Peter Dyreklev Acreo AB

CLIP WORKSHOP 27 NOVEMBER

2012

www.acreo.se

ACREO • Swedish research Institute • R&D

Broadband Technology Fiber Optics Nanoelectronics Printed Electronics Sensor Systems

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PRINTED ELECTRONICS TO MEET CHALLENGES

• Motivation

• Strategy

• Technology

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PEA A THIRD OF ALL FOOD THAT IS PRODUCED IS NEVER EATEN….

• In total 1 billion tons per year is wasted! • Huge amount of green house gases is released to no use! • In industrialized countries a great part is wasted by consumers!

From the report “Global food losses and food waste” (May 2011)

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MORE THAN 30% OF ALL MEDICINES ARE FAKE ACCORDING TO WHO….

Black Market Product Rankings : 1.Counterfeit Drugs$200 Billion 3.Counterfeit Electronics$169 Billion 4.Marijuana$141.80 Billion 12.Counterfeit Foods$49 Billion 13.Counterfeit Auto Parts $45 Billion 14.Counterfeit Toys$34 Billion 25.Counterfeit Clothing$12 Billion 34.Counterfeit Cosmetics$3.0 Billion 36.Counterfeit Aircraft Parts $2 Billion 40.Fake Diplomas and Degrees$1 Billion 44.Counterfeit Pesticides $735 Million 46.Counterfeit Money $ $182 Million 48.Counterfeit IDs and Passports $100 Million

Losses to Counterfeit Goods by Country: 1.United States$225 Billion 2.Mexico$75 Billion 3.Japan$75 Billion 4.China$60 Billion

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WEE NEED SOLUTIONS FOR BETTER USE OF OUR LIMITED RESOURCES!

We need solutions for increased security!

We need solutions for moving health care to home environment!

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Transistors Diodes Displays Interconnects/ Antennas

Printed components developed by Acreo

• Making components Displays Transistors Diodes Sensors Antennas

• Integration into printed systems • Hybrid solutions with Si-chips

Printed electronics offer a possibility to meet these challenges

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PRINTING FOR FUNCTIONALITY What is required for functional materials in general

• High resolution (better than 200 µm line width and space) • Good registration (better than 50 µm registration accuracy

between layers) • Sharp line edges • Small variations in printed height • No pin holes • Thickness control • Low surface roughness • Suitable surface energy depending on type of ink • Not all printing technologies are amenable

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PRINTED ELECTRONICS REQUIREMENTS – ELECTRICAL PROPERTIES

Rs = 100 mΩ/sq and thickness 5 µm corresponds to 3% of bulk conductivity value

Resistance

Conductor Width/length

Sheet resistance

Antenna Rs < 100 mΩ/sq Interconnects Rs ~ 1-100 Ω/sq

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HOW TO ACHIEVE THE CONDUCTOR?

Bulk metals ~mΩ/sq for ~10 um thickness Carbon paste 10-100 Ω/sq for ~10 um thickness Conducting polymers 10-100 Ω/sq for ~10 um thickness

Metal ink is needed

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DIFFERENT OPTIONS FOR METAL INK

Organometallic precursor

Flakes

Microparticles Nanoparticles

Screen printing

Flexo printing

Thermal curing

Photo curing

Ink type Inkjet Screen Flexo Thermal curing

Photo curing

Flakes (~5-10µm) No Yes No Yes No

Microparticle (~1-5µm) No Yes Yes Yes No

Nanoparticles (<0.1µm) Yes Yes ? Yes Yes

Precursor (solution) Yes ? ? Yes No

Inkjet printing

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CHALLENGES FOR PRINTING OF CONDUCTORS

Does not tolerate Small register errors Breaks in narrow lines Uneven surface covering Rough substrates

Some existing printing technologies are not easily used

Continuous lines Spaces without short circuit Step coverage

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LINE/SPACE INTEGRITY

Different printing methods offer various line/space performance.

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LINE/SPACE INTEGRITY

200x500 500x200

Design file

Printed result

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LINE/SPACE INTEGRITY

100x500

Design file

Printed result

500x100

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STEP COVERAGE Large topography Bad step coverage

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COMMERCIAL EXAMPLES SCREEN INKS

17

Company Ink name Ink type Curing temp/time Curing technology

resistivity [µΩ.cm] % bulk

Novacentrix Metalon HPS-021 Ag-flake 150C/30 min hot air /photonic 5 30%

TOYO-ink REXALPHA RA FS 005 Ag binder hot air 20 8% TOYO-ink REXHALPHA Radiation cure Ag binder UV 50 3% Johnson Matthey S-50 Ag binder 120/20min hot air 25 6% SUN 26-8204 (T39) Ag binder 120C/20 min hot air 30 5% SUN CRSN2442 (T246) Ag binder 150C/30min hot air 25 6% Dupont 5000 Ag binder 140C/1-1,5 min hot air 38 4%

Dupont copper ink CB200 micro copper binder 160C/30min hot air 50 3%

IIMAK Metallograph IIMAK IINK-SSC Ag coated Cu flakes (<10% Ag) 2-7 min/70 C hot air 93 2%

Advanced Nano products DGP Ag nano 120-150 C hot air 10 16% Agfa-Gevaert Agfa silver ink Ag nano 150 C/30 min hot air 5 29% IIMAK Metallograph IIMAK IINK-SSX Ag nano 2-7 min/70 C hot air 29 5%

PCHEM PSI-211 Conductive Screen Ink Ag-nano WB 140 C/15-90 sec hot air 9 18%

Ink-Tec TEC-PA-010 Ag hybrid 120-170/2-5min hot air 6 27% Novacentrix Metalon ICI-021 nano CuO Photonic Intrinsic Materials Intrinsic CP-001 Cu nano Photonic 8 20%

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COMMERCIAL EXAMPLES FLEXO INKS

18

Company Ink name Ink type Curing temp/time Curing technology

resistivity [µΩ.cm] % bulk

Novacentrix Metalon HPS-021 Ag-flake 150C/30 min hot air /photonic 5 30%

TOYO-ink REXALPHA RA FS 005 Ag binder hot air 20 8% TOYO-ink REXHALPHA Radiation cure Ag binder UV 50 3%

Few conductive inks for Flexoprinting

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PROCESSING CHALLENGES • Printing conductive inks is possible in standard printing equipment • A range of conductive inks are available • Drying and curing to get the low sheet resistance is crucial • Thermal curing possible

• Requires usually higher T than used in printing industry • Long drying/curing times gives low production speed

Even drying time 2 min Long ovens at reasonable speeds • Photonic curing is required for short curing time

• Requires more expensive inks – nano particles • Photonic Curing allows short curing time (~ms) High printing speed

Low cost ink necessary!

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PRINTING COST Example: RFID antenna, 12,7 cm2 Screen printing 10 m/min Ag-nano ink (thermal cured) Total production cost 0,153 €/pc Ink cost only 0,137 €/pc Limited cost reduction from increased production speed or machine costs Cu nano / micro ink (photonic curing) Total production cost 0,101 €/pc Ink cost only 0,085 €/pc Large saving (~33%) possible from ink costs CLIP approach!

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SUMMARY • Conductive printing possible with existing screen and flexo printing

tools • Drying and curing need to be addressed • Ink costs can be very high to get the lowest sheet resistance • Design of pattern to be printed is crucial for the end result • Range of applications can be widened with low cost inks

• CLIP gives a combination of low cost inks and higher production

speed

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