Emmett Howard - Flexible Polyimide as a Device Substrate Temporarily Bonded

Session 4: FPE Technologies

Flexible Polyimide as a Device Substrate Temporarily Bonded to Round Silicon Carriers Allowing Processing in Standard Rigid Semiconductor Equipment
Tuesday, June 20, 2017 
3:40 PM - 4:00 PM

Temporary Bonding of Polyimide to create a flexible substrate and electronic devices using silicon carriers with diameters from 1 inch to 12 inch is detailed. We show the materials and methods to create a user defined Adhesion Strength to the carrier for Polyimide film thicknesses <10um and ≥10um. We show Polyimide adhesion strength increases significantly as the Polyimide Film thickness decreases below 10um and we share our discovery of materials and methods to keep the adhesion strength in a low and narrow user defined range preventing damage to the devices during de-bonding.

The silicon carriers used to hold the flexible polyimide substrate rigid allows the use of conventional silicon semiconductor equipment to fabricate flexible electronic devices. Data shows our approach keeps the polyimide and carrier flat allowing for robust quality control of Critical Dimensions and Layer to Layer Alignment required during semiconductor device fabrication.

We also present the de-bonding of the flexible polyimide substrate with devices present using a low cost method which does not require the use of Chemicals, UV Light, Lasers (EPLaR), Heat, or Release Layers. Results of post de-bond and flex testing of the devices show no damage to the flexible substrate or flexible devices. The de-bond process does not generate any debris and eliminates the need for post de-bond cleaning.

The discoveries presented here by the Flexible Electronics and Display Center of Arizona State University provides a means for companies with conventional silicon semiconductor fabrication equipment to enter the Flexible Device Market.


Speaker's Biography

Emmett Howard: Process Engineer Principle and Section Head for the Photo Lithography and Flexible Substrate Bond and De-bond operations. He has been a member of the Flexible Display Center since 2009 and has over 30 years of experience in Semiconductors, Displays, and Ceramics Processing. Semiconductor processing includes EPI, High Pressure Oxidation, PECVD, Diffusion, PVD, RIE, Wet Etch, Photo Lithography and Defect Reduction. Display processing experience on Organic Light Emitting Diodes, Cold Field Emission, and Electro-wetting. Ceramics processing for RF devices with respect to Device design, Screen Printing, Laser Trimming, Materials Development and Firing. He holds B.S. in Information Systems from Western International University and a M.S. in Information Systems. Emmett currently has 14 issued U.S. Patents.


Emmett Howard
Flexible Electronics and Display Center of Arizona State University