Using Anisotropic Conductive Adhesives in Advanceｄ Medical Applicationｓ

Peter J. Opdahl, Ito Corporation

www.ito-group.com www.autoacf.com

www.bonding-equipment.com

Vocabulary

  ACA: Anisotropic Conductive Adhesive  ACF: Anisotropic Conductive Film  ACP: Anisotropic Conductive Paste

  Lamination: Placing the ACF on a substrate.   Mounting: Alignment and placing the two sides

of the assembly together prior to Bonding.   Bonding: The final application of heat and

pressure necessary to flow and cure the ACA.

What are Anisotropic Conductive Adhesives?   A system used to make both the mechanical and electrical

connection between two devices.   Mechanical connections at peel strengths up to 20N/cm.   Electrical connections at pitches down to 0.035mm pitch

  Minimum 0.010mm space between contacts.   Minimum 1500µm2 contact patch (Typically 30µm x 50µm).   Typical 5-7mΩ contact resistance for Au-Au bonds.   10-8Ω (10-7Ω after aging) electrical isolation.   Good electrical characteristics at >20Ghz frequencies.

  Adhesives are typically epoxy for medical applications, but are also available in acrylic/epoxy hybrids and as hotmelt adhesives.

  Particles can either be solid metal particles or Ni-Au plated compressible plastic spheres.

Anisotropic Conductive Film (ACF)

Conductive particles (SEM)

ACF( Optical Microscope)

　Binder (Thermoset Adhesive)

Conductive Particle

AuNi-Plated Polymer Core

Au-Plated Ni Particle

(3 -10um Diameter)

( 6um Diameter)

(10um Diameter) Pb Free Solder Particles

Low Temperature Low Pressure

Short Time

Substrate

Remove Release Liner

ACF Lamination

Device Alignment and Mounting

Completion Final bonding

Hotbar

Hotbar High Temperature

High Pressure Longer Time

Hotbar

Using ACF

Inside the Bond

Flex Copper Pad

"   As the two sides move together, the particles are trapped and crushed between them. This creates the Z-axis connection while maintaining isolation in the X and Y axis.

Conductive Particles Substrate Pad

Substrate

Typical ACF Assemblies COG

(Chip On Glass) COB

(Chip On Board) COF

(Chip On Flex)

ACF

LCD

IC

LCD

ACF

FOB (Flex On Board)

FOG (Flex On Glass)

FOF (Flex on Flex)

Reliability Data

Current Carrying Capacity   Gold-Gold bond   0.1mm2 contact area   1A current   85C/85% Rh Environment

Res

ista

nce

(Ω)

High Speed Signaling  Extensive testing to greater than

30Ghz shows no breakdown. S21 Transmission Coefficient

S11 Reflection Coefficent

Eye Diagrams

Initial 250hr 500hr

85C/85Rh 100C/-40C

The Next Generation of Medical Detector

  Principles of X-ray Detector:

Active Matrix Flat Panel Imagers (AMFPI) imaging system diagram: From Medical Imaging: Principles, Detectors, and Electronics, edited by Krzysztof Iniewski [3]

Next Generation X-Ray Detectors

  COF Module: Chip/Die on Flex by ACF for X-Ray Detector   Readout COF Module: ASIC/Die Size 12mmx5mm   Bump Size: 80 µm x 80 µm   Total > 220 I/Os(Analog Input 128 Channels, Digital Output 16 Channels)

  Flex Size: 70x15 mm60 μm pitch

  Gate Driver, COF Module:ASIC/Die Size 12mmx0.90mm   Bump Size: 30 µm x 60 µm   Total > 450 I/Os(Digital Output 263 Channels)

  Flex Size: 20x20mm40 μm pitch

Scintillator"

Readout"ADC" Addressing"

Active Matrix Flat Panel Imagers (AMFPI)

ACF Bond to readout input pads and X-ray panel.

Output/Input Digital Signal: ZIF Connector or ACF direct bond to board

ACF-COF (Chip-on-Flex)

The Next Generation of Medical Detector

Next Generation PET Imaging

  Principles of PET Imaging: Configurations

Next Generation PET Imaging Sensor

  Future Generation of PET: Potential Module Configurations

Next Generation PET/SPECT Sensors

  ACF-COF Module   Chip-on-Flex for PET/SPECT Detector

ACF-COF: Chip/Die/ASICs on Flex

SMT Component on Flex

ZIF Connector: Digital Output Signal

-- or -- Direct Flex-on-Board

with ACF

Silicon pixel array on flex. Current parameters 135C/0.8Mpa/15sec

Future parameters 130C/0.35MPa/15sec (For CZT, others.)

Next Generation Ultrasound Transducers

  Principles of Ultrasound System Diagram

Next Generation Ultrasound Transducers

  Miniaturization: Ultrasound Probe/Catheter

Migration of functionality in the ultrasound machine: From Medical Imaging: Principles, Detectors, and Electronics, edited by Krzysztof Iniewski [208]

Next Generation Ultrasound Transducers

  Miniaturization: Ultrasound Probe/Catheter

Catheter-based side-looking ultrasound probe: From Medical Imaging: Principles, Detectors, and Electronics, edited by Krzysztof Iniewski [208]

Next Generation Ultrasound Transducers

  ACF-COF/ACF-COB Module for Ultrasound Probe/Catheter   Proposed package has outer dimensions 1.0mm larger than cMUT or

PZT Array size.

Readout"Addressing"

cMUT or PZT array and COF: Chip on Flex-Rigid PCB for Ultrasound Probe/Catheter

cMUT or PZT Array

ACF-COF:Chip-on-Flex -- or -- ACF-COB: Chip on Board

Fold Flex

Final Product

Using Anisotropic Conductive Adhesives in Advanced Medical Applications

Thank you very much

By Peter J. Opdahl, Ito Corporation www.ito-group.com www.autoacf.com

www.bonding-equipment.com