Wafer Stripping via Through-Hole Solvent Diffusion
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Solution Overview
Problem
The existing methods for stripping thin semiconductor wafers from supporting plates are time-consuming and risk damaging the wafers due to heating and contamination from thermal expandable particles, necessitating a more efficient and safer method.
Innovation Solution
A stripping method using a hydrocarbon-based solvent with a viscosity of 1.3 mPa·s or less and a dissolving rate of 30 nm/sec or greater, applied through a through hole in the supporting plate, to dissolve the adhesive agent quickly and effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional dissolving methods are used to strip the wafer from the supporting plate, then the adhesive can be dissolved, but the process is time-consuming and reduces productivity
Solution Approach 1:
The patent changes the chemical parameters of the adhesive by specifying a particular composition ratio (5-20 parts by weight of compound (I) and 80-95 parts by weight of compound (II)). This optimized composition enables faster dissolving speed while maintaining easy stripability, directly resolving the contradiction between productivity and time consumption.
2Ease of operation
If heating is applied to release the releasing agent from microcapsules, then stripping can be achieved, but the thin wafer may be damaged due to thermal stress
Solution Approach 1:
The patent replaces the thermal mechanism (heating to release releasing agent) with a chemical mechanism (direct dissolving of adhesive through contact with dissolving solution). The adhesive layer is designed to be easily dissolved by the dissolving solution without requiring thermal energy input, thus eliminating thermal damage to the thin wafer while maintaining ease of stripping.
3Ease of operation
If thermally expandable particles are used in the adhesive, then pushing force is generated for stripping, but the wafer may be damaged and contamination occurs
Solution Approach 1:
The patent extracts and eliminates the thermally expandable particles from the adhesive composition. Instead of using particles that expand and generate pushing force (which cause contamination and damage), the invention relies on the inherent dissolving properties of the optimized adhesive composition, allowing clean stripping without harmful byproducts.
4Productivity
If the wafer is thinned to increase the number of chips mounted, then more chips can be mounted, but the wafer strength is weakened making it prone to cracking and curving
Solution Approach 1:
The patent applies a supporting plate to the wafer surface before thinning and processing operations. This preliminary support reinforcement prevents cracking and curving during subsequent handling and processing, enabling the wafer to be thinned to the required thickness (25-150 μm) while maintaining structural integrity throughout the manufacturing process.
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 significantly reduces the time required to strip the wafer from the supporting plate without damaging the wafer or leaving residues, enhancing the efficiency and safety of the process.
Implementation Method 1
dissolving the adhesive agent with a stripping solution, by contacting the stripping solution to the adhesive agent via the through hole
Implementation Method 2
the adhesive agent having a hydrocarbon resin as a viscous component, and the stripping solution being a hydrocarbon-based solvent
Data Source
AI summary
A method for stripping a wafer from a supporting plate to which the wafer is adhered via an adhesive agent, wherein the supporting plate has a through hole penetrating the supporting plate in a thickness direction thereof, the method including dissolving the adhesive agent with a stripping solution by contacting the stripping solution with the adhesive agent via the through hole. The adhesive agent has a hydrocarbon resin as a viscous component, and the stripping solution is a hydrocarbon-based solvent having a viscosity of 1.3 mPa·s or less and a dissolving rate of 30 nm/sec or greater to dissolve the adhesive agent.