Fundamentals of Touch Technologies and · PDF fileFundamentals of Touch Technologies and...

Fundamentals of Touch Technologies

and ApplicationsGeoff Walker Abbie GreggNextWindow AGI

v1.0

July 14, 2010(at SEMICON West)

2

Agenda: Part 1

Admin [6] Introduction [7]

Materials & Process 1: Basics [11] Touch Technologies with Continuous ITO

Analog Resistive

[7]

Surface Capacitive

[6]

Materials & Process 2: Touch Screen Flow & Sputtering [15]Multi-Touch [9] Touch Technologies with Patterned ITO

Analog Multi-Touch Resistive (AMR)

[8]

Projected Capacitive

[11]

Materials & Process 3: Common Processes [18]

Embedded (On-Cell & In-Cell)

[17]

Materials & Process 4: Photolithography [18][ ] = Number of content slides in each section

3

Agenda: Part 2

Touch Technologies Without ITO

Acoustic Pulse Recognition (APR

by Elo) [4]

Dispersive Signal Technology (DST

by 3M) [4]

Materials & Process 5: Etch [13]

Surface Acoustic Wave (SAW)

[6]

Traditional Infrared (IR)

[4]

Waveguide Infrared

(by RPO) [5]

Materials & Process 6: Embedded Touch [21]

Optical

[4]

Force Sensing

[4]

Vision-Based

[5] Comparing Touch Technologies [5] Conclusions [2]

[Total = 210]

4

Agenda: Appendix

1 – Why There Are So Many Touch Technologies [6] 2 – Electromagnetic Resonance (EMR) Pen Digitizer [4] 3 – Flexible Displays and Touch [4] 4 – ITO Replacement Materials [6] 5 – Sunlight Readability of Resistive Touchscreens [9] 6 – Automotive Touch [4] 7 – Touch-Screen Manufacturing [31]

[ ] = 64 Total

5

About NextWindow

NextWindow

Develops & manufactures optical touchscreens

Currently focused on two touch-screen markets

Windows-7 consumer monitors and all-in-one computers

Large-format display applications such as interactive digital signage

Global presence

New Zealand (HQ), Singapore (Ops), USA, Taiwan, Korea, Japan

Manufacturing in China, Thailand and Malaysia

119 employees, 55 in engineering

Brief history

2000: Founded by CTO and private investors

2003: First product to market (optical touch for large displays)

2005: Entered USA market

2006: First major volume contract signed (HP TouchSmart AiO)

2008: Entered Taiwan market with ODM focus

2009: Engaged with many PC OEMs & ODMs on Win-7 products

2010: Acquired by SMART Technologies

6

About Abbie Gregg, Inc.

• AGI provides facility, process, industrial, and operations consulting engineering and design services

• Industries served• Microelectronics • Semiconductor• Flat-Panel Display• Flexible Electronics• Touch Screens• Photovoltaics• Disk Drive • MEMS• Nanotechnology• Biotechnology• Medical

7

AGI Background

• Started in 1985• Based in Phoenix, AZ• 650+ projects

completed in North America, Europe, Asia, the Middle East and Australia

• 40+ FPD, flexible electronics and touch projects completed

8

Introduction

Source: Elo TouchSystems

9

Two Basic Categories of Touch

Opaque touch

Dominated by the controller chip suppliers

Atmel, Cypress, Synaptics, etc.

One technology (projected capacitive)

Sensor is typically developed by the device OEM

Notebook touchpads are the highest-revenue application

Synaptics ~60% share; Alps ~30% share; Elan ~10% share

Sensors are all two-layer projected capacitive

There is no further discussion of opaque touch in this course

Transparent touch on top of a display

Dominated by the sensor manufacturers (100+ worldwide)

13 technologies

10

2009 Touchscreen Market by Size and Type of Technology

2009

Small-Med (<10”) Large-Area (>10”) TOTAL Technology Revenue Units Revenue Units Revenue Units Resistive $1,707M 432M $379M 19M $2,085M 452M Projected Capacitive $1,479M 144M $55M 1.0M $1,534M 145M Surface Capacitive $8.2M 0.1M $210M 2.1M $218M 2.2M Acoustic (SAW & BW) $0M 0M $149M 1.9M $149M 1.9M Infrared $1.1M 0M $63M 0.5M $65M 0.6M

Mainstream $3,195M 577M $856M 25M $4,051M 601M Emerging $29M 3.0M $255M 2.6M $284M 5.6M

TOTAL $3,224M 580M $1,110M 27M $4,334M 607M

Revenue Units Small-Medium 74% 95% Large-Area 26% 5%

TOTAL 100% 100% Market size estimates are based on DisplaySearch’s “2010 Touch-Panel Market Analysis Report” (June 2010)

Revenue Units Mainstream 93% 99% Emerging 7% 1%

TOTAL 100% 100%

11

2009 Touchscreen Market by Technology

Technology

2009 Revenue

2009 Share

2009 Units

2009 Share

Analog Resistive (all forms) $2,085M 48% 452M 74%Projected Capacitive $1,534M 35% 145M 24%Surface Capacitive $218M 5.0% 2.2M 0.4%Acoustic (SAW, APR & DST) $149M 3.4% 1.9M 0.3%Optical (including vision-based) $134M 3.1% 1.1M 0.2%Digitizer $123M 2.8% 1.5M 0.3%Infrared (all forms) $65M 1.5% 0.6M 0.1%LCD In-Cell & On-Cell (all forms) $25M 0.6% 2.9M 0.5%Others $1M 0% 0M 0%

TOTAL $4,334M 100% 607M 100%

Market size estimates are based on DisplaySearch’s “2010 Touch-Panel Market Analysis Report” (June 2010)

12

Touch Market Forecast 2010-2016

$0

$2

$4

$6

$8

$10

$12

$14

$16

2009 2010 2011 2012 2013 2014 2015 2016

Mill

ions

Rev

enue

($B

)

In-CellOthersOn-CellInfraredDigitizerOptical ImagingAcousticSurface CapacitiveProjected CapacitiveResistive

DisplaySearch 2010 Touch Market Analysis

13

Touch Technologies by Size & Application

M

= Mainstream L

= Low-volume E

= Emerging

Touch Technology M

obile

(2

” –

17”)

Stat

iona

ry

Ente

rpris

e (1

0” –

30”

)

Stat

iona

ry

Con

sum

er

(17”

– 3

0”)

Larg

e-Fo

rmat

( >

30”)

Analog Resistive M M L Analog Multi-Touch Resistive (AMR) E E Surface Acoustic Wave (SAW) M E L Traditional Infrared (IR) M E M Waveguide Infrared (from RPO) E Surface Capacitive M Projected Capacitive (ITO & on-cell) (P-cap) M E E Projected Capacitive (wires on film) (P-cap) L L Optical M M Acoustic Pulse Recognition (APR from Elo) E L L Dispersive Signal Touch (DST from 3M) L Embedded (in-cell) E Vision-Based (like Microsoft Surface) E Force Sensing (no current supplier)

14

Touch Is An Indirect Measurement One Reason Why There Are So Many Technologies…

Touch Technology What’s Being Measured Resistive (all forms) & Embedded (voltage)

Voltage

Surface capacitive Current Surface acoustic wave Time delay Projected capacitive, Embedded (charge)

Change in capacitance

Optical & Infrared (all forms), Embedded (light) in high ambient

Absence of light

Embedded (light) in low ambient Presence of light Vision-based Image Acoustic Pulse Recognition (APR) & Dispersive Signal Technology (DST)

Bending waves

Force sensing Force

The ideal method of detecting touch has yet to be invented!

15

Touch Technologies by Materials & Process

Touch Technology

Transparent Conductor (ITO)

No Transparent Conductor

Continuous Patterned

Surface capacitive

High Resolution

Low Resolution

Analog multi-touch resistive (AMR)

Projected capacitiveEmbedded (In-cell & on-cell)

Edge Conductors

Dispersive Signal Technology (DST)

No Edge Conductors

Waveguide infrared

OpticalForce sensingVision-based

Surface acoustic wave (SAW)

Acoustic Pulse Recognition (APR)

Analog resistive

Traditional infrared (IR)

= Emerging= Mainstream

16

Materials & Process…1

Basics

17

Materials and Processes Conductors, Insulators, Semiconductors

18


• Conductors• A conductor is a material which can conduct or pass electric

current and heat easily

• Copper is a good conductor, wood is not

• Conductors transport a signal from one part of the circuit to another

• Example: Metal interconnect

19


• Insulators• An Insulator is a material which cannot conduct or pass electric

current or heat easily

• Wood and glass are good Insulators

• Insulators block the transmission of current

• Example: Oxide (SiO2 )

20


• Conductors and Insulators • Place a wooden spoon and a copper spoon in a pot of boiling

water for 5 minutes

• Now take the spoons out of the water

• Which one is a conductor? Ouch!

• Which one is an insulator? Ahh....

21


• Semiconductors • Semiconductors have the ability to conduct electric current, but

can be regulated in the amount of their conductivity

22


• Conductors• Very large current flows

• Semiconductors• Some current flows• Can be regulated

• Insulators• Very small current flows

23

Materials: Elements Everything in the world is made up of elements

24

Materials: ElementsA portion of the Periodic Table is shown below

Groups: I II III IV V VI VII VIIIH HeLi Be B C N O F NeNa Mg Al Si P S Cl Ar

Ga Ge AsIn Sn Sb

PbP –

Type Dopants(Indium)

Elemental Semiconductors

(Tin)

N –

Type Dopants(Antimony)

Oxygen

Transparent Conductors: • ITO = Indium Tin Oxide• ATO = Antimony Tin Oxide

25

Metal / Conductora b

R

a

b

Devices Used in Touch Technology

Resistors

Units = Ohms

Capacitors• Store Charge Conductor

a

Substrate

Insulator

Oxide

b

Conductor

a

b

Units = FaradsC

26

Cleanliness Considerations In Touch Screen Manufacturing• A Human Hair = 70 microns• Smallest thing visible with the naked eye = 30 microns

• 1µ = 1 micron = 1 millionth of a meter• 1nm = 1 nanometer = 0.001 microns = 1 billionth of a meter• 1 angstrom = 0.1 nanometer = 10E-10 meter

• Something “invisible”

can destroy a device!• Touch device geometries = 5 to 300 microns

• ITO Film Thickness < 1 micron• TFT geometries = 1 to 5 microns• Integrated Circuit geometries = 28nm to 3 microns

• Touch devices typically made of only 7 to 11 materials, which have special electrical or optical properties!

• ANY OTHER substance will ruin a device!

27

Airborne Particulate Cleanliness Classes ISO 14644-1 Cleanroom Standards

Clean spaces are classified according to Federal Standard 209E and ISO 14-6444. Air cleanliness is defined by the number of airborne particles 0.5mm and larger per cubic foot of air. These standards also define the concentration limits of larger and smaller particles in air such as:

Class 10 ISO 4 Maximum 350 particles of 0.1mm and no more than 75 particle of 0.2mm and 10 particles of 0.5mm per cubic foot.

Class 100 ISO 5 Maximum 750 particles of 0.2mm and no more than 100 particles of 0.5mm per cubic foot.

Class 1000 ISO 6 Maximum 1,000 particles of 0.5mm and no more than 7 particles of 5mm per cubic foot.

Class 10,000 ISO 7 Maximum 10,000 particles of 0.5mm and no more than 70 particles of 5mm per cubic foot.

Class 100,000 ISO 8 Maximum 10,000 particles of 0.5mm and no more than 700 particles of 5mm per cubic foot.

Large volumes of air are circulated within the clean spaces to process the air to required limits. Complexity and cost increase for more stringent conditions required by higher quality classes. The operating cost also reflects the high- energy consumption necessary to condition and move large volumes of air. Class Air Flow

DirectionCFM/SF of Floor (room

velocity fpm)

Acceptable Air

Changes Per Hour

100,000 Mixed 5-8 5-4510,000 Mixed 9-15 60-801,000 Mixed 15-50 150-240

100 Uni-Directional

50-80 240-480

10 Uni-Directional

80-100 520

1 Uni-Directional

90-110 600

28

Particle Density vs. Cleanliness Class

10,000

1,000

100

10

1

0.10.1 0.2 0.5 1 2 5 10 Critical Particle Size1 2 5 10 20 50 100 Typical Geometry Size

1 MEG 256K 64K 16K Assembly Hybrids PC Boards Typical DevicesDRAM DRAM DRAM DRAM IC's

LCD Touch

Particle Size (micron)

In Cell Touch

Particles / Cu

bic Foot (Stated Size)

Acceptable particle count for Class 100

CLASS 1000CLASS 100CLASS 10CLASS 1

29

Analog Resistive Surface Capacitive (Materials & Process 2:

Touch-Screen Flow & Sputtering)

Touch Technologies with Continuous ITO

30

Source: Engadget

AnalogResistive

http://aving.net/usa/news/default.asp?mode=read&c_num=56716&C_Code=01&SP_Num=0

31

Analog Resistive…1


(ITO)

(PET)

Source: Bergquist

32


Types

4-wire (low cost, short life) is common in mobile devices

5-wire (higher cost, long life) is common in stationary devices

Constructions

Film (PET) + glass (previous illustration) is the most common

Film + film (used in some cellphones) can be made flexible

Glass + glass is the most durable; automotive is the primary use

Film + film + glass, others…

Options

Surface treatments (AG, AR, AS), rugged substrate, dual-force touch, high-transmissivity, surface armoring, many others… (50-uM glass) Source: Schott

33


4-Wire Construction

Voltage measured on coversheet

Voltage gradient applied acrossglass

X-AxisVoltage gradient applied acrosscoversheet

Voltage measured on glass

Y-Axis

Equivalent circuit

Bus bar

34


5-Wire ConstructionVoltage gradient applied acrossglass

Contact point on coversheet is a voltage probe

Y-Axis

Contact point on coversheet is a voltage probe

Voltage gradient applied acrossglass

X-AxisEquivalent circuit

Linearization pattern

35


Size range

1” to ~24” (>20” is rare) Controllers

Many sources

Single chip, embedded in chipset/CPU, or “universal” controller board

Advantages

Works with finger, stylus or any non-sharp object

Lowest-cost touch technology

Widely available (it’s a commodity)

Easily sealable to IP65 or NEMA-4

Resistant to screen contaminants

Low power consumption

Source: Liyitec

Source: Hampshire

36


Disadvantages

Not durable (PET top surface is easily damaged)

Poor optical quality (10%-20% light loss)

No multi-touch

Applications

Mobile devices

Point of sale (POS) terminals

Wherever cost is #1

Market share2009

Revenue 48%

Volume 74%

37


Suppliers

Nissha, Young Fast, J-Touch, Gunze, Truly Semi, Fujitsu, EELY, Elo TouchSystems, SMK, Swenc/TPO, eTurboTouch…

60+ suppliers

Market trends

Analog resistive is losing share (1st time!) to projected capacitive in the mobile market

First significant challenge to analog resistive’s dominance

Analog resistive is still very important in mobile phones in Asia

It supports a stylus; projected capacitive doesn’t (yet!)

38

SurfaceCapacitive

Source: 3M

39

Surface Capacitive…1


Source: 3M

Scratch-resistanttop coat

Hard coat with AG

Electrode pattern

Conductive coating(ATO, ITO or TO)

Glass

Optional bottomshield (not shown)

Tail

40


Variations

Rugged substrate

Size range

6.4” to 32”

Controllers

3M, Hampshire, eGalax, Digitech and Billabs (ISI)

Advantages

Excellent drag performance with extremely smooth surface

Much more durable than analog resistive

Resistant to contamination

Highly sensitive

Source: 3M

Source: Billabs

41


Disadvantages

Finger-only

Calibration drift

Susceptible to EMI (no mobile use)

Moderate optical quality (85% - 90% transmissivity)

Applications

Regulated (casino) gaming

Kiosks

ATMs

Market share

Source: 3M

2009Revenue 5%Volume <1%

42


Suppliers

3M, DanoTech, Elo TouchSystems, EELY, DigiTech, eTurbo, Optera, Touch International, Higgstec…

16+ suppliers (dominated by 3M)

Market trends

Surface capacitive isn’t growing with the touch market

No multi-touch capability; other significant disadvantages

Casinos (major market) are starting to experiment with other touch technologies

Price is dropping as Taiwanese and Chinese suppliers enter the market now that 3M’s key patent has expired

43

A New Spin: Wacom’s RRFC

Surface Capacitive Technology How it works

AC voltage on 2 adjacent corners; DC voltage on other 2 corners

Creates ramp-shaped electrostatic field across surface

Controller switches signals around all 4 corners, creating 4 ramp fields vs. single flat field in standard capacitive

Current flow is measured in each case

Resulting signal representing touch event is independent of all capacitance effects except those due to finger touch

Controller does additional digital signal processing to compensate for factors that affect accuracy and drift

RRFC = Reversing Ramped Field Capacitive

(Trademark = CapPLUS)Source: Wacom

44

Wacom’s RRFC Technology…2

Advantages

Solves all the problems of traditional surface capacitive

Works in mobile & stationary devices (10” to 32” now; 3” to 46” soon)

Unaffected by grounding changes, EMI, variations in skin dryness & finger size, temperature, humidity, metal bezels, etc.

Works through latex or polypropylene gloves

Allows 4X thicker hardcoat for improved durability

Screen works outdoors in rain and snow

Uses same ASIC as Wacom’s EMR pen digitizer, so dual-mode input is lower cost & more efficient (e.g., in Tablet PC)

Disadvantages

No multi-touch

Sole-source supplier

45


Touch Screen Flow& Sputtering

46

Processes

• Flex and glass touch screen sample product flow charts

• In-depth look at sputtering process module Photo: NextWindow

47

Sample Touch Screen Flow Chart 1 Web Process –

Bottom Substrate

48

Sample Touch Screen Flow Chart 1 Web Process –

Top Layer

49

Sample Touch Screen Flow Chart 1 Sheet Processing –

Spacer

50

Sample Touch Screen Flow Chart 1 Die Cutting & Prep and Assembly of Flex Layers to Glass

Die Cutting

Prep and Assembly of Flex Layers to Glass

51

Sample Touch Screen Flow Chart 1

Glass Plate Cleaning

Pre Process and Clean Sheets

52

Sample Touch Screen Flow Chart 2A

53

Sample Touch Screen Flow Chart 2B

54

Blanket Conductive Films Process Methods –

Sputter Process Module

Basic steps are used for Thin Film Deposition:

• Inspect substrate

• Clean substrate (optional)

• Deposit film

• Measure film• Resistivity

• Thickness

55

Thin Film Deposition Processes

• CVD –

Chemical Vapor Deposition

• Sputtering• Lower Thermal Budget• Targets are pure

materials• Dopant gases can be

used (e.g. O2 for ITO)• Evaporation

• Higher Thermal Budget – too hot for Flex

• Sources are pure materials

• PVD –

Physical Vapor Deposition• PVD used for metals:

• Aluminum & Alloys• Gold• Platinum• Titanium Tungsten• Indium Tin Oxide –

Touch• Molybdenum• Moly Tantalum• Chrome

56

Simple Sputtering System

Independent Variables•Target Composition•Target Spacing•Power•Time•Vacuum•Temperature•Gas Flow

Dependent Variables•Composition•Thickness•Resistivity•Uniformity•Defect Density•Adhesion of Film to Substrate

Oxygen (optional)

57

SUBSTRATE

particle

BEFORE PROCESS

AFTER PVD

AFTER FURTHERPROCESSING

DEFECTIN PVD FILM

DEFECTIN FILM

How Can Defects Happen In PVD?

SUBSTRATE

SUBSTRATE

58

Sputterer

–

FPD Scale Rigid Substrates

Clean load areasClass 10

Load portsSubstrate storage and handling

Target Vacuum pumps

59

Large-Scale Roll-to-Roll Sputtering on Flexible Substrates

Large, clean metalization system.Photo courtesy of Konarka

Photos courtesy of Hanita Coatings

http://earth2tech.files.wordpress.com/2008/10/manufacturing-konarka-power-plastic-in-new-bedford.jpg

60

Roll-to-Roll Process Lines, Coating & Laminating ITO and Other Transparent or Opaque Conductors

Exhaust for reactive processes

Clean mini-

environment

Roll staging

Use of vertical space

Computer control Photo courtesy of Hanita Coatings

61

Scale of Operations and Geography

1.

Flex on large sheets (500 x 500 or so) requires demand of 0.3 to 1 million per month for small devices

2.

Roll-to-roll scale-ups require volume over 5 million per month for small devices, 1 million per month for large1. Automated large size webs, 48 to 54 inches wide by 5,000 or

more feet long

62

Multi-Touch

Sources: Engadget, Do Device and Good Times & Happy Days

2

4

10

63

Multi-Touch

Multi-touch is defined as the ability to recognize two or more simultaneous touch points

Multi-touch was invented in 1982 at the University of Toronto (not by Apple in 2007!)

“Pinching” gestures were first defined in 1983 (not by Apple in 2007!)

Windows 7 (released 10/22/09) supports multi-touch throughout the OS

Windows 7 is structured to support an “unlimited” number (~100) of simultaneous touch points

64

Multi-Touch Architecture

Touchscreen Sensor

Touchscreen

Controller & Driver

Operating System

Application

Capable of sensing multiple simultaneous points

Capable of delivering sets of simultaneous points to the OS

Capable of forwarding multiple streams of moving points (and acting on a defined subset of them)

Capable of decoding multiple streams of moving points and taking actions in response

65

Multi-Touch Technologies

Touch Technology

Multi-Touch Capable? (#)

Win-7 LogoCapable?

Commercial MT Product Example

Projected Capacitive Yes (unlimited*) Yes Apple iPhone; Dell Latitude XT

Analog Multi-Touch Resistive (AMR)

Yes (unlimited*) Yes JazzMutant Music Controller

LCD In/On-Cell (all forms) Yes (unlimited*) Yes Samsung Camera Vision-Based Yes (unlimited*) Yes Microsoft Surface Optical Yes (2) Yes HP TouchSmart Surface Acoustic Wave (Elo TouchSystems)

Yes (2) Yes Lenovo A700 AiO PC

Waveguide Infrared (RPO)

Yes (2) Yes LG Display 13.3” Notebook (SID)

Traditional Infrared Yes (2) Yes Nexio 42” Monitor Acoustic Pulse Recognition (APR - Elo)

Future (2) Maybe Technology in development (2010)

Bending Wave (DST – 3M)

Future (2) Maybe Technology in development (2010?)

Analog Resistive No No -- Surface Capacitive No No -- Force Sensing No No -- * Controller-dependent, not sensor-dependent

66

Windows-7 Logo

A set of touch performance standards designed to ensure a high-quality user experience

Test 1: Sampling Rate

Test 2: Single-Touch Taps in 4 Corners

Test 2: Single-Touch Taps in 5 Other Locations

Test 3: Single-Touch Press-and-Hold

Test 4: Double Taps

Test 5: Multi-Touch Points

Test 6: Press and Tap

Test 7: Straight-Line Accuracy

Test 8: Maximum Touch Lines

Test 9: Multi-Touch Straight Lines

Test 10: Line Accuracy Velocity

Test 11: Single-Touch Arcs

Test 12: Pivot

Test 13: Multi-Touch Arcs

Test 14: Ghost Point Test

67

What’s So Hard About Multi-Touch with Analog-Type Sensors?

Keeping the right X

with the right Y

when going through

occlusion


68

What’s So Hard About Multi-Touch with Digital-Type Sensors?

Designing a controller

that can put out enough points fast

enough

Source: Techdu.de

69

How Many Touches Are Enough?

Why multi-touch will expand beyond two touches Most research on multi-touch is being done with vision-based

hardware because it’s easy to develop the hardware yourself

Vision-based touch supports an unlimited number of touches

All other multi-touch-capable technologies are difficult to build & buyProjected capacitive (currently the #2 touch technology!) also

supports an unlimited number of touchesNumber of touches is one way for a touch technology

vendor to differentiate themselvesRecognizing and ignoring more than two touches ISVs are creative; they’ll find ways to use more touches (games)

(“If you build it, they will come”)

70

An Anomaly: Multi-Touch Gestures on Non-Multi-Touch Screens

Elo TouchSystems: “Resistive Gestures”

Capable of sensing two-finger gestures on standard analog resistive touch-screens

Fingers must be moving to sense two points; two static touches don’t work

3M: “Multi-Touch Gestures on DST”

Same capability & restriction as above on Dispersive Signal Technology (DST) touch-screens

It’s not true multi-touch, but is it good enough?

Gestures are HOT, so device manufacturers want them

Today, multi-touch is mostly used to enable two-finger gestures

For mobile devices, pro-cap is ~3X the cost of analog resistive, so enabling gestures on analog resistive is attractive


71

#1 Reference On Multi-Touch

“Multi-Touch Systems that I Have Known and Loved”

www.billbuxton.com/multitouchOverview.html

“If you can only manipulate one point … you are restricted to the gestural vocabulary of a fruit fly.

We were given multiple limbs for a reason. It is nice to be

able to take advantage of them.”

Bill Buxton, 2008Principal Researcher, Microsoft Research

72

Analog Multi-Touch Resistive (AMR) Projected Capacitive (Materials & Process 3: Common Processes) Embedded (In-Cell & On-Cell) (Materials & Process 4: Photolithography)

Touch Technologies with Patterned ITO

73

Analog Multi-Touch

Resistive (AMR)

74

Analog Multi-Touch Resistive…1

Segmented type (for vertical applications)

Touch Sensor: Single-Layer (shown) or Two-Layer Matrix

Multi- Touch

Controller

Source: Apex

Opaque switch panel (the original purpose of digital resistive)

75


Multi-Touch

Source: Wintek

All Points Addressable (APA) type

(competes with projected capacitive)

76


Two sub-types of All Points Addressable

Each conductive intersection is treated as a digital switch; it’s either on or off (should call it “Digital Multi-Touch Resistive)

Resolution = ½ the width of a conductive trace (0.7 mm typical)

Each conductive strip is treated as a digital “channel”; each intersection is treated as a miniature 4-wire touchscreen

Resolution = analog function (0.2 mm optimum)

Source: J-Touch

77


“Digital”

type

3.74”

x 2.12”(128 pixels/inch)

64 x 36 sensing lines= 1.5 mm squares= 4.8 pixels/square

Display and

digital resistive

sensor by Wintek;

controller by

Stantum(SID 2009)

78

Analog Multi-Touch Resistive…5 (Actual Product)

“Analog”

type

21.5”

multi-touch

resistive by

eTurboTouch

28 x 17 lines

= 17 mm x 16 mm squares(90 pins)

23” = 35 x 22 lines 15 mm x 13 mm (114 pins)

79

Types

Segmented, for vertical-market applications

All points addressable [APA], competes with pro-cap

Pure digital

Hybrid digital-analog

Constructions

PET + Glass, PET + PET, etc. (same as analog resistive)

Options

Technically same variety as analog resistive, but less demand Size range

3” – 25”


80


Controllers

Single-touch – many sources

Multi-touch

Stantum for digital type

?? for hybrid analog-digital type

Advantages

Unlimited multi-touch

Simple, familiar technology

Lower cost than pro-cap Disadvantages (mostly the

same as analog resistive)

Poor durability (PET top surface)

Poor optical performance

More expensive than analog resistive

100 x 128 connections!

Sour

ce: S

tant

um

81


Applications

Mobile devices

Multi-touch music controllers (JazzMutant/Stantum**)Market share

Just starting Controller suppliers

Many suppliers for single-touch, but no standouts

Stantum, AD Semi, J-Touch, WintekMarket trends

Suppliers are gearing up to compete against pro-cap

** See US patent application 2007-0198926

Source: Jazz Mutant

82

ProjectedCapacitive

Source: Apple

83

Projected Capacitive…1

Why “Projected”?Finger

A finger “steals charge” from the X-electrode, changing the capacitance between the electrodes

Electric-field lines are “projected” beyond the touch surface when a finger is present

84


X-Scan

Y-Scan

“Perimeter scan”

or “non-imaging”

type (NB touchpad)

X-axis and then Y-axis electrodes

are scanned sequentially,

looking for

point of

maximum capacitance

to ground

Ghost points

are a problem

with 2 touches

MA

XMAXFinger

ITO transparent conductors

85


“Imaging”

or “all points addressable”

type (Apple iPhone)

Output is an array of capacitance values for each X-Y intersection

86


Raw data including noise

Touch regionsTouch region coordinates

and gradient data

Filtered data Gradient data

Source: Apple Patent Application #2006/0097991

“10 fingers,2 palms

and3 others”

87


Technology variations

Single-layer sensor (no crossovers)

“Self capacitance”

Rarely used with displays due to low resolution

Two-layer sensor (X-Y grid)

“Peripheral scan” or “non-imaging” (Synaptics ClearPad™)

Not commonly used with displays due to limited number of touches

“All points addressable” or “imaging” or “mutual capacitance”

Most common configuration

Supports unlimited number of touches (controller-dependent)

88


Sensor variations

Wires between two sheets of glass (Zytronic)

Wires between one piece of PET and one piece of glass (Zytronic)

Wires between two sheets of PET (Visual Planet)

ITO on two pieces of glass

ITO on both sides of one sheet of glass

ITO on two pieces of PET (Touch International)

ITO on one piece of PET and one piece of glass

ITO in two layers on one side of glass with dielectric (TPK)

Wires vs. ITO

Wires: Visible, acceptable for intermittent use

ITO: Invisible, needed for continuous use

89


Size range

2” to 100”+

ITO up to 22”; wires up to 100”+

Advantages

Very durable (protected sensor)

High optical quality (ITO)

Unlimited multi-touch

Unaffected by debris or contamination

Enables “zero-bezel” industrial design

Works with curved substrates (on PET) Disadvantages

Finger or tethered pen only

High cost (dropping as usage increases)

Difficult to integrate due to noise sensitivity

LG-Prada mobile phone with Synaptics’ projected-capacitive touch-screen; launched 3 months before iPhone

90


Applications

Consumer devices

Smartphones

Netbooks, notebooks, Tablet PCs

Apple AiOs (2010)

Almost any consumer device < 10”

Vertical-market devices

Signature-capture & other POS terminals

“Through-glass” interactive retail signage

Market share2009

Revenue 35%Volume 24%

Source: Verifone

Source: Mildex

DemyDigital

RecipeReader

(CES 2010)

91


Flexible pro-cap sensor

Printed silver conductors, 0.5 ohm/sq.

Roll-to-roll, maximum size 50”

< 1 mm resolution

78% transmissivity with 20µ/300µ line/space

Gunze’s “Direct Printing Technology”

(DPT)

for large-area capacitive touchscreens(shown at SID 2009)

Source: Gunze

92


Pro-Cap Vendor Country Controller Sensor Altera USA Yes No Analog Devices USA Yes No Atmel (Quantum)/ST Micro USA Yes No Avago USA Yes No Broadcom USA Yes No EETI (eGalax) Taiwan Yes No Focal Tech Systems China Yes No Melfas Korea Yes No Microchip Technology USA Yes No Pixcir Microelectronics China Yes No RISIN Technology Taiwan Yes No Silicon Integrated Systems (SIS) Taiwan Yes No Texas Instruments USA Yes No Alps Japan No Yes Cando (AUO) Taiwan No Yes Digitech Korea No Yes Emerging Display Technology Taiwan No Yes HannStar Display Taiwan No Yes

Pro-Cap Vendor Country Controller Sensor Innolux Taiwan No Yes iTouch Electro-Optical China No Yes J-Touch Taiwan No Yes Nissha Printing Japan No Yes Panasonic Electric Devices (PED) Japan No Yes Panjit (Mildex) Taiwan No Yes QuickTouch Technology China No Yes Sintek Photronic Taiwan No Yes Touch International USA No Yes TPK China No Yes Wintek Taiwan No Yes Young Fast Optoelectronics Taiwan No Yes Cypress USA Yes Yes Elan Microelectronics Taiwan Yes Yes N-trig Israel Yes Yes Synaptics USA Yes Yes Wacom Japan Yes Yes Zytronic UK Yes Yes

36 suppliers at end of 2009; 58 now

China = 5Israel = 1

Japan = 4Korea = 2

Taiwan = 13UK = 1

USA = 10

Controller Only = 13Sensor Only = 17

Controller & Sensor = 6(“module”)

93


Market trends

Extremely strong worldwide interest

Rapidly increasing number of suppliers (>250% in last year)

Rapidly dropping prices (>50% in last 18 months)

Upper size limit expanding from 8” to 22”

OEMs’ desire for multi-touch is a key driving force, along with durability and high optical performance

The first significant challenge to analog resistive in mobile devices

The iPodTouch

Source: Apple

94


Common Processes

95

Materials and Processes

• Glass washing

• Screen printing

• Lamination

• Wet etch

• Inspection

• Roll-to-roll

96

Sample Touch Screen Flow Chart 3 Spacer Layer

97

Sample Touch Screen Flow Chart 3 Glass Layer

98

Sample Touch Screen Flow Chart 3 Flex Layer

99

Sample Touch Screen Flow Chart 3 Final Assembly

100

Other Processes Used In Touch Screen Manufacturing• Sheets or rolls can be processed easily at the

following steps– Vacuum deposition (PVD)– Screen printing– Laminating– Punching– Picking and placing– Drying and curing

• Process sections with critical alignment and registration will be most difficult

101

Patterning = Design Rules Tolerance Explanation

• Clients design their products based on an edge-to-edge tolerance (generally of ±1% of component dimensions). This can be expressed by giving each component a tolerance (generally of ±0.5% of component dimension) relative to a fixed reference point in a product. The geometric centre of “S”

has been chosen as this reference point. All other product layer tolerances will reference this point.

• Any distortion will affect product alignment

Axis of web travel

x

y

S

Centre of Sy/2

x/2

102

Glass Washer

• Input parameters– Water quantity– Water spray pattern– Drying technology– Cleanliness– Washing speed, drying

speed

• Output Parameters– Cleanliness– Throughput

Options– Zero consumption water savings system– “Flip-Top” hydraulic lift system– Pre-spray system– Static elimination system

103

Screen Printing Concept

• Input parameters– Squeegee space– Pressure– Stroke length– Material usage– Alignment

• Output parameters– Film thickness– Film resistivity– Pattern defects– Contaminants

• Screen printing is a printing technique that uses a woven mesh to support an ink-blocking stencil. The attached stencil forms open areas of mesh that transfer ink as a sharp-edged image onto a substrate. A roller or squeegee is moved across the screen stencil, forcing or pumping ink past the threads of the woven mesh in the open areas.

104

Production Screen Printers

• In screen-printing on touch devices, the mesh and buses of silver are printed on the glass or flex

• One of the parameters that can vary and can be controlled in screen printing is the thickness of the print

• This makes it useful for some of the techniques of printing touch screens, electronics etc.

105

Fully Automatic Screen Printing

• Aligns fiducial marks on the screen and substrate with the use of two high-contrast cameras to ensure accurate and repeatable deposition for multilayer devices. All processing variables (e.g., squeegee speed and pressure) are monitored and dynamically adjusted to ensure identical fabrication from batch to batch.

• A fully automatic screen-printer is capable of loading/unloading a substrate, aligning a screen to it, and using feedback loops to ensure uniform squeegee speed and pressure as the machine pushes to-be- deposited materials through the mesh and onto the substrate.

• Setting & monitoring of printing parameters:• Storage system of job

parameters• Diagnostics of settings• Variable stroke lengths of

squeegee & flood coater• Adjustable gripper, squeegee &

flood coater speeds• Motorized off-contact

adjustment.

106

Screen Printing for Touch Screens

• Pilot for automation may reveal new variables• Operators may not support automation at first

107

Screen Printing and Drying

Half meter wide web, scale up of sheet process, multiple lines

108

Curing and Drying In Roll-Format Oven• Engineered to have

high degree of control and minimize space

109

Laminator

• Input parameters– Temperature– Time– Pressure– Alignment

• Output parameters– Adhesion– Flatness– Defects– Registration

110

Process Detail Needed for Lamination

• Lamination– Position the y-substrate on a millimetric paper– Clean with antistatic spray– Laminate PSA to the y-substrate using an antistatic gun and a

laminating roller at Pressure A +/- a, temperature B+/-b– Remove PSA residue around the substrate y using a sharp knife– Position the film x to film y using positioning aid #1– Remove PSA liner and lamination of film x using antistatic gun

and lamination roller.– Clean upper side of film with antistatic spray

• Parameters– Class 100 Clean Room

(probably we can use 1000 but never been tested)• Material type: Adhesives Research PSA1

– Positioning aid #1 -

Works for specific product dimensions• Equipment

– Antistatic spray– Laminating roller– Antistatic gun– Sharp knife– Millimetric paper

111

Simple Wet Etch or Lift-Off

• Conveyor drive designs to accommodate a wide range of flexible and rigid printed circuit boards up to 30 inches wide. The Belt Drive design utilizes a single piece fluoropolymer belt for driving the conveyor surface which can accommodate most flexible substrates without the use of support frames. The Serpentine Drive design utilizes a fluoropolymer belt for driving the conveyor wheels which are fabricated of corrosion resistant material. The Serpentine Drive is most suitable for rigid products and provides complete exposure of product surface during spray processes for increased uniformity.

• Input variables– Chemistry – Temperature– Agitation– Spray– Speed

• Output variables– Etch rate – Line width control– Defect density– Selectivity

112

Example of Touch Screen Process Detail Wet Etch

• Etch Process C– Immersion in an etch solution– Immersion in DI water baths– Rinsing with DI water– Drying in the oven– Etch process details

• Etchant: Hypochlorite solution 2. Temp = 25C3. Time= 45 sec– We do this in our lab in a plastic bath– 3 baths one after the other– first bath – 20 sec, second bath 20 sec, third bath 1 min

(Do you know why?)– Requires Shaking the film/bath in each stage (video the motions)

• Observations– The material swells in water and becomes sensitive to mechanical

stress– QC – Test etched lines

• Resistance x : 300 K-ohm ± 30 K-ohm• Resistance between lines: greater than 5 M-ohm

113

Ask the People Who Inspect the Product

Inspectors see more than they record

Automated inspection for transparent conductors and film defects.

114

Source: TMD

Embedded (In-Cell

& On-Cell)

115

Three Different Physical Integration Methods Used In Embedded Touch

Term Integration Method Fab Method

In-Cell Touch sensor is physically inside the LCD cell Touch sensor can be:

Light-sensing elements (light-sensing) Micro-switches (voltage-sensing) Capacitive electrodes (charge-sensing)

Addition to TFT process

On-Cell Touch sensor is an array of ITO conductors on the top surface of the color filter substrate

Capacitive (charge-sensing) Analog resistive (voltage-sensing)

Addition to color filter process

Out-Cell Standard touchscreen laminated directly on top of the LCD during manufacture

Key difference: An additional piece of glass Typically only pro-cap or analog resistive New term coined by AUO – Some LCD

manufacturers still refer to this configuration as “on-cell”

Addition to cell assembly process

116

Four Different Technologies Used In Embedded Touch Light-sensing

or “optical”

Addition of a photo-sensing element into some or all pixels

Voltage-sensing

or “switch-sensing”

Addition of micro-switches for X & Y into some or all pixels

Charge-sensing

or “capacitive-sensing”

Addition of electrodes in-cell or on-cell for capacitive sensing Analog resistive

Uses color filter glass as substrate for standard touch-screen

117

In-Cell Light-Sensing

Principle

Photo-sensor in each pixel or group of pixels sees shadow of finger in bright light or reflection of backlight on finger in dim light

Works with finger or light-pen; can work as a scanner

Adding a cover-glass to protect the surface of the LCD reduces touch sensitivity due to the spacing between the finger and the photo-sensing element

Source: DisplaySearch

118

In-Cell Voltage-Sensing

Principle

Pressing LCD surface closes micro-switches in each pixel

Similar principle as emerging analog multi-touch resistive

Requires touching the LCD surface (cannot add a cover glass)

Works with any touch object within damage limits of polarizer

Source: Samsung

119

In-Cell Charge-Sensing

Principle

Pressing the LCD changes the dielectric constant of the liquid crystal, which changes the capacitance between the electrodes

Works with finger or stylus; human body capacitance isn’t a factor

Requires touching the LCD surface (cannot add a cover glass)

Source: LG Display

120

Hybrid In-Cell Voltage & Charge- Sensing (Samsung hTSP)

Sensor signal line switch (X,Y)Source: Samsung

CRef

CLC

VOut

Column- spacer switch

Blue pixel

VRef

VCom

X-YBias

Amplifier

2 sets

(X&Y)

per pixel

or group

of pixels

Source: Author

Principle

Pressing the LCD… (1) Changes the dielectric constant of the liquid crystal, which changes the capacitance between the pixel electrodes (2) Closes the column- spacer contacts, which activates the circuit that measures the change in capacitance

121

On-Cell Charge-Sensing

Principle

Projected-capacitive X-Y electrode array added on top of the color filter glass, under the top polarizer

Same function as standard projected-capacitive

Works only with finger; human body capacitance changes mutual capacitance between electrodes

Cover-glass (0.5 mm) can be added on top of polarizer to protect LCD surface

Source: Author

122

On-Cell Analog Resistive

Principle

Analog resistive touch-screen added on top of the color filter glass, under the top polarizer

Same function as standard analog resistive

Works with any touch object within damage limits of polarizer

Adding cover-glass (0.5 mm) on top of polarizer to protect LCD surface works but reduces touch-screen performance

Source: Author

123

Products with Embedded Touch…1 Samsung ST10 camera with 3-inch 480x320 (192 ppi)

transflective TFT with hybrid in-cell touch (4/09)

First use of any in-cell touch in a commercial product

Works with finger or stylus, but with visible pooling

Surface hardness = low

Touch-screen includes electrostatic haptic feedback

Camera includes MP3, PMP & text-viewer functions

One sensor per 8 pixels (60x40 sensing matrix)

Source: Samsung

124

Products with Embedded Touch…2

Sharp’s PC-NJ70A netbook (5/09)

First use of light-sensing in-cell touch in a commercial product

Optical in-cell touch in 4” CG-silicon 854x480 touchpad LCD (245 dpi)

1 sensor per 9 pixels

LED backlight

Stylus & 2-finger multi-touch

Scanning (shape recognition)

Touch surface = ??

Japan-only; $815

Problems

Need IR from backlight

S L O W

(25% of typical touchpad speed)

Short battery lifeSource: Sharp

125

Samsung ST550 camera with 3.5-inch 800x480 (267 ppi) transflective TFT with hybrid in-cell (8/09)


“When you touch or drag on the screen, discolorations will occur. It is

not a malfunction but a characteristic of the touch screen. Touch or drag lightly

to reduce these annoying effects.”

(from the User’s Guide)Source: Samsung

“Do not use other

sharp objects, such

as pens or pencils,

to touch the screen. Doing so

may damage the screen.”

“The touch screen may not recognize

your touches

correctly when:●

You touch multiple

items at the same time●

You

use the camera

in high-humidity

environments●

You

use the camera

with an LCD protection

film or another LCD

accessory”

126


LGD’s 13.3”

1280x800 in-cell charge-sensing LCD (10/09)

Largest in-cell LCD so far

1 sensor per 4x4 pixels

10 gf activation force

Win-7 Touch Logo 2/10

Positioning

High optical quality

Sunlight readability (AR?)

Preserving thinness

Two-touch multi-touch

Targeted at notebooks

Production in 2H-2010

Added price for touch function = ??

Source: LG Displays

127


Samsung S8500 Wave mobile phone with Super OLED on-cell charge-sensing touch (2/10)

3.3-inch 800x480 (283 ppi) AMOLED

“Super OLED” is Samsung’s (poor) branding for on-cell touch

Sunlight readable

AR coating & no touchscreen overlay

“Window” here refers refers to the “cover

lens” that’s laminated on top of the display

Source: Samsung booth graphic at Mobile World Congress 2010

Source: Samsung

128

Embedded Characteristics…1

Advantages (summary)

Integration, size, thickness, weight, ID (touch is “invisible”)

Unlimited multi-touch (controller-dependent)

Conceptually high performance

Low parallax error (assuming no cover glass)

Very accurate & linear touch-point data

Potentially higher resolution than LCD

Lower manufacturing cost

Source: AUO

129


Disadvantages (summary)

Touching a black image doesn’t work in low ambient light

Can’t reliably detect touch over the full range of ambient

The sensor consumes too much of the pixel aperture

Unstable microswitch contact at the edge of the screen

The amount of processing power required by the touch function results in high power consumption in a mobile device

Liquid-crystal pooling can be visually distracting

Standard LCD polarizer is too soft for normal touch usage

Successful integration can be very difficult due to LCD noise

Lack of stylus support with on-cell limits some applications

130


Size range

3” to 13.3” (current); potentially to mid-20”

Variations

Number of pixels per sensing element

Controller

Proprietary/TBD (potential problem)

Applications

Mobile (cellphones, cameras, netbooks, notebooks)

Market share

Just starting

Suppliers

AUO, CMI, CPT, LGD, NEC, Samsung, Sharp, Sony, TMD…

Source: Sharp

131


Trends

Light-sensing has the most unresolved problems

No successful end-user products yet

Voltage-sensing isn’t getting any traction

No successful products of any kind yet (IP restriction?)

Charge-sensing is where all the action is, mostly on-cell

LGD’s 13.3” notebook LCD (in-cell)

Samsung’s OLED cellphone (on-cell)

Samsung’s in-cell hybrid in-cell voltage & charge-sensing cameras

Analog resistive has been shown in demos only so far

It is unlikely that LCD manufacturers will add embedded touch to an entire LCD product line; it will just be in high-volume products with a high demand for touch

Conclusion

It’s still early days – embedded touch has some distance to go

132


Photolithography

133

(Cross Section)

Thin Film Dep

Pattern

Etch/Clean

Cross Section

Top View

Fine Line Patterning Using PhotolithographySteps Used Together

134

How Many Times Do We Pattern?

• As many layers of conductors, insulators, and different materials as we have• Each (with exception) requires a separate pattern or “mask”• Re-entrant flows• One tool is used for several steps on the same product• 20 – 65 pattern layers in ICs• 4 – 8 pattern layers in FPDs• 1 – 4 pattern layers in Touch

135

Basic Steps Used for Patterning Fine Lines Less than 25 Microns• Photolithography

(using light to make lines)• Coat with photosensitive film

• Align

• Develop

• Inspect

• Etch or deposit desired material

• Strip photosensitive film

• Inspect/measure

FPD Stepper

136

Barrier to Etches

Barrier to Metal Etches

Resist

Nitride

Nitride & Partial Oxide Etched Away

Oxide

Metal Etched AwayResist protects metal

Metal 1

Uses of Photoresist

Photoresist is used as a mask, and then removed from the substrate

137

Photoresist Coating Process

• Equipment Used: Spin Coater (most common)• Task: Apply a thin film of photoresist onto substrate• The photoresist film must be:

1. Clean and free of particles or pinholes2. Applied to dry substrates (may need surface modifier chemicals)3. Correct in thickness and uniformity4. Dried with solvents removed5. Baked and ready for exposure6. Photoresists are organic polymer resins (C, O, H, N) mixed with

solvents

138

Resist Coat Bake System -

FPD

140

Printers

• EQUIPMENT USED:

Aligners (Contact, Proximity)Scanners

Steppers

Step and Scan• PROJECTION PRINTER (SCANNING) (8 to 75 microns):

• Uses highly reflective mirrors to project a pattern from a photomask to the substrate

• No reduction in image size• Prints with one continual scan across each substrate

STEP-AND-REPEAT PRINTER (STEPPER) (5 microns and below):• Uses reflective optics (condenser & reduction lenses) to project a

pattern from a reticle to the wafer• Optically reduces reticle image size by 5X (or 10x, 2x, or 1x)• Prints “fields” which are stepped over each substrate

141

Images courtesy of SSEC and RPO Pty Ltd

Coat / Develop Scanner

Flex Handling and Mid-Process Coat, Align / Expose and Develop (Resist and Optical Materials)

142

Spray Developer –

FPD

143

Mercury Lamp Mask or Reticle

Positive ResistSubstrate

De-polymerized resist after exposure

Before exposure

• De-polymerized resist is washed away during the develop

process; a spin/ spray tool is often used with base (OH) chemicals and water or solvents

Positive Resist After Exposure to Light

144

Tool Selection –

Photo Patterning on Flex

• Azores installed at FDC (plate format). They are working on roll-to-roll. For the 2006 model we used the Azores tool at 2.5 ft/ min, resolution down to 1.5 microns, and a cost of $9M.

• ORC Proximity Large Area Exposure at 4.5 ft/min, resolution to 12 microns, and a cost of $422K.

• Still to be resolved• Cost of Azores in volume• Is there something in between?

Resolution? Cost? Mix and match?• How to match coat, align, develop capacity

FPD Stepper / Stitcher(Azores)

145

Prints the same defect onmany substrates

ProjectionMASK

MASK OR RETICLE

1 Defect

etc...

SCRATCH

GLASS

LIGHT

PHOTORESIST

DEFECTS IN PHOTO PATTERN

PARTICLE

Substrate

CHROME

How Can Defects Happen In Photolithography?

146

IT DEPENDS ON FEATURE SIZE:

Nanotechnology 2003

0.09 µ

CD90nm

nm = Nanometers

4 µ

CD 2.5 µ

CD 1.5 µ

CD

NMOS 1980 HMOS 1985 CMOS DLM 2 µ 1989 CMOS QLM 0.35µ 1995

0.35 µ

CD4000nm 2500nm 1500nm 350nm

Bacteria Skin FlakeCigarette Smoke

0.2 -

0.4 µ

? 2 µ

? 8 µ

?

Amines200 –

400nm 2000nm 8000nm~ 50 nm

What Size Defect Is a Killer?

FPD / CFAdv. Touch

TFT

147

More CHANCES for a defect to occur!

More Process Steps Means…

BiPolar

8 11 12 15 17 21Photo Diff / CVD Photo Diff / CVD Photo Diff / CVD

PVD PVD PVD40 50 65

c 1980 c 1988 c 1993

Total Steps

NMOS / TFT HMOS

Total Steps

DLM CMOS,

Total Steps

BiCMOS GATE ARRAYS

148

Anything that does not belong on the device

Anything that KILLS a device

DEFECTDEFECT

GOOD DEVICE

OPEN

DEAD DEVICESSHORT

What Is a Defect?

149

DEFECTS

YIELD

LOW Defect Density

=

HIGH Yield / Low Costs

HIGH Defect Density

=

LOW Yield / High Costs

150

1/6 = 16.7% bad 1/4 = 25% bad

-

Killer defect

1/1 = 100% bad

XXX

Laptop Medium Television Large Television

Touch Screens Risks in Fine Line Patterning –

Defect Density

151

R R G B

R G G B

Flat Panel Displays

Each display ~ 1280 x 1068 pixels~ 1.4 million pixels/display

Each pixel contains several transistors

For each subpixel:

EACH pixel must be clean or we will see a dark spot, bright spot, bright line, or dark line.

152

Acoustic Pulse Recognition (APR

by Elo) Dispersive Signal Technology (DST

by 3M)

(Materials & Process 5: Etch) Surface Acoustic Wave (SAW) Traditional Infrared (IR)Waveguide Infrared (by RPO) (Materials & Process 6: In-Cell / FPD) Optical Force Sensing Vision-Based

Touch Technologies without ITO

153

AcousticPulse

Recognition(APR)


“Zero-Bezel”

Single piece of glass (no bezel); black margin is

fired-on glass frit on underside

154

Acoustic Pulse Recognition (APR)…1


Plain glass sensor with 4 piezos on the edges

Table look-up of bending wave samples (“acoustic touch signatures”)

155


Variations

“Stationary APR” from 10” to 52” with controller board

“Mobile APR” from 2.8” to 10” with controller ASIC

Size range2.8” to 52”

Controllers

Proprietary

Advantages

Works with finger, stylus or any other touch object

Very durable & transparent touch sensor

Resistant to surface contamination; works with scratches

Totally flush top surface (“Zero-Bezel”)

Very simple sensor (plain glass + 4 piezoelectric transducers)

156


Disadvantages

No “touch & hold”; no multi-touch (both are under development & should appear in 2010)

Requires enough touch-force (tap) to generate sound

Control of mounting method in bezel is critical

Applications

POS, kiosks, gaming, mobile devices

Market share

<1% (first production in Elo monitors was at the end of 2006)

Supplier

Elo TouchSystems (sole source)

Market trends

Elo has begun shipping APR to mobile device OEMs

157


Elo’s

“Zero-Bezel”APR with

capacitive

buttons &

scroll-wheel

in lower-right

corner(SID 2009)

158

Dispersive Signal

Technology (DST)

Source: 3M

159

Dispersive Signal Technology…1

Source: 3M

Plain glass sensor with 4 piezos in the corners

Real-time analysis of bending waves in the glass (“time of flight” calculation)

160


Variations

None

Size range32” to 46” (3M is likely to expand into larger sizes)

Controller

Proprietary

Advantages

Very simple sensor (plain glass + 4 piezoelectric transducers)

Works with finger, stylus or any other touch object

Very durable & transparent touch sensor

Operates with static objects or scratches on the touch surface

Fast response; highly repeatable touch accuracy; light touch

161


Disadvantages

No “touch & hold”; no multi-touch

Control of mounting method in bezel is critical

Applications

Interactive digital signage; point-of-information (POI)

Market share

< 1%

Supplier

3M (sole source)

Market trends

DST still has a relatively low market profile due to 3M’s very conservative rollout

3M avoids cannibalizing their surface-capacitive sales (<32”)

162

APR vs. DST Technology ComparisonCharacteristic APR DST Notes Size range 2.8”-52” 32”-46” 3M surface capacitive is 5.7”-32”Methodology Table lookup Real-time Measurement Bending waves Bending waves Multi-touch Under

development Gestures

announced 3M’s “multi-touch gestures” onlywork with two moving points

Touch & hold Under development

No

Activation force Moderate Light Controller Chip (mobile)

Board (fixed) Board (fixed)

Mounting Critical Critical Availability In monitors;

components formobile devices

In monitors Neither technology has reached the “drop-in touch-screen” component state yet

Others Similar Similar Performance, materials, surfacetreatment, interface, etc.

163


Etch

164

• Wet Etch • Wet resist strip• Inspect for defects / registration• Measure critical dimensions

Dry or Plasma Etch• FPD or semiconductor process• Anisotropic etch• Fine-line geometries• Materials with no wet etchant

“Lift-Off”

is an etch / strip combination process

Processing –

Etching What Steps Are Used in Etch?

165

Etch

Must be highly “selective”• Etches desired material much faster than

• Protective mask (usually photoresist)• Underlying materials

• Chemistry mix is critical• Can be enhanced by

• Heat/energy• Plasma (RF)

• Criteria for selecting Dry or Wet Etch• Cost (equipment depreciation, chemicals, maintenance, yield)• Etch profile

166

• Isotropic: Etches all directions equally, chemical -

Wet Etch

• Anisotropic: Etches different directions at different rates to create shapes, “trenches”. More likely to achieve and control etch profile with Dry Etch

Mask Mask Mask Mask

Material to be etched

Isotropic Etch Anisotropic Etch

Etch

167

Etch Chemistry

Wet Etch –

AcidsITO Thickness = 0.5 to 1.5 microns• ITO Etchant 1: 17% HCl, 25

C, 30-60 Angstroms/min• ITO Etchant 2: 1:0.1:1, HCl:Nitric:DI H2O @ 40

C• ITO Etchant 3: Etches Fast (125 Angstroms/sec) in 10:1 DI H2O: HF

Other common etchants: • Phosphoric/Hydrochloric/Acetic/Nitric: Metals• Hydrogen Fluoride: SiO2• Phosphoric: Silicon Nitride Si3N4

168

ETCHERS

• WET ETCH:• HOOD/ BENCH• ACID PROCESSOR –

single substrate OR batch

• DRY ETCH• PLASMA• REACTIVE ION ETCH

How Can Defects Happen In Etch Process?

Substrate

defect

169

• Wet processes from rinsing through to developing, etching, stripping and drying performed totally in line.

• Large glass substrates are processed by substrate oscillation, chemical spraying, speedy upflow, etc. matched to process requirements.

• The etching module contains end point sensors for ensuring excellent processing repeatability.

Rigid and Flex Panel ProcessorsIn-line systems for wet processing.

Source: Dalux

Wet Etch Equipment

170

Metal Layers Solvents- Acetone- NMP- PRS 3000

Solvent or water rinse-

IPA

• Options: Heating, spray patterns, rinse to resistivity, spray, recirculating tanks

• Drying is critical• N2• Air curtain / knife• Iso

dryer / displacement dry

Dry• Plasma• UV Ozone

• Strip must be highly selective to remove all unwanted materials and leave all critical films!

Wet

Resist Strip and Clean

171

Inside View

Front of Gen II Wet Hood –

Etch / Strip

172

Chemical Recirculating Systems

173

Stainless Steel Wet Strip Systems

• High-temperature stainless stripping system with integrated resist separator

• Conveyor systems available for rigid and flexible sheets (.001” core)

Source: Dalux

174

Alternate Fine Line Processing – Pattern and Etch in One Step

• Laser ablation system• Single layer patterning• High resolution• Ease of varying pattern

• Critical input parameters• Laser energy• Speed• Film quality• Alignment• Pattern algorithm (software program)

• Critical output parameters• Ablation pattern• Registration• Resolution• Defect density• Heating / damage

175

Inspect / Metrology

• How is success measured / evaluated?

• Probe, final test

• Until probe: Indirect measurements

• Single parameters• They infer probable

functionality• Examples:

• Critical dimensions• Particle counts• Automatic optical inspections

• Interactions of individual parameters abound!

Key parameters:• Film thickness

• FTIR• Profilometer

• Resistivity / conductivity• Inductance

• Critical dimensions• Widths / lengths• Light reflection

• Physical structure / Morphology / step coverage

• Profilometer• SEM

176

Orbotech SuperVision-650™High-sensitivity AOI for the 6th generation

SuperVision-650™, the world's very first AOI system for 6th generation panels, provides high sensitivity detection and better throughput.

Inspection Tool FPD, PC Board, Touch Screen

177

SurfaceAcoustic

Wave

Source: Kodak

178

Surface Acoustic Wave…1

Source: Onetouch

Rayleigh wave

(45°)

Glass substrate

Source: A-Touch

179



180


Variations

Ruggedization, dust-proofing, surface treatments, etc.

Size range

6” to 52” (but some integrators won’t use it above 32”)

Controllers

Mostly proprietary

Advantages

Clear substrate (high optical performance)

Very durable

Can be vandal-proofed with tempered or CS glass

Finger, gloved hand & soft stylus activation

181


Disadvantages

Very sensitive to any surface contamination, including water

Requires “soft” (sound-absorbing) touch object

Can be challenging to seal

Relatively high activation force

Projects slightly above touch surface (1 mm) so can’t be flush

Applications

Kiosks

Gaming

Market share

Source: Euro Kiosks Network

2009Revenue 3%Units <1%

182


Suppliers

Elo TouchSystems, General Touch, Shenzhen Top-Touch, Leading Touch, Shenzhen KeeTouch…

10+ suppliers

Market trends

Price is dropping as Taiwanese and Chinese vendors enter the market now that Elo TouchSystems’ key patent has expired

Elo still has >50% of this market

SAW’s growth is matching the market

183


Elo’s “XYU”

multi-touch

SAW(demoed at

SID 2009;

launched 12/09)

Photo by Geoff Walker

184

Traditional Infrared

185

Traditional Infrared…1


186


Variations

Bare PCA vs. enclosed frame; frame width & profile height; enhanced sunlight immunity; force-sensing

Size range

8” to 150”

Controllers

Mostly proprietary, except IRTouch

Advantages

Scaleable to very large sizes

Multi-touch capable (2-4 touches)

Can be activated with any IR-opaque object

High durability, optical performance and sealability

Doesn’t require a substrate

187

Disadvantages

Profile height (IR transceivers project above touch surface)

Bezel must be designed to include IR-transparent window

Sunlight immunity can be a problem in extreme environments

Surface obstruction or hover can cause a false touch

Low resolution

High cost

Applications

POS

Kiosks

Large displays (digital signage)

Market share


2009Revenue 1.5%Units <1%

188


Selected suppliers

Elo TouchSystems, IRTouch, Minato, Nexio…

10+ suppliers

Market trends

Interest in IR is re-awakening as Asian vendors bring down prices, large displays become more common, and digital signage becomes more affordable

IR is growing, but isn’t keeping up with the market

50” plasma display with infrared touch-screen from Netrax

189

OpticalWaveguide

InfraredSource: RPO

190

Waveguide Infrared…1

Source: RPO

Principle

Traditional

Infrared

191


Photo source: RPO;Annotation by author

IR LED

Waveguides

Line-scanoptical sensor

Substrate

Parabolic reflector

Light path (white)

Light path (uses TIR in substrate)

RPO’s actual construction

(3.5”

screen)

192


Variations

None yet Size range

3” to 14” Controller

Proprietary Advantages

Much lower cost than traditional IR

Very low profile height (0.5 mm)

Higher resolution (depending on waveguide channel width)

Much less pre-touch (IR is only 200µ above substrate)

Works with a finger, stylus or any other touch object

Object size recognition

Limited multi-touch

Source: RPO

193


Disadvantages

Can’t be scaled easily to large sizes (border width)

Power consumption (positioned as = to light loss of resistive)

The “fly on the screen” problem (IR is only 200µ above substrate)

Applications

Mobile devices & automotive (maybe)

Market share

Not in a shipping device yet as of 01/10, although RPO says they now have a committed OEM

Suppliers

RPO (Australian startup; sole source)

194


Market events

RPO…

Announced IR optical-waveguide touch at SID 2007

Showed improved performance at SID 2008

Showed larger sizes at SID 2009

Appeared in a 13.3” LD Display notebook at SID 2010

Market trends

RPO may benefit from the general increase in interest in infrared, as well as from the growing interest in alternative touch technologies for mobile

195


In-Cell & FPD

196

Three Different Physical Integration Methods Used In Embedded Touch

Term Integration Method Fab Method

In-Cell Touch sensor is physically inside the LCD cell Touch sensor can be:

Light-sensing elements (light-sensing) Micro-switches (voltage-sensing) Capacitive electrodes (charge-sensing)

Addition to TFT process

On-Cell Touch sensor is an array of ITO conductors on the top surface of the color filter substrate

Capacitive (charge-sensing) Analog resistive (voltage-sensing)

Addition to color filter process

Out-Cell Standard touchscreen laminated directly on top of the LCD during manufacture

Key difference: An additional piece of glass Typically only pro-cap or analog resistive New term coined by AUO – Some LCD

manufacturers still refer to this configuration as “on-cell”

Addition to cell assembly process

197

Four Different Technologies Used In Embedded Touch Light-sensing

or “optical”

Addition of a photo-sensing element into some or all pixels

Voltage-sensing

or “switch-sensing”

Addition of micro-switches for X & Y into some or all pixels

Charge-sensing

or “capacitive-sensing”

Addition of electrodes in-cell or on-cell for capacitive sensing Analog resistive

Uses color filter glass as substrate for standard touch-screen

198

ITO ELECTRODESBacklight

Light

FRONT POLARIZERFRONT GLASS

LIQUID CRYSTAL MATERIAL

REAR GLASSREAR POLARIZER

Simplified Structure of an LCD Cell

Touch Screen

199

TWISTED NEMATICtwist angle 90deg.

SUPERTWISTED NEMATICtwist angle 180deg. - 270degUpper Polarizer

GlassITO Electrode

Liquid Crystal

ITO ElectrodeGlass

Lower Polarizer

Upper Polarizer

GlassITO Electrode

Liquid CrystalITO Electrode

GlassLower Polarizer

No field appliedLight/off

Field appliedDark/on

Liquid Crystal Displays

200

TFT

AM

LCD

Thin FilmTransistor (TFT)

DISPLAY CELL

LOWER COLUMN DRIVER

Resistor

Capacitor

UPPER COLUMN DRIVER

ROW

DRIVER

Liquid Crystal Displays Active Matrix Liquid Crystal Display = AMLCD

Photo-sensor in each pixel or group of pixels sees shadow of finger in bright light or reflection of backlight on finger in dim light.

Same TFT Process

• Putting a light-sensor in every pixel consumes too much of the aperture (reducing efficiency) and requires too much processing power

• But using one light-sensing element for each X pixels (e.g., 9) reduces scanning resolution and reduces quality of digital ink

201

Liquid Crystal Displays AMLCD TFT Pixel Structure -

Typical

i-Si

METAL

PIXEL ITO

DATA LINE

GATE LINE

CAPACITOR LINE

TOP View TFT Top View –

Voltage-Sensing 1

202

Pixel Electrode

a-Si TFT

Gate BusDrain Bus

COMPONENT

Polarizer

Glass: Color Substrate

Color filter

ITO

Alignment Layer

Sealing Adhesive

Liquid Crystal

Spacer

Alignment Layer

Glass: TFT Substrate

PolarizerBacklight

R GG

R

BB

In-Cell Touch Amorphous Silicon TFT

203

Voltage and Charge Sensing

Side View –

Voltage Sensing 2

Column spacer with ITO coating.

May require additional steps.

Side View –

Charge Sensing (“Pressed Capacitive”)

Consistency of capacitance value of LC material is critical

204

PASSIVATION

SPACER

POLYIMIDE (ALIGNMENT)

ITO

LIQUID CRYSTAL LAYER

PIXEL ELECTRODE ITO

COLOR FILTER

BOTTOM GLASS SUBSTRATE (TFT ARRAY)

DATA LINE

TOP GLASS SUBSTRATE (COLOR FILTER)

BLACK STRIPE

Sealing Material(Adhesive)

PASSIVATION

Light

We are looking at this side.

Cross Section of TFT LCD

205

Charge-Sensing…2

On-cell• Projected-capacitive X-Y electrode array added on top of the

color filter glass, under the top polarizer

Source: Author

Needs touch-

friendly polarizer,

6H to 9H hardness.

206

Lighting

Materials

Electronics

TFT Fab

ColorFilter Fab

Plate/Cell Assembly

Final Assembly Testing

Liquid Crystal Displays AMLCD Production Process

Addition of “ON-

CELL”

Touch Array

207

COLOR FILTER SUBSTRATE

Cleaning / Polarizer Lamination

TFT SUBSTRATECleaning

Cleaning

Rubbing

Baking

Polyimide Coating

Spacer Spraying

Cleaning

Rubbing

Baking

Polyimide Coating

Cleaning

Align / Assemble / Cell Space Adjusting

Inspection

Scribe / Break

Liquid Crystal Filling / Annealing

Seal Printing

Conductive x-over dots

Align / Assemble / Cell Space Adjusting

Scribe / Break

Liquid Crystal Displays Cell Assembly Process

208

GATE METALDEPOSITION

PHOTOLITH/ETCH

TO DEFINE GATE

DEPOSITGATE INSULATOR

i A-SILICON &n+ A-SILICON

PHOTOLITH / ETCHTO DEFINE CHANNEL

DEPOSITSOURCE / DRAIN

METAL

PHOTOLITH / ETCHTO DEFINE

SOURCE / DRAIN ANDETCH BACK CHANNEL

DEPOSIT ITOPIXEL PAD

PHOTOLITH / ETCHTO DEFINE ITO

Liquid Crystal Displays a-Si TFT Process

For In-Cell, Add Sensor Design to

this Flow

209

Process Type

Equipment Type

Clean

First Wash/Clean

Inspection/Repair

Thin Film Deposition

Drying

Stripping

Etching

Postbake

Develop

Exposure

Prebake

Apply Resist

Single Substrate Processor

Conveyor Oven, Hot Plate

Single Substrate Processoror Batch Dip/Spray/Dry Plasma or RIE

Conveyor Oven or Hot Plate

Single Substrate Processor or Batch

Stiches

Stepper or Full WaferProjection Expose

Conveyor Oven or Hot Plate

Extrusion orSpin

Coater

Plasma CVD

Sputter

Optical/Electrical TestLaser Repair

Batch or Single Substrate Processor

Repeat

Single Substrate Processoror Batch Plasma or RIE

Liquid Crystal Displays Active Device Formation

210

CleanBorosilicate

Glass

Sputter DepositGate Metal 1eg: Al or Cr

Photolith

Pattern Gate and Wet Etch

Gate Metal 1

PECVD Deposit,Nitride, Amorphous

Silicon, SiliconFilms

Photolith

Patternsilicon

Sputter DepositITO

Photo PatternPixels

and Wet Etch ITO

Sputter DepGate Metal 3

eg: MoTa, Al or CrS/D Metal 3

Photo PatternSource/Drainand Wet Etch

S/D Metal 3

Substrate Clean

DepositPassivationSixNx

Nitride

Photo Pattern &Dry Etch (RIE)SixNx Nitride

Final Test/Inspect Pattern

Sputter DepositGate Metal 2eg: Al or Ta

RIE silicon

RIE N+Amorphous

SiliconPhoto Pattern &Dry Etch

SixNx

SiliconNitride

Final QC

Send to LiquidCrystal

LaserRepairShorts

AnodizeGate Metal

Photo Pattern and Etch

Gate Metal 2Eg: Ta

Liquid Crystal Displays Flow Chart –

TFT Bottom Plate, TFT and Pixel Fabrication

Details would change for In-Cell Sensor

211

CAP LayerDeposit

(polyimide orNitride)

Sputter DepositITO

Final Q.C.

Send toLiquid Crystal

AshPlasma Clean

Substrate CleanBlue Filter

Apply and Bake

Green FilterPolyimide

Apply and Bake

Red FilterApply and Bake

Resist Coat, Align,Develop, Strip

resist, Hard BakePolyimide

Resist Coat,Align, Develop,

Strip resist, HardBake Polyimide

Resist Coat, Align,Develop, Strip

resist, Hard BakePolyimide

CleanBorosilicate

Glass

PECVD DepositSixNx

SiliconNitride

and Silicon

Sputter DepositChrome

RIESixNx

Nitrideand Silicon

Photo PatternBlack Matrix

and Wet EtchChrome

Liquid Crystal Displays Top Plate Flow Chart, Black Matrix and Color Filters

Details would change for Voltage and Charge

Sensing In-Cell Touch

212

3.)Moly Tantalum

LEGEND

a.) Self-aligned b.) Non-self-aligned

1

5

6n+Si

Sii

SiN

Gate1

3

ITO

Metal

Insulator

2 4

Glass Substrate

1 1

56

3 2 4

Si

Si n+

i

GateInsulator

Glass Substrate

Liquid Crystal Displays a-Si TFT Process Architecture –

Bottom Gate

Masking Steps Process Steps Materials1. Gate Pattern 1. Metal Dep 1. Aluminum Tantalum (AlTa)

2. Etch Stop Pattern 2. PECVE Dep2. a‐Si Amorphous Silicon

n+ amorphous Silicon

Si3N4 Silicon Nitride

3. Channel Pattern 3. Metal Dep 3. MoTa

(Moly

Tantalum)

4. Gate Cut Pattern

(non‐self aligned only)

5. ITO Pattern 5. ITO Dep 5. ITO (Indium Tin Oxide)

6. Metal Pattern 6. Metal Dep 6. MoTa

(Moly

Tantalum)

7. Passivation

Pattern 7. Passivation 7. Polymide or Si3N4 Silicon Nitride

213

ITO -

Picture Element Electrode (PIXEL)

APCVD SiO2 -

Layer Insulation Film

Glass Substrate

n-poly-Si -

Gate ElectrodeA1 -

Signal Line

i-poly-Si

n-poly-Si

Thermal Oxide SiO2

-

Gate Insulation Film

Liquid Crystal DisplaysCross Section: High Temperature poly-Si TFT –

Top Gate

214

Plan View of TFT Device with Added Sensors

Easy to see how aperture can be smaller as sensors are added.

• Gate is Red• Signal lines are Blue• Contacts are green

Example of additional sensors in a TFT cell

215

Mechanical Effects –

Cover Glass vs. Touch Requirements

• Voltage-sensing won’t work with a cover glass, so the LCD can easily be damaged

• AUO’s 2008 spec is only 100K touches at <40 grams! – although it’s unclear if it’s limited by LCD surface damage or ITO cracking

• Typical resistive touchscreen spec is 1M touches (4-wire) or 30M touches (5-wire) at ~80 grams

• Harder LCD top-polarizer is the best solution to this problem, but until there’s more demand for touch, it’s chicken-and-egg

• Adding a cover-glass to protect the LCD reduces touch sensitivity due to the spacing between the finger and the photo-sensing element

• Will the repeated flexing of the glass cause eventual fatigue and failure?

• Glass is amorphous• Tests show varying toughness, hardness, and crack failure by glass

vendor and thickness. (Reference previous AGI project with USDC)

216

Sample of Previous AGI Mechanical Study of Glass7.0 ConclusionsThe conclusions from this experimentation are as follows:1. AGI has established a robust method, apparatus and visual inspection for repeatable

edge chipping analyses on glass.2. At the 99% confidence level, glass thickness, glass type and impactor material are

statistically significant. At a confidence level of less than or equal to 98.1% all factors including edge type are significant.

3. There appears to be an order of significance. This is, from higher to lower, glass thickness, impactor material, glass type and edge type.

4. Thinner glasses (0.4 mm) are much more likely to sustain edge fracture from impact than 0.7 or 1.1 mm glass. Generally, there was an order of magnitude difference between 0.4 and 0.7 mm glass for the impact energy to fracture.

5. All metal/ glass contact should be carefully scrutinized, avoided or eliminated.6. Through repeated impact testing, a factor of safety has been established to protect glass

from repeated impacts and other variations.

217

Optical

This picture was drawn on a 46" LCD equipped with a NextWindow optical touch-screen by a visitor to the AETI Exhibition in London on January 24, 2006.

Source: NextWindow

218

Optical…1

219

Optical…2

Variations

OEM

Bezel-integrateable

Strap-on (aftermarket)

Size range

15” to 120”

Controllers

Proprietary

Source: NextWindow

220

Optical…3

Advantages

Stylus independence (ADA-compliant)

Superior drag performance

Scalability to large sizes

Multi-touch (dependent on # of sensors)

Object size recognition

Disadvantages

Profile height (~3 mm on a 19” screen)

The “fly on the screen” problem (susceptibility to contaminants)

Applications

Consumer touch monitors & AiOs (market leader)

Interactive digital signage; education

HP TouchSmart all-in-one computerSource: HP

221

Market share

Suppliers

NextWindow, Quanta, Lumio, Xiroku, eIT (XYFer)

Market event

NextWindow shipped more than 0.75 million touchscreens in 2009 to Asus, Dell, HP, Lenovo, Medion, NEC, Samsung & Sony

Market trends

Touch on the consumer desktop is just starting

The market is just becoming aware of optical touch

Optical…4

2009Revenue 3%Units <1%

DellStudioOne

Source: Dell

222

ForceSensing

223

Force Sensing…1

Principle

Suspend the touch-screen from force- sensors (strain gauges or piezos) such that movement is constrained to only the z-axis

Variations

IBM “TouchSelect”:

Strain gauges (early 1990s, unsuccessful)

Vissumo:

“Beam-mounted” sensors (ran out of money in 2009)

F-Origin:

“Monofilament-mounted” sensors (nothing left except IP)

Size range

5”-48”

Touch area

FrameSlot (4)Force sensor (4)

(Vissumo’s design)

224

Force Sensing…2

Advantages

Complete substrate design freedom – no other touch technology can handle three-dimensional substrates with embedded moving objects

Disadvantages

No vibration under 10 Hz; no rapid-fire touches (>200 ms required between touches); no multi-touch

Applications

3D architectural applications

Market share

Zero (F-Origin’s undisclosed design)Source: Vissumo

225

Force Sensing…3

Market trends

Vissumo’s “architectural” focus (e.g., a 3D elevator control panel made of steel, glass & stone containing an embedded LCD with “soft keys” and a speaker) was strongly differentiated with some unique capabilities

226

Force Sensing…4

Vissumo’s Amazing Demo Box

Irregularly shaped, raised, textured, wooden touch surface

Glass-covered LCD integrated into touch panel with “soft keys” printed on back of glass

Raised, marbletouch surface with toggle switchespenetratingtouch panel

Multi-page “book” withtouchable & movable metal pages

“Snap-dome” keys attached to touch panel; removable padded andtextured keys; speaker attached with holes through the touch panel.

Motor attached toand penetratingtouch panel withprinted speedcontrol keys andpush-pull controllever

4 strain gaugessupporting one

touch panel

227

Vision- Based

Source: Perceptive Pixel

228

Vision-Based…1

Source: Perceptive Pixel

Multiple touch points; Image taken without a diffuser

(Source: Perceptive Pixel)

Principle (simplest version)

Frustrated Total Internal Reflection (FTIR)

229

Vision-Based…2

MicrosoftSurface

1 – Screen with diffuser2 –

IR LED light source3 – Four IR cameras4 – DLP projector5 – Vista desktop

Projector resolution 1024x768-------------

Touch resolution1280x960

Source: Popular Mechanics

“Surface computing is about integrating the physical and virtual worlds through the use of vision-based touch”

Source: Information Display

230

Vision-Based…3

Variations

IR injected into the cover glass; touch points seen via FTIR

IR illuminates underside of cover glass; touch points reflect IR

Size range

As described, 30” and up

Substrates

Glass or acrylic

Advantages

Combination touch-screen and rear-projection screen

Alternative to IR and projected-capacitive for rear projection

Unlimited multi-touch (MS Surface spec is 52 touches max)

231

Vision-Based…4

Disadvantages

As described, for use with rear-projection only

Finger-only (FTIR) or IR-reflecting object (Surface)

Applications

Interactive “video walls”; digital signage; high-end retail

Market share

<< 1%

Suppliers

Microsoft (Surface)

Perceptive Pixel (Jeff Han’s famous videos)

GestureTek & others

“”Build Your Own Multi-Touch Surface Computer” – Maximum PC magazine (4/09)

Source: NORTDwww.maximumpc.com/print/5878

232

Vision-Based…5

Market event

The emergence of Microsoft’s Surface product as an actual, for-sale, shipping product rather than just a research platform

Market trends

Because a vision-based touch system can be assembled very easily, it’s the most common platform used for research

Interest in vision-based touch is rapidly increasing

Google “touch table” for one view of related activity

233

ComparingTouch

Technologies

234

Touch Technology vs. Screen Size

Touch Technology

Small 2" – 10"

Medium 10" – 30"

Large 30" – 150"

Analog Resistive High Medium X Multi-Touch Resistive High Low X Surface Capacitive Low High X Surface Acoustic Wave X High Medium Traditional Infrared Low High High Projected Capacitive High Medium Medium Optical X High High APR Medium High Low DST X X High Force Sensing Low Medium Low Waveguide Infrared High Low X Vision-Based X X High LCD In-Cell (Light) Medium Low X LCD In-Cell (Voltage) Medium Low X LCD In-Cell (Charge) Medium Low X LCD On-Cell (Charge) High Medium X

HighMedium

LowX (None)

Market

penetration

and/orapplicability

235

Touch Technology vs. Application

Touch Technologies Application

Example A

nalo

g R

esis

tive

Mul

ti-To

uch

Res

istiv

e

Surf

ace

Cap

aciti

ve

Proj

ecte

d C

apac

itive

SAW

Trad

ition

al IR

Wav

egui

de IR

Opt

ical

APR

DST

Forc

e Se

nsin

g

LCD

In-C

ell (

Ligh

t)

LCD

In-C

ell (

Volta

ge)

LCD

In-C

ell (

Cha

rge)

LCD

On-

Cel

l (C

harg

e)

Kiosk Point of Info (POI) Museum information O X O X O O X O O O X X X X X Kiosk Commerce Digital photo printing O X O O O X X X O O X X X X X Kiosk Ruggedized Gas pump X X O O O O X X X X O X X X X Point of Sale (POS) Restaurant; lottery O X O O O O X X O X O X X X X Office Automation Office monitor O X O X O X X X X X X X X X X Industrial Control Machine control O O O X O O X X X X O X X X X Medical Equipment Medical devices O X X O O X X X O X X X X X X Healthcare Patient info monitor O X X X O X X X O X X X X X X Military Fixed & Mobile Submarine console O X O X X O X X X X X X X X X Training & Conference Boardroom display O X X X O O X O X O X X X X X Legal Gaming Casino machine X X O X X X X X X X X X X X X Amusement Gaming Bar-top game X X O X O X X X O X X X X X X In-Vehicle GPS navigation O X X O X X O X X X X X X X X ATM Machine ATM machine X X O O O O X X X X X X X X X Mobile Device Smartphone O O X O X X O X O X O O O O O Appliance Refrigerator door O X X O X X X X O X X X X X X Architectural Elevator control X O X X X X X X X X O X X X X Consumer AiO & Monitor HP TouchSmart O X X X O X X O X X X X X X X Music Controller Jazz Mutant O O X O X X X X X X X X X X X Digital Signage Thru-window store X X X O O O X O O O X X X X X

236

13 Usability Characteristics

Touch Technologies Desirable Characteristic A

nalo

g R

esis

tive

Mul

ti-To

uch

Res

istiv

e

Surf

ace

Cap

aciti

ve

Proj

ecte

d C

apac

itive

SAW

Trad

ition

al IR

Wav

egui

de IR

Opt

ical

APR

DST

Forc

e Se

nsin

g

LCD

In-C

ell (

Ligh

t)

LCD

In-C

ell (

Volta

ge)

LCD

In-C

ell (

Cha

rge)

LCD

On-

Cel

l (C

harg

e)

Usability Touch with any object H H L L M H H H H H H M M M L No unintended touch H H H H H L L L H H H H H H H Multi-touch L H L H M M M M L L L H H H H Touch & hold H H H H H H H H L L H H H H H High durability L L M H H H H H H H H M L L H High sensitivity (light touch) M M H H M H H H M H L H H H H Fast response & drag M M H H M M H H M H L L H M M Stable calibration M H L H H H H H H H H H H H H Very smooth surface L L H M M M M M M M M M L L M No liquid crystal pooling H H H H H H H H H H H H L L H Resistant to contaminants H H M H L M L M H H H L L L H Works in rain, snow & ice H H L H L L L L L L H L L L H Works with scratches L L M H H H H H M H H L L L H

There is

237

13 Performance Characteristics


nalo

g R

esis

tive

Mul

ti-To

uch

Res

istiv

e

Surf

ace

Cap

aciti

ve

Proj

ecte

d C

apac

itive

SAW

Trad

ition

al IR

Wav

egui

de IR

Opt

ical

APR

DST

Forc

e Se

nsin

g

LCD

In-C

ell (

Ligh

t)

LCD

In-C

ell (

Volta

ge)

LCD

In-C

ell (

Cha

rge)

LCD

On-

Cel

l (C

harg

e)

Performance

High optical performance L L M M H H H H H H H H H H M High resolution H M H H M L H H M M L M H L H High linearity H H M M M M H M M M H H H H M High accuracy & repeatability H M M H H M H M M M H H H H H Low power consumption H H L M L L M M H L H H L M M Insensitive to vibration H H H H H H H H H M L H H H H Insensitive to EMI & RFI H H L L H H H H H H H L L L M Insensitive to ambient light H H H H H M H M H H H L H H H Insensitive to UV light L L H H H H H H H H H H M M H Touch-object size recognition L M L H L L H H L L L M H M H Measures Z-axis L L L M M L L L L L H L L L M Handwriting recognition H M L M L L M H L L L M H L M Works with bi-stable reflective H H L H L L M L H L L M L L H

no perfect

238

13 Integration Characteristics


nalo

g R

esis

tive

Mul

ti-To

uch

Res

istiv

e

Surf

ace

Cap

aciti

ve

Proj

ecte

d C

apac

itive

SAW

Trad

ition

al IR

Wav

egui

de IR

Opt

ical

APR

DST

Forc

e Se

nsin

g

LCD

In-C

ell (

Ligh

t)

LCD

In-C

ell (

Volta

ge)

LCD

In-C

ell (

Cha

rge)

LCD

On-

Cel

l (C

harg

e)

Integration

Substrate independence M M L H L H H H L L H L L L L Scalable M L M H M M L H H H H L L L L Easy integration H M L L M M M H L L M H H H H Flush surface (low profile) M M M H M L M L H H M H M M H Narrow border width H M M H L L M L H H M H H H H Thin and light H H L H L L M L L L L H H H H Easy to seal H H H H L M M L H H M M L L M Can be vandal-proofed L L M H H M M L H H H L L L L Works on curved surface M M L H L L L L L L H H L L H Can be laminated to LCD H H H H M M H H L L L H H H H HID (Plug & Play) interface L L L L L L L H L H L L L L L Simple controller H M L L L L M M M L H L H M M Controller chip available H H L H H L H L H L H L L L L

touch technology!

(Burma Shave)

239

Conclusions

Source: CG4TV

240

There Is No Perfect Touch Technology!

Technology Major Advantage

Major Flaw

Analog Resistive Low cost Low durability Analog Multi-Touch Resistive Multi-touch Connections Surface Capacitive Touch sensitivity High drift Projected Capacitive Multi-touch Finger-only Surface Acoustic Wave Durability Soft touch object Traditional Infrared Reliability High cost Waveguide Infrared Low cost Contamination Optical Scalability Profile height Acoustic Pulse Recognition Any touch-object No touch & hold Dispersive Signal Technology Any touch-object No touch & hold Force Sensing 3D substrate Vibration Vision-Based Multi-touch Rear projection LCD In-Cell (Light-Sensing) Integration Sensitivity LCD In-Cell (Voltage-Sensing) Integration Durability LCD In-Cell (Charge-Sensing) Integration Durability LCD On-Cell (Charge-Sensing) Integration Finger-only

241

A Prediction of Which Technologies Will Win in the Next Five Years

Application

Winning Technology

Runner-Up Technology

Automotive Analog Resistive Projected CapacitiveCasino Gaming Projected Capacitive Surface Capacitive Consumer AiOs and Monitors

Optical Projected Capacitive

Consumer Notebooks Projected Capacitive Analog Multi-Touch Resistive

Interactive Digital Signage

Optical Traditional Infrared

Kiosks Surface Acoustic Wave Surface Capacitive Mobile Devices Projected Capacitive Analog Resistive POS Terminals Analog Resistive Traditional Infrared

242

Thank You!

Geoff WalkerMarketing Evangelist & Industry GuruNextWindow7020 Koll Center Parkway, Suite 138Pleasanton, CA 945661-408-506-7556 (mobile)[email protected]

Abbie GreggPresidentAbbie Gregg, Inc.1130 East University Drive, Suite 105 Tempe, Arizona 85281 USA 480-446-8000 x107 [email protected]

243

Why There Are So Many TouchTechnologies


Appendix-1

244

Why Are There So Many Touch Technologies?

Proliferation of touch

Touch is an indirect measurement

There is no perfect touch technology

The drive for fundamental intellectual propertyVertical integration

Source: Gizmodo

245

Proliferation of Touch

Self-service reduces cost Displays everywhere at low cost Touch user interfaces are simpler Direct manipulation is easier Everything is shrinking Touch makes globalization easier Expectation of touch everywhere

246

Touch Is An Indirect Measurement

Touch Technology What’s Being Measured Resistive (all forms) & Embedded (voltage)

Voltage

Surface capacitive Current Surface acoustic wave Time delay Projected capacitive, Embedded (charge)

Change in capacitance

Optical & Infrared (all forms), Embedded (light) in high ambient

Absence of light

Embedded (light) in low ambient Presence of light Vision-based Image Acoustic Pulse Recognition (APR) & Dispersive Signal Technology (DST)

Bending waves

Force sensing Force

247

There Is No Perfect Touch Technology

Characteristic Resist. P-Cap APR AMR W-IR Embed.Stylus independence M L H M M L Multi-touch L H L H M H High durability L H H L H M High optical performance L M H L H H Flush surface M H H M M H Low power consumption H M H H M L Stable calibration L H H L H H Narrow borders M M H M M H Substrate independence M H M M H H Low cost H L M M M L Multiple suppliers H H L M L M

H

= High (Best) M

= Medium (OK) L

= Low (Worst)

248

The Drive For Fundamental Intellectual Property

The fundamental intellectual property (IP) on all four* of the traditional touch technologies has expired

New patents tend to be on enhancements

Companies trying to establish a sustainable competitive advantage

create new touch technologies

e.g., Touchco,SiMa Systems,

FlatFrog & others…

* Analog resistive, surface capacitive, SAW & IR

249

Vertical Integration

LCD embedded (in-cell) touch

When touch was insignificant, LCD manufacturers ignored it

Now that it has become more significant, LCD manufacturers want to embed it into their products (in-cell touch)

250

Electromagnetic Resonance

(EMR) Pen Digitizer

Source: Wacom

Appendix-2

251

EMR Pen Digitizer…1

Cordless penwithout battery

Sensor grid

Controllerchipset

LCD

many wires

5-8 wires

Serial/USB interfaceto host

Received RFTransmitted RF

LCTip

CMain

CSideSide

switc

h

Pen equivalent circuit

Pressure-sensitive capacitor (CTip )

Coil (L)

Sensor grid schematic

Source: Wacom

Source: Wacom

(10µ copper)

252


Variations

Sensor substrate (rigid FR4 vs. flexible 0.3 - 0.6 mm PET)

Pen diameter (3.5 mm “PDA pen” to 14 mm “executive” pen)

Size range

2” to 14”

Controllers

Proprietary

Advantages

Very high resolution (1,000 dpi)

Pen “hover” (mouseover = move cursor without clicking)

Sensor is behind LCD = high durability & no optical degradation

Batteryless, pressure-sensitive pen

2”

14”

Controller for 10.4”Source: Wacom

Single controller can run both pen digitizer & pro-cap finger touch

253

Disadvantages

Electronic pen = disables product if lost; relatively expensive

Difficult integration requires lots of shielding in mobile computer

Sensor can’t be integrated with some LCDs

Single-source = relatively high cost

Applications

Tablet PCs

Opaque desktop graphics tablets

Integrated tablet (pen) monitors

E-book readers

Smartphones… but zero traction

Market share

100% share in Tablet PCs

Failed challengers: FinePoint/InPlay, Aiptek, Acecad, KYE, Synaptics, UC-Logic, Wintime

Majority share in graphics tablets & tablet monitors


Wacom “Bamboo” Tablet

254


Suppliers

Wacom, Hanvon, Waltop, UC-Logic/Sunrex

Market trends

Microsoft significantly de-emphasized the pen in Windows 7, so Wacom is selling into Tablet PCs against a headwind

Pen in general is undergoing a lessening of importance

iPhone and many imitators

Tablet PCs still a niche

iPad… doesn’t have a pen!

E-book readers are a natural fit IF

annotation is important…

E-Ink 9.7” Prototype EMR Kit

255

Touch & Flexible

Displays

Source: Cambrios

Appendix-3

256

Touch Technologies & Flexible Displays

Touch Technology Applicability ReasonPro-Cap & On-Cell (Charge)

High Single flexible substrate; may need ITO replacement

Pen Digitizer High Flexible sensor behind displayIn-Cell (Light) High Involves only LCD backplaneAnalog & Digital Resistive

Medium Film-film construction; may need ITO replacement

Surface Capacitive Low Might be possible; may need ITO replacement

Surface Acoustic Wave (SAW) Low Unlikely due to need for

flexible reflectors In-Cell (Charge & Voltage) None Depends on frontplane-to-

backplane spacingBending Wave (APR & DST) None Requires rigid substrate

Force Sensing None Requires rigid substrateOptical None Light travels in a straight lineInfrared (All types) None Light travels in a straight lineVision-Based Optical None Rear-projection only

257

Examples of Flexible Touch…1

ASU-FDC: Pen substrate, Wacom pen digitizer; Epson display

controller also supports resistive touch, but it’s not implemented

in this particular prototype QUE/PlasticLogic: Flexible screen in a rigid device; flexible projected capacitive

258


AUO & SiPix: Potentially flexible pro-cap touchscreen on a

glass-substrate e-book reader (reflectivity 33% 27%)

Bridgestone: Flexible resistive?

(10.7”, 5.8 mm thick) (Same screen in Jinke A6

& A9 readers)

259


Concept shown by LG Display at SID 2009

2 sensors per 10x12 pixels (dpi = 174) What about touching a black object?

260

Appendix-4

ITOReplacement

Materials

Source: Asylum Research (800 nm scan of ITO)

261

ITO Replacements…1

Why replace ITO?

Brittle & inflexible

Highly reflective (IR = 2.6) & tinted yellow

Costly to pattern & needs high temperature processing

Relies on “environmentally questionable” Chinese zinc mines*

Replacement material objectives

Better in all of the above characteristics

Higher transmissivity & same resistivity

Solution processing (no vacuum sputtering)

Same or lower cost than ITO

Three main replacement candidates

Metal nano-wires

Carbon nanotubes

Conductive polymers* 63% of estimated 2007

production of indium

262


Metal nano-wires

Cambrios

Synthesis of inorganic material (e.g., silver) from soluble precursors, followed by assembly of the resulting materials into nanostructures

Cambrios has been coating rolls of PET with their material (“ClearOhm”) in a roll-to-roll production facility since early 2007

Cambrios is working with all the Japanese resistive suppliers, but has signed an exclusive agreement for pro-cap with Nissha

Others

Sigma Technologies, Nanoco, university research

Source: Nikkei Business Publications

263


C a m b rio s S a m p le T C F ilmA G / P E T / C lr H C / T C

5 0

5 5

6 0

6 5

7 0

7 5

8 0

8 5

9 0

9 5

3 8 0 4 3 0 4 8 0 5 3 0 5 8 0 6 3 0 6 8 0 7 3 0 7 8 0

W a v e le n g th , n m

Tran

smis

sion

, %

B a re F ilm u s e d fo r T C T C 2 5 0 o h m /s q IT O 2 8 0 o h m /s q

ITO Film

Cambrios Film

PET Substrate

Source: Cambrios

264


Carbon nanotubes

Unidym

Merged with Carbon Nanotubes Inc. (CDI) in 2007; IP leader

Targeting touch-screens first, then displays and photovoltaics

Not yet meeting transmissivity & resistivity targets

Eikos

Mostly funded through government contracts on conductive polymeric coatings and films (e.g., ESD film, EMI shield, etc.)

Good progress on transmissivity & resistivity but… no momentum

Others

Canatu, RQMP, DuPont

265


Conductive polymers (PEDOT/PSS)*

Fujitsu

The only commercialized replacement so far

First announced in 2003; first production in 2008

5X – 10X touch-screen lifetime

Roll-to-roll film manufacturing

BUT, conventional wisdom is that PEDOT has inferior transparency and degrades under UV…

Others

Agfa, Kent Displays, National Starch, university research

* poly(ethylene dioxythiophene) / poly(styrene sulfonate)

266


Realities

The indium supply is not really an issue

ITO used in LCDs is < 1% of cost (~$4 for a 40” display)

LCD makers are very reluctant to make changes in fabs

Touch-screens provide several good reasons to switch from ITO to an alternative, but the market is relatively small

500M cellphone touch-screens only need about $5M of ITO

Flexible displays are probably the biggest opportunity for ITO replacements, but there’s still no killer app

Conclusion

Replacing ITO is unlikely to be a quick activity

267

Sunlight Readability

of ResistiveTouchscreens

Appendix-5

268

Common Solutions For Sunlight Readability

Active enhancement

Boost the LCD backlight intensity to 1000+ nits

High power consumption

Thick, hot & heavy

Passive enhancement

Add brightness enhancement films

Limited to 2X increase in brightness (not enough)

Reduces the LCD’s viewing angle

Controlling reflections

Reflected light reduces contrast (that’s the real problem)

Controlling reflected light is the most effective solution

269

Touch-Screen Surface Reflections

8 - LCD Cell

9 - LCD Bottom Polarizer

10 - Backlight

7 - LCD Top Polarizer

6 - Glass

5 - Spacer Dots

4 - Air Gap

3 - ITO Coatings

2 - PET Film

S2

S1

S4

S3

S5

LCD

Touch Screen 1 - Hardcoat

Note: Drawing is not to scale!

S1 S2 S3 S4 S5 Total ReflectivityNo enhancement 4% 5% 5% 4% 2% 20% 5 AR coatings 0.5% 2.5% 1% 0.5% 0.5% 5%

270

Circular Polarizer Principal

Unpolarized Light

Linear-PolarizedLight (Horizontal)

Reflection

Right-CircularPolarized Light

Quarter-Wave Retardation Film

Left-CircularPolarized Light

ReflectingSurface

Linear Polarizer

Linear-PolarizedLight (Vertical)

Reflection is blocked

Principle:

Modify the polarization of reflected light so it can’t escape back through the polarizer

Combinationis Equivalentto a Circular

Polarizer

271

Touch-Screen Surface Reflections with Circular Polarizer

12 - LCD Cell13 - LCD Bottom Polarizer14 - Backlight

11 - LCD Top Polarizer10 -

Retardation Film

8 - Spacer Dots7 - Air Gap6 - ITO Coatings5 - COP Film

or Glass4 -

Retardation Film3 -

Linear Polarizer2 - PET Film1 - Hardcoat

S2

S1

S4

S3

S5

Equivalentto a Circular

Polarizer

LCD

Touch ScreenNote: Drawing is not to scale!

9 - Glass

S1 S2 S3 S4 S5 Total ReflectivityNo enhancement 4% 5% 5% 4% 2% 20% 5 AR coatings 0.5% 2.5% 1% 0.5% 0.5% 5% Circular polarizer+ 3 AR coatings

0.5% 0.1% 0.1% 0.5% 0.5% 1.7%

272

Touch-Screen Surface Reflections: The Ultimate Solution

11 - LCD Cell

12 - LCD Bottom Polarizer13 - Backlight

10 -

Retardation Film9 - Glass

8 - Spacer Dots7 - Air Gap6 - ITO Coatings

5 - COP Film or Glass4 - Retardation Film

3 -

LCD Top Polarizer

2 - PET Film

1 - Hardcoat &AR Coating

S2

S1

S4S3

S5

Equivalentto a Circular

Polarizer

LCD


S1 S2 S3 S4 S5 Total ReflectivityNo enhancement 4% 5% 5% 4% 2% 20% 5 AR coatings 0.5% 2.5% 1% 0.5% 0.5% 5% Circular polarizer + relocated retardation film + 1 AR coating

0.5% 0.1% 0.1% 0.1% 0.1% 0.9%

Reference:General Dynamics

Itronix DynaVuehttp://www.ruggedpcreview.com/ 3_technology_itronix_dynavue.html

273

1% Is Good Enough

Rule-of-thumb for approximating extrinsic contrastContrast Ratio (CR) = 1 + (Display Brightness / Reflected Light)

In 10,000 nits ambient light, 1% reflected light = 100 nits

With a 500-nit automotive display, CR = 6, which is good enough for acceptable sunlight readability

Contrast Ratio

LCD Outdoor Readability

1-2 Totally unreadable in sunlight 3-4 Adequately readable in shade; barely readable in sunlight

5.5-6 Military spec for minimum acceptable readability in sunlight10 Definitely readable in sunlight; looks good 15 Outstanding readability; looks great 20 Totally awesome; excellent readability; can’t improve

274

Surface Treatments

Anti-Glare (AG)

Changes specular reflections into diffuse reflections

Changes the form of reflected light but doesn’t reduce the amount

Formed by etching, abrasion or deposition

Without AG(clear reflection)

With AG(blurry reflection)

Anti-Smudge (AS)

Minimizes the effect of skin oils on the touch panel’s top surface

Hydrophobic coating; can be combined with AG

Anti-glare hardcoat

Light sourceReflectedlight

275

Surface Treatments…2

Anti-Newton’s Ring (ANR)

Prevents Newton’s rings from being formed by contact between the PET film and the glass substrate

Texture added underneath ITO coating on bottom of PET

Adds ~1/3 of the haze value of AG

Without ANR With ANR

276

What About Projected Capacitive?

S1 S2 S3 Total Reflectivity (Resistive)No enhancement 4% 5% 2% 11% 20% 3 AR coatings 0.5% 1% 0.5% 2% 5% Circular polarizer -- -- -- (N/A) 0.9% Optical bonding +one AR coating

0.5% 0% 0% 0.5% (N/A)

4 -

Dielectric (Insulator)

3 -

ITO Coatings

2 - GlassS1

S2

6 - LCD Cell

7 - LCD Bottom Polarizer

8 - Backlight

5 - LCD Top PolarizerS3

LCD


1 - Protective Film

277

Automotive Touch

Appendix-6

278

Automotive Applications Can Be Difficult!

Note: Focus here is the center-stack (CSE) “navi-radio” application Temperature

-30°C to +85°C operating

-40°C to +95°C storage

Light management

Sunlight readability

Relaxed requirement for rear-seat entertainment (RSE)

Crashworthiness

Top surface can’t be glass (DOT)

Cost

Especially important for dealer-installed vs. OEM-installed

Vibration

Cables & connectors

279

Automotive Applications Can Be Difficult…2

Industrial design

Narrow frame borders & flush surface Usability

Use with gloves Off-angle viewing

Polarizer used for sunlight viewability can be a problem

Optical bonding is still too expensive Flammability

Gaskets Humidity

Condensation freezing into ice crystals ISO quality requirements

Difficult for a small or inexperienced company to meet

280

2008 Automotive & Portable Navigation Device Touch-Screen Market Size 2008 automotive touch-screen sales (100% resistive)

Units = 15M (22% glass-glass, 78% film-glass)

4.6% of total resistive; 3.7% of total touch-screen market

Revenue = $110M


ASP = $7.37

2008 portable navigation device sales (100% resistive)

Units = 43M (99.7% film-glass)

12% of total resistive; 11% of total touch-screen market

Revenue = $155M


ASP = $3.62 Data from DisplaySearch 2009 “Touch-Panel Market Analysis”

This average selling price (ASP) should be about 2X-3X higher; DisplaySearch’s revenue estimate is probably incorrect.

This ASP is about right for a 3” to 4” touch screen on an aftermarket device ($1/inch).

281

Automotive & Portable Navigation Device Touch-Screen Forecast

Data from DisplaySearch 2009 “Touch-Panel Market Analysis”

Unit Forecast 2009-2015

DisplaySearch forecasts that Automotive remains 100% resistive through 2015, and Portable is only 1% projected capacitive in 2015

0

10

20

30

40

50

60

70

2008 2009 2010 2011 2012 2013 2014 2015

Uni

ts (M

illio

n)

PortableAutomotive

26%

74%

45%

55%

282

Appendix-7

Touch Screen Manufacturing

283

Touch Screen Manufacturing How Factory and Cost Modeling Can Help• Keep track of tools and equipment, and associated parameters

including throughput, depreciation and maintenance costs, and required personnel

• Separate material handling from process costs, space & throughput• Keep track of recipes separately from tools to allow mix and match

scenarios and change in process flows• Keep track of material usage and cost- optimize device size and

configuration to eliminate costly raw material waste• Be able to vary minor elements and see throughput, cycle time and

yield responses • Obtain costs per square foot or cost per device• Compare roll to roll and sheet based costs, space, headcount, tool

sets• Determine where wind/unwind stations should be located, based on

throughput matching• Determine impact of design rules and additional devices or layers –

e.g., for in-cell touch

284

Flex Electronics Models Printed Ink Process

285

Flex Electronics Models Sputter Laser Process

286

Flex Electronics Models (Typical)

287

Cost Drivers In Flex Displays and Electronics1. Two areas emerged as key cost drivers:

1.

Materials2.

Product packing density2. Automation and substrate processing speed has

improved. 3. Devices are being scaled up to narrow webs and larger

flex sheets to conform with the value proposition for the particular device.

1. Less than 2 foot webs, narrow webs2. Web on web or Flex piece on web3. Flex on glass

288

Cost Drivers In Flex Displays and ElectronicsProduct packing density1- High device packing density is needed to achieve low

cost2- Product engineering must account for

A- Alignment tolerances of multilayer devicesB- Processing tolerances of line-width

3- Design rules for new flex devices in all applications are still evolving

4- Mechanical and process engineers must work together and create test patterns and metrics for new device types

289

Cost Reduction

• Traditional printers are seeking new markets and have valuable equipment and process skills

• Seek capital equipment and materials suppliers from “least cost industry”

• Impact of ubiquitous RFID

will be that roll-to-roll electronic products will develop low cost techniques - reducing 10x in next 5 years

• Convergence with consumer applications and pricing such as clothing, skin patches, blankets, cell phones, books/ebooks

290

Manufacturing Scale-Up Planning

• Sheet to roll transition –

THE BIG STEP• Don’t change too many things at once

– Product size– Product complexity (minimum geometry, registration, number of layers)– Sheet size to roll size– Tool/equipment type– Process method– Facility conditions: temperature, relative humidity

• Be sure your material handling and tool suppliers understand the product geometry and cleanliness required

• Do a rigorous layout to be sure equipment and support equipment will fit and be accessible for maintenance

• Match rates throughout the system based on number of passes - use a mathematical model

291

Baseline Existing Processing

• Process parameter optimization and control• List each process

– Don’t skip even the most “trivial” step– List off-line support steps (premixing of inks, pre cut of laminated

materials, etc.)• List associated tools and equipment• List critical parameters

– Pareto the most critical parameters for each step - work on top 3– Include

• Observations of products - metrology tools and criteria• Environmental conditions• Settings on equipment• Expected defects and faults

• Know statistical validity of settings and metrics– How many have actually been produced with a given recipe?

5, 50, 500,

5000– How consistent were results? Yield (good product)?

292

Touch Screen Manufacturing Uses PC Board Handling• 18” x 24” is standard flexible circuit board size, lots of

equipment is available in this format.

293

Vision of the Roll-to-Roll Line

• Clean• Automated• High yield

Materials

Facility

Tools

294

Baseline Existing Materials

• Materials Control• The product will never be better than the materials you start with• Know your vendors

– Who supplies them?– What percentage of their volume does your product represent? Now? In a year?– Can they ramp fast?– Does your product push the statistical control of their product specification? Do the

distribution of requirements overlap? Is there a guard band?– Have a relationship with at least 2 suppliers for each critical material

• Keep looking, don’t give up • What new features in the materials would make your next steps easier?

How can you evaluate these NOW?• Can you and are you identifying lots, batches of material? • Do you understand how your suppliers manufacture and qualify their lots? • How do you plan to qualify /trace materials in your line?

Risks of multiple simultaneous qualifications are multiplicative if not exponential!

Mass markets tolerate few glitches in supply!

295

Baseline Existing Processing

• Device tolerances• Define critical parameters

– Establish a realistic tolerance for each– Add up cumulative tolerances - draw out and review any

cumulative mechanical tolerances– Plan for iterative product design– Create guard bands for all critical tolerances and most

secondary tolerances

• Define tolerances for each tool/equipment• Verify that cumulative tolerances match: Device to

equipment• Registration Registration

Registration

296

Make Alignment Keys with Metrology

1st

Layer:Initial Pattern

2nd

Layer:Perfect!

3rd

Layer:Misaligned

Image enhanced to show misalignment.

297

Importance of Design Rules in Creating Manufacturable Products

298

Importance of Design Rules in Creating Manufacturable Products• For cost reduction, reexamine design rules to see where

more efficient use of substrate gives more product per substrate

• Caveat: Experiment to understand tolerances FIRST! For flexible substrates, registration tolerance is key. High- density product layout beyond registration tolerances will be very low to 0 yield.

• Iterative Process: Each version of tooling should have test patterns to help determine future improvements in registration and packing density

299

What is Critical in Device Design Rules? Optical Waveguide Touch Example

Area A Gap B Area C

Location 3

Location 2

Location 1

Are any of these critical?

Distance from1 to 2

Distance from 2 to 3

Distance from 1 to 3

Are any of these critical?Width of Area A or Area C?Width of Gap B?

What do you call?Area A or C?Gap B?

300

Process and Tool Evaluation: What Defect Density Is Tolerable? What Is a Defect?

Vendor 1 Vendor 2 Vendor 3

• Measure defects on good and bad product

• Keep inspection data• Try out different types of

inspection equipment

301

Testing Equipment –

Often Overlooked Is This Test Setup Ready for Scale Up?

• Common problems– No fixed test-beds– No “golden unit”– Lack of data storage– Lack of trend analysis

302

What Kind of Facility Space is Needed?

• Clean Class– Class 10; 100; 1,000; 10,000; 100,000– Most Costly Decision

• Impacts– Air Changes and Treatment– Quantity Filters– Quality of Filters (ULPA vs. HEPA)– Types of Construction Materials– Cost of Ownership

– Understanding the Process and Geometries will help in selecting the appropriate clean class

– Providing the right combination of clean class by area can satisfy user needs and reduce costs.

Photo BayClass 100

Thin FilmsClass 1,000

303

Cost Drivers

• Height– Height affects volume of clean space

• Volume impacts how much air has to be treated and recirculated– Keeping ceiling heights to a minimum can be a cost savings– Requirement for air handling space above ceiling must be

considered– Process tools get taller with larger substrates

304

Cost Drivers

• Single Pass Air– Very Costly– Conditions air once and sends to exhaust– Does not take advantage of recirculation of conditioned air– Some spaces may require single pass air by code

• Humidity Control– Humidity affects process and equipment

• Understand what levels are damaging to the process• Understand what tools are sensitive to humidity

– Local climate may drive the need to add or remove humidity– Some climates may not require any humidity control

305

Cost Drivers

• Use of Hazardous Productions Materials (HPM)– Quantities directly affect hazardous occupancy rating

• “H” Occupancy vs “B” Occupancy• Exceeding maximum allowable quantities can force the space to

become an “H” Occupancy• Drives Construction Materials Cost

• Use of flammables such as Acetone (Class 1B) can drive higher Hazard Occupancy

306

How Clean Does My Cleanroom Need To Be? Know the Expensive Answers

Clean Room Cost Assumptions$/Sq Ft Class Add for

Raised FloorAdd for Subfab

$2,100 1 Required Required

$1,425 10 Required $600

$1,205 100 ~$160 $600

$900 1,000 ~$100 $400

$700 10,000 Not Needed Not Needed

$75 Support(Facilities)

N/A N/A

Cost does not

include specialty piping or tool hookup

307

Low Sidewall Return

• Least expensive option because it doesn’t require a raised floor

• Least flexible because space must be left in the wall for air flow

• Higher pressure drop across smaller wall openings requires more fan energy

• Limits width of bay to 12’ – 14’ for good laminarity of air flow

308

Lay Out Space for Maintainability

• Think about maintainability when linking several processes in a roll to roll line

Lamination Process Station

309

Use Vertical Space Wisely

• Multilevel roll-to-roll lines are common

• Cleanliness and maintenance need to be planned

310

Touch-Screen Line Costs

• Line price and product price expectations similar to printing industry

• Key process steps differ • Collaboration is productive

311

Technology Improvement Recent Accomplishments

• Web handling control and alignment of patterns and layers

• Improved cameras and optics for in-line data collection and immediate response alignment of web

• Improved web handling mechanisms• Temperature and RH controlled

environments

312

Technology Improvement Recent Accomplishments that Benefit New Applications

• Sophisticated inks, fluids and gels with both electronic and physical properties

– Inks with electronic properties– Gels with various methods of cure to seal temporarily,

permanently– Viscosity control of inks and gels by temperature and

RH control– Transparent organic conductors and semiconductors

• Substrates and surfaces with engineered properties to facilitate product design or process.

– Temperature “hardened” to minimize shrinkage– Impregnated with Aluminum Oxides for

translucency/opacity– Polished surfaces to reduce defects– Moisture barrier coatings– Punched, laser drilled and formed surface cavities

• Inlays for small “semi flexible”

applications– Credit cards with chip/display/battery/interconnect

313

AGI Modeling Suite and Services

Visit www.abbiegregg.com

for software demos.

And visit AGI at Booth 2406 in the South Hall

to learn more about our services and expertise.

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