder,printingenvironmentandthequalityofmetalmask.

The three important elements to screen printer work are metal mask, squeegee andsolderpaste.Suctionblockisabaseblocktosupportthebottomoftheboardbyabsorbingitinordernottomoveincaseofprintingsolderspasteonthesubstrate.Theback-uppinisalsoinuse.

80-90%ofthedefectsintheproductarecausedbyinappropriatescreenprinting.

DuetothegradualdevelopmentoftechnologyinSMTcomponents,itgetsincreasinglydifficulttominiaturizethechipsizeanddensity,ICleadpitch,ballsizeandmetalsoldermask is reduced on the issue of the production specification, therefore, one must firstensurethequalityofscreenprinting.

TypesofScreenPrinter:

1.ManualScreenPrinter2.SemiautoScreenPrinter3.In-LineAutoScreenPrinter

Figure5.12

In low volume production, manual screen printing was used. As component sizechanges to finepitch,manualprintingchanged to semiauto.Mostcompanies todayareusingfullyautomaticscreenprinters.

OperatingProcess:

PCBloadontable.

Fiducialmarkreorganizationbycameraandcorrectpositionadjustment.

Table-uptoprintingposition.

Squeegee-downonstencilmask.

SolderpasterollingbysqueegeeforprintingonPCB.

Afterprintingsqueegee-upandtable-down.

Printingconditioninspectionbycamera.

PCBoutfornextstage.

Figure5.13

ScreenPrinterParameters:

(1)Squeegeepressure:Settingatthe1Kgpressureper5cmsqueegee.

(2)Amountof soldercream:Solderheight is1.5 to2cm longon stencilwhile rollingfrommetalmask.

(3)Processingspeed:Themostappropriatespeedis30to40mm/sfor0.5pitchabove,20to25mm/sforfinepitch.

(4)Squeegeeangle:60�issuitable(45�isalsoalright).

Nowmaximumprintershavefixedthesqueegeeangle.

(5) Printing work environment: Temperature 24 to 26�C, moisture 45 to 65%.

Moistureover65%bringsspatterphenomenon.Ifmoistureisbelow45%,theviscosityisincreasedduetotheevaporationofsolventcomponentinsideflux.

Limited screen printer supported for temperature and moisture control module. So weneedtocontroltheSMTshopfloorenvironment.

CheckPointforPrinting:

1.InputPCB&Stencil:

(a)CheckthepackingconditionandexpirydateofPCB.(b)Checkthestencilaspermodel&versionwithPCB.(c)Beforeloading,cleanthedustonPCB.(Useaircleaningmethod)

2.ProgrammingProcess:

Asperx,y,tdatamakesetupchart.

EnterF1andF2PCBandstencilmarkdatainprogram.

SetupBackuppin/plate.

MatchthepositionofPCBandstencil.(Useoffsetadjustment)

Setupprintingspeed.

Setsnap-offdistanceandseparationspeed.

Majorinspectionpointselectionandteaching.

Figure5.14

ProgrammingCheckPoint:

Figure5.15

Whilemaking program, fiducialmark selectionwill also depend on the cycle time. Toreducethecycletimeneedstoselectlessmovingdistanceofcamera.

In above diagram, the camera’s travelling position is in zigzag manner during thereorganizationoffiducialmarkonPCB.Thiswillincreasecycletime.

Toreducethetravellingtimeofcamera,thebelowdiagrammethodistobereferred.

Figure5.16

Itneedsoptimizationofthedistanceofcameramovement.

FiducialMark:

If fiducialmark is 1�, then select the searching areawindow size 3mmX3mm i.e. 3timesoftheactualmarksize.

Types:

StencilMark–Blackcolour

PCBmark–Whitecolour

Figure5.17

3.PasteprintingonPCB

(a)Followsolderpasteprocedure.(FIFO,aging,mixingandupdatethereports)

(b)Cleanthestencil.(Updatestencilstrokesinhistorycard)

(c)Checkthebackuppinpositionwithbackuppinpositionjig.

(d)Checkandcleansqueegee.

(e)Cleanthem/conrail,ontableandonbackuppin/plate.

ScreenPrinterWorkInstruction:

Figure5.18

4.Inspection:

Testprinting

•Do the printing on 5 PCBwhich is covered by vinyl paper. (Transparent plasticcoverisusedforwrappingthestencil).•CheckthePCBformissing,nosolder,lesssolder,excesssolderandshiftissues.•IftheprintingisOK,removethepaper.Itreducescleaningprocess.•IfprintingisNG,checktheparametersandadjustasperoutput.

PrintingCheckPoint:

Visualassessmentofpastedepositsoffersaquickandhelpfulguidetowhethertheprocessisundercontrol.Checkfor thedefectssuchasslumping,scavenging,bridging,peaking,etc.

TypesofDefect:

1.Missing/NoSolder

(a)Missingsolderduetostencilblockage.Thestencilgetblockdueto-

–Driedsolderpaste.

–Dustonstencil.

–Solderpasteexpired.

(b)Nosoldercomesduetolesssupplyofsolderpasteonstencil.

2.LessSolder

–Driedsolderpaste.

–Duetodust.

–Wrongdesignofstencilaperture.

3.ExcessSolder

–DustonPCB.

–Bigstencilaperture.

–Wrongsettingofbackuppin.

–Driedsolderpasteremainsonstencil.

–Solderpasteonrail.

4.Bridge/SolderShort

–Duetoexcesssolder

5.SolderShift

–Mistakeinprogramming.

–Mistakeinparametersetting.

Figure5.19

Forfinepitchproduction,ifprinterhascyclestopfunctionandiflinestopsformorethan5min.givethecyclestop.Thiswillreducetheproblemsrelatedtosolderpaste.

AutoCleaning:

Aspermyexperiencetheautocleaningfrequencyshouldbe

•For0.4pitch–->1timeafter3PCB.•For0.5pitch–->1timeafter5PCB.•Morethanabove–->1timeafter8PCB.

Thereare3modesinscreenprinterforautocleaning.

1.Drycleaning

2.Dry+Wetcleaning

3.Wetcleaning

ManualCleaningProcess:

Setthefrequencyfortopandbottomsideproduction.Alsorepeattheprocessiflinestopsformorethan20min.

Cleanthesqueegeebyspatula.

Collectthepastefromthesidesofstencilbyspatula.

Whileremovingstencil,makesuresqueegeeisatbackside.

Cleanthestencilbywiperpaperandcleaningsolution(IPA).Don’tcleanthestencilfromupperside.

Carefullycleanthesharpedges.

Cleanwithwiperpaperandcleaningsolution.

Aftercleaningre-insertstencilandpass1PCBfortestprinting.

IfprintingisOK,starttheproduction.

IfitisNG,checkthedefectandagainrepeattheprocess.

Figure5.20

MisprintPCBManualCleaningProcess:

Figure5.21

InScreenPrinterSolderPastcontrollingSpecification:

1)CheckFIFOandExpirydate.

2)Alwaysupdatesolderpastejaropeningtimeinreport.

3)Atstart,fillupstencilwith1/3ofsolderpastejarandthenincreasetheqty.

4)Afterproduction,removetotalpastefromstencilandstoreindifferentjar.

5) For expiration of solder paste check the data sheet specification of solder paste andfollowthesame.

ScreenPrinterSetupChart:(SolderPastePrinting):

Figure5.22

ParameterExplanation:

Figure5.23

(1)Availableframesizes:FreeSizeresponseisavailableMin.650�550mmandMax.736�736mm.(Almostallthecomponentsofnewequipmentispossibletosubstitute.Inprevious cases in older equipment, it requires to reproduce or reload a fixed-sizemetalmaskofthesamemodeltoothercompany’sproduction.)

(2)LimittoPCBsize:ThelimittolowerandhigherPCBsizes.

(3) Quality:Repeat print quality, (metal mask defective ratio) 2 penetration of solderpaste(finepitch0.4phichbelow,BGA3�below)

(4) Printing cycle time: Inspection time with two ways: one includes time with 2Dinspectionandanotherexcludestimewith2Dinspection(whenSPIisseparatelyused,itis acceptable to exclude 2D inspection, on the other hand, when having no SPI, it ispossible toask for investing to2Dfunctionequipment for possibility to producehigherendandcomplexproductsinthefuture.

(5)Convenienceofusingequipment:Thedifficultyofoperatingsystemandtraining.

(6) Difficulty of equipment maintenance: Training of equipment maintenance andpossibilityofself-maintenance.

(7)Sparepartssupplyandannualmaintenancecosts:Usecommonsparepartswhichare easily available in market. When dealer does not have the parts at the time ofequipmentbreakdown,longtermwaitingandtheexpirationofwarrantycausehighercostforreplacementparts.

(8)Safetyequipment:Accidentpreventionsafetysystem.

(9)Investmentshouldbeconsideredbysafetystandardsofequipmentbymanufacturerandmadefastaftersalesandwarranty.

5.4SolderPasteInspector(SPI)

Figure5.24

Inearlyerabigcomponentwasused(i.e.above1608andmorethan0.5pitchIC),hencenoinspectionoptionwasavailableinpasteprinter.WhensmallcomponentwasusedforSMTmanufacturing, the2D inspectionoptionwasadded toScreenprinter.WhenBGAandfinepitchICwereintroduced,2Dinspectionwasnotenoughasitcheckedonlythepresence of solder paste, hence Solder paste inspectionmachinewas introducedwhichalsocheckedthevolumeofSolderpaste.

Majorityofthedefectsarerelatedtosolderpasteprintingprocess.Theincorrectprintingincreases the costly rework on the assemblies. Hence, it needs to monitor the printingquality for the fine pitch components. The solder paste deposition is checked by usingSolderpasteinspectionm/c,oftencalledasSPI.SPIsystemsmeasurethevolumeofthesolder pads before the components are applied and the solder melts. SPI systems canreducetheincidenceofsolder-relateddefectstostatisticallyinsignificantamounts.

In SMT 70 to 80% defects are due to screen printing. After mounting rework cost isincreasedveryhigh,thereforeSPIisrequiredtoimprovequalitylevel.

–SPInow isused forBGAproductionbecause if solderdefect comes, it needs toreplacetheBGA,whichisveryexpensive.–Usedincostlyproduction.–UsedinQualityproduct.

TheSPIforcomponentabove1608sizesisnotrecommendable.Itcanbefilteredby2Dinspectioninscreenprinter.

Purpose:Afterscreenprinting,solderpasteprintingconditionneedstobechecked.

InspectionPoints:Lesssolder,Excesssolder,Missingsolder,Soldershift,Soldershortandsoldervolumecheck.

Need to control 95% pass rate while programming. If not achieved, real defective orimitation(falls)defectiveneedstobecheckedfirst.

Ifrealdefective,then

–Needstocheckscreenprinterprogramsetting.–Screenprintertoolsettingandcondition(StencilMask,BackupPin/BackupPlateandSqueegee).

Ifimitationdefectivethen

–DodebuggingofSPIInspectionProgram.

Figure5.25

SPIProgrammingFlowChart:

Importthegerberdata.

TeachthefiducialofPCB,Mark1andMark2.

SetthetolerancewithbothprintedPCB.

1.BarePCB–1

2.PrintedPCB–2(1standlastPCBbeforeautocleaning)

Adjustthetolerancefortheerrorpointinprogram.

Checktheresultanddebugtheprogramagainaccordingly.

Figure5.26

ComponentinspectionbycameraActualCamera

Figure5.27

DebuggingProcedureforBelow95%PassRate:

Checkthecurrentpassrate.Ifitisbelow95%,followthebelowprocedure.

Informtolineleaderorprogrammertocheckit.

Programmerneedstochecktheexactreason.

Adjustthetolerancetoeachpositioninprogram.Thisistobedonebyprogrammer(responsibleperson)only.

Afterdebugging,lineleaderwillchecktheresultandstarttheline.

AgaincheckwhetherthePassRateisabove95%ornot?

If95%isachieved,continuetheproduction.

Ifnotachieved,informtoprogrammerforcorrectdebugging.

Figure5.28

WorkInstruction–SPI:

Figure5.29

CheckSheet:

Figure5.30

(1)InspectionMethod

(2)InspectionRange:Height,VolumeandAccuracy.

(3)Cycletime,programminganddebugging.

(4)Resultfeedbacksystem:Communicationwithscreenprinterforautocorrection.

(6)Sparepartssupplyandannualmaintenancecosts:Usecommonsparepartswhichare easily available in market. When dealer does not have the parts at the time ofequipmentbreakdown,longtermwaitingandtheexpirationofwarrantycausehighercostforreplacementparts.

(8)Investmentshouldbeconsideredbysafetystandardsofequipmentbymanufacturerandmadefastaftersalesandwarranty.

5.5Mounter

Purpose-Used formounting various components, such asResistor, Inductor,Capacitor,IC,Filter,BGA,Transistor,etc.

TypesofMounter

(1)Gantrytype(onebyonemount):

Itislowspeedproductionequipmentusingafterrotaryhighspeedchipmounterin1990’s.Gantrymounterisgraduallyusedasmulti-mountersforsmallquantityproductionlines;itisalsothebasisofmodulartypeequipmentwhichcameoutin2000’s.

Nowgantry type isalsoreplacedbymodular type. (E.g.Panasonics,Samsung,JukiandYamaha)

Figure5.31

(2)Rotarytype-Tablemoving

Nowrotarytypeischangedtomodulerotarytype.Inthistype,headismovingwhiletableisfixedandithasrotatinghead.(E.g.Nxt)

Todayproductionofrotarytypemounterisstoppedduetoitsbigsizeandheavyweight.Somountersarechangingintomodulartypewhichwillincreasethemoduleandspeed.

Figure5.32

(3)ModuleMount

In themodular type equipment, the speedof eachmodule is not fast, dependingon theaddedquantityof themodule theproductioncapacity increases,and ithasadvantage inrequiring a smaller area and the lighter weight of equipment than rotary type. Foroptimizing the loadingprogram, thesupplyof requiredcomponentsneeds tobeworkedseparatelythroughmanyfeederssothatitguaranteesmaximumefficiencyasthequantityofproductionrequirementgetshigher.

Figure5.33

1)Programming:

BeforeProgrammingPreparation-

Datarequireforprogramming

1.X,Y,K&positiondata ProgramPositionandrotate

2.Gerberdatawithsilkdata Verificationofposition(foroffsetAdjustment)

3.BOM1.Verifylocationandvalue

2.Tomakepartlibrary

4.PCBLocationmap VerifylocationwithBOM

5.DataSheet Componentsizeanddimension

6.Bare&AssyPCB PCBsizeandthicknessandtoverifythemounting.

ProgrammingProcess:

Positiondataconvertintom/clanguage.

Positiondatawillcomebyexcel,textfile.

Sometimesdatacomeinmirrorimage.Therefore,itrequirestoselectthePCBdirection.

EnterPCBX,Ysize.FromGerberbyCAM350s/w.

Adjusttheoffset.CompareX,YpositiondatawithCAM350,differenceneedstoadjust.

MakefiducialmarkdataM1andM2X,Yposition,typeandsize.DatatakefromCAM350.

MakepartdataofR,L,CandIC,connectoretc.allcomponentmountingonPCB.

Ifthereistraycomponent,maketraydata.

Selectthecorrectfeederaspercomponent.

Selectthenozzleaspercomponentsize.

No.ofarrayinonepanel.EnterdistancefromoriginPCB.

1PCBpositiondatamakingarrayPCBmountingprogramwithoptimizedtacktime.

Figure5.34

Explanation:

(1)CADConvert:

–TaketheX,Y,KdatafromPCBCADdatainexcelandtxtfile.

–Checkthatthedatashouldbeinmmnotin�m.Ifwrong,informtoR&Dtoprovideinmm.

–BeforeCAD convert, if RLC (No polarity) component having rotation of 180� and270�,convertitto0�and90�respectively.

–Convertthedatainm/clanguage,asm/cwillnotreaddatainexcelortxtfile.ThisiscalledCADconvert.

(2)SelectPCBdirection:

– InCADconversionpositiondata isof topandbottomside.Sometimesone sidemayhavemirrorimagedata.Thefrontimagedataiscorrect.

– If it is inmirror, it canbedirectly converted in front image. If difficult to convert inexcel,multiplyYpositiondataby-1.

(YpositionX-1)

Figure5.35

(3)PCBSize:

InCADconverterneedstoenterarrayPCBsize.ItcanbetakenbymeasuringactualPCBsizebyverniercaliperbutIsuggesttakingfromgerber.AfterenteringPCBsize,doCADconversion.

(4)OffsetAdjustment:

AfterCADconversion,needstoverifymountingposition.Eachm/chasdifferentorigin(0, 0) corner.Data can come in anywhere in quadrant,which requires to take at originposition.

Select any one component in PCB (E.g. C101), then check X, Y data distance of thiscomponent and compare the data in program.Adjust the difference (Offset adjustment)andthePCBwillcomeatorigin(0,0)position.

Figure5.36

(5)FiducialMarkData:

Afteroffsetadjustment, thePCBposition iscorrect.Nowwe’ve tomakefiducialmark.Takethedatafromgerber.

Iffiducialmarkiswrong,mountingwillbemismatched.Addthetypeoffiducial,selectandenterthesize.

TypesofFiducialMark:

Mostcompanycommonlyusesbelowfiducialmark.

OtherTypeofFiducialMarks:

Figure5.37

E.g.ofwrongselectionofFiducialMark

Figure5.38

Result:Mountingpositionanglechange.

Figure5.39

Result:Mountingpositionwillshift.

Figure5.40

Result:MountingpositionwillshrinkinX-axis.

Figure5.41

Result:MountingpositionwillshrinkinY-axis.

Figure5.42

Result:Mountingpositionwillextend.

(6)PartData:

It is very important in part library to have Part size, Shape, Nozzle section, Feederselectionandtraydata,becauseifpartlibraryisdifferentitgivespartinspectionerrorandcomponentplacementpositionwillbewrong(shiftortiltmounting).

SpecialComponentSpecification:

Component PartLibrary Requirement

1.x,y,tdata

2.Nozzleandfeederdata

3.Bodycolour(Blackorwhite)

1.x,y,tdata

2.Leadsize

3.Leadqty

4.Leaddistance

Transistor

1.x,y,tdata

2.Leadsize(L,W)

3.Leadqty

4.Leaddistance(Pitch-P)

1.x,y,tdata

2.Leadsize

3.Leaddistance

4.Leadside

5.SidewiseleadqtyandPitch

6.Polaritymark

1.x,y,tdata

2.Leadsize

3.Leaddistance

4.Leadside

6.Polaritymark

1.x,y,tdata

2.Ballsize

3.Ballpitch(P)

4.Lighttype

Filter

1.x,y,tdata

2.Leadsize

3.Leaddistance

4.Leadside

Figure5.43

ExamplesofAutoCreatePartLibrary

ChipComponent

Figure5.44

A’ClassComponents

Figure5.45

I’llnotsuggestautocreateoptiongivenbymanufacturer.Ifautocreatepart libraryismadeBGAandICdroppagewillincrease.Therefore,specialcomponentdimensionsneedtoenterbyspecificationasperdatasheet.Afterenteringdata,toleranceistobegiven.

A.FeederSelection:

Selectthefeederaspercomponentpackages.

Thedifferentfeedersareoffollowingsizes.

•8mm–2pitch&4pitch•12mm•16mm•24mm•32mm•44mm•56mm

PitchIdentification:

Spooltype Pitch

Figure5.46

Figure5.47

B.NozzleSelection

TypeofNozzleasperManufacturer

FujiCP-6FujiNxt

Figure5.48FujiMachineNozzles

Figure5.49PanasonicNozzles

JukiKE730-760

JukiKE2010-2040

Figure5.50JukiMachineNozzles

C.TrayData:

Ifcomponentissuppliedbytray,thetraydataneedstobeadded.

1.Traysize-X:TraytotalXsize

Y:TraytotalYsizet:Trayinsidedepth

2.Shiftdata-X:1sttonextcomponentpocketdistanceinx-axis.

Y:1sttonextcomponentpocketdistanceiny-axis.

3.QtyofTray-X:Qtyofcomponentpocketinx.

Y:Qtyofcomponentpocketiny.

4.StartPosition–1stcomponentpickuppositionx,y.

5.EndPosition–Lastcomponentpickuppositionx,y.

6.Selectamongm/ctraycabinetnumber.

Figure5.51

(7)ShiftData

Aftermakingpart library forcompleteprogram, itneeds toenter shiftdata. InprogramonlyonePCBdataisgiveni.e.originPCB.

E.g.TakeadistancefromoriginPCB.

Figure5.52

IfXshiftdatais75mm

Quad. X Y

B -75 0

C -150 0

Figure5.53

Ifxshiftdatais75mmandYshiftdatais50mm

Quad. X Y

B 0 50

C 75 50

D 75 0

2)Optimization:

Optimization is the last activity in programming. Program cycle time depends onprogrammer skill. When you’ve done optimization by manufacturing optimizationprogramonly,youdon’thaveoptimizationrulesormethods.Theprogramwillbeonly70to80%optimized.

Fromnowon,I’dliketointroducemymethodofprogramoptimization.

Programmerneeds to remember,what kindof program they aremaking andbygettingstimulationintheirbrainmoreperfectprogramwillbemade.

1.GantryMachineandModularMachine:

Gantryandmodularm/careheadmovingm/c.Followingthingsneedtoremember.

(1)Simultaneouspickup-Reducethepickuptime.

Theheadofthism/cismoving.Therefore,themovementofheadisrequiredtoreduce.Soif 6 head separately picked up parts 2 or 3 times, itwill lose the time. If possible, 6componentspickupatonetimeismust.

(2)qRotateforR,L,C-(make270�—>90�&180�—>0�)

R,L,Ccomponentshavenopolarity.Thus,therotationtimeisunnecessarilylost.BeforeCADconversion,inexcelR,L,Cmustchangetherotation270�—>90�and180�—>0�.

(3)Use100%Pre-rotationforA’Classcomponent-

Pre-rotationfunctionisarotationofcomponentbeforerecognitionbycamera.Hence,themountingqualitywillbebetter. Ifpre-rotationisnotused,aftercamerarecognitionofcomponentitrotatespartlybeforemounting.Inthiscaseafterrecognitionofcameraifm/cornozzleconditionischanged,defectiveslikeshiftandtiltmaybeobserved.

Hence, ifyouwant toavoid thiskindofdefectiveand ifm/chas this function,usepre-rotationfunction100%.

RotationbeforecameraRotationaftercameracheck

check(Pre-rotation)

Figure5.54

(4)ReduceAutoNozzleChange(ANC)-

Nozzlechange isalsooneof thecausesof time loss.Minimize thechangeofnozzle inprogram.

(5)Selectthecomponentaccordingtotheirsizesfromsmalltobig-

If following this method, the nozzle change can be minimized. Therefore, small sizecomponentmustbefinishedfirst.

BadProgram

1005/16081005/1608/20122012&TR,IC,CN

Figure5.55

GoodProgram

10051608/2012TR,IC,CN,etc.

Figure5.56

(6)SelectHeightfromlowtohigh.

Despite the same size connector or IC, lower height component is to bemounted first.Thiscanavoidthedefective.

Figure5.57Size–SmalltoBigandHeight-Lowtohigh

2.RotaryMachine:

Thism/cisX,Ytablemovingtype.Thus,headisalwaysatthesameposition.

Figure5.58

(1) Needs to select minimum distance between 1st mounting components to nextmountingcomponent.

IntacktimeX,YdistancedependsonX,Ymotoraccordingtowhatkindofmotorisusedineachm/c,tacktimedistancewillbedifferent.Ifyouwanttoknowhowmuchdistanceliesinspecifications,youneedtoaskmanufacturer.

E.g. CP643E fujim/c in specification distancewas 16mm,whichmeans out of 16mmdistancewillbeextraloss.

Wrongmethodofmounting

Correctmethodofmounting

Figure5.59

(2)Minimizethefeederchange.(ifpossible,nextdevicefeederonly)

Thisisalsothesamethingaboutdistance.Minimizethedevicechangedistance.

Figure5.60

(3)qRotateforR,L,C-(make270�-90�&180�-0�)

R,L,Ccomponenthasnopolarity.Thus the rotation time is unnecessarily lost.BeforeCADconversion, in excelR,L,Cmust change the rotation270�—>90�&180�—>0�.

(4)Nozzlechange

Nozzlechangeisalsooneofthecausesoftimeloss.Inprogramminimizethechangeofnozzle.

(5)Selectfromsmalltobigaccordingtocomponentsize

Iffollowingthismethodyoucanminimizethenozzlechange.So,smallsizecomponentmustbefinishedfirst.ReferFigure5.57.

(6)SelectHeightfromlowtohigh.

DespitethesamesizeconnectororIC,lowerheightcomponentistobemountedfirst.Insodoing,wecanavoidthedefective.ReferFigure5.57.

WhileIdealtwithODDproducts,athinghappenedwhenIstartedtoproducemobile.

We started to domobile production with Panasert BM123, the billboard (Refer Figure5.61)defectontheresistercontinuedtooccurinlargevolumesandthusitmadevirtuallyimpossibletocarryouttheproduction.Afterverypossiblecauseswereexaminedonebyone,therootcausewasidentifiedwithnozzle.

Figure5.61

InPanasert seriesmount, the nozzle tip portion is rectangular in shape and is observedlargerthantheappliedchipsize.ItwasnotaproblemforthelowdensityODDproduct.Whenahighdensitymobileproductisprogrammed,however,thesmallsizeresisterwasmountedwithcapacitor,whichcausesamajorproblem.

As the capacitor size is higher than that of resister and thus resisterwasmounted aftercapacitor,nozzlecouldnotgofullydownbybeingobstructedbycapacitorandtheresistordroppedbynozzleontothemountingposition.ReferFigure5.63.

Drawing Nozzletype Componentsize

SA-Nozzle1.0/0.8 1005

S-Nozzle1.5/1.0 1608

Figure5.62

1st,2nd&3rdarethemountingsequence.

Figure5.63

Hence, the problem was settled by correcting the program to mount all resisters firstbeforecapacitors.Theprincipleusedherewastomountfromthelowersizecomponentuptothehigherone.ReferFigure5.64.

1st,2nd&3rdarethemountingsequence.

Figure5.64

If the standard of program optimizing which I proposed is applied while doingprogramming,variousproblemsmightbepreventedduringtheproduction.

PickuptoMountingProcedure(Gantrym/c):

Figure5.65

PickuptoMountingProcedure(Rotarym/c):

Figure5.66

ModelChangeoverProcedure:

Inproductprocessmodelchangeover is thebiggest loss time.Manycompanieshavenocorrect procedure andmethod.Currently, individual person takes changeover.Hence, ifyouwanttoreducechangeovertimeyouneedtomakecorrectprocedureandseparatetheresponse before changeover. Team is formed and changeover procedure is continuouslyrevised.

MakeBeforechangeoverandatchangeoverprocedures.

BeforeChangeover:

Figure5.67

AtChangeover:

MakechangeoverteamwithProgrammer,maintenance,m/coperatorandshiftin-chargeandlineleader.

Separatethejobresponsibility.

Startthechangeoverasperplan.

1.LoaderandUn-loader1)Railadjustment.

2)Magazineadjustmentandsetting.

2.ScreenPrinter

1)Stencilsetting.

2)Backuppin/plateadjustment.

3)Railadjustment.

4)Programloading.

5)Sampleboardprintingandverification.

6)PrintingOK,startprinting.

3.Chipandmultimounter

1)Programloading.

2)Railadjustment.

3)Feederloading.

4)Backuppinsetting.

5)Mountingpositioncheck.

6)LCRtesting.

7)LCROK,startproduction.

4.ReflowOven

1)Railadjustment.

2)Settingtemperature(Programloading).

3)Profilecheck.

4)ProfileOK,startproduction

1)Programloading.

2)Railadjustment.

3)Backuppinadjustment.

4)PCBpassratecheck.

CheckthetotalprocessasperChangeoverchecksheet.

Checkthe1stPCBfromPrintingtofunctionaltesting.

IfOK,starttheproduction.

IfNG,immediatelyinformtoProductionIn-charge.

Figure5.68

AfterchangeoverCheckList:

AfterchangeoverChecksheet

SN Item CheckPoint Status

1. Material 1. Materialavailableasperlotqty

2. Loader&Un-loader,bufferconveyer

1. Magazinealignment

2. Pusherposition

3. Railsize

4. Pitchselection

1. Railsize

2. Squeegeecondition

3. ScreenPrinter

3. Stencilmask-model&stroke

4. Backuppinposition

5. Parameteraspersetupchart

6. Online2Dinspection

7. FirstPCBprintingcondition

4. Chip&MultiMounter

1. Railsize

3. ProgramandProductionmodel

4. Loadingcheck

5. FirstPCBmountingcondition

6. Polaritycheck

7. LCRtestresult

5. ReflowOven

1. Railsize

2. ProgramandProductionmodel

3. Parameteraspersetupchart

4. Profileresult

5. FirstPCBcheckafterreflow

6. AOI 1. Railsize

3. ProgramandInspectionmodelname

4. 10PCBinspectionresult

5. PassRate

Figure5.69

PartChangeProcedure:

Rotarym/ccan’tchangefeederduringmountingtimebecauseoffeederbasemovement.Itcan’tattachextension(splicing)reelandneedstochangefeederafterthematerialisuseduporfeederbasestops.

Gantrym/candmodularm/ccanextend(splicing)newreelduringmounting.Hence,partchangetimecanbesaved.

Duringpartchangerecordingreportisveryimportant.Whenaccident(wrongmounting)happens,we can verify all history by recording.That’swhy some companies are usingbarcodesystem.

Figure5.70

PartChangeReport:

Figure5.71

DroppedPartProcess:

OnlyA’classdropcomponentcanbereused,whichcanbeverifiedvisually.

If possible drop component is able to collect and remount, it is to be done duringmanufacturingsameproduct.

Manycompaniesaremanuallymountingdropcomponentsbutthismaymakedefective.Ifyoubuycovertapeonly,repackitinsamereel(whichisalreadyused)andthenitcanbemountedbym/c.

Figure5.72

DailyProductionReport:

ManycompanycontrolsproductquantitybuteachproducthasdifferentQPSinPCB,thusit isverydifficult tocontrol the target.Therefore,SMTproducthas tobecontrolledbypoint.Thesamplereportisattachedbelow.Thereportshowsproductioncontrolbypointanddetaileddowntime,printconditioncheckandfeederloadingcheck.Youcanmodifyanduseitforyourproduct.

InDailyproductionReportAtoFindicatesas�A=QPSinPCB

B=ProductionQty(PCBwise)

C=ProductionQty(Pointwise)=A*B

D=TargetPoint=1hrtarget*workinghrs.

E=Sumoftotalpointproduction

F=OperatingRate=E/D

DailyProductionReport:

Figure5.73

(1)LimittoPCBsize-limittothelowerandhigherPCBsizes.

(2) Loading speed mentioned in equipment specification: Since loading speed inequipment specifications is theoreticallyobtained from thebest test conditionwithoutloss in time, it is not possible to achieve practically. But it is used as equipmentcomparisondata.

(3)Expectedproductioncapacityfromappliedproduct:Theproductioncapacitywithlosstimeallowance.SinceSMTequipmenthasdifferentmountingmethodsandaccordingtoeachbrandofequipmentandcharacteristics,suitableuseofequipmentdependsontheproductionofPCBtypeandcharacteristicofeachcompany.

(4)Accuracy2Quality:Mountingprecision.Mountingprecisionofequipmentdependsonhowpreciselycameraimages(vision)recognizethepartsandhowaccuratelythemotorofX,Yaxiscalculatesthemovingdistanceperpulse.

(5)Partrecognition(vision)method

• Front light: Recognition is reflected by the amount of light 2 It has accurateprecision, but easily affected by external environment and the changes set bydissimilarparts.• Back light: Recognition by part’s shadow 2 It can recognize the subtle changescausedbyshadowofpartbuttheprecisionisless.• Laser: Used to recognize parts that require high precision. Subtle change of thecomponents is very sensitive. Currently three kinds of equipments are used torecognizetheextentanddeterminemountingofparts.

Front light only uses equipment; front light and laser use equipment, front light andbacklight and laser equipment all use together. Each vision type has advantage anddisadvantageandallpartneedstomeetenvironmentcondition.

PersonallyIrecommendtheequipmentwiththelastoption.

Inactualproductionenvironment,productivityandthelossofmaterialisdirectlylinkedtotheresponsivenessofequipmentandprecisioninloading.

Theexistingstandardshapeofpartsinelectronicsisrapidlychangingintovariousshapeswhich are continuously developed and released. Mounter manufacturers develop andupgradevisionsoftwarerespondingto thenewpartsandprovidetoclient.Suchsupportshouldbecheckedbyus.

(8)Sparepartssupplyandannualmaintenancecosts:

Usecommonsparepartswhichareeasilyavailableinmarket.Whendealerdoesnothavethepartsat thetimeofequipmentbreakdown,longtermwaitingandtheexpirationofwarrantycausehighercostforreplacementparts.

(9)Safetyequipment:Accidentpreventivesafetysystem.

(10) Investment toequipment shouldbeconsideredbysafetystandardsofmanufactureranddonefastaftersalesandwarrantyofequipment.

5.6ReflowOven

History:

Reflowovenisusedtohardenthesolderpasteorglueproduct.

It is a machine used for soldering of surface mount electronic components to printedcircuitboards(PCB).

Figure5.74

TypesofReflowOven:

(1)IR(InfraRed)Type:

AirReflow-ConveyertypeandCabinettype

N2Reflow-ConveyertypeandCabinettype

(2)BlowerType:

AirReflow-ConveyertypeandCabinettypeN2Reflow-ConveyertypeandCabinettype

TheIRandBlowerreflowareof2typesAirreflowandN2reflow.Bothcanbeusedasconveyertypeorcabinettype.

Although beginning of SMT IR reflowwas used,most company now use blower typereflowoven.

IRtypecanbeusedforsmallQPS(numberofcomponentperPCB)productandforBGAreworkpurpose.HigherQPSwithBGAproductsneedstouseblowertypeonlytoachievegoodquality.

AirreflowcanbeusedforPbproduction.Hence,forPbsolderproduction,noneedtouseN2reflow.

N2reflowisdesignedtoreflowsPCBinanoxygen-freeatmosphere.Nitrogen(N2)isacommongasusedforthispurpose.Thisminimizesoxidationofthesurfacetobesoldered.N2reflowiscommonlyusedforPbfreeproducts.AirreflowcanalsobeusedforPbfreeproducts if there is no BGA semi-conductor. The difference from N2 and air reflowsolderingiswettingandvoidquality.

AirReflowSolderingPhotos:

Figure5.75

N2ReflowSolderingPhotos:

Figure5.76

From year 2000 on words world wise major companies have made continuousimprovementofsolderpasttomeetnewenvironmentalandgreenrequirement.

Instartingof2000solderpastechanges fromPbsolder toPb free.Around2010solderpastechangesfromPbfreetoHalogenfree.

Belowtablewill indicate thechanges insolderpaste,numberofzone in reflowand thetypeofreflow

SolderPaste Pbsolderpaste PbandPbfreesolderpaste Pb/Halogenfreesolderpaste

Reflowzone 3zone 5zone 7zone 8zone Morethan10zone

Reflowtype Airreflow N2reflow

Figure5.77

In7zonereflowPbfreeproductiondependsonreflowmanufacturerdesign.

Reflow has IR and Blower type but this time about blower type reflow only is to beexplained.

1)TemperatureProfileSetting:

Soldering condition depends on reflow profile, but many companies do not correctlycontrollingtheprofilesetting.

The1ststepinprofilesettingistomakecorrectdummyPCB.

MakingdummyPCBisveryimportantprocessasprofileresultdependsonconditionofdummyPCB.

The thermocouple (TC)will sense the temperature at its 1st twist point, hence thewireneedstobeproperlyattachedtoPCBpad.

Figure5.78shows that the1st twist is outside the solder joint, hence theprofilewill bewrong.

Figure5.78

2)ProfilePCBPreparation:

Figure5.79

GlueProfile:

Figure5.80

SolderPasteProfileTypes:

RamptoSpikegraph(RTS):

Itisaleanergraph.Startingatstartofsegmentandendingatpeaktemperature,thesoak

periodispartoframp.

Figure5.81RamptoSpikegraph

Ramp–Soak-Spikegraph(RSS):

In this type of graph the soaking period is easily noticeable and itwill allow sufficienttimetoassembliestoreachequilibriumoftemperature

Figure5.82Ramp-Soak-Spikegraph

SolderpasteprofilehastwotypesRTSandRSS.

RTSprofilesettingiseasytoset,butitisdifficulttocontrolthequality.

RSStypeofgraphisdifficulttoset,butthroughthisgraphwecancontrolthequalityoftheproduct.Hence,RSStypeoftemperaturesettingisrecommendable.

TypesofDefects:

Figure5.83

Examplesofhowtocontrolqualityofproductbysettingprofiletemperature.

Thedefectalsomayoccurduetootherreasons,buthereI’veexplaineddefectsarisenduetoreflowtemperature.

1.ColdSolder:Causes–Preheattemperatureistoohighandlong

–Peaktemperatureofreflowistoolow

Figure5.84

2.Bridge:Causes–Inreflowing,viscosityofmeltingofsolderpasteishigh.

–Inpreheating,solderpastefalls.

Figure5.85

3.SolderBall:Causes–Preheatisnotdonesufficiently.

Figure5.86

PbSolderPasteStd.Graph:

Figure5.87

Pre-heatingZone:

Theinitialheatingzoneistosetatahighrampratesothatthesolventcarrierisrapidlydrivenofftopreventanymovementofcomponents.Thisheatingshouldnotexceed2to3�C/sec. Too rapid rise in the preheat zone will result in thermal shock to thecomponentsandsolderpaste.

SockingZone:

Themainpurposeofthesoakzoneistothermallyequalizeallsurfacesbeingsoldered.

Aslower rateofheating isnecessary toensure thatactivationof the flux ismaximized.Thisheatingistypical0.5�to0.6�C/sec.

ThefluxcoversthesurfaceofthesolderandbeginstowetoutontothecomponentleadsandPCBpadsinthe150�to180�Crangefor60to90sec.

ReflowZone:

At 183�C solder reaches at its liquidus temperature. The individual solder particleschangesintoonemassofliquidsolder.Atthispointthesolderbeginstowetthesurfaceofthecomponentleads.

Theinter-metalliclayerisformed.

Rapid heating is used to ensure that the entire assembly quickly reaches a temperatureabovetheliquidusrangeofthealloy.

40 to 75 seconds is recommended for the alloy surfaces to interact and form a soundelectricalandmechanicalconnection.

PbFree/HalogenFreeSolderPasteStd.Graph:

Figure5.88

PreheatingZone:

1. Speed of preheating zone set up 1 to 2�C/sec. Very Rapid Heating brings aboutobstructionofspread-ability/bridge.

2.Temperatureofpreheatingzonesetsup60 to100sec to150 to200�Cvery longorshortzonebringsaboutsolderball.

3.Slopeofpreheatingzonesetsup0.5to2�/sectoslope2.

SockingZone:

Themainpurposeofthesoakzoneistothermallyequalizeallsurfacesbeingsoldered.

ThefluxcoversthesurfaceofthesolderandbeginstowetoutontothecomponentleadsandPCBpadsinthe180�to200�Crange,for60to100seconds.

ReflowZone:

ThereflowzonewillbesmallerforPbsolderpastascomparingtothePbfree.

ForPbfreesolderpast,theperiodabove220�Cneedstobeof40to60sec.

•TemperatureofReflowZonesetsup230to245�C.VeryRapidheatingofreflowzonebringsaboutobstructionofspread-ability.

Thepeaktemperaturewillbedependedoncontentsofsolderpast.

•Very slowspeedof coolingbringsabout falling-offof strengthandmovementofparts.

Followingthesolderpastemanufacturerrecommendsprofile.

MajorDifferenceBetweenPbSolderandPbFreeSolderPaste:

ThemainreasonforchangeinthesolderpastefromPbtoPbfreeisduetoenvironmentalregulations.TheoptimizationofPbfreesolderreflowprofilesismorecriticalthanthePbsolderpaste.ThemaindifferencebetweenPbandPbfreesolderpasteare

1)MeltingPoint-ThemaindifferencebetweenSn/Ag(Pbfree)andSn/Pb(Pbsolder)isthattheSn/AghasahighermeltingpointthanSn/Pbsolderpaste.ThenominalmeltingpointofPbfreesolderpasteis220�CandthatofPbsolderis183�C.

2) Reflow temperature- Themelting point of both solder paste is different. Hence, thereflowpeaktemperaturesettingforPbfreesolderpasteis230�to245�CandforPbsolderpasteis220�to230�C.

3)Wetting-ThewettingprocessinPbsolderpasteisfasterthanthatofPbfree.

4) Shinning- After soldering, shinning of solder joint is more in Pb solder paste ascomparing toPb free solderpaste.Hence, thevisual inspectional iscritical inPb freesolderproducts.

SetupChart:

Figure5.89

WhytakingProfileisneeded?

1.Tomakenewproductstandardcondition-

Itisnecessarytomakenewproductstd.profileaseveryPCBsize,thicknessandnumberofcomponents(QPS)isdifferent.

Somecompanyusesoneprofile forallmodels.Thiswillbeverydangerous forquality.Profileshouldbetakenatleastonceaday.

Seethebelowexampletounderstandthefact.

E.g.-Ifwewanttoboilthedifferentamountofwateratsametemperatureindifferentsizeofpot,thetimetakenbyboththewatertoboilwillbedifferent.

Figure5.90

SamecasewillbeappliedforsettingtemperatureprofilefordifferentPCB.Hence,modelwise different PCB is required to set the correct temperature profile as number ofcomponent,PCBsizeandnumberofarraywillbedifferentfromallmodels.

2.Changesinweathercondition

Eventhoughm/cisinstalledinsidethecompany,theprofilesettingmightgetaffectedincase outside condition changes. Hence, profile needs to be checked, if the outsideweatherconditionchanges.

3.Tocheckreflowcondition

Setthefrequencyofprofiletaking.

Thesameprofilegraphsareneeded,whensamedummyPCBisusedatsametemperaturewith same weather condition. If there is any problem in m/c function, you need toidentifyitbyprofilegraph.

PracticeforHowtosetProfile:

1) 1st set the temperature at constant temperature i.e. at 150�C same as glue profile.ReferbelowgraphFigure5.91.

Figure5.91

E.g.ofZonewisetemperaturesetting

Zone Zone1 Zone2 Zone3 Zone4 Zone5 Zone6 Zone7 Zone8

Top 180 170 160 160 160 160 160 160

Bot 180 170 160 160 160 160 160 160

2)2ndsetramptospikegraph.Referbelowgraph[Figure5.92].

Figure5.92

Top 120�C 140�C 180�C 210�C 240�C 270�C 265�C 260�C

Bot 120�C 140�C 180�C 210�C 240�C 270�C 265�C 260�C

3)Thenadd1st&2ndtemperaturesettingtogetramp-soak-spikegraph.

Figure5.93

4)FinallyyouwillgetRamp-Soak-Spikegraph.

Figure5.94

Top 210 200 190 190 230 260 270 250

Bot 210 200 190 190 230 260 270 250

WorkInstruction–ReflowProfile:

Figure5.95

N2ReflowOven:

SomeovensaredesignedtoreflowPCBsinanoxygen-freeatmosphere.Nitrogen(N2)isa common gas used for this purpose. This minimizes oxidation of the surfaces to besoldered.

Nitrogen inserting can produce better solder joints because it reduces the risk ofoxidization.AsperspecificationN2shouldbemaintainedbelow1000PPMandthenwecangetbestsoldering.

Nitrogen insertion is good for an assembly that has one or more of the followingcharacteristics:

•Fine-pitchcomponentslikeBGA,ICetc.•Costlyorimpossiblereworkassembly.•Complexassemblies.•Requirementsforhighproductreliability.

AdvantageofN2

ThemainadvantagesofusingNitrogen forPb-FreeAssembly in the reflowprocessv/satmosphericairareasfollows:

Improved soldering quality: Less re-oxidation of IC terminals, resulting in increasingsolder joint strength. Higher surface tension minimizes solder balling when using finepitchleads.Lessoxidationalsoimprovesthewettingonbarecoppersolderlands.

ImprovedProcess:ImprovedsolderingofBGAandotherdevices.ThisismoreapplicableforPb-FreeAssembliesthatwouldbeRoHScompliant.

OtherBenefits:Visualappearanceofthesolderjointsurfacewillbesmootherandshinier.Especially forPb-FreeAssembly itmakes it easy to inspect and rework.Larger surfacetensioncanholdlargerandheaviercomponentsonbottomsidewhenperformingdoublereflow.

DisadvantagesofN2

Themaindisadvantagesofusingnitrogenareasfollows:

• Cost of Nitrogen: The singlemost important aspect of Nitrogen usage is the cost ofinstallingtheNitrogenplantandconstantlyreplenishingthetankwithliquidnitrogen.

• Precise solder paste print required: A higher surface tension can result in a highernumberofsolderbridgesatveryfinepitchdevicelevels,ifthesolderpasteprintisin-accurate.

• Possibility of tomb stoning:This is especially true, in case very fine pitch devices orsmallchipwithpoorsolderabilityareused.

BasicCircuitofN2Generator:

Figure5.96

1.Outsidetemperaturecondition–5to35�C

2.Inputairpressure–above0.75MPa

3.Oilinair–below2PPM

(1) Difference between setup and actual temperature: The variation of temperaturebetweensetuptemperatureinequipmentprogramandtemperatureinsidereflowoven.Ifbiggapoccursbetweensetup temperatureandmeasured temperature in theequipment,there is temperature loss in the reflow, thus it is most important to maintain a stabletemperature.

(2)Compositionoftemperaturecontrolzone:Forpossibilityofproductionwithleadfreesolder,atleast7zonesisrequired,butmostappropriatenumberofzoneswouldbe7to8zone, with separate zones for cooling. As temperature zone increases, the length ofequipmentgetslonger;henceappropriateequipmentisrequiredforappropriatesite.

(3)Handlingabilityof reflowequipmentdue tochange inprocesssettingforupcoming

products: Often it is a wrong idea to use reflow oven configuration from the previousprocess.DependingonSMTlinesetup,theconfigurationofreflowovenisdifferentforeach product cycle time. The limitation of reflow oven’s handling ability of changedprocessshouldbechecked.

(4)Startuptime:Aftervacationoroffday,whenequipmentispoweredonfromtheoffposition,thetimeisrequiredforreflowoventoreachsettemperatureindifferentzonestillstable production is possible. Among SMT line equipments, the reflow oven takes thelongest time to become operational for production. The down time to begin productionmostlydependsonthestartuptimeofreflowoven.

(5) Heatingmethods: Benchmarking and checking equipment are required as there areunique and individually designed type of equipments by different reflow ovenmanufacturers.Adetailedreviewofequipmentisrequired,sincemorethananythingelsethelifeofheaterisimportant.

(6) Flux filter system, cleaning and maintenance of oven: In case of preheating andheatingzone,mostofthefluxisevaporatedandreleasedbytheheatinthezone,butinthecoolingzonethefluxgetssolidifiedandremainsthereandpiledup,anditisthebiggestcauseoffailureofreflowovenconveyorandthefan.Themaintenancecycleandlifeofequipmentisdeterminedbythequalityoffilterandexhaustsystem.

(9)Sparepartssupplyandannualmaintenancecosts:Usecommonsparepartswhichareeasilyavailableinmarket.Whendealerdoesnothavethepartsatthetimeofequipmentbreakdown, long term waiting and the expiration of warranty cause higher cost forreplacementparts.

5.7AutomatedOpticalInspector(AOI)

OfflineAOIInlineAOI

Figure5.97

TheAOIisusedforPCBinspection;acameraautonomouslyscansforvarietyofsurfacefeaturedefects (Likeopen, short,missingcomponents,wrongcomponentsetc…)whichcan’tdetectvisually.

AOI is able to perform most of the visual checks performed previously by manual

operators(VisualInspection),andmuchmoreaccuratelythanthat.

InthiswayAOIisusedearlyintheproductionprocesstodetectproblemsinthesolderandassemblyareaofaPCBandinformationcanbeusedtofeedbackquicklytopreviousstages,avoidingtheproductionoftoomanyboardswiththesameproblem.

Process:

AnAOIsystemcanacquiremillionsofdatapoints(pixels)inafractionofasecond.

AOIvisuallyscans thesurfaceof thePCB.Theboardis litbyseveral lightsourcesandobserved by a scanner or by a number of high definition cameras. This enables themonitoring of all areas of the board, even those hidden in one direction by othercomponents.

AOI ismost commonly used for highQPS and small component production (less than1608and0.5mmpitch).

Hence,noneed touseAOI for smallQPSandhigh sizeproducts (more than1608and0.5mmpitch).

TheAOIdetectionaccuracyforfindingdefectsdependsnotonlyonthecapabilityoftheinspection system (m/c) but also on the accuracy of the program supplied by the user(programmer).

Purpose:

Visual inspectionresult isdifferentdependingonpersonandas thecomponentbecomesmore compact, difficultly to catch the defect by visual inspection increased, but AOIinspectioncanguaranteethequality.

InspectionPoints:

Bridge, Insufficient Solder, Open Solder, Missing Component, Lift Component, Shift,Skew Component, Polarity, Tomb Stone, Turnover, Wrong part, Pad Scratch, Foreignparticle,FliedcomponentunderQFP/BGApackage.

Defects:

1)Missing:itemdoesnotexist.

Figure5.98

2)Shift:Chip/ICLeadshifted.

Figure5.99

3)Bridge/Short:ShortbetweenChips/IC.

Figure5.100

4)NoSolder/LessSolder:SolderingLeadsidelessthan1/3.

Figure5.101

Figure5.102

1)Programming:

AOIProgrammingProcedure:

InAOIprogrammingneedtomakedefectivelibraryofeachdefect.

Figure5.103

2)Debugging:

AOIDebuggingProcedure:

Iftherearemoreimitationdefect(Fallscall),followthebelowprocedure.

Informtolineleaderorprogrammertocheckit.

Programmerneedstochecktheexactreason.

Adjustthetolerancetoeachpositioninprogram.Thisistobedonebyprogrammer(responsibleperson)only.

Afterdebugging,lineleaderwillcheckresultandstarttheinspection.

Againcheckwhetherfallscallreducedornot?

Ifitisreduced,thencontinuetheinspection.

Ifnotachieved,thenagaininformtoprogrammerforcorrectdebugging.

Figure5.104

AOIInspectionReport:

Figure5.105

(1)Inspectiontime:Thetimeofinspectioncycleformanufacturedproduct.

(2)Detectionability:Theabilitytodetectdefectiveitemsbyvisualinspection.Thereisnofixedruleaboutdetectionabilityofanautomaticinspectionmachine.Themostefficientwayofinspectionistomakeprecisetestatthebeginningonvariousbadsamples,andthen to apply the tests on actual production. After consultation with equipmentmanufacturers,itisageneralwaytocheckthedemoequipmentinactualproductionlineforacertainperiodoftime.

(3)Newprogramsetupandstabilizationtime:Opticalautoinspectionmachineworksbyinput programandhas no function to self-determine faults.After settingupof a newprogram, thedebugging timeshouldbeshort to reducepseudofault,andpseudofaultfinding should be corrected immediately.During the verification of actual productionline, it is important not only to check detection capability, but to check the ratio ofpseudofaulttorealfault.

5.8X-RayMachine

It is the equipmentwhich uses x-rays to check the soldering condition and position ofparts like BGA, PLCC, filters on board which is impossible to check with visualinspectionorthroughAOI.

Itisusedtocheckthefaultcauseanalysisininitialproductionandsampleinspectionintheproductionline.ByX-Raywecancheckposition,butcan’tdetect100%coldsolderproblem.

Figure5.106

It is expensive equipment and still is at an early stage of automation, thus completeinspectionofmanufacturingprocesscannotbeappliedtotheonlineproduction.

It isusedtocheckforinitialproductionandsamplinginspection,duetothepresenceofless number of movable parts and inline system x-ray is also available but it is notrecommendabletouseit.

X-raytubesareoftwotypes:

1)Closedorsealedtubes

Traditionally,x-rayinspectionsystemshaveusedclosedx-raytubes,wherethevacuumisproduced during manufacture and the sealed tube allows no access to the componentswithin.

2)Openordemountabletubes

Inrecentyears,openordemountablex-raytubeshavebecomemorepopularbecauseoftheir ability to provide much higher magnification, much better resolution andserviceabilitybyallowingaccesstotheconsumableitemsoftargetandfilament.

StructureDiagramofX-rayInspection:

Figure5.107

DefectDetectionbyX-Ray:

1)Bridge/Short

Figure5.108

2)OpenSolderjoints:Insufficientwettingofthesolderpaste.

Figure5.109

3)Voids:

Figure5.110

WorkInstruction

Figure5.111

5.9Router

ItistheequipmenttoseparatethePCBguideofcompletedproductinSMTlinefromtheactualPCB.Automationforequipmentisdonetopreventdefectsduetobreakingofpartscausedbymanualseparation.

Offlinerouter

In-linerouter

Figure5.112

Purpose:

For separation of the PCB, previouslywe usedV-cutting by hand.ButV-cut has someproblem.WhenPCBishandledduringcuttingtheguide,componentdamageandbrokenissuesareobserved.Hence,routercuttingisusedtopreventsuchproblems.

ArrayPCBPCBafterrouting

Figure5.113

V-cut(V-grooving):

Figure5.114

A lot of company still use v-cut for cheaper product and for expensive and qualityproductsusingrouter.Hence,avoidcomponentdamageduringcutting.

Programming:

Forprogrammingbackupplate required, formakingbackupplatePCBGerberdataandmountedsamplePCBrequired.

Figure5.115

ModelChangeoverProcedure:

Figure5.116

RouterBitControl:

Inrouterplentyofscrapcomesbybit. Ifbit lifefinishescuttingside,dustwillcomeorcuttingwillbe improperand finallybitgetsbroken.At that timePCBget scrapped.To

avoid this thebit life cycle time is tobe set asperbitmanufacturerdata sheet.Bit lifemeanscuttinglength,hence,lifecyclemodelwiseneedstosetdifferently.

E.g. The Figure 5.117 & Figure 5.118 is of 2 different models PCB, having differentnumberofcuttingpointsanddifferentcuttinglength.

Figure5.117

Numberofcuttingpoints=22

Eachpointcuttinglength=4mm

Totalcuttinglength=88mm

Figure5.118

Numberofcuttingpoints=14

Eachpointcuttinglength=5mm

Totalcuttinglength=70mm

Asthecuttinglengthof2differentmodelsPCBisdifferent,therouterbitlifewillalsobedifferentforthesemodels.

RouterBitControlSheet:

MonthlyRouterBitControlSheet(Month)

Date OpeningStockBitType

Rec.Qty

TotalQty

IssueonM/C

Qty Bal.QtyReturnQty

ChangeDetails

Doneby

Checkby Remarks

Figure5.119

WorkInstruction–Routercutting:

Figure5.120

Routerm/cCheckSheet:

CheckItem CheckPoint Time Mon TueWed Thru Fri Sat Sun Model Remarks

BitChangeFrequency

ChangetheRouterbitasperFreq.CuttingPoint:_____

CuttingPointInspection

AftercuttingcomparethePCBwithgoldensample

PCBInsertconditioninJig

CheckthePCBinsertconditionintojig.

SuctionCondition

ChecktheProgramVersionmatchwithPCBVer.

ModelChange

VerifyBy

Figure5.121

CheckPointForinvestment:

(1)Capacitytowork:Cuttingdistancepersecond(mm/sec).Thelongerthedistancepersecond,themoreisthecuttingcapacity.

(2)Precisionoftherouter:Moving/operationaldistanceper1pulseofmotor(mm/pulse).Theshorterthemovingdistanceperpulse,themoreprecisecuttingispossible.

(3)Life of SpindleMotor: Since the life of themotor is short, themaintenance cost ismore. Warranty and price of the motor should be checked when the motor needsreplacement.

(4)Dustcollectorcapacity:Dustcollectioncapacityofrouterpowder.Powderfromrouteroperation can cause fatal effect to the body through the respiratory system. Forprotectionofworker,strongsuctionpowerofdustcollectorisrequired.

(5)Program:Makingprogramshouldbesimple,easyandtakeshorttimetofinish.

SMTMANAGEMENT

6SMTPROCESSMANAGEMENT

6.13W5S

Thelinemanagementofproductiondependsonhowtopreventalllossanddefectsintheproductionactivityinadvance.Theabilityofcompanyisdecidedbyhowmuchstandardsofwork,procedure,datamanagementandimprovementofanalysisareworkingproperly.

Production linemanagement basically requires 3W5Swhich should be the basis of allproductionactivities,andparticipationandpracticeofallmemberiscompulsory.

Thequality shouldbe improved through3W5Sbypreventingdefectcausing factors inadvanceand3W5Sincreasesutilizationofspaceinproductionline.

3W is ameans for visualmanagement ofmaterial: It allows anyone to easily identifymaterialwithvisualwhetheritisWhere(fixedposition),how(propercontainer)andhowmuch(fixedquantity).

TheFiveElementsof5S(Japanese)

Seiri–Putthingsinorder.

(removewhatisnotneededandkeepwhatisneeded)

Seiton–Doproperarrangement.

(Placethingsinsuchawaythattheycanbeeasilyreachedwhenevertheyareneeded)

Seiso–Clean

Keepthingscleanandpolished;notrashordirtintheworkplace)

Seiketsu–Purity

(Maintaincleanlinessaftercleaning-perpetualcleaning)

Shitsuke –Commitment (Actually this is not a part of ‘4S’, but a typical teaching andattitude towardsanyundertaking to inspireprideandadherence tostandardsestablishedforthefourcomponents)

TheFiveElementsof5S(English)

Self-Discipline – Ensuring that the systematic organization, visual placement andcleanlinessaretobemaintained.

Systems–Maintainandcontinuallyimprovethepreviousimprovements.

Sweeping–Keeptheareafreefromdebris,dirt,oil,itemsnotneeded.

SystematicArrangement–Identifyingwhatitemsarerequiredandwhicharenot.

Sorting–Itemsshouldbeeasilyretrievable,easytoget,andvisuallyeasytosee.

6.2EducationandTraining

Smallandmediumcompaniesnormallydonothaveanytrainingprogramorcan’tprovide

propereducation.

1.Theydon’thaveenoughmanpower.

2.Resignationrateishigh.

3.Replacementpersonnelarerarelysupplementedbeforequitting.

Duetotheabovereason,incasemanpowerisbadlywanted,theyareforcedtobefilled,thustrainingperiodbecomesshortandtheyarecommittedtotheproductionlinewithouthavingpropertraining.

Incaseofcompaniesthatcannotcarryoutthetraining,thereisnotrainingprogram,lackof time, lack of training manual and no trainer at all. In case personnel with propertrainingandwithnotrainingworkinthefield,hugedifferenceisshownintheirabilityofachievingproduction improvement.Personnelwith trainingmake fewermistakes, rarelyreportproblemsanddonotjudgeworkintheirownway,whilepersonnelwithouttrainingmakeunnecessarymistake,judgetheworkandmakedecisionbythemselvesthanreport.

Most SMTproduction and quality incident ismainly caused byworkmanship problem.Theonlywaytoreducebadworkmanshipis toelevatetheskillandchangethemindofworkerthroughconstanttraining.

TrainingProcedure:

Figure6.1

TrainingProgramChart:

Figure6.2

WhenISOauditorvendorauditiscarriedout,thefirstthingtocheckistrainingprogram.

Thecontentsoftrainingprogram:

1)Newmanpowertraining

•Companyintroduction•Companypolicy•Basicknowledgetraining•Mindtraining,

2)OJT(On-Job-Training)

3)Outsidetraining.

OnJobTrainingReport:

Figure6.3

EachPersonTrainingHistoryCard

Figure6.4

Whennewpersonnelcomein,theyshouldbecommittedtothefieldaftertakingminimumtraining.Procedure andwork instruction has to be used for on-job-training.When eachpersongetsthetraining,traininghistorycardshouldbeupdated.

Andquality education and technical training shouldbe continuously conducted in extratime. Production lines do not and cannot always producewithout being stopped.Using

thatextratime,theeducationshouldbeconducted.Ifnecessary,thetrainingtimeshouldbemadeafterconsultationwithproductionmanagementdepartment.

If managers are aware of the importance of training with firm will, training can beconductedandon-joberrorsbytheuntrainedpersonnelcanbereduced.

Before“Keepbasicstandards”areinstructed,thebasicistobetaughtandstandardsaretobemade.

6.3Organization

1) Many companies do not make organization and specify the job description. Somecompanieshaveorganizationbutjobdescriptionisnotspecified.Organizationrequiresto decide the position of a person and specifying to whom report and order areconducted.

2) If organization is made and job responsibility is not described, work will not becompletedsmoothly.Ifoneworkishandledby2to3personsandsomeproblemsarise,noonetakestheresponsibilityofit.Hence,thecorrectorganizationshouldbemadeinthefirstplaceandjobdescriptionneedstobemade.Forbetterresultsthisneedstobecontinuouslyrevised.

Figure6.5

JobDescription:

SMTPosition JobDescription

Manager

1.SMTtotalplanningandproductioncontrol.

2.Monthlyproductionandmanpowerplanning.

3.Workingtargetplanningandfollow-up.

4.Maintenance,sparepartandtraining,planningandfollow-up.

5.Qualitycontrol.

6.Materiallosscontrol.

7.SMTlayoutandprocessinvestmentverification.

8.Manpowermanagement.

Production

1.Lineandmanpoweroperatingplanistobemadebasedonproductionplan.

2.Resultmanagementistobeconductedbasedonproductionplan.

3.Eachlineoperatingefficiencyistobemonitor.

4.Qualitymanagementandtraininginprocess.

5.Workingguidelineandworkprocedureneedtobemade.

6.Materiallossandscrapcontrol.

7.ECNchangeaspercustomerrequirement.

8.Newmanpowertraining.

9.Manpowertrainingandmanagement.

10.MakedailyproductionReport.

11.Absenteeismcontrol.

12.Workinstructionverificationandmajorqualityissueanalysisandimprovement.

13.WIPcontrol.

Operator

1.Lineoperatinganderrorclear.

2.Dailym/cconditioncheckandmaintenance.

3.M/ctroubleshootsreporting.

4.Monthlym/cmaintenanceSupport.

5.Productionreport,Materialchangereport.

Inspector

1.ProductInspection.

2.FillInspectionReport

3.WIPkeepinSSR(Magazine).

4.QualityissueinformationtoIn-charge.

Maintenance

1.Makingweekly,monthly,yearlyplanandcarrying.

2.M/coperatingandmaintenancetraining.

3.M/chistorycontrol(makem/chistorycard).

4.Planningfornewmodelprogram.

5.M/coperatingproceduremakingandtraining.

6.Stencilsmaskordering.Inspectionandspecificationcontrol.

7.Analysisoftopworstdefectsandsolution.

8.Settingreflowprofile.

9.Sparepartcontrol.

10.SMTinvestmentandjigcontrol.

Programmer

1.MassproductionandNewmodelprogramming.

2.Supportformodelchangeover.

3.Makingm/coperatingprocedureandtraining.

4.LinewiseprogrammanagementandOSsoftwaremanagement.

5.ECN(ECO)changemanagementandmodelwisehistorycontrol.

6.ModelwiseBOMmaking.

7.Programoptimization.

8.Makingfeederlistandissuemanagement.

Material

1.Monthlyreconciliationandlossanalysisreporting.

2.Dailymaterialshortagemonitoring.

3.Dailymaintainingmaterialissueandreceptionlist.(drop,r/w,scrap,defective)

4.Materialkittingasperplan.

5.Updateofthemateriallistasperissueandcompletionwithgoodqty.

DataControl

1.Productionreport-daily,weekly,monthly,yearly.

2.Qualityreport-daily,weekly,monthly,yearly.

3.Absenteeismreport-daily,weekly,monthly,yearly.

4.Consumablepartcontrol-daily,weekly,monthly,yearly.

5.Alldocumentfillingandmanagement.

1.Incomingmaterialconditioncheck.

2.A’Classcomponentscheckbyspecification.

3.Consumablepartinspection.(Solderpaste,glue,stenciletc.)

4.Supplierproductcheck.

1.1stproductinspection.

2.Materialloadingcheck.

3.Selfauditcheck.

PQC 4.Afterchangeovermaterialvaluecheck.

5.ReworkPCBcheck.

6.Drop(Bulk)componentinspection.

7.Stopthelineforrepetitivedefects.

1.Productionsamplingcheck.(AsperSamplingCheckStd.)

2.Stopthelineforrepetitivedefects.

3.Linewisedefecttrenddatamonitoring.

4.Inspectorinspectionlevelmonitoring.

Figure6.6

6.4MaterialManagement

Materialisrequiredforstartingproduction.Thetopicinthischapterwillbenotincludingpurchasingmaterial,itincludesproductsproducedafterwarehousing.Whatwearetalkingabout isafterstoring thematerial in theproductionsite, themanagementofmaterialbythepurchasingdepartment ormaterial department of the parent company, suppliers andlogistics.

Theproductionmaterials received for storageandsent to the suitabledepartment in thematerialsitearecategoricallydivided,(thereisnostandardexplanationaboutwhatisbeendiscussed,itisjusttheownwaytoorganizethings)thesupplytypesare–Trunkeysupplytype,Modelwise/VendorwiseTrunkeysupplytype,Halfkittingsupplytype(appropriateforsmallandmediumcompany),Fullkittingsupplytype.

1)TrunkeySupplyType:

In this type totalquantityofmaterial isstoredandhandledat theproductionsiteby theMainstoreworkerwhocollectsandsupplythematerialeachtimeaccordingtoproductionplanningtothesuitablelineandmanagesthedata.InsmallcapitalSMTCompanyattheinitial stages of investment, comprising less than 2 lines of production generally startswiththistypeofmaterialmanagementpattern.

However,inmanycasesthepersononwhomthistypeofmaterialmanagementisreliedonisabsent (quit jobetc), in thatcase this typeofmaterialmanagementsystemrapidlycollapsesandsothetrainingandjobtransferfornewemployeerequirestobedonewell.

Advantage:

a)Itcanbeoperatedwithminimumnumberofpersonnel.

b)Minimumspaceneedstobemaintained.

Disadvantage:

In case of BOM list consisting less number of materials for products in the line ofproduction there is no problem but if the BOM list consists of various materials forproductsintheproductionline,thentherearedisadvantagesasfollows

a)Oncematerialissourcedforpreviousmodel,itisimpossibletoreturnmaterialfornextupcomingmodelinproduction.

b) It is realistically impossible to findmaterial loss by calculating once a month, it ispossibleonlytocheckmissingparts.Attheendofthemonthitishardtofindthecauseandanalyzeprogressinimprovement.

c) In theproductionsite, theactualproductsanddatahardlymatchessinceoccasionallymateriallosshappensduringproduction.

d)Intheproductionsite,theactualproductsanddatahardlymatches,itisimpossibletodopredictivemanagementofmaterialbyavailabledata.

e) In case the model changeover, material items needs to be checked, loss of time iscausedasmaterialpreparingtimegetslonger.

Figure6.7

Incaseof inability tomakeseparatematerialstore, this typeofmaterialmanagement isappropriate for small company which cannot operate with more number of people ornumberofmaterialtypesrequiredforproductionislessandthereisnoissueofmix-up.

2)Modelwise/vendorWiseTrunkeySupplyType:

There is not big difference with Trunkey supply type of material management, thedifferenceisthatmainstoreisseparatedinSMTwhichholdsspecificstockofmaterialsandstoremanagementforeachvendee.

DuringEMSproductionfromreceivingorderfrom2to3othercompanies,materialcanbemixedandwrongcomponents andmaterial calculation losswill occur. In suchcase,changingfromTrunkeysupply type tomodelwise/vendorwiseTrunkeysupply type isrequired.

AftermaterialcomesinSMTstorefrommainstore,itisseparatedandstackedby‘modelwise/vendorwise’material.

Onlywheninitialmaterialistakenouttoline,specificmaterialseparatelygoesintolinebymodelandtheremainingmaterialofpreviousprocessmodelistransferreddirectlytothenextmodel.Eachtimethematerialmanagementpersonnelcollectremainedmaterialin the line and supply in applied line depending on the production line plan, andwhenthere is short supply of item, only additional material will be supplied and data ismanaged.

In ‘model wise/ vendor wise supply type’ excess quantity of A’ Class material is alsosuppliedtoproductionline.

Most small capital company which has run less than 3 years, start to produce afterinvestedSMT,isgenerallytakewiththistypeofmaterialmanagementpattern.

However,inmanycasesthepersononwhomthistypeofmaterialmanagementisreliedisabsent (quit job etc), in that case this type of material management system rapidlycollapsesandsothetrainingandjobtransferfornewemployeerequirestobedonewell.

Advantage:

a)Itcanbeoperatedwithminimalpersonnel.

b)Minimumspaceisrequired.

Disadvantage:

Oncematerial is sourcedforpreviousmodel, it is impossible to returnmaterial fornextupcomingmodelinproduction.

a) It is realistically impossible tofindmaterial lossbycalculatingonce inamonth, it ispossibletocheckonlymissingparts.Attheendofmonthitishardtofindthecauseandanalyzeprogressinimprovement.

b)Due to customerdemanding continuousproduction at the closingofmonth, carryingoverlossishighertothenextmonth.

c) In case of unexpected change in production plan, material preparation is harder.(Presentproductionmaterialcollectingandsupplyingseparatelytakeslongertime)

d) In the production site the actual products and data hardly matches, occasionallymateriallosshappensduringproduction.

e)Intheproductionsitetheactualproductsanddatahardlymatch,itisimpossibletodopredictivemanagementofmaterialbydata.

f)Incasemodelchanges,materialitemsneedtobechecked,lossoftimeislongerbecausematerialpreparingtimegetslonger.

Figure6.8

3)HalfKittingSupplyType:

It is the material supply type by half kitting in material department. Only A’ Class(expensive) material and exclusive material quantity (including loss) will issue to linedependingonproductionplan(workorder).

After the previous process model is completed and quantity of commonly used chipmaterial is checked, it will transfer to next model kitting. Before transfer, commonmaterialneedstodoinventory.

Whenthereisactualshortageitemininventory,theadditionalrequestgiventomainstoreandmainstorewilldokittingwithA’Classcomponentsalongwiththerequirement.

After receiving half kitting material from main store, SMT store will do full kittingaccordingtoline.

Instoretheidealwayistoissuefullkitting.IncaseofEMSandnopurchasingcompany,theywillreceivematerialfromvenderasperproductionplan.Incaseofsinglelinetherewillbenoproblem.

Butifhavingmorelines,itisdifficulttosupplymorereelunittotheline.

However, some companies buy less cost material by themselves to increase theproductivity.

Advantage:

a) Exclusive and A’ Class material from SMT store is not released excessively, thematerial loss and time lost for material finding shortens. Systematic material storemanagementispossible.

b)ShortageofmaterialandlossinafinishedLotcanbecheckedrightaway,analysisofcauseandimprovementpointcanbefoundsoon.

c)Thedifferencebetweenstoreissuestandarddataandactuallinedataisless.ThusDatamanagementispossible.

d)Thetimerequiredforpreparationofmaterialforchangeinmodelislow.

e)Calculationoflotlossbymodelandbylinelossispossibleforkittingover-releaseofcommonlyusedmaterial,incaseitishardtodoactualcheckingoflossinsiteattheendofmonth, we can solve the problem by assuming typical data and apply lot balancemanagementmethod (for commonmaterial usuallyUnit price is lowand so commonlossratedoesnotaffectmuch).

Disadvantage:

a)2to3workersshouldbeaddedinmaterialdepartmentandSMTmaterialmanagement(formaterialkittingandcheckingquantity).

b)Separatepreparingspaceisrequiredinmaterialdepartmentfor1ststepkittingandinSMTstorefor2ndstepkitting.

c)Whenthereisshortageofitemcollectingmaterialfromlineandsupplyseparately,thereispossibilityofwrongcomponent(incasesupplyfromonereeltotworeelstheremaybereadingerrorcausedbymissingmarking).

d) If production plan changes occasionally,material preparing is hard. (Material shouldnotbereleasedwhenmaterialkittingisincomplete)

e)WhenexclusiveandA’classmaterialisissuedfromhalfkitting,bulkmaterialismadebyreelcutting.Ifthebulkmaterialispoorlymanaged,lossanddefectmightbecaused.

f)Whilekitting,iflossofexclusiveandA’classmaterialsisnotconsidered,ittakeslonghourstocompletethelot.

Figure6.9

4)FullKittingSupplyType:

Mainstorewilldomodelwisefullkittingaccordingtoproductionplanquantity(includesloss)andsupplytoSMTstore.

After receiving thematerial to SMT store entering the data toMRPbymodel and linewiseissuethematerial.A’ClassmaterialasICetc.willbeissuedasperproductionplan.

Afterfinishofmodelallmaterialwillbereturnedtomainstoreafterinventory,materialofnextmodelbeforechangeover,materialkitreceivedfrommainstoreafterenteringdatainMRPwill issue to line.Mainstore fullkittingsupplyandSMTstore fullkittingsupplymanagementarepossible.

Advantage:

a)Allitemsarecontrolledbymainstorelotwiseandmodelwise,hencereducethetimelossandimprovethestoredatareliability.

b)AtLot finishing,material shortage and loss can be checked.The cause analysis andimprovementpointwillbedoneimmediately.

c)Mainstoredataandactuallinequantitydifferenceisless.Hence,bymainstoredatacancontroltheshortage.

d)Completingoflotcanbedonesmoothly.

e)Preparingmaterialbeforemodelchangeover,losstimeisless.

f) Model wise inventory is possible right after production, inventory by lot, not bymonthly,iseasierforanalysisandimprovement.

g)Whentomainstorekittingworktransferred,SMTstoreremovedorminimized.

Disadvantage:

a)Material worker for kitting and quantity checking worker should be separatelyrequired.b)Materialkittingzoneisseparatelyneeded.c)Incasemodeldiscontinued,overstockofnon-usedmaterialcanbeoccurred.d) If production plan changes occasionally, material preparing is hard. (materialshouldnotbereleasedwhenmaterialkittingisincomplete)e)Forfullkitting,keepingextramaterialisrequired,sostockingmaterialincreases.

Figure6.10

Forchangingprocessofmaterialmanagement,useTrunkeysupplytypeafter initial linesetupduetoshortofworkerandpriorproduction,halfkittingsupplytypeisusedduetoworker supplement and Material Requirement Planning ( MRP). After expansion oradditional investment, finally full kitting type can be used if company becomes parentcompanyafteritgettingbigger.

MaterialManagementMethod:

In SMT,material and time is directly related to profit,materialmanagement deal withcompany’scapitalbusinessandisextremelyimportant.

In case of unwanted andover stockingwill lead to non-used asset expense to purchasematerialandadditionallaborcosts.Ifpropertimematerialisnotsupplied,andlinestopsduetoshortageofmaterialandlinemodelchangeswillcausetimeloss.

1)BOM(BillofMaterial):

FormaterialmanagementfirstofallBOMshouldbementioned.

BOMislistofeachproductcontainingdataofeachpart,quantityandspecification.

ModelwiseMRPdataneedstobecreatedbyBOM.

ExampleofPartsList(BOM):

Figure6.11

BOMconsistsofPartNumber (Eachpart code) /VendorNumber (Eachvendercode) /Description (specification) /Qty (QPS) and Reference LocationNumber. Figure 6.11 isoneofthesamplesanditscontentisatvariantaccordingtocompanies.

Parentcompaniesthatareabletopurchasethematerialhavetheirownpartnumbersbutvendor (Supplier) companies do not. Part number is uniquely given by each company.Hence,itisdifferentaccordingtoeachcompany.

E.g.-PartNumberof1005TypeResisterof0OHMareasbelow

053000212VK47CJ000

47CJ00002Novatel

REA51-000-102Telson

06-00026-012Appel

ERHZ00004012LG

2RF0R0JC20K2LGI

500000000012Pantech

OwnproductmanufacturingcompanymakestheirownpartnumberrulesandwarehouseismanagedbyMRPsystemwithadditionallymanagedbarcodesystem.

WithBarcodesystemSMTmaterialmanagementisgettingeasier.

Whenproductionmaterialischangeditpreventsuseofwrongcomponent.

IfVenderCompanyhasonlyonecustomerthencustomergivenpartnumberandbarcodesystemcanbeused.Butifcustomerincreasestomorethan2to3thanitwillbedifficulttocontrolbycustomerpartnumberandbarcodesystem.

InthiscaseVendorCompanyneedstomaketheownpartnumberrulesandsystem.

Whenenteringthepartnumberofcustomerinsystemduringdevelopingtheprogram,itneedstocomeasvendorownpartnumber.

Butifthecustomerchangesandnewcustomerisadded,atthattimeduetomanyvariablesthevendorcompaniesarefacingdifficultyinmakingtheirownsystem.

High investmentcapital is requiredbyvendor,with limitedapplicationandpartnumbercan’tbecomputerizedtotally.

Presently there is no clear solution for vendor company procurement. It may solve bymakingworldwise/countrywisepartnumberstandardizationforVendorCompanies.

Previouslytherewasarelationbetweenpartnumberandactualpartvaluebutduetosomesecurityreasonsnowproductcompanyismakingtheirownuniquepartnumber.

2)MaterialProcess:

BOM formation is done by product’s developer (R&D) from initial stage, based on itsbasicdata information. Itspreparation isdone forpartpurchasingorder,warehouseandproductionplanquantity.

Withorderfromsales,productionplanismadefromproductionmanagementdepartment,BOMproductionworkorderwillbeissued.

Whenproductionstartsafterdevelopmentprocess,BOMismadeaftercheckingPartlistandtheninputincomputer.

In material department, part number is given after incoming inspection, and deliversmaterialbasedonproductionorder.

E.g.MaterialBOMcompositionandwarehouse

Figure6.12

So far production plan by using MRP or ERP system and BOM formation after partnumber is given tomaterialwarehouse is a simple procedure,with computerizedworkactualtimeinventoryandmonitoringispossible.

Howevernoncomputerizedcompanyusesexcelprogramtomanageeachdepartment.

The accuracy of result depends on personal ability depending on man power inmanagement,otherwisetheactualmanagementisimpossible.

3)ManagingKittingSystemandIssueAfterMaterialLoadinginFeeder:

Many companies have chosen kitting system after initial line set up due tomodelwisematerial inventory and higher data accuracy than Trunkey system as mentionedpreviously.

In kitting system managing type, there are full kitting and half kitting, not manycompaniesareabletohandle‘Fullkitting’realistically,itismoreefficientwaytomodifyfrom‘halfkitting’.

a)Basedonorderofproductionbymaterialdepartment,MaterialStoredoesthekittingasperworkorder.

ModelwiseissuethematerialtoSMTstoreafterhalfkitting.

DothecommonmaterialkittingforshortageiteminSMTinventorylistasperreelunit.AndA’Classandexclusivematerialkittingasperworkorderqtyincludingloss.

(MainstoreneedstocheckmaterialphysicalqtywithSMTmaterialpersonaspermaterialkittinglistandenterintheERP/MRPsystem).

Aftermonthlyinventory,at1stmaterialissuetimeneedstosupportfullkittingformodelwisecommonmaterialtotheSMTlinetillnextmodelkitting.

(If kitting is impossible due to shortage of commonmaterialwhen kitting bymodel inSMTstore,kittingsystemwillnotbeeffectiveduetolosstime).

b)InSMTstoremodelwisefullkittingisdonebyreceivedmaterialfrommainstoreand

returnedcommonmaterialfromtheline(needstocheckactualphysicalqtyofreturnedmaterial).

c)MaterialloadinginfeederaftermaterialreceivingfromSMTstore.

Material loading in feeder, bymodelwise feeder loading list as perSMT lineplan andafter complete of loading issue to line. (SMT store prepares the kitting list aftercompleting the physical checking with material loading member and MRP systemshouldbeentered)

d)InSMTlineaftercompletingproduct,productionwill returnallof leftmaterial fromkitting before starting the production of nextmodel. (All receivedmaterial kitted bymodel should be returned to prevent bulkmaterial shortage , inventory checking andcalculationoflineloss)

e)Separatethematerialfromfeederandupdateinlisteachitemcountingquantity.Afterchecking,materialisreturnedwithlisttoMainStore.

f) After receiving thematerial, domodel wise inventory and calculate the loss. Checkinventory data and actual qty balance. According to inventory data the next modelmaterialshouldbereceivedfrommainstore.(Iftherearealotoflossinparticularitem,dophysicalcheckingandanalyzetheactualreason)

g) Inmaterial department calculated data fromSMT line supplied is computerized andappliedtonextmodelkitting.

Figure6.13

AsFigure6.13isshown,itisnotthebestwaybutcurrentlymanycompaniesoperatetheverifiedwaythroughtrialandfailure.

Accordingtocompanyorganizationandproductssomedifferencesshouldbemodifiedbycompany’scharacteristicandrequiredconditions.

First of all, enough manpower (T/O) support is necessary. The organization should befixedforbuildingkitting,feedersettingandinventory.

Securingsufficientspaceisnecessaryforkitting,feedersettingandcomponentcounting.Forpreparingnextmodeltheextrafeederandtrolleyisrequired.

NecessaryRequirementforKittingSystem:

1)Manpowerwithorganization

2)Area(Space)forkitting,feedersettingandinventory.

3)Extrafeederandfeedertrolleysfornextmodel.

Advantage:

a)SincedifferencebetweenactualmaterialandMRP/ERPisnotmuch,mainstorecanbemanagedbypre-estimateddata.Hence,tracingandactiontimegetsquicker.

b)Shortageofmaterialcanbeavoidedduringproductionbecauseofkittingsystemwhichenableschecking thedata inadvance. (Incaseoffullkitting,materialshortageoccursoccasionallysincematerialconditioncan’tbecheckedbeforeproduction).

c)AccordingtoproductionplanonlyrequiredA’Classandexclusivematerialisissuedtolinewhichcanreducetheloss.

d) Issuing and retrieving of line wisematerial can be avoidedmixing upwith anothermodel andkeepingdropmodelmaterial on shop floor for long time. (After completeproduction,collectallofthemandreturntostore)

e)Thissystemenablesmodelwiseandlinewiseinventory.Theultimategoalistomanagelinewiseinventory.

f)Aftercompletionofproduction,detectingandanalyzingthereasonanditsimprovementispossibledependingonmodelwiseinventory.

g)Sincematerialispreparedbeforechangeoverbykitting,loadingmaterialonfeedercanreducethechangeovertimeandimprovethelineoperatingefficiency.

h)Monthly inventory makes easy to complete by collecting the model wise inventoryresultaftercompletionofproduction.

i) After completing the setting of the organization with process, even changing inmanpowerandrelyinglessmanpowerskillwillnotaffecttheprocessofproduction.

Bar code system of material in SMT line needs separate investment for programdevelopmenttopreventwrongloading,bydemandingadditionalERP/MRPfunction.

Inmaterialmanagementprocesstherecenttrendisasfollows.

TheinitialstartfromtheTrunkeysupplyafterexperiencingstepwiseimprovementwillbereachedtothematerialloadinginfeedersupplystep.

Aftermaterial controlling byERP/MRP data, JIT (Just In Time) supply systemwill bealsopossible.

Trunkeysupply2Vendorwise/modelwisesupply2Halfkittingsupply2fullkittingsupply2materialloadinginfeedersupply2JITsupply

2)SelfCheckingList:

1)IsmaterialmanagementbyusingERP/MRPsystem?

2)Doyouhavepartno.managementruleandhaveyouused?

3)Whatkindofmaterialsupplysystemdoyouhave?

4)Islinewiseinventorymanagementdoneperiodically?

5)Ismateriallossanalysisandimprovementdone?

6)Doyouhavemonthlyinventory?

7)Howmuchmateriallossdoyouhavefrominventoryresult?

If acompanyhasa lotof lossmaterial andcan’t complete inventoryorcarry itover tonextmonth, it shouldbecheckedwhichmaterial supply system isusedandwhich itemmaybedetectedinselfcheckinglist.Andoncetheproblemisfound,ithelpstoimproveandtheproblemcanbesolved.

When there are problems the original reason needs to be identified and solved. Ifadditional investmentand time is requireda lotof companiesdonot attempt this.Theyonlymaketemporarysolutionsandaddupcheckingprocess.

Another problem again adds multiple checking processes. (The manpower will beincreasedfurthermoreintheprocess)

Althoughmaterialmanagement is primary andvery important process,most companieswould not attempt to invest for improving the process. It is because the improvementefficiencydoesnotguaranteethebenefitregardingtheresultafterinvestment.

IjoinedaSMTcompanywhichhadmanufacturedmobileEMSfor2years.

Company’s goalwas tomake profit, and for that purpose production department has atargetforproductivityandqualityimprovement.

Inthiscompany’scase,accumulateddeficitwasmorethan$2millionin2yearsandSMTdepartmentfailstomakeprofitwastingmoney.

WhenIanalyzedthelosstimeinthefirstplace,thereweremanyproblemssuchas

1)Alotofm/cbreakdownduetooldm/candlackofmaintenance.

2)Frequentmodelchangeoveraccordingtovariousmodelsforsmallquantity.

3)Alotofmaterialshortageduringproduction.

4)Difficulty of closing the inventory in one year and not identifying status ofmaterialloss.

5)DisparitybetweenSMTlineandstorematerialdata.

Thefirstpriorityamongtheseistoimprovethematerialprocess.IchangedtheTrunkeysupplysystemtofullkittingsupplysystem.

SMTstoredidfullkitting,preparingmaterialtofeederbeforechangeover.

SuchImprovementwasObserved

1)Changeovertimewasreduced.

2)Materialshortageduringproductionwassolved.

3)Model and lot wise inventorywas started and inventory closingwas possible everymonth.

4)Lossstatuswasabletoanalyzeandlossimprovementstarted.

5)Materialwasmanagedaccordingtodata.

Theseimprovementsweredonewithin3monthsalthoughitwasnoteasy.

Themain problem in the processwas to persuade seniormanager about importance ofmaterialprocessandobtaintheirapproval.

And another one month was spent in order to make process because of conflict withmanagerforgettingfullkittingsystemsupportfromthemainstore.

Nextproblemwasmanpower(T/O)issuetomakeapreparationfor thematerialkittingandfeederloading.Thecompanyhesitatedtoincreasemanpowerbecauseitcouldaffectmanufacturingcost.

ImprovementChart:

Figure6.14

IntheabovecharttheimprovementstartedfromAprilanditsimprovedresultwasshownfromJune.

ThesuccessofimprovementandsettlementoftheprocesswasdependeddirectlyonthemindofCEOandseniormanagers.ThatisthereasonwhytherearenotmanysuccessfulcasesalthoughsettingISOandERPsystems.

For approval of the ISO certificate requires to prepare a lot of things, renew theorganization and the process and prepare ISO format documents. But in reality actualwork does not follow in accordancewith ISO system.The reason is that theCEO andseniormanagersdonotwantallthosecomplicatedprocesses.

And ERP system also was very difficult in succeeding due to the same reason.WheninvestedinERPtheychoosethecheapersystemandthusitcan’tbeproperlyfunctionedandmodifiedcompanyprocess,sofinallyincompleteERPsystemisoperated.

Generally, improvementofcompanyisutterlyuptoCEOandseniormanager’ssupport.Without their strong support, there arises conflict with other departments and theimprovementhastobediscardedontheway.

Theabovecompanycouldnotimproveatallinthose2yearseventhoughkittingsystemwassuggestedbecausetherewasnosupportfromCEOandseniormanager’s.

BakingWorkInstruction:

Figure6.15

De-Humidifier(DryChamber)WorkInstruction:

Figure6.16

Figure6.17

Figure6.18A’ClassMaterialManagementProcess

SMTMaterialTemperature/HumidityManagementSheet:

Figure6.19

6.5QualityManagement

•ImportanceofQ/C•SMTlinecheckbyPositiondetectiontype•SMTQualitydatamanagement•BSN(BoardSerialNumber)Management

1)ImportanceofQualityManagement

The goal of QualityManagement is customer satisfaction. The meaning of ‘customer’means final customer for company. In production site, customer is the next relateddepartment,tosayinmoredetail,itshouldbemanagedwiththeconceptof‘nextprocessisacustomer’.

The relateddepartment to production is supplyingdepartment and supplieddepartment.ForexampleinSMTrelateddepartment,theproductdevelopmentdepartmentreceivesthepartlistfromR&D,afterverifying,itneedstomakeBOMandenterinERP/MRPsystem.TheBOMshouldbeverifiedproperly topreventfromanyprobleminnextprocess,buterrorofBOMcan reduce itsquality level.Afterqualityaccident inproduction line, thedefectshouldbesegregatedandre-inspectionandreworkshouldbecarriedon.

Inmain storewhenwrongmaterial (similar component, barcode labelmistake and qtymistake) issues toSMT, it is fortunate if it is foundbeforeproductionbut ifnot, itwill

cause quality accident. The defect should be segregated and re-inspection and reworkshouldbecarriedon.

AndallerrorordefectiveinSMTprocesswilltransfertonextprocess.The80to90%ofassemblyqualityisdependedonSMTqualitylevel.Sotheaccuracyofpreviousworkwillinfluence the quality of company and quality in process which is directly related withproductivity.

In Production site,management suggestsmanyways to improve productivity andmostimportantthingsamongthemistoimprovequality.

Fore.g.ifcompanyhas10%defectiveinprocessandproductionperhouris100qty,thenactualo/pis90qtyonly.Inaday8hoursofproductionoutof800productsproduced80aredefectivesoonly720aregoodproduct.Thereforeifdailyproductiontargetis800,itwillneed1extrahouri.e.9hoursofproduction.Thusincreaseof1morehourperdayfor25workingdayswillhave25hoursmore.

Ifqualityisimprovedonly5%fromthem,wecanreduce12.5hourinamonth.With12.5hours,1250moreproductscanbeproduced.

Simplyput,ifdefectiveoccurs,additionalreworkwillincreasereproductionexpenses.

Condition–DefectRate=10%

Capacity=100PCB/hr

8hrs=>TargetCapacity=800

ActualProductionoutput=720

Defective=80

9hrs=>TargetCapacity=900

ActualProductionoutput=810

Defective=90

Figure6.20

2)TypeofInspectionProcess:

SMTlineproductioninspectionhasvariouswaysdependingonpositionof inspection.Iwillexplainonlyadvantageanddisadvantageinofflinetypeandin-linetypeinspectionprocess.Itisbasedonpersonalexperienceandknowledgeupuntilnow,sincethereisnoaccuratetechnicaldatareferenceinthisfield.

SampleInspectionm/clayoutformobilemanufacturing

Figure6.21

SomecompaniesinstallonemoreAOIbeforereflowbutitisnotnecessary.

1)Off-lineinspectiontype

Aftercompletingproduction inSMTline,off-line inspection (cellprocess) is separatelyconductedatdifferentpositions.

Figure6.22StructureofLine

Figure6.23StreamofLine

Thissystemcanbeusedwhenthequalityofcompanyisguaranteed,asdefectdetectionfeedbackislate.

Inofflineprocessproductistransferredbymagazinerackunit(SSR)tonextstage.Onemagazine can stock 50 panels, if 2 arrays PCB, then onemagazine can stock 100 qty.BetweenSMTandinspectionthereare2magazinestocksandwhenyoufindthedefect,itmeans200defectivehavealreadyoccurredandalthoughyougivefeedbacktoSMTline,theproblemisgoingonoritisalreadyfinished.Ifproblemkeepsonhappening,youmayfindthereasonbutyoualreadyhave200defectivestoberepairedandifalreadyfinishedyou can’t find the reason and improve it.Many SMT beginner companieswhich setupofflineinspectionprocesscan’timprovethequalityanditwillbefetaltothequality.

Advantage:

a)Canreducetheinvestmentcost.(e.g.3SMTline,2AOI)

b)lineandinspectionlinecanoperateseparatelywithoutbeingdisturbed.(Abletofocusonurgentmodelfordispatch).

c)Itcanbemanagedwithlessmanpower.

d)Itdoesnotaffectproductionincasesomeworkersareabsent.

Disadvantage:

a)Duetolatefeedback,itishardtotakeactionimmediately.

(In case of small lot production, after production is over it is hard to find causes andimpossibletoimprovethem)

b) Ability of inspector is hard to check, one inspector who examines many productsreducesconcentrationandresponsibility.

c)LineproductsinspectionisnotfixedtoonepersonandifthePCBisnotinspectedandpassedtonextprocess,itishardtotraceandidentifywhomtheresponsibleoneis.

d)Linewisedatamanagementishard.

2)In-lineInspectionType:

In-lineinspectionistoputAOIandvisualinspectioninproductionprocessofSMTline.A lot of mobile manufacturing companies are prone to make their products in in-lineinspectionsystem.

Figure6.24StructureofLine

Figure6.25StreamofLine

Advantages:

a)Detectionpointofqualityaccidentisfast(Sinceimmediatedetectionispossibleduringproduction,confirmationofcauseandmeasuresarefastandaccurate).

b) Measuring detection ability of AOI and inspector is easy and due only to theexaminationofthefixedlineofproducts,concentrationandsenseofresponsibilityareincreased.

c)Linewiseinspectionenablestrackingandmanagementincaseoffailingdetection.

d)Linewisemanagementofqualitydataiseasy.

Disadvantages:

a)SMTline-wisefixedAOIandpersonnelarerequired.

b)SMTlineislengthened(Securingspaceisrequired).

c)AOIprogramshouldbeready(Ifprogramisnotavailable,inspectioncan’tbedone).

d)Itishardtocopewhenlineinspectionpersonnelareabsent.

As shown above, advantage and disadvantages of off-line and in-line inspection aresimplysummedupand incaseofsmallcapitalcompanies,off-line inspection ismostlyselectedtoexamine.Primaryreasonisinvestmentissuessuchascost,manpower,space,etc.Sincedefectivedetectionpointgetslateinoff-lineinspection,sometimesproductionisalreadycompletedinacertainSMTlinewheninspectorfindsfault,andfaultcannotbeidentifiedinmanycases,becauseproductionprocessisprettymuchdone.Hencetype1of

in-lineinspectioncanberecommendedfirstforlow-qualitysmallproductcompanies.

Itisnoproblemtotakeoff-lineinspectionforthecompanythathasaccumulatedprocessknow-how to take substantial measures against the cause of defective and to maintainsteadyqualitytoacertaindegree(100PPM)duetostableequipment,butthereliealwaysdangerousfactors,sinceearlydetectionofqualityaccidentisdifficult.

(Whiledefectivedetectionofoff-lineisafterproducing200PCBs,in-linerequirestotakemeasureonlyforabout20PCBsinproductionline.)

Currently,many companieswith high capital are propelling to arrange basically in-lineAOI.

Some companies arrange inspection before reflow oven in SMT product line and thereason is to reduce defective by committing manpower since quality of product is notguaranteeddue tooldequipmentand repairing/maintenance. It is right to takemeasuresagainstdefectiveofequipment,notdesirabletocontrolbycommittingmanpower.

Most efficient way to decrease fault in SMT production is to handle PCB as less aspossible. IfhandlingPCB ismore,possibilityofworkmanshipdefectwillbe increased.PCBhandlingbeforecuringprocesscan’tguaranteethequalityofproduct,only1stboardsampleinspectionisrecommendedbeforereflow.

ThestandardSMTprocessdoesn’trequireanyextramanpowerexceptm/coperatorfromPCBloadingtoun-loadingandifanyextramanpowerisusedforinspectionorinsertion,itmeansthereisaproblem.

3)QualityDataManagement:

InordertomanageSMTprocessquality,currentproductqualitystatusshouldbeanalyzedaccuratelyinthefirstplace.

Possible improvement of target can be processed after accurate analysis of process; theweakpointofmostSMTcompanyistoneglectqualitydatamanagement.

Althoughbannerofqualitytarget,‘100PPMachievement’or‘6sigmaachievement’aredisplayedinthecompany,mostofthemarenotrealisticandfarawayfromthetarget.

Althoughitisobservedthattheinternalqualitydataofasuppliercompanyisnottoobad,theremightbegreatdifferencewhencomparedwithcustomerquality.

Forexample,ifinternalqualityofasuppliercompanyis1,000PPMandcustomerqualityisover1 to2,000PPMthatmeans the internalqualitydataofSupplierCompanyisnotreal,itismodified.

Basically,qualityshouldmeettherequiredtargetofcustomers,theycan’tbutmodifythedatainevitablysincetheycan’texposeitduetolackofqualitymanagementmethodandbadqualityoftheirproducts.

Theproblem is that the reliabilityofaccumulateddataandaccuracyofdaily inspectionreport are low, hence those data can’t be used for quality analysis and improvementmanagement.

As the standard of internal analysis of SMT data is not specified, the data can’t beanalyzedandutilized,productqualityarenotmatchedwithqualitydata.

(1)CriteriaforSMTDefectiveData:

SMTqualitydatashouldbecontrolledbyPPMunit.PPMmeansPoint(Part)PerMillion,whichismanagementofeachmaterialpoint.

IncaseSMTdefectdataiscalculatedbyproductunit,defectratioindataresultcomesoutextremelyhighandachievementtargetof100ppmisimpossible.

For example, if model A has total 100 points, 10 points of defect occur from 1,000productsanddataofcalculationisasfollows.

Model ProductQty Point Prod.Point NGQty NGPPM

A 1,000 100 10,000 10 100

Figure6.26

Model ProductQty NGQty NGPPM

A 1,000 10 10,000

Figure6.27

As indicated in the Figure 6.26, 10 points defect result show 100 PPM, calculating byproductqtymultiplyingtotalpointsofeachproduct.

1000X100=100,000point

(10/105)X106=100PPM

TypeofFigure6.27,10pointdefectresultshow10,000PPM,calculatingbyproductqty.

(10/103)X106=10,000PPM

If100PPMistoachieve,thetargetis1defectin10,000products,whichisnotpracticallypossible.

ForassemblytheSMTPCBisonepointandpartslikecables,moldingpartetc.areotherpoints. So, controlling defective data by PCB qty in assembly is correct in terms ofmethod.

ForSMTonepointiseachcomponentqty(R,L,C,IC,TR,CN,etc.)SoinSMTalldataneedtobecontrolledbyeachpointnotbyPCBqty.

Improvementofqualitycanbeprocessedbyrealistic targetwithnormalcriteria.Due toerror by analysis with wrong method and huge gap between target and result, noimprovementisachieved.

Since, target isnotachievedfor long time, thewillof improvement is frustratedandnoimprovementcomesout.

Standard data controlling and accurate analysis of quality are critically important forqualitymanagement.

Forthosewhocalculatequalitylevelinpercentage

1% is 10,000 PPM. If percentage unit is still used, it seems less defective quality but,convertingittoPPMunitindicatesabove10,000PPM.Percentageunitcannotbeusedforimprovement.

(2)ImportanceofQualityReport:

Aproblemoflowqualitycompanyisthatthereliabilityofaccumulateddataandaccuracyof daily inspection report are low, hence no quality improvement activity is carried outaccordingtodata.

Or even though there is activity for improvement, they make a temporary solution orimpromptumeasurewhendefectiveoccurs.

Forimprovementactivityisaccuratedatacollecting

The first condition forPPMmanagementofdefectiveand improvement through toolof6sigmaistomanageaccumulateddata,anditistoimprovequalitystartingfromtheworstdefectivecaseamong theaccumulateddata.Reliabilityof accumulateddatadependsonaccuraterawdatafrominspectionreport.

Thereasonsofnotwritinginspectionreportisasfollows-

1)Inspectorisnotavailable.

2)Supportforotherproduct.

3)Unskilledwritingbynewmanpower.

4)Modifieddataduetoqualityaccidentinhugeqty.

5)Dataomissionoffrequentdefectsonpurpose.

6)Reportisnotwrittenduetolackofmanagement.

Fornormalwritingof inspection report, familiarityandmaintenance through trainingofwritingmethodshouldbeconductedandaccustomedbydailycheck.

Beforewriting inspection report, it is compulsory to check criteria of defect anddefinedefectiveitems.

In case of visual inspection, since defect criterion is individually different, it should bestandardized.Ifitishardtojudgebyinspector,itneedstobeadjustedbymanager.

Forwritinginspectionreportnameofdefectiveshouldbewrittenupbysameterminology.

If defective names are not standardized, different names fill up for the same defect orwrongdefectivename is selected.Aftercollectingdata fordefectanalysis,wrongresultcomesoutduetonon-standardizeddata.

Forexample,thedefectivethathassolderinICleadpadbutnotconnectedcanbewritten‘LeadOpen’or ‘OpenSolder’or ‘LiftUp’. Incase there isnochipmaterialwhere it issupposed to be, it is written ‘no component’, or ‘component missing’, hence, it isnecessarytospecifydefectiveitemsandsharethecommonterminologiesinthecompanyforeasierdatacollectionandanalysis.Inaddition,sinceterminologyfordefectiveitemsisvariant from different company, training even for experienced workers from other

companyisrequiredwhennewworkersareentered.

(3)DataAccumulationManagement:

Oncedailycheckreportiswrittenthenthefailuredatashouldbecollectedbylineandbymodel.Dataaccumulationmanagementshouldbedonebydaily/weekly/monthly. Ifyouhaveacomputerizedsystem,afterinputofthedata,itiseasytooutputtheresultswiththedesiredformataccordingtoday/week/month/line/model/nameofdefect/nameofparts.

However, if you do not have a computerized system, usually Excel can be used toaggregate the data. Additional manpower is needed due to time-consuming fordevelopment of the company-specific management models and for input data andproducingthedesiredresults.

ItmightbeseveralwaystoputbaddatausingExcel,butthepivottableisconvenienttousewhichIeverused.Itwouldbelittlebiteasiertomakedataifyoumanagearawdatainputformattousethepivottablebeforeinputthedata.

1)First,inputdataandthensettheitemstooutput.

2Year/Date/model/line/side/nameoffaulty/referenceno/quantity/type,etc.

2)Createtheformanddeployitforthetrainingtowritedailycheckreportastheitem

2Typecanbeincludedinthedailycheckreportorcanbeclassifiedwhileinputthedatabytraining.

3)Inputdatainaccordancewiththeformofthedailycheckreport

2trainingforinspectorsaboutthenameoffaultyandregulationsshouldbepriority.

Itshouldbecarefulofthecellsmergingorhavingaspacewhileyouinputdatabecauseyoucannotgetthedesiredresultsfromthem.

Inputdata:

Year Date Shift Model LINE Top&Bottom

NameOfDefect LocationNo.

2012 02-01 I B 2 BOTTOM CompShift C224

2012 02-01 I B 2 BOTTOM CompShift C413,C100,C408,J300,C227

2012 02-01 I B 2 BOTTOM Billboard FL305,R100

2012 02-01 I B 2 BOTTOM Billboard R100

2012 02-01 I B 2 BOTTOM CompMissing R100,R117

2012 03-01 I C 3 TOP Upsidedown LD303,LD302,LD306,LD309,LD308,LD311,LD300,LD313,LD312

2012 03-01 I B 2 BOTTOM Billboard FL305,FL304

2012 03-01 I B 2 BOTTOM CompShift S200,J300

2012 03-01 I B 2 BOTTOM CompMissing C232

2012 03-01 II B 2 BOTTOM CompMissing L410,C331

2012 03-01 II B 2 BOTTOM Billboard FL302

2012 03-01 II B 2 BOTTOM CompShift C408

2012 03-01 II B 2 BOTTOM LessSolder R343

2012 04-01 I A 1 BOTTOM CompShift SW101

2012 04-01 I A 1 BOTTOM Bridge U401,U101

2012 04-01 I B 2 BOTTOM CompShift J300,C408

2012 04-01 II B 2 BOTTOM CompShift CN302

2012 04-01 II A 1 BOTTOM CompShift S301

2012 06-01 I B 2 BOTTOM Tombstone L409

2012 06-01 I B 2 BOTTOM CompShift CN302

2012 06-01 I B 2 BOTTOM CompShift J300

2012 06-01 I B 2 BOTTOM LessSolder U400

2012 06-01 I B 2 BOTTOM CompMissing J300

2012 06-01 I B 2 BOTTOM CompMissing Q200

2012 06-01 II B 2 BOTTOM Tombstone C407,C431

2012 06-01 II B 2 BOTTOM CompLifted U101(Extracomp.underBGA)

2012 07-01 I C 3 TOP CompShift LD301,LD313,LD305,LD300

2012 07-01 I C 3 TOP Upsidedown LD309,LD311

2012 07-01 I B 2 BOTTOM Billboard FL305

2012 07-01 I B 2 BOTTOM CompMissing C326

2012 07-01 II B 2 BOTTOM CompMissing R110

2012 08-01 I E 4 TOP CompShift D402

2012 08-01 I B 2 BOTTOM CompMissing J300

2012 08-01

I B 2 BOTTOM CompMissing

2012 08-01 I B 2 BOTTOM CompShift J300

Figure6.28

4)AfterinputtingthedatathePivotTablefunctionistobeusedandthedesiredvalueistobecopiedtoanoutputmanagementsheet.

For example, the following data will come out if the Figure 6.28 data is arrangedline/defectiveofname/date/quantityisshownasfollows.

Figure6.29

Theoutputresultcanbemovedtolinewisequalitycontrolsheet.Modelwisedefectcanbe alsomoved using the same pivot table after getting output according tomodelwiseparameter.

OutPutData:

Figure6.30

Usingapivottableprovidesagreathelpfortrackingthecausesofdefect,sincethevarietyof results of desired parameters is to be seen and the distribution chart of frequentdefectiveitemscanbetraced.

(4)HowtoUsePivotTables:

1)First,theareaofdataforprintistobemarkedbydragging.

Figure6.31

2)ThePivotTableandPivotChartreportistobeclickedinmenuitemdata.

Figure6.32

3)Whenthemenulikebelowcomes,thenclickOK.

Figure6.33

4)Movetheiteminthedesiredconditionbydragging.Youcanchangetheitemlater.

Figure6.34

The change of the result is possible bymoving or removing the desired data from theabovethePivotTablelist.

In thesamewayasabove,youcangetqualityresultmodelwise, linewise,defectwiseandwhateverwise.Thenmanagementanddefectiveanalysiscanbedone.

5)FaultyConditionManagementChart:

Sheetofdefectconditionbasedonthelinewisemonthlyqualitycontrolchart,modelwisemonthlyquality control chart needs tobeupdated, reviewedandmanageddaily/weeklybasis.

LinewisemonthlyQualityControlChart

Figure6.35

ModelwisemonthlyQualityControlChart

Figure6.36

Continuousactivitiesofimprovementshouldbecarriedoutstartingfromtheworstdefectinqualitycontrolchart.

Operatorandsupervisormusthavetheskillandeffort toimproveprocessfailureswhilemanagers and quality teamhave the responsibility of improvement ofmanagement andmaterialissue.

4)BSN(BoardSerialNumber)Management:

Itwas already applied to some companies that produced high price products.However,cheaperproductscompaniesorsmallmanufacturerswhichdonothaveclearBSNconceptdonotyetapplyit.

The reasonofapplicationofBSN toPCBAis tomanage thehistoryofproductsand totrackwitheasewhendefectsoccur.

FollowingisanexperiencefromthemobilephoneOEMcompany.

In case of products of major companies, BSN is applied to the development andmanufacturingprocess.And thebarcode labelattached toPCBAis readbyscannerand

savedinEEPROMorflashmemoryoftheproducts.Thehistoryofproductsisthensavedinnetworkdatabaseandcanbeefficientlymanaged.

However,theproductsofsmallcompaniesarenotbuiltinBSNsystem.

ThustheydelayedBSNsystemduetolackofunderstandingofnecessityinspiteofmyrequestofitsadoption.ThatiswhyIstartedmyownoff-lineBSNprocessfortrackingthehistoryofproducts.

Oneday,duringtheproductionofonemodel,aqualityaccidenthappenedduetotheR&Dissueandchipcomponentneeded tobereplaced. Itwasdifficult todiscern theproductssinceitcouldnotbeidentifiedbyvisual.

ThusitwassolvedbytrackingtheproductionhistoryaccordingtoBSNonPCBAgivenfromSMT.Afterthat,theimportanceofBSNwasrecognizedandfullsupportwasgivenandfinallyBSNsystemwassuccessfullysetup.

Incasethereisnoprobleminproducts,BSNapplicationisnotmuchnecessary,However,in casedefecthappensorproblematicproduct is found,history trackingmanagement isextremelynecessaryanditisusefultosegregatequalityaccidentproductinSMT.

IncaseofaproductwithoutBSNsoftwaresystem,BSNstandardshouldbecreatedfirstand the labelattachingareaneeds tobeapprovedbyR&D.StandardofBSNshouldbesimplymanagedanddistinguishedbymodel/destination/PCB/productdate/serialnumber

Figure6.37

After attaching it to the SMT completed products, it should be managed to keep therecordingindailyproductsreport,inspectionreportandrepairreport.

BSNProcedure:

Thereare2typesofstickerprintingmethods.

1)Online(linewisePCandLabelPrinteravailable):

Figure6.38

2)Offline(OnePCandLabelPrinterforalllines)

Figure6.39

Incaseofproducingtheproductsofmajorcompanies,productiondateisoftenrequired,butitisquitedifficulttomeetforvendorcompanies.

Inorder to print out exact quantity of daily products, a label printerwill beneeded foreachlinetoattachrightafterproductioniscompleted,butinvestmentforthelabelprinterwithPCandsoftwarefromthevendorcompanyisdifficult.

In case only one label print is used, daily production quantity should be predicted linewiseanditisimpossibletopredictwithoutanyvariation.Iflinehasmaterialproblemorequipmentproblem,itcannotcompleteproductionplanandBSNlabelwillberemainedandneedstoscrapthem.Afterscrap,labelneedstobereprintedandprinthistoryinthe

logbookalsotobechanged.Itisadoubleworkandmisprintcanbeoccurred.

BSN is written already in daily report and trackingmanagement is enabled. And afterassembly the product serial number is given and used. Thus production date is notnecessarilytobeinsertedinthelabel.Sincetrackingisnotaproblemtomajorcompanies,productiondateshouldnotbedemandedtothevendorcompany.

5)PPMCalculation:

WhatisPPMinSMT?

PPM-PointPerMillion(PartPerMillion)

1%-10,000PPM

–SMTcannotusepercentageunit.

–Ifyouusepercentageunit,youcannotcontrolSMTQuality.

–InSMTqualitytargetis100PPM.

Achieving100PPMmeansthatcompanyhaveperfectprocess.

SMTqualitycontrolmethodisPPMwhichmeanspointcontrol.

Butmanycompaniesareusingwrongmethodofdatacollection.

SoinSMTalldataneedstobecontrolledbypointnotbyPCBqty.

In SMT each component (R, L, C, TR, IC, etc.) is one point. Hence, number ofcomponentsperPCBwillbetakenwhilecalculatingthePPM.

E.g.Totalno.ofcomponentperPCBis100,ProductionQtyis100anddefectivePCBis2,thenPPMwillbe

PPM=TotalNo.ofdefectsX106

(PointsXProd.Qty)

=1/(100X100)X106

=200PPM

Figure6.40

WhileinAssemblylinewiththeassemblyparts,PCBA(SMTfinished)isconsideredasonepoint.

E.g.Totalnumberof assemblypart is9, productionqty is100anddefectivePCB is1.ThenwhilecalculatingPPMthenumberofpointswillbe10includingthePCBA.

PPM=TotalNo.ofdefectsX106

(PointsXProd.Qty)

=1/(10X100)X106

=1000PPM

PCBAAssyPartsFinalProduct

Figure6.41

6.6AnalysisofProductiveCapability

Analysis of production capability is very important since it is the basis of planning ofproduction and analysis of efficiency.When the production line capacity is calculated,some companies use the first programmed cycle time for setting the capacity based onanalysisofproductionefficiency.

WhenthefirstprogrammedmodelisnotproperlyoptimizedandLOB(LineOfBalance)isnot improved,efficiencyofequipment isusuallyreduced, thus it isnotappropriate tosetitasthestandardtarget.

Thismethodseemsaccuratebecauseitusesactualdata,butitisnot,itisdependedontheprogrammer’sskillandeffort.

And theCEOormanagerwhoarenot familiarwithSMTorSMTbeginnergetswrongideaofspecifiedCPHbymachinemanufacturerbutitcannotbethestandardsinceitisthespeed without any loss (programming loss, change over loss, etc.) under the bestconditions.

Production capacity is different dependinguponmachine andneeds to be controlledbypoints.Basedonmachinecapacity,linewisetargetcapacityistobecalculatedandsetitasproductiontargetandmanagedit.

1)LineProductionCapabilitywithCalculateLossofEquipment:

Equipmentwisechipmounterapplies70%efficiencyofspeedinspecificationandmulti-mountcalculateswithapplicationof30-50%efficiency.Thiscalculation ismeasuredoncondition of the maximum efficiency after the optimization of each equipment wiseprogramandLOB.Thecapacityiscalculatedincludingprogramlossinthebelowtable,but thelossofproduct lineoperationisnot.(Change-over,materialchangeandmaterialshortage,etc.)

Programminglossvariesdependingonequipment,experienceisrequired.

Figure6.42

2)LineCapacityIncludingLossofLineOperation:

Figure6.43

(Exampleof)Lossoflineoperation

1) Model change-over timing (variation depending on organizational capacity ofcompany).

2)Numbersofmodelchange-over(canbereducedbycorrectplanning).

3)Materialchange.

4)Dailylinemeeting(dailyproductionplan).

5)Shiftchangeover.

The line efficiency is decideddependingonhowmuch loss time is reduced among theabove factors. If around20%of loss is considered, itwouldbe thepossible productiontarget.

Productioncapacity=(EquipmentSpecificationcapacity–programloss)–Lineoperationloss

6.7ProductionPlan

Aftermakinglinewisestandardproductioncapacity,daily/weekly/monthlycapacityneedsto be calculated. Based on the calculated capacity, production planning is to beestablished. In production planning, holiday should be excluded. When target is notachieved,off-dayextracapacitycanbesupplied.

Thefollowingexampleshowsthecalculationofmodelwisepossibleproductionquantitywithpoints.Linewiseplanningcanbeestablishedandmanagedbasedonthisdiagram.

Possibleproductionquantityaccordingtothemodel

Figure6.44

Accordingtothecustomerorder,productionplanningisestablishedandenteredintoERPandworkorderisissued.

InSMT,basedonworkorder,linewiseproductionisplannedandmodelchange-overisdecided. Model change –over is the main cause of loss time in production, therefore,modelchange-overshouldbeminimizedwhileplanning.

Reasonsofmodelchange-over

1.Inordertoproducenextmodelaftercompletionofcurrentmodelproduction.

2.Changeoverduetochangesinproductionplan.

3.Duetomaterialshortage(materialisnotavailable).

Theabovearethecausesofchange-over.Productionplanningchangecanbereducedbyraising the ratio of achieving the production plan and inspecting material beforeproduction.

All staff from other department is gathered for production planning and some conflictoccurs between the planner and SMT production team regarding target productionquantity.

Thereasonisthatthemethodofanalyzingtargetcapacityisdifferent.Thusstandardtarget

shouldbesamesothatthedisparitycanbesettled.

Doyouhaveabasicstandard?Whatisyourbasicstandard?

6.8StandardizationofProductionProcessandProcedure(workmanual)

In assembly line, all process and work instruction are supported from productdevelopment department, whereas few companies support for SMT line. Thus mostcompaniesstandardizetheSMTworkprocedurebyitself.

Well-runningSMTCompanywithstandardizationandworkprocedureiswellorganized.However, inefficient companies use the procedure of other companies which is notmatchedwiththeiractualwork.

SMTworkinstructionandprocedureareactualworkingmanual.Inordertoreduceerrorandlossassoonaspossible,eachprocesssequenceandcontentsneedtobedetailed,thuseveryoneisabletooperatewithsimpletrainingaccordingtoworkmanual.

ListofProcedureandDocument:

Figure6.45

SMTDocumentsList

Sr.No. DocumentName

1 DailyProductionReport

2 PartChangeReport

3 DailyPastePrinterReport

4 AOI/VIInspectionReport

5 SolderPasteMixingDetails

6 Temp.MonitorChart

7 StencilCheckSheet

8 CheckSheetforStencilCleaner

9 StencilMaskHistoryCard

10 ScreenPrinterCS

11 ScreenPrinterPassRateSheet

12 QualityStatusMonitoringChart

13 MonthlyRouterBitControlSheet

14 PreventiveMaintenanceReport

15 MaterialIssueNote

16 MaterialReturnNote

17 WristbandCS

18 OQCInspectionReport

19 IGIReport

20 ProcessAuditReport

21 ESDauditreport

22 DailyReworkDetails

23 PastePrinterSetupChart

24 ReflowSetupChart

25 ROMWriterSetupChart

Figure6.46

Theabovedocumentswillbeaddeddependingonthecharacteristicsofeachcompanyandallprocedurescanbe theobjectofnecessarymanagement for fieldworkaswell as theabovelists.

Most cases of production and quality incidents are caused by not complying withprocedures and standards or by insufficiently made processes. When production and

qualityincidentoccur, thecheckpointiswhetherit isdoneaccordingtoproceduresandwork instruction and whether there are any problems with the procedure and workinstruction.Someworkersareattributedtotheirfaultandpunishedbycertainmanagers,but it could be a cause to undermine the organization, thus, it should be accuratelyevaluated.

Incaseproceduresandstandardsarenotcomplied,re-trainingoftherelatedpersonnelisrequired and the corresponding sanctions should be followed. In case procedure andstandardizationarenoneorinsufficient,itistheproblemofmanagement,thus,theoverallproceduresandregulationsneedtobereviewedandrevisionandreoccurrenceshouldbepreventedafterrevisionofproceduresandworkinstructions.

6.9OperationEfficiencyAnalysisandManagement

Thepurposeof line efficiency analysis is to improve lineproductivity to themaximumcapacity by analyzing loss status and removing inhibitory factors. And it is also tocalculateactualoperating time, excludingdown time fromplannedproduction timeandanalyzingoutcomeofactualproductionincomparisonwithactualoperatingcapacity.

Inorder toanalyzeproductionefficiency,reportfromtheSMTlineshouldbecorrect inthe first place. Inaccurate report may cause the wrong analysis. For accurate report,classificationof linedown time shouldbe created so that common terminologymaybesharedanderrorsmaybeeliminated.

Only if detailed information about the down time is provided, accurate analysis andimprovementispossible.

ExampleTablefordowntime

Figure6.47

If raw data of down time recorded in report is controlled by pivot tablemethod as thequalitydatacontrol;desiredresultscanbeeasilygottenandusedinvariousformatswithlittletime.

Somecompaniesconsideroperatingefficiencyas thesumofcapacityofequipmentandmanpower.SMTapplicationofplannedproductiontime,however,shouldbecalculatedbyequipmentstandardsexcludingmanpowerforhigheraccuracyofthedata.

Inthecaseofassemblyline,whenpersonnelareincreased,thecapacityisalsoincreased.In SMT line, unless equipment is increased, capacity will not be increased, althoughmanpowerisincreased.

In assembly line, thus, planned product time is changed according to the number ofmanpower,whileinSMTline,plannedproducttimeischangedaccordingtothenumberof equipment.Hence, inSMT lineexcluding the rateofmanpowerchange, theplannedproducttimewillbechangedwhenequipmentisaddedorequipmentbreakdownoccurs.

CalculationofOperatingEfficiency

(1)Retentiontime:Regularworkinghours(8hr)

Companystipulatedregularworkinghoursexceptforlunchandbreaktime.

(2)ExtraTime:overtime(O/T)

Timeafterregularworkinghoursareextended.

(3)PlannedproductionTime:Retentiontime+extratime

Thetotalrunningtime.

(4)Downtime:theline-stoppingtime

Thetotalstoppingtimeduringoperation.Itshouldberecordedindetailbyclassification.

(5)Actualoperatingtime:Plannedproductiontime-downtime.

Actualtimeoperatedforproduction.

(6)Linecapacity:Itfollowsthelinewisecapacitytable.

Itvariesaccordingtolinewiseequipmentcompositionandperformanceofequipment.

(7)TimeEfficiency:(Actualoperatingtime/plannedproductiontime)x100

It is a percentage of line operating time over planned production time. Decrease ofoperating efficiency means increase of down time, hence time efficiency can beincreased by improving major causes through analyzing the down time in detailaccordingtofactors.

(8)ProductionEfficiency:(ActualProductionPoint/TargetPoint)×100

TargetPoint:PlannedProductionTime×Linecapacity/min

ActualProductionPoint:ProductionQuantityXModelQPS

Itisthepercentageofactualproductionpointovertargetpoint.

Timeefficiencyhasnottodowithproductionmodelandequipment,whereasproductionefficiency varies according to equipment or production model, hence it is closelyconnectedtoproductionplanning.

(9)ActualOperationalEfficiency:

(ActualProductionPoint/(ActualOperationTime×LineCapacity/Min))×100

It is thepercentageofproductionpointover targetpoint that canproduceduringactualoperation.Theactualoperationalefficiencyhasnothingtodowithdowntime,sincedown

timeisalreadyremovedfromplannedproductiontime;henceitindicatessoleproductivityofproductionline.

Factors of decreasing operating efficiency are error in applying of line capacity orproductionmodelmaynotbesuitable,personalskillorconditioninlinemanagement.

Iemphasizeagainthatthemostinsufficientanddifficultthingisdatamanagementintheon-site production line. Few companies analyze accurately and manage operationalefficiencyasrareinthecaseofquality.

Thereasonwhyoperationaldata is incorrect is inaccuraterawdataof loss time indailyreport.Causesofinaccuraterawdataindailyreportareuncleardefinitionandstandardofloss time,unmatchedstandarddueto thewrongmethodofcalculatingcapacity(refer tothepreviouscapacitycalculation),lackofeducationforsharinginformation,andunsettledmanagementprocess.

And operational rate should be analyzed and reported daily, weekly, periodically, andimprovementgoalshouldbesetforthenextmonthbyanalyzingoveralloperationrateattheendofmonthsothatinvolvementoffieldpersonnelshouldbeencouraged.Alltheseparts aremanagement elementswhich need to be done in elementary andmiddle-levelmanagement.

6.10ProgramManagement

Programmanagementisbroadlydividedintoprogramcreatingprocess,ECOapplicationprocess andprogrambackupprocess.Copyofother company’sdocument in equipmentmanagement can be applied; however, the standard of creating program name and partdatanameshouldbefixedaccordingtothecompany.

The standard of program name and part data name might be already created in somecompanies,butmanycompaniesdonothave them thus, appropriate standard shouldbemadeandused,sinceequipmentandproductscouldbedifferentaccordingtocompany.

The reasonwhy standardof programnameandpart dataname is created, is to preventincidentscausedbymisusage.

1)ProgramName

Inthecaseofprogramname,whenmodelwiseprogramnamewithoutstandardiscreated,severalsimilarnamesmightbeeasilyfoundinonemodel.

Eg.Ybsettop–pp

Ybsettop–mp

Ybsettop–test

Ybsettop–test1,etc.

Amongtheprograms,therearelotsofprogramswhicheventhepersoninchargedoesn’tknowthus,itisdifficulttodistinguishpropermodelbyonlyprogramname.Todistinguishtherightprogram,openingeachprogramisinevitable;hence,accidentsmayarisecausedbymisapplicationofprogram.

SampleProcedureforMakingProgramName:

Figure6.48

E.g.2_A_Top_00(line2_modelA_Topside_00Revision)

2)PartDataName

Similarly, part data names are unlimitedly created as MSM 5100_1, MSM 5100_Lee,MSM5100_test…fromonepartnameMSM5100,hence,itishardtodistinguishwhichmaterialdataiswantedanddataiskeptonbeingcreatedaccordingtoprogrammers.

ExampleofMakingPartDataName:

Hence,topreventprogramaccidentsanddiscernthetruthandfalsehoodofdatabyname,standardslikeprogramcreatingprocedureandprogramnameshouldbeclearlycreatedsothattrainingprogramandinformationmightbeshared.

Usually thecompanies thathavemore than4SMTlineshavenomanagementproblem,sinceprogramisoperatedbyseparatepersonnel,butmostcompanieswithlessthan4lineshavedifficulty for regularmanagementdue tonopersonnel,which increases the riskofaccident.

Itisefficientwaytopreventaccidentsbymanaging,developingprocessbyprogrammersthemselvesandraisingtheirsenseofresponsibility.

Figure6.49

ProgramManagementFlowChart:

Figure6.50

6.11Equipmentmanagement

The purpose of equipment management is to prevent equipment failures throughpreventive conservation activitieswith regular preventivemaintenance and tomaximizeefficiency by extending the life of equipments so that quality and productivitymay beimproved.

RegardingSMTequipmentmanagement,equipmentconservingactivitiesforTPM(TotalProductiveMaintenance) isgenerallymentioned,but therearenotmanycompanies thatcan propel TPM management. Small and medium companies, in reality, do not raiseexpertsandconductcontinualmaintenanceactivity.

Similarlyinequipmentmanagement,equipmentwiseoperationalprocedure,maintenanceprocedure, maintenance standard, standard check pointy, check sheet, etc. should bedocumented and educated in the first place, and annual preventive maintenance planshouldbeestablishedandcarriedoutaccordingtotheplan.

Sincemostmediumsizecompanieshaveequipmentexpertsforset-up,maintenanceandrepair of equipment, documentation regardingmaintenance is almost done, but problemoccursinactualoperationofplan.

ThereisnoproductionmanufacturerthathasnotreceivedISOcertificationandISOalso

requestspreventivemaintenanceactivityaccordingtoannualmaintenanceplan.

Major companies have developing department that has separate maintenance team foroperation supportedbyequipment technologiesandmeasure for trouble shootingand isorganized for conducting preventive maintenance, hence, they are generally able toconductmaintenancewithwell-plannedscheduleafterstoppinglineproduction.

Smallandmediumcompanies,however,cannotgetsupport fromproductiondevelopingdepartment,thus,theyneedtoconductself-maintenanceactivity.Inthiscase,manpowerisoneofproblems,butthebiggestproblemistokeepdeadlineofdispatch.Sincemeetingdispatchdateisdirectlyrelatedtothenextorder,productionplanalwaysgetfirstpriorityandpreventivemaintenanceplan is kept for the latter, hence,maintenance activitywithorganizedplanisdifficult.

Mostcompaniesdonotallowmaintenanceplanbystoppinglineduringtheweek.

Hence, although regular maintenance is usually scheduled on a holiday, but in casecustomer company requests more production or shortage of production target. Sinceplanned maintenance can be difficult due to lack of maintenance day, the second bestoptionispartialmaintenanceperformingincaseofoff-lineproduction.

For planed preventive maintenance, senior managers are requested to be aware ofimportanceof thepreventivemaintenance forwhichstrongwillofCEOisnecessaryasthepracticalconditionofTPM.

BasedonsuchwillofCEO,productiondevelopingdepartmentshouldcontrolproductionplan and the planned maintenance is possible only when Customer Company mayunderstandandallowit.

SMTmanagersshouldconductsystematicallypartialmaintenancethatcanbedoneasoffirstorder.

Inordertokeepequipmentmaintenance,itisnecessarytogetexpendablesparepartsthatrequire periodic replacement. Spare parts should be purchased and kept periodicallywithin SMT budget after the cost of maintenance and repair is determined by annualbudget and approved by CEO. The amount of money used for purchase is to besummarizedandreportedmonthly,andannualcostshouldbeanalyzedmonthlybywhichtheappropriatequantityofpartsshouldbereflectedtothenextyearbudget.

1)MachineSparePartManagementSheet:

Figure6.51

ConsumablePartManagementSheet:

Figure6.52

MaintenanceProcedure:

Figure6.53

2)MachineBreakdownProcedure:

Figure6.54

Howmuchdoyouknowaboutyourlossinproduction?ThisisCostToCompany…

6.12LossAnalysis

Figure6.55

1)ProgrammingLoss:

1)Usem/cmanufactureroptimizationprogramonly.

2)Programmerdoesnothavecorrectskillofoptimization.

3)M/cconditiondoesnotsupportforsimultaneouspickup.

Due to aboveproblem,30~40% losses comes inprogramwhich reduces the capacity.Hence,programmerneedstrainingforcorrectwayofdoingprogramoptimization.

2)ProcessLoss(DownTime):

1)Doesnothavecorrectprocedure.

2)Doesnotknowcorrectworkingmethod.

3)Doesnothavecorrectworkinstruction.

4)Doesnothavemanpowerwithcorrectskill.

Duetoabovereasons,duringproductionmorethan20%downtimeisobserved.

E.g.Changeover,Materialsupply,M/cbreakdown/stoppageetc…

3)ManpowerLoss:

1)Doesnothavecorrectmanpowerrecruitmentprocedure.

2)Doesnothavecorrecttrainingandevaluationprocedure.

3)Doesnotfollowthecompanyculture/policyproperly.

Duetothesereasonspersonmakesmoredowntime,resultinginbadquality.

4)QualityLoss:

1)Programmingloss-Mountingprogramhaveproblem.

2)Processloss.

3)Manpowerloss.

Duetoabovereasongoodqualityisnotobtained.

5)MaterialLoss:

1)Programmingloss–Nocontrolofdroppage.

2)Processloss–InSMTnomaterialmonitoringprocess.

3)Manpowerloss–Noknowledgeofmaterialreuse.

4)Qualityloss–Repairingcost.

Duetoabovereasonmateriallosswillbehigh.

6.13Maintenance

MaintenanceactivityisveryimportantforcontrollingQuality,Capacityandforoperatingm/cforlongerterm.

The companywith nomaintenance teammakes contractwith agency.Since there is noengineerwithmaintenanceskill,forsmallproblemalsotheycallagencyandhence,theylosethetime.

Also they do not have correct knowledge of maintenance. During maintenance manyproblemsmayoccursuchaspart loss,assembly loss,wrongassemblyorpartdamaged.That’swhycompanypeoplegetafraidofmaintenance.

Ifyouraiseskilledmanpowerincompanyformaintenance,youcansavemoneyandtime.Hence, you need to get correct training from the m/c manufacturer and maintenancemanual.

Maintenanceprocedureisexplainedbelow.Thismaynotgetfromm/cmanufacturer.

1)Planning:

If company has maintenance team, they will make plan, otherwise production personneedstomakethemaintenanceplan.

Theannualmaintenanceplanneedstobemadeaccordingtomonthlyplan.

Maintenanceplanshouldbealwaysmadeasperproductionplan.

Makemaintenanceplanasperbelowcategories-

(1)Dailycheckofm/ccondition–Donebyoperatorasperchecklist.

Thisisoperator’severydayactivity.Eventhoughchecklisthasalotofoperator,theyjustfillit,notcheckingactualm/ccondition.

Hence,havingrealcheckbyoperatoriseverycompany’schallenge.

(2)Weeklymaintenance–DonebyoperatorandMaintenanceteam,cleaningandoilingonly.

Thisactivityneedstodowithmaintenanceteam,followingtheseitemsbymanufacturermaintenance manual. Cleaning and oiling item is to be maximum. Items are sensor,camera,headshaftetc…

If not doing this activity, a lot of small errors like pickup miss will be happened anddefectivewillbeincreased.

(3)Monthlymaintenance–Donebyoperatorandmaintenanceteam

Theseitemsfollowbymanufacturermaintenancemanual.

Dependingonthemovingpart,thereareballscrew,LMguide,shaftandwithmotor(X,Y,Zaxisandmounterheadetc…),whichneedstodooiling,greasingandconsumablepartchange.

Itisveryimportantactivity,forthisneedstostoplineduringmaintenance.

Forthisactivity,itisnecessarytomakecorrectprocedure,maintenanceteamandplan.Ifnotdoingthisactivity,m/clifecyclewillbereducedandm/ctroublewillbeincreased.

Somedaybigmoneywillbealsospent.

(4) Quarterly / 3 months, Half yearly / 6 months, Yearly maintenance – Done bymaintenanceteamwithagencyperson.

M/cconditionisimportantpointtocheckwithagencypersonandm/caccuracytestalsoneedstodo.

After maintenance calibration needs to do with agency engineer or who can do thecalibration.

2)Preparation:

(1)Manpower–Beforemaintenanceplanismade,m/cwisemanpowerrequirementistobeseparatedfromthejobresponsibility.

M/cwisemanpowerneedstofixduringmaintenance.Thiscanavoidthemistakeandgetresponsibility.

(2)Tools–Forassemblyandde-assemblytoolsarerequired.

Useonlygoodconditionedtools,becauseusingbadAllenwrenchanddrivewilldamagethescrews.Thistimeyoucanopenandclosetheassemblybutcannotbeguaranteedfornexttime.Nexttimeyou’llgrindorheatthescrewforremovingandifyoudon’thavesparescrewanotherscrewwillbeinsertedorkeepmissing.

Sameproblemmayhappeninallcompanies.

Usingproperandcorrectsizetoolistobeusedalways(notsmallandnotbig.)

(3) Oil and Grease – Use oil or grease clearly written in machine wise maintenancemanual.Needstousesametype.

(4)MaintenanceTable–Coveredwithwhitecotton.

Ifworkisdonewithouttableorondirtytable,thesmallpartcanbeeasilylost.

Thuswhenmaintenancetableisprepared,whitecottonisrecommendedtoliedownonthetable.

Aftermaintenance1or2screwsmaybelostorextramaybeturnedup.Thescrewislostand difficult to found it or if wrong assembly is done extra screwwill be appeared.

That’swhyextrapartneedstobecheckedandlostpartistobefoundinmaintenance.Ifthemaintenanceworkisdoneonwhitetable,allpartscanbeeasilyfound.

(5)CleaningMaterial–Cotton,cleaningsolution.

(6)Smallbox–Forkeepingscrewstoavoidmisplacingduringmaintenance.

Loader/Un-Loader:

1)Cleansensor.

2)Updownballscrewandshaftcleaningandgreasing.

Figure6.56

ScreenPrinter:

1)OnX,Ytable,backuppin,onrailandinsidem/cneedstoclean.

Ifdustremainsexcess,drysolderwillincreasegapandhence,solderingproblemsmaybeincreased.

Inscreenprintercleaningisveryimportantaspect.

3)Cleaningonsensorarea.

Uselintfreecottonforcleaning.

4)MovingAxis:

Y-axis,Z-axis,squeegeeupdown,LMguideandballscrewoilingandgreasing.

MaintenanceCheckList:

Figure6.57

Mounter:

1)Needs tocleandropcomponentonX,Y tableand insidem/cfeederbase,dumpboxeveryshiftduringmodelchangeover.

2)Cleaningonsensorandcamera.

3)Uselintfreecottonforcleaning.

4)Havetocheckvacuumlevelandchangefilter.

5)Nozzleandinsideheadshaftdustcleaning.

5)MovingAxis

XandY-axis,Z-axis,head,LMguideandballscrewoilingandgreasing.

PreventiveMaintenanceCheckSheetforMounter:

Figure6.58

Reflow:

1)Insidem/cfluxcleaning.

2)Fluxfiltercleanorchange.

3)Conveyerchainandgearcleaningandoiling(hottemperatureoil).

4)Cleanbymetalbrush.

5)Conveyerwidthadjustaxiscleaningandgreasing(hottemperaturegrease).

6)Atleastoneday/onetimeneedstocheckreflowtemperatureprofileforcheckingm/ccondition.

PreventiveMaintenanceCheckSheetforReflow:

Figure6.59

SPIandAOI:

1)CameraandSensorcleaning.

2)MovingAxis:

X,Y,ballscrewandtablecleaningandgreasing.

6.14MonthlyClosing

Everydepartmentevaluatesactualachievementagainsttargetbymonth/quarterly/semi-annually / yearly. SMT closing has no difficulty if organization is well configured toprogresssmoothlyaccordingtoprocesswithoutanytroubleasitismentionedsofar.

Processgoeswellwhenproductionandqualityaresetupwithpracticalstandardsothatrawdataiswellcreatedandanalyzedandwhenaccuratelycalculatingsystemformaterialisfixedonmonthlybasisinaccordancewithcompanysituation.

Forthecorrectclosingreport,monthlyclosingmustbeproperlydonebydepartmentwise.

Dataofclosingreportcontainsproductionstatus /operation ratestatus /qualitystatus /inventory calculation / spare part transaction history / expendable supplies transactionhistory.Thesedataaretocheckwhetheroveralldirectionofimprovementisappropriatebased on collected monthly closing data to review improvement rate against previous

achievementandimprovementrateagainsttarget.

Production data can get by putting the achievement closing data in order to be againsttargets,operationratestatusbyanalyzingmonthlySMToperationdata,qualitystatusbyaggregatingmodelwisemonthly quality data, inventory calculation by puttingmonthlyinventorydataofaggregatingmodelwiselossstatusandlossstatus(includingwaste)inorder,andsparepartandexpendablesuppliestransactionsbyputtingtheminorder.

Whenmonthlydata is collected, itwill be closingwithquarterly / semi-annual / yearlydata.

6.15Conclusion

ForSMTBeginners

Every SMT beginner puts weight on learning mounter knowledge. They would notattempt to learnsmallequipment. Itneeds toask,however,whichequipmentyouknowexceptmounterandhowmuchyouknowabout themounterandwhetheryoucandrawoperationalprocessflowchartofloader.

Thefirstthingtolearnequipmentistoknowoperationalprinciple(step)inthefirstplaceandtheentirelineequipmentistobestudiedratherthanputtingweightonmounter.

Onceoperationalprincipleofallequipmentsfromloadertoun-loaderisunderstoodthenother typeofequipmentscanbeeasilygrasped.Moreover,basicsmustbe laidwell.Asbuilding with weak foundation is prone to collapse and cannot be built higher, SMTrequiressolidfoundation.Withoutlayingfirmfoundation,SMTskillcannotbeimproved.

IfyouareabeginnerofSMT,learnthecharacteristicsofconsumablematerialsinthefirstplace. The usage of tools of which I provide the details is to be studied. And thenequipmentistobelearnedstartingfromloader.Soonafter,youshalleventuallybecomeaskillfulSMTprofessional.

ForCEOsandManagers

In SMT management, TMP, ISO and 6 sigma are all good methods, and yet the firstpriorityand themost importantdeciding factor for successofprojectwhether it is ISO,TPM,ERPoranynewconceptconsultingisthestrongwillofCEO.

Likewise,theimprovementofSMTalsodependsonthestrongwillofCEOthatenablesinputofcapitalformanagement,professionalsandcontinualinvestment.

ImprovementandsettlementofsystemwithoutCEO’sstrongcommitmentwillbeboundtofaileventuallydespitethefinefront.

The first thing thatoccurs topeople regardingSMT is equipment centeringonmounterknowledge, and thuspersonnelwith the expertise of equipment is preferredwhenSMTmanagerisrequired.

SMTequipmentgrowsconstantlyandmajorcompaniescontinuetoinvestforSMTbasedoncapital,establishorganizedprocessinmanufacturingtechnology,minimizemanpowerthroughdatacomputerizationandcontinuetomakeadditionalinvestment.

Small and medium companies, however, cannot make investment as much as majorcompanydoandtheydonotdevelopmanagementskillandstayinthesameinitialphase

due to lack of knowledge and information. Thus the direction for managers of SMEstowardimprovementshouldbeasfollows.

ThemanagementofSMTcanbeboileddown toobserve standard, establishproceduresandmanagedata.

Overall processes of SMT and standards should be organized in the first place and theworkon-siteanddeterminationcriteriashouldbeobservedaccordingtothestandard.Asstressed several times earlier, equipment management is only a part of the SMTmanagement,butthebasisbywhichmaterial,quality,productivity,equipment,etc.canbemonitoredandmanagedonthewholeisdatamanagement.

After collecting data from the SMT field, if activities like understanding situation 2analysis of problems 2 improvement 2 checking aremade into the regular cycle in thefield,productivityandqualitywillbeboundtoimprove.

In order to become SMT manager from engineer, know-how of equipment should bepassed onto the subordinate first to reduce time for equipmentmanagement, and investextratimeforselfdevelopmentasSMTmanager.

The biggest problem of engineer is not to share his know-how with others so thatequipmentismanagedpredominantlybyparticularindividuals.Itcauseslackoftimeandlowleveloperatorsmaylearnpartiallyaboutequipmentmanagement,asaresult,overallmanagementofSMTsystemcannotbedevelopeduntilthisviciouscycleisgoingonandon.

Examine yourself now whether you are just operator or manager and if you identifyyourself as operator, I hope youmay change your direction as soon as possible and bebornagainasmanager.

Ialsohadconcentratedonequipmenttoomuchasengineerwiththeaboveidea,butitwaspossible forme to obtainmanagement knowledge of variant other departmentswhen Ipassedonmyknow-howaboutequipmentsonebyonetoothers.

ThereisoneprincipleIlearnedthatifyougivesomethingtoothers,youwillnotloseit,butgetbetterthing.

7IMPROVEMENTRESULT

ImprovementResultofACompany:

1)Prod.CapacityImprove-30%

Model Status MaxTime%Improve Prod.Qty Actualproduction%Improve

ABefore 32

23.4225 170

32Now 24.5 290 250

B Before 49 8.8 80 60 10

Now 44.7 89 67

Figure7.1

Belowisthecostsavingcalculationforonemodel.

ModelAproduction–Before170/hr

Now250/hr

Perhr–80qtyincreased

Daily–80X22=1,760

Monthly–1760X25=44,000

If1PCBpriceisRs.50,then

Costsaving/monthwillbe–44,000X50=Rs.2,200,000

(2)Quality:

Before I started, the tentativePPMwasmore than10,000PPMandwithin3months isreducedto2,842PPM

Figure7.2

ImprovementResultofBCompany:

1)Production:

Operating efficiency improved 30%→ saving investment of 1 SMT line (4machines),reducedworkingdays.

2)Quality:

TotalNG3500PPM→1500PPM /VisualNG1100PPM→350PPM→Saved reworkcost

3)Material:

FromMay20080.06%→0.03%changeacceptancelossrate(%)

4)Manpower:

Manpowerreduced50%eachline

Eachline10persons→5persons

(1)ProductionCapacityImprovement:

Figure7.3

(2)QualityImprovement:

Figure7.4

(3)ReduceinMaterialLoss

Figure7.5

8TERMINOLOGY

• AOI (Automated Optical Inspector): Before AOI, all products are inspectedvisually.ItisamachinethatinspectstheappearanceofcompletedPCBafterreflows.Itisoperatedbyin-lineandoff-linedependingonproductionprocess.• Assembly: In order to perform certain functions, combining combination ofdifferenttypesofcomponentsonthePCB.•Audit:AuditinSMTisverificationofproductionprocess.• Bar Code: Represents numbers and letters by a bar mark with various sizes(diameter)andspacingisprintedtoidentifybytheM/C(reader)forreading.•BareBoard:Boardconsistsofpadsandalayerwithoutanypartsorcomponentsonit.• BGA (Ball Grid Array): The part with solder balls attached to the ground ofpackagewithgridwithoutlead.• BOM (Bill of Material): Database of the constituent parts or components of aparticular product information and synthesized information about the relationshipbetweenparts.•BSN(BoardSerialNumber):AuniquenumbergiventothePCBA(finishedSMTproduct)isusedtomanageaproducthistory.•BulkFeeder:ThecommonwayofpackagingSMTcomponentsarereelpacking/traypacking/stickpackingparts,itisadevicethatsuppliesthecomponentswhicharenotinthepackage.•Capacitor(charger,Condenser):Thecomponentrepeatstheprocessofcurrentflowtothechargeanddischarge.ThebasicunitisFarad(F)andiswrittenasPicoFarad(pF).•Chip1005Typeparts:It ischippartnamedbylengthandwidth.1005meansthematerialwith1.0mmlengthand0.5mmwidth.•Chip1608Typeparts:It ischippartnamedbylengthandwidth.1608meansthe

materialwith1.6mmlengthand0.8mmwidth.•Chip2012Typeparts:It ischippartnamedbylengthandwidth.2012meansthematerialwith2.0mmlengthand1.2mmwidth.• Chip Land: It is part of the conductor pattern used for the attachment ofcomponents, especially it is for the attachment to surface-mount components. Forgoodadhesionofsoldering,landsizeshouldbesmallassameaschip.•ChipMounter: It is the equipmentwhichmounts various standard chipmaterialswith high speed on the land portion of PCB with cream coated with solder oradhesive glue. (Large part can be somewhat limited or may be impossible). It isdividedintorotarytypeandpickandplacetypebyoperatingsystem.Otherwayishigh speed machine and medium speed machines depending on the speed ofoperation.•CleaningPaper:ScreenPrintersupplyingpaperisusedtocleanmetalmaskwhichcanbecomecontaminatedbycontinuousprintingprocess,itisusedduringautomaticcleaningprocessinfixedperiod.•Coil(Inductor):Acoil isapassiveelectroniccomponent thatstoresenergyin theformofmagneticfield.TheunitofcoilisHenry(H).•Conveyor:ThetransportmechanismstomovePCBfromfrontlinetonextprocessautomatically.•CreamSolder:Itisapastemixtureoftinsolderpowderandspecialfluxpowder.Sn(tin),Pb(lead)andAg(silver)arecompositepowdermaterials.Thecompositeratiovariesbymanufacturer.SolderpasteisavailablewithPbandPbfree.•CuttingNipper:Asharpendcuttingtoolusedtocutwireorsmallmetalwithcertainsize.•CycleTime:Eachprocessofproductionortestingtimefromstarttoend.• Defect: A product or part deviated from the accepted concept of normal.Majordefective,minordefective.•DIP(DualInlinePackage):Partsinsertedbytwopinsorleadline.ItiscommonIC,named, since it is insertedwith two rows into the hole on thePCBwith 7.62mmwidth2.54mmpitch.• Dispenser: An automatic machine that is designed to release bond on the PCBbeforemounting the components.Generallyused in the caseofboth sidemountedPCBforfixingthecomponents(IC,flipchip,etc.)onbottomside.•WristBelt/Band:Staticelectricityinthebodycoulddamagecomponents,soabeltiswornonthewristtosendstaticchargedowntothegroundtopreventdamageofcomponentsduetostaticelectricity.•ECO(EngineeringChangeOrder):Toimprovetheproductortoenhancethedefect,instructionsonthechangesofcomponentsortechnologydevelopmentcanbeissuedinthedocument.•ECN(EngineeringChangeNote):After issueofECO, internalnote ismadeaftermakingchangesinBOM.•EmergencySwitch:Facilityforimmediatestoppinganequipmentorm/cduringan

emergencyforthesafetyandprotectionofpersonorequipment.• EMS (Electronic Manufacturing Service): Manufacturing company consignedmainlymanufacturingandprofessionalserviceofelectronicproducts.Manufacturingproducts in its own factory in the traditional way was to give up by outsourcingproduction,soequipmentinvestmentisgoingtoreducetherisk.• ERP: ERP application package is the concept which is a step ahead from theexisting MRP system. The process goes from the concept of MRP (MaterialRequirementPlanning) for theCompanies smoothmaterial /purchasing toMRP-II(Manufacturing Resource Planning). Furthermore concept of ERP systems forinformation integration between the organizations-wide are being developed. ERPsystem integrates all business processes such as production and materialsmanagement, quality management, facilities management, sales and customerrelationshipmanagement,accountingandcostmanagement,projectmanagementandpersonnelmanagement,unlikeMRP-IIsystem.•Feeder:Adevicetosupplypartscontinuous/automatically.Dependingonthesizeandshapeofthepart,kindsoffeederstobeselectedaredifferent.•FiducialMark:Fiducialmarkisveryimportantforverifyingtheposition.

(Screen Print printing position, Chip Mounter mounting position, Inspection m/cinspectionposition)

Ifthereisnofiducialmarkoritcan’tbeused,theproductqualitywillhavenoguaranty.FiducialmarkneedstomakebyR&Ddesignstandardrules.

•FIFO:FirstInFirstOut.•Flux:Thechemicalactivatortoremoveandactivateoxidesonthemetalsurfacetoensure soldering operation to occur properly. It is a cleaning thing removingcontaminants at the object and surface oxide in solder. Rosin flux is the activeingredientofchlorine, fluorine,bromineandcontainingsurfactantsofhalogen inasmallamount.•Fuse:Apartstoprotecttheelectricalcircuitorequipmentduetooverload.•GerberData:Photodata(filmworkingdata)formattedbydatatype.Itiscommonlycalledtogerbera.ItisneededtocreateametalmaskofSMTdataandalsotogetthecoordinatesofSMTmountingdata.• Glue: A liquid to serve as bond to fix parts to the PCB. Often used for axialcomponentslikeautoinsertionandmixed-mountprocessforPCBmanufacturing.•Grease:A lubricating oil to allow the smooth operation of equipment drive (ballscrew,LMguide,gear).Ball screwandLMguidewhichhasprotrudingnippleareinjectedbytheinjectors.• Inspection: The process ofmeasurement, research, and testing by comparing theproduct and the requirements for products as well as by identifying inferiority orsuperiorityaccordingtothespecification(standards).•ISO(InternationalStandardsOrganization):ISOisasystemrecognizingassuranceofthequalityandreliabilitybyinternationalstandardsestablishedin1987onquality

management and quality assurance rating the system of the supplier providingproducts or service. In other words, the system had developed with the idea thatqualitysystemshouldbetrustedforcontinuousreliabilityofyourproductorservice.TheISO9000andISO2000seriesconsistofthefollowing-

– ISO 14000: To make Environmental Management System to protect the globalenvironment.– ISO 9000: Quality management and quality assurance standards (guidelines forselectionanduse).– ISO 9001: A Quality assurance model of design, development, production,installationandservice.–ISO9002:TheQualityassurancemodelintheproductionandinstallation.–ISO9003:Qualitysystemelements(instructions)infinalinspectionandtest.–ISO9004:Qualitymanagementandqualitysystemelements(Instructions).–ISO9001:2000andISO9001:2008

•JIT(JobInstructionTraining;just-in-time):Itisasystemcontrollingproductionbyeach process, to reduce intermediate inventory. Following process gets needed-quantity material only when it needs, former process produce only those needquantity, it can improve productivity by avoiding unnecessary, unbalanced,unreasonablethingsinproductionsite.ItiscalledJITreducedfromjustintime.Theadvantageisreducingthesupplyofstockbyoperatingproductionlinedependingonsold goods. It is worldwide famous management style to affect America’s SCM(Supply ChainManagement). However, weak point is that this system is workingonlywhentheproductionsystemisoperatedwithoutanyerror.•Kitting:Preparationofitems(material)withrequiredquantitiesinaccordancewithBOMdirectedbytheproductionquantityafterreceivingproductionorder.• LCRMeter: An instrument to measure the value of coils (Inductor), capacitors,resistors,etc.•Lead:ConnectingthepartswiththePCBlandandsoldercomponents.•LeadLength:Thelengthofleadofthepart/component.•LeadPitch:Theintervalsbetweenleads.Distancebetweentheleadcenterandthecenterofadjacentlead.•LeadThickness:Thethicknessofleadinparts/component.•LeadWidth:Thewidthofleadinparts/component.•Loader(PCBAutomaticfeeder):Theequipmentusedforauto-supplyingthePCB.There are 2 types; one is themagazine loader using amagazine rack and other isvacuumloaderprovidingthebareboardwiththevacuum.•LOB(LineOfBalance):Maximizingproductionefficiencyofalinebydistributingeachm/cmountingtacktime.•Magazine/SSR (StaticSafetyRack):A rackused to store thePCB.Alsouse forputtingthePCBintom/csuchasloaderorun-loader.

•MajorDefect:Defectwhichcausesseriousmalfunctioningofaproduct.•Manhattan(Tombstone):Thestateofrisingchipcomponentssuchasresistorsandcapacitorsbysurfacetensionofsolderononesideatthetimeofthereflowsolderingoflead.•Marking:TheformatofthenotationofsymbolorletteringmarkedonthePCBsuchaspartnumberorpartposition,etc.•Maker:Manufacturer.•MELF:Cylindershapecomponentshavingmetalendcaps.• Metal Mask / Stencil Masks: A tool used to apply solder paste to the desiredlocationbyopeningaholetofitthematerialonPCB.0.08~0.15mm(3milto5mil)thicknessmetalmaskiscommonlyused.•MinorDefect:Unacceptabledefectivewhichisnotactivatingasthemajorfunction.• MRP (Material Requirement Planning): MRP has been proposed to reduceinventory,oneofthebiggestheadachesappearedintheyearof1970.Thisisasimplesystem of material management. In this era the objective was to remove theinefficiencyorwasteofcorporateresources.Itisbasedonthecriteriainformationofmaterialrequirementsplanning(MRP)andproductconfigurationinformationsuchasBOM (Bill Of Material), Routing Sheet, MPS: Master Production Schedule, andInventoryRecord.•MRPII:MRPII (ManufacturingResourcePlanning II) is theexpandedconceptofMRP to effectivelymanage all the resources as well asmaterials produced in the1980’s.MRPIIwasemergeddue toenvironmentalchanges fromcustomer-orientedbusiness from the mass production in small variety to small quantity batchproduction.TheMRPisthemanufacturingactivitysystemforafeasibleproductionplan adding an automatedprocess data acquisition, contractmanagement, financialmanagementandsalesmanagementcapabilities.Inthebroadestsense,itisoneoftheManagementoftheproduction,amethodofmanagingtheflowfromrawmaterialstofinal finished product. It allows for optimal supply of materials by respondingimmediately to changing circumstances by providing this information at the entireproductionsystemwhen thedesignandproductionplanschange. It isnecessary todirect to get materials to the supply purchasing staff and instruct processing andassemblytotheadministrativestaffforsupplyingtherequiredmaterials(what),whenneeded (when), how much amount required (how much) and where to the place(where).•MultiMounter:Adeviceequipping thevariousmaterials (IC,TR,Conn., etc.) athigh speedon the landportionofPCBcoatedwith solderor adhesiveglue (It hasbeenconfiguredtodofineworkforalargepart).•Nozzle:ItisusedformountingvariousSMDcomponentswhicharesuppliedfromfeederorcartridgeonthePCBafterstickingbypneumaticpressureadsorption.Thisisaconsumablepartandneedstobereplacedafteracertainperiod.•OEM(OriginalEquipmentManufacturer):Itmanufacturesproductorcomponentsthatarepurchasedbyanothercompanyandretailedunderthatpurchasingcompany’sbrandname.OEMrefers to the company thatoriginallymanufactured theproduct.Whenreferringtoautomotiveparts,OEMdesignatesareplacementpartmadebythe

manufactureroftheoriginalpart.ItisknownasOEMproductionorOEMsupplies.•Optimizing(ProgramOptimizing):Thingstomaximizeproductionefficiencyaftermakingprogram.Thesamemodel,themountingpointstable,feeder,andminimizingdowntime.•PAD:Acopper electrical conductionpattern towhich surfacemount componentsaresoldered.• Part Data: Information of component (Part) for recognizing the component bycamerainthemachine.• Part Number: A number that is distinct or identifies the components in productwhichuniquelymadebytherulesofcompany.• PCB: Printed Circuit Board, as the acronym. It is used to electrically connectelectronicscomponentusingconductivepath(Pad).Whentheboardisnotpopulatedbyelectricalcomponents(Capacitor,resistor,etc.),itisreferredasPCB.• PCBA (Printed Circuit Board Assembly): Semi-finished products after SMTprocesshavebeencompleted.•Pitch:Spacingordistancebetween the leadsofSMTparts suchas ICaswell asconnectororsolderbump.•PLCC(PlasticLeadlessCarryPackage):LeadheadingintotheinsideofIC.•Pre-Heating:TopassupPCBwithacompleteassemblycoatedwithsolderpasteinthereflowheater.Thisisintendedtoraiseafluxtotheactivationtemperature;atthesametimeit is toprevent thesubstratefrombeingtransformedbyheatshockfromthecontactwithhigh-temperaturesolder.•Profile:Agraphshowing therelationshipof temperatureversus timeofsolderingobjects in the reflow.The typeofprofiledependson thecompositionof thesolderpasteandbrand.Inaddition,theconditionofbeingmoltenofsolderpastedependsonthe formofeachmodeldue todifferent thermalcapacityon thenatureof thepart,PCB.•Program:Tocreatealistofcommandstoallownormalproductionofscreenprinterormounter.•QFP(QuadFlatPackage):AflattetragonICofwhichleadheadingout.•QPS:QuantityPerSet,NumberofcomponentsperPCBorinoneproduct.•RawData:Unprocesseddocumentssuchasdailyreportwritteninthefield.• Reflow Oven: Heating equipment used to fix the components on the PCB. TheelectroniccomponentsareplacedinfixedpositiononthePCBbychipmounterandthenthesolderpastedissolvesandcomponentgetsolderedtoPCBpadfollowingthecoolingprocess.•Repairing:Restorationoffailedproductandfunctionaldefective.•Resistor:Partopposingtheflowofcurrent.ItsunitisO(ohm).•Reworking:Repeatingthemanufacturingprocessonceormore.•ROMWriter:Adevicetowritetheprogram(BIN,HEXfile)onROM,flashROM,etc.

•Routing:OperationtocutthePCBaccordingtoagivenshapeanddimensionswithcuttingtool.•ScreenPrinter(printer):AdeviceforprintingsolderpasteonthesurfaceofthePCBtosolderthecomponentstobemounted.Dependingonthesizeandconditionoftheequipment,itcanbedividedintomanualoperation,semi-automaticandautomatic.•Squeegee:Theaimistoprintthesolderpastebyrollingitintoopeningswithrubberandmetalon themetalmask.Toobtainagoodprintingcondition,squeegeeshape,material,hardness,speedselectionareimportant.•Short(Bridge):Theterminalsofcomponentsorcircuitconnectedbysolderpaste.• Skip: Particular materials not mounted by machine due to various reasons inprogram.•SMD(SurfaceMountedDevice):ThedevicesorcomponentsusedinSMT.•SMEMA(SurfaceMountEquipmentManufacturersAssociation):SMTmachinetomachineinterfacestandards.•SOIC(SmallOutlineIntegratedCircuit):SmallICwithleadheadstowardsoutsideinbothdirections.•SOJ(SmallOutlineJunction):SmallICwithitsleadheadstowardsinsideinbothdirections.• Solder Fillet: Concave section of the joint where the solder paste bonds thecomponentstothesurfaceofPCB.•SolderBalls: It is state that solderpaste around the leador electrode is scatteredwith small ball shape when mounting products are soldered in reflow oven. It islikelytooccurwhenamountoffluxincreasesinsolderpasteorpreheatingconditionsarepoor.•SolderResist:Heat-resistantcoatingmaterialcoatedonaspecificareainPCB.Itisathinlacquer-likelayerofpolymerthat isusuallyappliedtothecoppertracesofaprinted circuit board (PCB) for protection against oxidation and to prevent solderbridgesfromformingbetweencloselyspacedsolderpads.•SolderWire:Threadshapeleadtodosolderingbyusingiron.•Solvent:SolutionforcleaningPCB.•SOP(SmallOutlinePackage):TheIChavingitsleadheadingoutinbothdirections.•SOT(SmallOutlineTransistor):Asmalltransistorhavingitsleadheadingout.•SparePart:Reservedextraparts for repairing equipmentor replacingpart duringpreventivemaintenanceactivity.• SPC (Statistical Process Control): It means process is managed by statisticalmethods.Statisticalmanagementisnotbasedondeterminationbyaperson’sfeelingsorestimation,itshouldbebasedonscientificdatatofaceproblemsandfindsolutionorimprovementways.• Spec. (Specification): It means technical specification or guide lines, it usuallymeansstandardtodeterminenon-defectiveinSMT.•SPI (SolderPast Inspection): It isprocessordevice to inspect stateof the solderpasteprintingbeforemountingprocess.Thereis2Dtypewhichinspectsonlyprinted

areaand3Dinspectionwhichincludesheightofsoldering.•Tester:Metertomeasurevoltage,current,orresistance.• ThicknessGauge:Tool tomeasure the thickness in narrow gapwhich cannot bemeasuredwithverniercaliper.•Throughhole:Holesthroughelectricalinsulationontheboardbydrillingfollowedcopper plated holes to flow electricity between inner-outer layer, its functions areelectricalinterconnectionandmountedaholetofixparts.•Transistor:Semiconductorwhichamplifiescurrent.•Under-fill: Liquid to apply to increase bond strength to partwhich is vulnerablefromshocksordroppingsuchasBGAorflip-chip.•Un-loader(PCBAutomaticStorageDevices):ThemachinestorageofthePCBAinmagazinerackafterreflowoven.•Vendor:SuppliertotheParentcompany.•VenireCaliper:Aninstrumenttomeasuresizeofpartanddistanceofcomponentsprecisely.•WIP:WorkInProcess.Uncompletedproduct.• Work Table: A table for verification and calibration of the operations state byinsertinginthemiddleoftheprocess.•6sigma:6sigmamanagementwasperformedfirstatMotorola in1987,and thenGE,throughSonyinKorea,SamsungSDIhasbeenineffectsince1996.Currentlyitis widely applied to the most car companies and electronics companies. 6 sigmarefersonly3and4defectsoutofonemillionproducts.6sigmainnovationsremovethe cause after analysis by SPC data requiringwide activities to secure level of 6sigma.

REFERENCEData:

http://en.wikipedia.org/wiki/Surface-mount_technology

http://en.wikipedia.org/wiki/MELF_electronic_components

http://en.wikipedia.org/wiki/Printed_circuit_board

http://www.radio-electronics.com/info/data/smt/what-is-surface-mount-technology-tutorial.php

Images/Photos:

http://www.google.co.in/imgres?sa=X&biw=1366&bih=559&tbm=isch&tbnid=gggqig3MjU8pAM:&imgrefurl=http://www.wissamhtc.com/pcb.html&docid=Qw_3K1zmREWthM&imgurl=http://www.wissamhtc.com/images/pcb.jpg&w=500&h=465&ei=zF2oUd7SK4StPOmpgcgI&zoom=1&iact=hc&vpx=1086&vpy=115&dur=3681&hovh=216&hovw=233&tx=106&ty=146&page=1&tbnh=141&tbnw=152&start=0&ndsp=21&ved=1t:429,r:6,s:0,i:99

www.blogs.indium.com

www.smtchn.com

http://sanweiesd.en.made-in-china.com/product/fotQdnrVJHcS/China-Anti-Static-Circulation-Box-3W-9805318-.html

Loader-SamsungLD300/500

Un-loader-SamsungUD300/500

ScreenPrinter-PDTNPS300S

SPI-PEMTRONTROI-5500H,TROI-5700H

Mounter-FujiNxt,FujiCP-642,Samsung411/421,Casio,PanasonicNPM-D2

ReflowOven-HellerMKIII,TSMA70/N70-iseries

AOI-PDTPA500

VacuumLoader-SamsungLD-150V

GateConveyer-Samsung

X-Raym/c-SEC

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