Broadband Light-Absorbing Adhesive for Wafer Detachment
Solution Overview
Problem
Current methods for detaching silicon wafers from rigid carriers during 3D integrated circuit manufacturing often involve harsh chemicals, mechanical damage, or high temperatures, which are undesirable due to potential harm to the wafer surface or inefficiencies in the process.
Innovation Solution
A broadband light-absorbing adhesive is combined with an adhesive material and applied to a transparent carrier, allowing for the attachment and subsequent detachment of substrates, such as wafers or polymeric films, using a flashlamp to heat the adhesive and loosen the substrate from the carrier, thereby facilitating easy removal without chemical solvents or high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If harsh chemicals or high temperatures are used to detach substrates from carriers, then the detachment process is effective, but the substrate surface may be damaged or the process becomes inefficient
Solution Approach 1:
The patent replaces mechanical or chemical detachment methods with a photothermal system. A light-absorbing layer is deposited on the carrier, and when illuminated by a flashlamp, it converts optical energy to thermal energy, heating the adhesive layer and enabling substrate detachment without mechanical force or harsh chemicals, thus avoiding substrate damage
Solution Approach 2:
The patent changes the thermal parameters of the detachment process by using pulsed light illumination to rapidly heat the light-absorbing layer and adhesive. This controlled thermal parameter change allows selective heating of the adhesive layer without excessively heating the substrate, achieving effective detachment while minimizing thermal damage
2Strength
If traditional adhesive materials are used, then the substrate can be attached to the carrier, but the detachment process requires harsh chemicals or high temperatures
Solution Approach 1:
The patent uses a composite structure consisting of a light-absorbing layer (such as metal or metal oxide) deposited on the carrier surface, combined with a conventional adhesive layer. This composite material system provides both strong bonding capability and selective photothermal response, enabling damage-free detachment through light illumination
Solution Approach 2:
The patent substitutes the traditional thermal or chemical detachment mechanism with a photothermal mechanism. The light-absorbing composite material converts optical energy to heat locally at the adhesive layer, replacing the need for harsh chemicals or high-temperature processing that would otherwise be required to break the adhesive bonds
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method allows for efficient and damage-free detachment of substrates by converting light energy into heat, reducing the need for harsh chemicals and mechanical stress, and enabling precise control over the detachment process, thus improving the manufacturing efficiency and minimizing thermal shock to the substrates.
Implementation Method 1
a broadband light-absorbing material is combined with an adhesive material to form a broadband light-absorbing adhesive
Implementation Method 2
a light pulse from a flashlamp is utilized to heat up the broadband light-absorbing adhesive in order to loosen the substrate from the bonded stack
Data Source
AI summary
A method for attaching and detaching a substrate from a bonded stack is disclosed. A broadband light-absorbing material is combined with an adhesive material to form a broadband light-absorbing adhesive. A layer of the broadband light-absorbing adhesive is then applied on one side of a transparent carrier. A substrate is placed on the broadband light-absorbing adhesive and the transparent carrier to form a bonded stack. The substrate can be a wafer or a polymeric film. At this point, processing steps can be performed on the substrate. After the processing steps have been completed, a light pulse from a flashlamp is utilized to heat up the broadband light-absorbing adhesive in order to loosen the substrate from the bonded stack such that the substrate can be easily detached from the bonded stack.