PB-Free Solders in Automotive IIb - Higher Logic · Pb-Free in Automotive Electronics Part II...

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Pb-Free inAutomotive Electronics Part II

James (Jim) McLeish IPC-PERM Meeting July 27, 2017


Introduction - James (Jim) McLeish,([email protected]) 40 years of Vehicular, Military and Industrial Product Engineering Experience

Practical, Hands on Practicing Engineer for Design & Launch of High QRD Products,Experience in Automotive QRD, Analysis/Development/Validation (A/D/V) DfR, PoF,Test Technology Development, Warranty Problem Solving, Root Cause/Failure Analysis

Product Design, Development, Systems Engineering & Production(Chrysler & GM - 14 yrs) ESA/EFC Digital Task Force (1st Microprocessor Based Engine Controller) - Chrysler Corp.

3 Patents Automotive Electronic Control Systems - GM Adv. Product Engineer & GM E/E Engineering Center

System Engineering and Architecture Planning - GM Saturn Project

E/E Engineering Manager - GM Military Vehicle

Validation, Reliability, Quality Assurance, Warranty Problem Solving & Test Technology Development(GM - 16 yrs) Technical Specialist/Team Leader in Quality & Warranty Problem Solving and

Japanese Mizenboushi (Preventative Measures) Quality by Design Methods: GD3, DRBFM, DRBTR

Reliability Manager for GM Chevrolet-Pontiac-Canada Engineering

Manager GM Reliability Physics (Advance QRD, A/D/V & Test Technology Development)

Author or Co-author of 3 GM Reliability/Validation Test Standards

Michigan Automotive Office Manager & Senior Technical Staff(DfR Solutions – Rochester Hills, Michigan - 10 yrs). Principle Investigator for E/E Warranty/Failure Analysis and Root Cause Problem Solving

E/E Manufacturing Process Optimization, Yield Improvement

QRD Demonstration, Product Validation and Accelerated Testing

Design Reviews for Proactive Problem Prevention

Core Member SAE – E/E Reliability Standards Workgroup & Reliability Lead US-ISO-26262 Functional Safety Delegation

Member – Automotive Electronic Council (AEC)

Taught Automotive Quality/Reliability Segment – Automotive Enrg. Master Program Lawrence Tech U. Southfield MI 2007-09

Taught Intro to Physics of Failure Tutorial at RAMS


o DfR Solutions is a Engineering Consulting, FailureAnalysis, Environment & Life Testing Lab &CAE Software Development Firmo Focused on the Quality, Reliability & Durability (QRD) of

Electrical & Electronic Systems, Components, Materialsand their test, fabrication and assembly processeso > 450 projects per year

o Formed by senior scientists from DoD/ NSF funded research at theUniversity of Maryland to develop the Physics-of-Failure approachto achieving Ultra Reliability, Product Integrity &Safety for E/ E Technology

Introduction - DfR Solutions(Design for Reliability)

E/E Materials &Failure Analysis Lab

Chem. Lab

X-RayMicroscopy

CAE Modeling &Sherlock ADA CAE App

SW Development DurabilityLife

Testing

BeltsvilleMaryland HQ.


o 2004 GM E/ E Leaders Started Investigating Issues on the Conversion to RoHSCompliant (Pb-Free) for Embedded Automotive Electronics.

o In 2005 GM Management Embraced RoHS/ Pb-Free as a PR Initiative toDemonstrate GM Commitment to Green/Environment Issues.o Propose a Directive to Push GM E/ E Systems Suppliers to Move to

Full RoHS Compliance ASAP.

o E/ E Personal Push Backo Raising Concerns about the Potential

QRD Risks of RoHS.o Got Approval & Funding for Investigation

Into Potential RoHS Riskso First GM Project with the

new firm DfR Solutions.o Identified Risks that Needed

to be Addressed

Pb-Free at GM


o Defined RoHS/Pb-Free issues to be covered in GM’s Design Review Based on Failure ModeProcess for Review of Supplier’s E/E Module/System Design.

o Defined How to Adjust Thermal Cycling Life Test Correlation for Pb-Free FatigueCharacteristics from Tin/Lead.

Pb-Free at GM – Info From the DfR Report & Other Sources Incorporated intoNew Guideline Appendixes - Dec. 2005 Revision to GMW-3172

GMW-3172 - General Specification for E/E ComponentAnalytical/Development/Validation (A/D/V) Procedures for Conformanceto Vehicle Environmental, Reliability and Performance Requirements.


DRBFM a More Advanced Form of FMEA, a part of theJapanese Mizenbohshi (Preventative Measure) GD3 Process

Mizenbohshi• Identify & prevent QRD problems

from blooming into existence(Early during design-development)

Using the GD3 Tools• Good Design.

- Incorporation of Best PracticesDesign & Manuf. Processes

• Good Discussion- DRBFM - Design ReviewBy

Failure Mode- Standardized In SAE J2886

Ref:http:/ / www.dfrsolutions.com/ hubfs/ DfR_Solutions_W ebsite/ Resources-Archived/ W hite-Papers/ Manufacturing/ Introduction-to-Japanese-Style-Mizenboushi-Methods.pdf?t=1500998127372

• Good Dissection.- DRBTR - Design Review by Test Results

Ref: http:/ / books.sae.org/ pd251136/


o UNITED STATES COUNCIL FOR AUTOMOTIVE RESEARCH LLCo Founded in 1992 to strengthen the technology

base of the U.S. auto industry throughcooperative research and development.

o As automotive markets globalize, competition fromboth Japanese and European automakers intensified,Chrysler, Ford and GM saw that technical collaborationwas occurring among their overseas competitors

o The U.S. Congress provided an opportunity for a wide range of research &development collaborations involving industrial competitors by passing the 1984Cooperative Research Act.

o USCAR was formed to manage and coordinate the research projects.o USCAR is composed of specialized groups that focus on specific research areas to:

o Accelerate technical development,o Provide common solutions for the automotive supply base; common specs,o Provide a critical mass for scaled solutions,o Accomplish what no single company can do alone.

2008 - USCAR Started a Team to Consider Common Pb-FreeValidation Requirements for Automotive Pb-Free Electronics

The following proposed plan is the progress theteam has accomplished in commonization of testvalidation and methods.

This review is to determine if the team shouldcomplete the plan for all three OEM’s and pursuerespective approval from each companiesgoverning body.

Lead Free Validation Testing TeamProposed Plan

USCAR common testing to change leadedproduct to lead free for high reliability, containedcost, and reduced testing time.

Investigate common testing of lead products tolead-free products.

Lead Free Validation Testing TeamProposed Plan

GM Test Criteria

• (A) Thermal Shock (TS + PTC 37 / 96 d)Un-powered, cased units. # cycles depends on Tmax (Tmin= -40), Dwell time at Tmin and Tmax = 10 min:

– Tmax = +85C, 632 cycles– Tmax = +105C, 927 cycles– Tmax >= +125C, 1000 cycles before PTC & Cyclic Humidity,

then 1000 more cycles after Cyclic Humidity

• (B) Powered Temperature CyclePowered and Monitored. Cased units. # cycles depends onTmax (Tmin = -40), Dwell time at Tmin and Tmax = 10 min:

– Tmax = +85C, 211 cycles– Tmax = +105C, 309 cycles– Tmax >= +125C, 248 cycles

• (C) Vibration ScreenPowered and Monitored. This is a “1-hour” test to detectany intermittent failures caused by Thermal Fatigue tests. Itis as long as it takes to complete 1 PTC cycle. It requires a0.5 Grms Random Vibration profile in the axis perpendicularto the plane of the circuit board. A Thermal Cycle shall beapplied equivalent one PTC.

• (D) High Temperature ExposurePowered and Monitored. Cased units. Ambient temp =Tmax. 500 hrs.

Chrysler Test Criteria (cased units)

• (A) Thermal Shock- Un-powered with mating connectors.- 100 Thermal Shock cycles from -40°C to Tenv.max

• (B) Powered Temperature Cycle- Intermittently powered and monitored.- Cycle from -40°C to Tenv.max, which is locationdependent. Tenv.max is 85°C, 105°C, 125°C, or 155°C.- Cycle count depends on 10 or 15 year verificationtargets, and a location dependent ∆T experienced by the device. Typical cycle requirements are 541 to 581 for 10year targets; 811 to 872 for 15 year targets.

• (C) Vibration- Chrysler does not currently do this mini-vibration test,

but agrees to this test for electronics with lead-freesolder.- Powered and monitored.

• (D) High Temperature Exposure- Powered with maximum load as specified in theproduct specification.- Test temperature is Tenv.max (85°C, 105°C, 125°C, or155°C)- Test duration depends on 10 or 15 year verificationtargets, the temperature distribution in the mountinglocation in the vehicle, and the %operating time withvoltage applied to the device. Typical test durations are1380 hrs to 2400 hrs.

Areas under Construction

GM Test Criteria

• (E) Shock / PotholePowered and Monitored. The # of shocks, pulseduration, and amplitude depends on mountinglocation of component in vehicle:

– Unsprung Mass: 100G, 11ms, 20 shocks x 6directions.

– Sprung Mass: Passenger Compartment: 12G, 20 ms,400 shocks x 6 directions.

– Sprung Mass: Other areas, including Cradle/FrameMounted: 25G, 10 ms, 400 shocks x 6 directions.

• (F) Combined VibrationPowered and Monitored. Thermal Cycling from Tminto Tmax shall be applied (1 cycle = 8 hrs). RandomVibration profile and duration is location specific:

– Unsprung Mass: 11.0 Grms, 16 hrs/axis (car), 36hrs/axis (truck)

– Sprung Mass: 2.0 Grms, 16 hrs/axis (car), 36 hrs/axis(truck)

– Engine/Trans Mounted: 13.0 Grms, 44 hrs/axis.

Areas under Construction

Chrysler Test Criteria (cased units)

• E) Shock / Pothole- Powered and monitored.

- 10 half-sign shocks/axis in each +/- direction- each shock is 11 ms duration with amplitude of 500m/sec2 (50 g)

• (F) VibrationVibration per ISO 16750-3

1 thermal cycle for first 8 hours of the testIntermittently powered and monitored when powered.

12 hrs / axis- Unsprung Mass: 10.94 Grms Random

- Sprung Mass: 2.84 Grms Random- Engine Mounted: 18.4 Grms Random plus sine.- Trans Mounted: 9.85 Grms Random plus sine.


o Auto OEMs Never Agreed to a Common Industry Validation Processo Each OEM considers validation a comparative QRD advantage.o The OEM plans were focus on general durability aspects rather than specific Pb-

Free concerns such as Tin W hiskerso Each OEM took info back to incorporate into their own internal requirements.

o Auto Industry Never Developed Industry Specific Pb-Free Standards.o Instead choose to allow the E/ E industry to develop Pb-Free specific requirements.o Allow their E/ E SystemSuppliers to adopt the appropriate measures.o Have E/ E SystemSuppliers Justified their Approach in Design Reviews

that exposed OEM personnel to latest development and best practices.

2008 - USCAR Started a Team to Consider Common Pb-FreeValidation Requirements for Automotive Pb-Free Electronics

Lead Free Validation Testing Team Team MembersJennifer Senish – GMChristopher J. Lucarelli – GMDennis Craggs – ChryslerKeith Hodgson – FordEric Honowetz – LearPete Sinkunas – TRW (Chair)Jim McLeish – DfR Solutions

October 9, 1008


o RoHS/ Pb-Free Compliant Consumer & Automotive Electronics started toappear in 2005 (~12 years ago).

o EU mandatory as of 7/ 1/ 06 & then rapidly expanded globally.o As noted by Dr. Ron Lasky of Indium - Feb 2013,

Ref: http:/ / www.indium.com/blog/has-lead-free-rohs-compliant-assembly-reliability-and-cost-arrived.php.

o There have been no “the sky is falling”-type of reliability issues since this time”.

o “No one has ever commented that they have noticed an increase in electronics fails”.

o The general public is unaware & when questioned will ask “W hat’s Lead-free?”

o Conclusion is that “product reliability is not practically worse”.

Status of Pb-Free / RoHS Conversion – In General


o The Implementation of RoHS/ PB-Free has resulted InQuality/ Reliability/ Durability Improvements in Automotive Electronics.o W as not an inherent characteristics or automatic.

o Required understanding differences (produced by Physics of Failure Research).

o Developing new strategies for compensating for the differenceso Resulting from diligent compliance to the principled of the

“Continuous Improvement” and 6-Sigma Quality / Zero-Defectsprocesses embedded in the automotive quality culture.

Status of Pb-Free / RoHS Conversion - Automotive


o Top Automotive OEM leadership have championedthe development of a lean (efficient), continuous improvement, problem preventionquality culture throughout all levels of their organizations and their supply chain.o Extensive resources for training, change management & new

QRD&S process/ tool development, validation & implementation.o Industry Cooperative Collaboration on

o ISO/ TS 16949:2009 Application of ISO 9001:2008Quality Management Systems for automotiveproduction and part organizations

o Automotive Industry Action Group (AIAG)o APQP “Advance Product Quality Planning.o Automotive Design and Process FMEAo PPAP “Production Product Approval Process”.

o Collateral benefits from Electronic Industry’sTech & Reliability Physics driven efforts to:o Improve Fabrication Technologyo Reduce Quality Defectso Prevent W ear Out Mechanism to Extend Durability Life

Market Forces Led to the Creation of a Lean,Automotive Quality Culture Since the 1970’s

CultureThe way a group

thinks, acts & interacts


Continuous Improvement

o The ongoing effort to improve products, services,or processes has evolved from a quality philosophyinto a fundamental business principle.

o Supplier buy in and involvement driven bylong warranty periods that provide field failure data &by OEM’s holding suppliers contractually, financially responsible for thewarranty cost of field QRD+S issues of their components / systems

ContinuousImprovement


By Comparison the Transition from “Through-Hole) Electronics to Surface Mount Electronicsdid not go well & Led to the introduction of Physics of Failure into Automotive E/E

Actuarial MTTF Predictions(Even w/Current In House Failure Rate Data)

Can Have Significantly Differencesfrom the Actual Results

Because Historic Data Do Not Accountfor the Actual Failure Mechanisms that

Caused Field Failures

- Passenger Compartment ModulePrediction off by 2x,

- Under Hood ModulePrediction off by 8-10x

Note:P.C. = Passenger CompartmentU.H. = Under hood, the Hotter

Engine Compartment


Evolution of E/E TechnologyDurability Life is Directly Related to E/E Material & Component Packaging Technology

.

Single Sided Then Thru-holeDIP Integrated Circuits1970 ‘s- Today~4 up to 68 I/O, 1” x 3.5”Up to 10 Meg Hz Speeds.

1st Generation Quad Surface MountJ Lead PLCC, 1982 - Today~6 Up to 160 I/O, 1.5 in sq.,Up to 100 Meg Hz SpeedsSource of Many Reliability Problems.

2nd Generation Quad Surface MountFine Pitch Gull Wing I.C, 1993 - Today~54 Up to 450 I/O, 1.75 in sqUp to 250 Meg Hz Speeds>10 Time the Life of J Lead in Auto ECMs.

No Lead Chip Scale Packaging (NLCSP)(LCCC, QFN, DFN, SON, LGA)2002 - Today~8 - 480 I/O, .75 in SQGigi Hz SpeedsCan have significantly reduces life

Bump & Ball Grid ArraysLeadless Attachments1996 - Today~24 - 1000 I/O 1.2 in. sq500+ 1000 Meg Hz Speeds.Life Varies Greatly w/Size & Conf.


Thermal Cycling Durability Capabilities of IC Packages

o IC packages without a flexible terminal lead to absorb thermalExpansion/Contract motions, have a high amount of thermal expansion stressapplied to the small, low profile under body solder joints,which accelerate solder fatigue failure.

o Solder Attachment Cycles to Failureo Order of magnitude (10X) reduction from QFPso 3X reduction from BGAs

Laminated BGAs:TTCL: 3,000 to 8,000

Flat No Lead/Chip Scale(FNL/CSP)

TTCL: 1,000 to 3,000

*TTCL = Typical Thermal Cycle Life-40° to +125°C

Package TypeTypical Thermal Cycles to Failure

(-40C to 125C)

QFP >10,000

BGA 3,000 – 8,000

QFN 1,000-3,000

Gull Wing Leaded QFPsTTCL: >10,000


o Melting/Processing Temperatures of Pb Free Solder have Hotter Melting Pt. (227˚C)& Processing Temperatures (up to 260˚C) than SnPb Solder (183 ˚C/ 223 ˚C).o Enabled Pb-Free soldered electronics to endure hotter temperatures & more thermal cycling

o Resulted in the need to develop:o Higher Temperature PCB Laminate Materials and IC Encapsulation Materialso More Capable Soldering Processes: 5-6 Zone Reflow Ovens Replaces by 8-10 zone units.o Corrosion Resistant W ave Soldering Equipment.o Solder Paste/ Fluxes Tailored for: Longer and Hotter Soldering Profiles.

o Denser SnPb Solders W ick & Self Align Components, PbFree Solders Slump.o Required revised PCB pad geometries.o Required More Accurate Component Pick & Place / Chip Shooter Assembly Equipment.o Required new Standards for Visual Inspection, Automatic Optical Inspection, X-Ray Inspection.

o Initially E/ E Assembly Equipment & Processes retrofitted from SnPb to Pb-Freeprocessing produced higher PCB assembly defect/ rework rates.o As New Equipment Optimized for Pb-Free Came Online,

Defect/ Rework Rates Dropped & Product QRD Improved.

Understanding the Differences & Challenges of Pb-Free- Led to QRD Improvements


o The Rockwell Collin’s JCAA/ JGF-PP No Lead solder Project:Performed -55C-125C Thermal Cycle Testingo Lead-free performed better in 51 cases, tin-lead better in 31 cases & 1 drawo Results differ with Thermal cycle Parameters: Temperatures, Delta T, Ramp Rate, Dwell Time.

Ref: iNEMI Effect of Temperature Cycling Parameters on the Durability of Pb-Free Solders

o W hile Pb-Free solders can endure hotter temperatures, they are harder and more brittle,rapid stress transitions condition are higher risks.

o Over Accelerated Tests with highly accelerated rapid ramp rates may not produce results thatreflect durability under actual in service conditions.

o In automotive thermal cycling conditions, SAC305 Pb-freesolder generally last longer that SnPb.

o SAC305 is also more susceptible to fracture in shock.

o Understanding these details of susceptibilities, enablesE/ E designer to adjust other design factors to mitigatethe highest risk stress condition to achiever thedesired durability-reliability.o Example provide a housing with additional damping to reduce

shock stresses transmitted to PCB components & their solder joint.

Application Durability

Source: iNEMI Pb-Free Alloy Characterization Project Rpt:Part III - Thermal Fatigue Results For Low-ag Alloys


o Tin W hisker growth has been correlated to an overall compressive stress(close to the yield limit of tin) in combination with a stress gradient (- 50MPa/μm)toward the surface. Influenced by 4 basic mechanisms:o Growth of irregular intermetallic compounds (IMC) between Cu and Sno Mismatch of CTE between the base material & tin plating (e.g., delta CTE > 8 ppm)o External mech. force on tin layer over a long time (i.e. press-fit, clamping / not bending).o Corrosion-induced whisker growth (humid environment).

o W hisker risk mitigation relies on a checklist and process control.o Select a Matte or Low Stress Tin Finish using low carbon/ organic content tin platingo Use Underplating (such as a Nickel Barrier layer) to Reduce Intermetallic Formation.o The base metal is treated to limit anisotropic intermetallic growth via surface roughening.o Anneal for 1 hour at 150ºC within 24 hours of plating.o Avoid Applying Compressive Loads on Plated Surfaces.o Use conformal coating to reduce stresses due to oxidation or corrosion.

o The DFR Solutions Failure Analysis lab has not see Tin W hisker issues in manyyears.

Tin Whisker Risks– The Mitigation & Process Control are Working


o Innolot/ 90iSC (From Heraeus, Henkel Alpha Metals)o Developed by a European consortium in early 2000’s to increase creep resistance by

reducing the strain range or energy being dissipated with each thermal cycle.o Developed to be a “drop-in” replacements for SAC305 with improved thermal cycle

performance are currently under development and performance evaluation.o A 6 Part Alloy: Sn-3.8Ag-0.7Cu-3.0Bi-1.4Sb-0.15-Nio Results in ~30% of increased thermal cycling durability over SAC305o But the 6 component solder is more expensive and harder to control

Future High Reliability PbFree Solders- Currently Under Development & Performance Evaluation

Source: LIVE. Dr. R. Ratchev (Bosch) 2008


o Koki SB6NX58-M500SIo A New 5 Part Alloy: Sn - 3.5Ag - 0.5Bi - 6.0In - 0.8Cuo Developed by a European consortium in early 2000’s to increase creep resistance by n.o Up to ~80% of increased thermal cycling durability over SAC305o Also is more expensive and harder to control.o Independent results now yet published.

Future High Reliability PbFree Solders- Currently Under Development & Performance Evaluation


o IPC has concluded that the economic inefficiencies in producing electronics for highreliability applications such as military and aerospace will force conversion to lead-free technologies in the near future.o ITRI is predicting a 95% conversion to lead-free E/ E Components in these markets by 2023.o The main driver is the increasing scarcity of leaded components, for which an increasing price

differential will create 'tipping points' over the next 10 years.

o The study was based on 83 electronic manufacturers/ suppliers to these high reliabilitymarkets who are dependent on a dual, leaded and lead-free supply chain.o A number are experiencing rising costs as lead-free components are converted back to

leaded using reballing technologies, where chips are dismantled and the solder on individualdevices is replaced.

o These rising costs are an increasing burden on the industry and will drive change in thecoming years.

o Source: https:/ / www.itri.co.uk/ solders/ news-4/ tipping-point-for-lead-free-over-next-decadeJune 10, 2015

High Reliability Industries Tipping Point For Lead-Free- Expected Over Next Decade


o The Conversion to RoHS / Pb-Free has not resulted in decreased Reliabilityo Benefits derived from Material and Physics of Failure Research for understanding

the differences an risks and developing new compensation/ mitigation strategies.

o QRD in Automotive Electronics actually improved.o Due to Diligent Compliance to the Automotive “Continuous Improvement” and

6-Sigma / Zero-Defects Culture.

o Electronic material and technologies evolve faster than any technology knownto man.o Every time such changes have occur have required updates to design, processes and

QRD approaches.

o The Hi-Rel Defense and Aerospace industries have the opportunity to benefitfrom the methodologies used and lessons learned in the auto industry as theyneed to convert to Pb-Free electronics.

Summary


Thank you!

For Further Questions / DiscussionContact:

[email protected]

Discussion, Feedback, IPC Participant Volunteers(Requires Further Discussion with IPC Leaders - Jan Pedersen & Thomas Ahrens Interested)

PB-Free Solders in Automotive IIb - Higher Logic · Pb-Free in Automotive Electronics Part II...

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