Laser De-Bonding, High Tg, Temporary Bonding Adhesive Solutions
Focused laser debonding for separating device wafer from the glass carrier is the existing predominant method in the use of temporary bonding adhesive that has high Tg and modulus.
To maximize throughput for wafer processing with high strength temporary bonding, AI Technology, Inc. engineered innovative polymer structures for the WPA-LD product series:
- High Tg of 240ºC
- Low melt-lamination temperature < 150ºC
WPA-LD, unlike typical high Tg and high modulus temporary bonding material, has:
- Great compliance
- Easy residual removal with solvent
AIT’s Next Generation of De-Bondable Products:
All of these three adhesive solutions maintain high mechanical stability and high thermal stability for wafer processing at least up to 350ºC even in an oxidizing environment
WPA-LD-350: Novel Temporary Bonding Film Adhesive
- Adhesive based on modified cyanate ester polymer
- Tg of 240ºC
- Designed for use with a glass carrier for ease of focused laser de-bonding.
WPA-LD-350-L: Liquid dispensable version of WPA-LD-350
- Apply and B-stage on the device wafer to form film adhesive and heat laminate with glass carrier.
WPA-LD-PR-350: Innovative Laser-and-peel-clean temporary film adhesive
- AIT’s laser debonding WPA-LD-350 with a 10µm thin layer of coating of AIT’s clean peel-release WPA-PRCL-350 on both sides
- To separate device wafer and glass carrier a focused laser can be used
- After separation, simply peel the remaining film from both the device wafer and glass carrier. No residuals, no cleaning required
Wafer Lamination Processes with High Tg Temporary Bonding Adhesive:
Film format temporary bonding adhesive from AIT is an improvement from standard materials. This format increases throughput by eliminating intensive film forming processing.
AIT’s WPA-LD adhesive film products may be melt-laminated with temperature from 140 to 160C. Please see the infographic below.
WPA-LD-350 is available with a film thickness of 20µm, 100µm, 200µm, and 400µm for use with any wafer or panel topography.
WPA-LD-PR-350 is available with a film thickness of 100µm, 200µm, and 400µm for use on bumped wafers and panels.
For those with a preference or setup for liquid dispensable products, WPA-LD-350-L is dispensed and b-staged to a film format.
Workflow for Debonding and Cleaning:
The debonding processes are similar to typical focused laser debonding of high Tg temporary bonding adhesive. The solvent removal of residual adhesive with the designated user-friendly solvent solution is within minutes at a temperature less than 80ºC.
Detailed High Tg Temporary Bonding Adhesives:
The following table describes the key properties and processing recommendations for WAP-LT-350 and WPA-LT-PR-350 that incorporated an additional clean peel-release interface layer.