Presentation is loading. Please wait.

Presentation is loading. Please wait.

Phic t Roll-to-Roll Manufacturing of Flexible Displays Carl Taussig, Bob Cobene, Rich Elder, Warren Jackson, Mehrban Jam, Albert Jeans, Hao Luo, Ping Mei,

Similar presentations


Presentation on theme: "Phic t Roll-to-Roll Manufacturing of Flexible Displays Carl Taussig, Bob Cobene, Rich Elder, Warren Jackson, Mehrban Jam, Albert Jeans, Hao Luo, Ping Mei,"— Presentation transcript:

1 phic t Roll-to-Roll Manufacturing of Flexible Displays Carl Taussig, Bob Cobene, Rich Elder, Warren Jackson, Mehrban Jam, Albert Jeans, Hao Luo, Ping Mei, Craig Perlov, Hewlett-Packard Company, Palo Alto, CA Frank Jeffrey, Marcia Almanza-Workman, Kelly Beacom, Steve Braymen, Bob Garcia, Jason Hauschildt, Han-Jun Kim, Ohseung Kwon, Don Larson, Phicot Inc, Ames, IA

2 phic t Introduction Why we need paper-like displays Self-Aligned Imprint Lithography (SAIL) Benefits and challenges of roll-to-roll (R2R) manufacturing SAIL basics green manufacturing for green products toolset for 1/3m wide line worlds first R2R active matrix displays Outline

3 phic t Sustainability Millions of tons/year US Paper & board disposal, 2005 US EPA 1 / 3 waste is paper… of which 43% is print 36m tons/yr Newspapers 12 Commercial print 7.35 Office 6.6 Magazines 2.5 Books 1.15 Packaging & other 47.7 Standard mail 5.8 Directories 0.65

4 phic t Macro-Trends Are Helping to Drive Electronic Paper Clean TechnologyMobile Internet Printed ElectronicsDigital Media *courtesy of Mike McCreary, E Ink

5 phic t Electronic Publishing is a Multi-$B Addressable Market $100B- $300B annual publishing industry today, about the same as the whole current display industry* Mobile electronic books have not previously succeeded because they lacked the attributes of paper: low cost, outdoor readability, light weight (low power), &mechanical toughness. A library in your hands *courtesy of Mike McCreary, E Ink

6 phic t Newspapers Need an Alternative to Paper Paper newspaper subscriptions are dropping sharply –12 hour delay in receiving news –newest generations of people are on-line much more –increased sensitivity to ecology issues Newspaper profitability is under pressure as a result –increasing energy costs –On-line subscriptions are growing but it takes on-line subscribers to make up for one lost paper subscription* Digital distribution enables personalization –Geographic localization enhanced –Individually targeted content and advertising A paper-like reader appliance is needed –Low cost, portable, daylight readable, mechanically tough *courtesy of Mike McCreary, E Ink

7 phic t Paper Newspapers and the Environment 1/5 ton per subscription per year OIL *courtesy of Mike McCreary, E Ink

8 phic t Economic Reasons to Move From Paper Newspapers Composite Newspaper Business Profile* *Published by Bill Richards (former NY Times and Washington Post reporter) 100,000 Circulation $83.9M Revenue $72.1M Total Cost ~10% Profit Newspapers could eliminate $27M (~38%) from its variable budget by moving away from printed newspapers But it will be critical to keep subscriptions and advertising rates high with electronic newspapers *courtesy of Mike McCreary, E Ink

9 phic t Introduction Why we need paper-like displays Self-Aligned Imprint Lithography (SAIL) Benefits and challenges of roll-to-roll (R2R) manufacturing SAIL basics green manufacturing for green products toolset for 1/3m wide line worlds first R2R active matrix displays Outline

10 phic t Challenges & Benefits of R2R Electronics Fabrication BenefitsChallenges Lower substrate costLower process temperature Steady state processing: high-throughput, high-yield Defect repair Lower cleanroom requirementspatterning Cheaper equipment - better scaling? Limited equipment available – no previous generation

11 phic t Photolithography Imprint lithography InkjetPhysical mask Laser ablation Throughput Moderate: limited by step & repeat / stitching High: > 5 meters/min LowLimited only by deposition Low Resolution Limited by substrate flatness ~10μ 100nm demonstrated >10μ10μ -100μ~10μ Alignment Limited by substrate flatness ~10μ Self alignment possible External sensor required poor~10μ Issues Scaling to large areas costly New technology Materials must be jettable Cleaning, particles Thermal effects, selectivity Imprint Lithography is the Best Choice for R2R Patterning

12 phic t a R2R Process for Manufacturing Active Matrix Backplanes Based on Plasma Processing and Self-Aligned Imprint Lithography Vacuum deposition of metals, dielectrics, & semiconductors 5μ5μ Multiple mask levels imprinted as single 3D structure Patterning completed w/ wet & dry processes deposition imprint etch deposit spin resist align/expose develop strip/clean etch deposit etch imprint etch mask Conventional Photo-Lith SAIL

13 phic t Iowa Thin Film Technologies is now PowerFilm Solar

14 phic t Basic Imprint Lithography Process ~40nm lines on 50μ polyimide Multilevel structures on flex at 5m/min Pixel speed depends linearly on mobility but inversely with the square of channel length 6: etch 5: release 3: emboss 4: cure with UV 1: coated substrate 2: coat with polymer 1μm1μm 4 levels in 0.5 μ step heights 20 m

15 phic t SAIL encodes multiple patterns and alignments into thickness modulations of a monolithic masking structure SAIL: Self-Aligned Imprint Lithography Photolithography SAIL Multiple masking and alignment steps required Different mask used to pattern each layer Single mask used to pattern all the layers multiple times Process induced distortion of 200ppm results in 20μ misalignment over 10cm No misalignment because mask distorts with substrate

16 phic t Imprint mask on TFT stack consisting of Top metal Contact layer (optional) Semiconductor Dielectric Bottom metal Process produces complete backplane: TFT Pixel electrode Data line Crossover Gate line Etch exposed stack all the way to the substrate undercutting the bottom metal in the thin regions to isolate the gate lines and the TFTs Etch the polymer down to expose the layers covering the gate lines Etch through top metal and (optionally) other layers to form crossovers Etch polymer a second time to expose area covering TFT channel Etch top metal and contact layer to define TFT channel Remove remaining polymer to expose completed backplane Disassemble array one layer at a time to expose structure. Begin by removing top metal Next remove contact layer to expose channel semiconductor Then remove semiconductor to expose gate dielectric Finally remove gate dielectric to expose gate lines that were isolated by the undercut SAIL backplane: patterning process flow

17 phic t SAIL solves alignment problem & saves money cost per ft 2 Cost of Patterning Backplane materials costs for R2R photolith & SAIL R2R SAIL R2R photolith (AGI) Multiple photoresist applications dominate photolithography process materials costs

18 phic t Green manufacturing for a green product Less is better: 50μm thick plastic vs. 0.7mm thick glass Less process materials: removal of photolith reduces process consumables Energy costs: –transients involved in batch consume energy; steady state is more efficient –Reduced clean room requirements: Smaller equipment footprint

19 phic t HEPA filter The web rolled on the core is its own clean room Ambient Process Vacuum Process

20 phic t 330mm imprint system Gen10 cluster tool Equipment footprint comparison between R2R and flat panel

21 phic t Patterning scaling: R2R imprinter compared to panel stepper comparison made at equal throughput Scaling similar for R2R and panel; cost much lower for R2R

22 phic t PECVD Scaling: R2R photovoltaic compared to panel comparison made at equal throughput Again; scaling similar for R2R and panel; cost much lower for R2R

23 phic t is shown as a function L in Figure Performance of Full-SAIL a-Si TFTs Full SAIL TFTs with thinner dielectrics have greatly improved performance on-off ratio > μA on-current mobility from linear portion of transfer curve as high as 0.8 cm 2 /V/S near linear scaling of I on vs 1/L to L~2μm Channel Length [μm] Mobility [cm 2 /V/S] 1.E 0 1.E-3 1.E-2 1.E-1 1.E 0 1.E 1 1.E 2

24 phic t Initial display demonstrators SAIL Backplane on flexible substrate Worlds first active matrix display made exclusively with R2R processes (including E Ink Front Plane)

25 phic t Yield Improvements: Pareto process at work Process flow Process StepSeverity Thin film deposition Shunt defects 1/mm 2 Stress control unstable Particle generation low ImprintingMaster defects low Stamp defects med Imprint process low EtchingEndpoint control med Process design med Device testContact liquefaction low Probing errors/damage low A bubble defect, voids are formed by insufficient volume of photopolymer to fill mold A crack defect typically results from imbalanced deposition stress Nonuniform imprinting results in premature mask erosion and feature loss Tenting defect formed by particle between stamp and substrate at imprinting time or by void in stamp pinhole defect in metal caused by etchant diffusing through pinhole in oxide Bridging caused by breakage of imprint stamp in narrow (~2u) regions

26 R2R tool development production solar cell deposition 4 imprinter 13 RIE 13 imprinter 13 wet etcher 10 drum PECVD

27 phic t Next steps towards commercialization September 22, 2008 PowerFilm announced that it has taken a license to the SAIL technology October 6 th, 2008 PowerFilm announced it has won a $1.4M / year cooperative agreement from the U.S. Army for development of a 'self powered flexible display'. HP Labs and PowerFilm will collaborate on the contract. PowerFilm Solar has created Phicot as a subsidiary to commercialize the technology

28 phic t Acknowledgements The authors gratefully acknowledge the support of their collaborators and sponsors -- FlexTech Alliance - contract RFP04-112F ARL contract W911NF E Ink Corporation ASU Flexible Display Center


Download ppt "Phic t Roll-to-Roll Manufacturing of Flexible Displays Carl Taussig, Bob Cobene, Rich Elder, Warren Jackson, Mehrban Jam, Albert Jeans, Hao Luo, Ping Mei,"

Similar presentations


Ads by Google