Flexible, Hybrid Electronics by Micro-Transfer-Printing

Christopher A. Bower, X-Celeprint

Micro Assembly Unlocks New Opportunities

for Wafer Fabricated Devices

“Micro-Transfer Printing” (µTP)

The promise of high-performance devices

anywhereWafer Fabricated Devices

Single-crystal

Fine lithography

(ICs, LEDs, Lasers, etc…)

Plastic, Glass, Ceramic, Paper

Other semiconductors

Rapid, Precise Microdevice Assembly via Printing

1. Form undercut microdevices, anchored at endpoints

2. Transfer them to a target substrate by elastomer stamp printing

3. Interconnect to form systems

Rate Dependent Adhesion

slow lift-off fast lift-off

> 10 cm/sec

Nature Materials, 5, 33 (2006)

“The adhesion between the solid objects and the stamp is rate-sensitive owing to the viscoelastic behavior of the elastomer”

“if you place the stamp on the layer of chips and peel it off quickly the chips adhere to the stamp.

Impress the stamp on the target substrate and peel it off slowly, the chips adhere to the target.” Ken Werner [http://www.displaydaily.com/display-daily/28030-the-only-disruptive-technology-at-display-week]

Precise dispersal of devices from dense arrays

Populated Stamp

Non-native “Target” Substrate

1st transfer 2nd transfer

Densely packed micro componentsDispersed micro components

Source Wafer

Printing

Patterned stamp

Precise dispersal of microscale LEDs

Stamp Fabrication

7

Silicon Master Low-Pressure Injection Molding Elastomer Stamp

Stage (x, y)

Print Head (z, θ, Tx, Ty)

Optics (x, y, z)

Automated Micro Transfer Printing

Semprius Factory, Henderson, NCRTP, NC

Semprius, Durham, NC

stamp + motion + optics

1. pick-

up,

2. print,

3. clean.

[repeat]

Tyndall National Institute, IrelandR&D Printer, imec, Ghent, Belgium

Examples of Printed LEDs

µLED Displays

10

100 µm

1 cm

0.2 mm

SID 2016

• 128RGB x 128 PMILED Display

• > 98,000 interconnections

Science 325, 977 (2009).

Plastic Display with Printed Inorganic LEDs

Active Matrix Display with Printed iLEDs and µICs

Two 180nm ASICs (> 400T)

Semi-additive Copper RDLSID 2016

Summary and Acknowledgements

Releasable high-performance microscale devices (LEDs, ICs, etc…)

+

High speed, room temperature, deterministic assembly

+

Interconnection methods compatible with plastic substrates

= a coherent technology approach to high performance plastic electronics

Thanks to the X-Celeprint team.

Thanks to the John Rogers lab at University of Illinois – Urbana-Champaign

Thanks to the technical staff at Semprius, RTI Int’l, and Tyndall Nat. Inst.

Micro Assembly Unlocks New Opportunities

for Wafer Fabricated Devices

“Micro-Transfer Printing” (µTP)

The promise of high-performance devices

anywhereWafer Fabricated Devices

Single-crystal

Fine lithography

(ICs, LEDs, Lasers, etc…)

Plastic, Glass, Ceramic, Paper

Other semiconductors