Epoxy-Modified Polysiloxane Temporary Adhesive for Wafer Thinning
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Solution Overview
Problem
Existing temporary adhesives for semiconductor wafers fail to provide adequate stress resistance during polishing and easy detachment, leading to potential breakage or deformation of thinned wafers.
Innovation Solution
A temporary adhesive composed of components (A) and (B), where (A) is cured by a hydrosilylation reaction and (B) is epoxy-modified polyorganosiloxane, with a specific mass ratio, ensuring high adhesion for polishing and easy separation post-processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a temporary adhesive is designed to provide high adhesion force during polishing, then stress resistance is improved, but detachment becomes difficult
Solution Approach 1:
The adhesive composition is segmented into multiple functional components: a polysiloxane base component providing adhesion, and a specific additive component (containing silane-modified polymer and metal catalyst) that enables controlled detachment. This segmentation allows the adhesive to provide strong bonding during polishing while maintaining ease of removal afterward through the specialized additive system.
Solution Approach 2:
The adhesive's properties are changed through specific compositional parameters: using polysiloxane with controlled molecular weight and viscosity, adding silane-modified polymer at specific concentrations (0.1-10 wt%), and incorporating metal catalysts. These parameter changes enable the adhesive to transition from a strong bonding state during polishing to an easily removable state after processing.
2Productivity
If the wafer is thinned by polishing to enable layering, then integration density is improved, but the wafer becomes fragile and prone to breakage
Solution Approach 1:
The temporary adhesive provides beforehand cushioning support to the thinned wafer during the polishing process. By maintaining strong adhesion to the support substrate throughout thinning, the adhesive prevents wafer breakage and deformation. After polishing completes, the adhesive's detachment properties allow clean separation without damaging the now-thinned but structurally sound wafer.
Solution Approach 2:
The temporary adhesive acts as an intermediary between the thinned wafer and the support substrate. This intermediary provides mechanical support during the vulnerable thinning process, enabling high integration density through aggressive thinning while maintaining wafer integrity. The specialized composition allows the intermediary to be removed cleanly after serving its protective function.
3Ease of manufacture
If conventional adhesives are used for temporary bonding, then spin coating properties are achieved, but heat resistance during processing is insufficient
Solution Approach 1:
The adhesive is formulated as a composite material combining polysiloxane base components with silane-modified polymer additives and metal catalysts. This composite structure provides both the desired spin coating properties (from the polysiloxane matrix) and enhanced heat resistance (from the crosslinked silane-modified polymer network formed during processing).
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
The adhesive offers excellent spin coating properties, heat resistance, and easy separation, allowing for efficient polishing and subsequent three-dimensional integration of wafers without damage.
Implementation Method 1
the adhesive containing a component (A) to be cured by a hydrosilylation reaction
Implementation Method 2
a component (A) containing a polyorganosiloxane (a1) and a polyorganosiloxane (a2), and a platinum group metal-based catalyst (A2)
Data Source
AI summary
A temporary adhesive having excellent spin coating properties of a circuit side of a wafer and a support, and excellent heat resistance when the circuit side of the wafer or the support is attached to an adhesion layer or a rear surface of the wafer is processed, and is capable of easily separating the circuit side of the wafer from the support after polishing the rear surface of the wafer, and simply removing a adhesive attached to the wafer or the support after the separation. The adhesive contains a component (A) to be cured by a hydrosilylation reaction, and a component (B) containing an epoxy-modified polyorganosiloxane at a ratio in % by mass of the component (A) to the component (B) of 99.995:0.005 to 30:70. The component (B) is an epoxy-modified polyorganosiloxane having an epoxy value of 0.1 to 5.