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Electronics Miniaturization using Fine-Feature

Nanosilver conductors

Fine feature (<10 microns) trace/space capability

• Maximum component density• Fully encapsulated silver conductors• Quick, inexpensive prototyping

Encapsulated component blocks• Rugged/robust• Minimize dead volume• Easy test of subsystems

Low Capital Equipment Costs

2

Nano-silver conductor fabrication

1. 1st Squeegee Fill 2. Low T bake

3. 2nd Squeegee Fill5. Full oven cure

4. Residue removal

Finished circuit

Conductor resistivity ~ 3X bulk Ag

Laser ablate channels

Pulsed UV laser

3

Embedded nanoparticle silver conductors

• Nanoparticle conductor advantages:– Eliminate photolithography

– Conductor width limited only by laser focal spot size.

• <10 micron trace/space demonstrated

• Controllable aspect ratio

– Additive, green process

Embedded conductor Conventional conductor

Substrates:

• 15 micron traces• Two sides with via

• ABF

• LCP

• MicroLam

• Mylar

• Alumina

Polyimide

Stretchable conductors

Embedded conductor

Polyimide

6

Quasi-conformal circuitry

MCUSensor

Stretchable circuits connect miniature modules

• Wearable sensors

• Conform to irregular shapes

Embedding in elastic polymer

Fine pitch coil on 1 mm tube

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High packing density

> 1000 components/cm3

0201 resistors

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Narrow traces reduce layer count and cost

Nanosilver

•2 layers•15 to 30 micron traces•$1000 for first 10 substrates•1 day turnaround

12 mm

8 mm

Conventional copper

•4 layers•75 micron traces•$7800 for first 10 substrates•12 day turnaround

• Miniature systems using readily available SMT components

• Low cost ASIC equivalent

• Adaptable to prototyping/low volume production

• Simple manufacturing scale-up

11

Miniature module fabrication

1. Encapsulate components

2. Fabricate fine feature interconnects on thin substrates

• Nanoparticale silver conductors

• Laser direct-write processes

3. Connect components using conductive adhesives

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Component Encapsulation

Carrier film

SMD

Flat surface

Mold

Encapsulant

Exposed pads

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Thermal cycling tests

0 ohm surface mount resistor

Silver traces and pads

Conductive epoxy

Microvia

500 cycles/no failure

-50 C to 150 C

10 minute cycles

Chain resistance vs time

-50C to +150C Testing of 50-component Daisy Chains

Underfill

Using the modules

3D stand alone assemblies

Miniature subsystems connecting to PCB’s or cables

Solder connection

FR4 or Flex

Body orientation sensor

• Accelerometer/magnetometer

• Wireless transceiver

• Modular construction

• Mount on helmet

• 20mm x 25mm footprint

• Powered by coin cellMCU/Sensor module

Programming cable (temporary)

Radio

Miniature wireless sensors Microcontroller

Radio

Battery

Sensor module

Microcontroller

Radio

Battery

Sensor module

9-axis wireless motion sensor

Smart cable

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Capital Equipment Required

Paste fill & clean station

Integrated Laser/PnP/Dispense Encapsulation mold

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Capital Equipment NOT required

Resist exposure system

Etching/Plating tanks

Resist stripper

Lamination Press

20

Scaling to higher volume

Paste fill & clean station

UV laser system

Epoxy Dispenser

Encapsulation mold

Pick and Place

Summary

• Highly miniaturized circuits using nanosilver conductors

• Simplified design and fabrication

• Modular construction

• Quick/inexpensive prototyping

• Green processes

• Minimal capital equipment