Temporary Wafer Adhesive Composition for Blade and Slide Peeling
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Solution Overview
Problem
Existing temporary adhesives fail to provide adequate adhesiveness and applicability in both high temperature environments and room temperature, and are difficult to peel off without damaging the adherend or leaving residues, limiting their use in semiconductor wafer processing.
Innovation Solution
A temporary adhesive composed of a polyvalent vinyl ether compound, a polymer with hydroxy and/or carboxy groups, and a thermoplastic resin, which upon heat treatment, increases molecular weight, exhibits high Tg and low viscosity, enabling both blade and slide peeling methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a wax type temporary adhesive is used, then strong tackiness is achieved, but the adhesive component adheres to the blade and is very difficult to remove
Solution Approach 1:
The patent uses a polymer with adjustable molecular weight (10,000-100,000) and controlled crosslinking degree to achieve optimal balance between tackiness and removability. By controlling the molecular weight and crosslinking parameters, the adhesive provides strong initial bonding but allows clean removal without blade adhesion problems.
Solution Approach 2:
The patent creates a composite adhesive system combining a base polymer with specific molecular weight characteristics and crosslinking agents. This composite structure provides both the strong tackiness needed for bonding and the controlled removability required for clean peeling, avoiding the blade adhesion issues of pure wax formulations.
2Strength
If a wax type temporary adhesive is used, then strong adhesiveness is achieved, but the viscosity decreases in high temperature environment and it is difficult to fix the wafer
Solution Approach 1:
The patent selects polymers with molecular weights in the 10,000-100,000 range and controls the crosslinking degree to maintain optimal viscosity across temperature variations. This parameter control ensures the adhesive remains sufficiently viscous at elevated temperatures to provide strong bonding while allowing removal at lower temperatures.
Solution Approach 2:
The patent utilizes the phase transition characteristics of the polymer-crosslinking system to achieve temperature-dependent behavior. The adhesive maintains a gel-like state at high temperatures providing strong bonding, then transitions to a more removable state at lower temperatures, enabling clean peeling without residue.
3Strength
If a curable type temporary adhesive is used, then good high temperature adhesiveness is achieved, but the viscosity cannot be reduced by heating and cannot be used in slide peeling method
Solution Approach 1:
The patent employs a dynamic adhesive system where the polymer maintains crosslinked structures for strength but includes components that can reversibly change viscosity with temperature. This dynamic behavior allows the adhesive to provide strong bonding at processing temperatures while becoming removable at lower temperatures for both blade and slide peeling methods.
Solution Approach 2:
The patent controls the molecular weight (10,000-100,000) and crosslinking degree to create a reversible viscosity change capability. This allows the adhesive to transition between a high-viscosity bonded state at elevated temperatures and a lower-viscosity removable state at ambient temperatures, enabling compatibility with multiple peeling methods.
4Strength
If the molecular weight of resin components is increased to improve adhesiveness, then good high temperature performance is achieved, but the viscosity increases and applicability deteriorates
Solution Approach 1:
The patent optimizes the molecular weight parameter to the specific range of 10,000-100,000 and controls the crosslinking degree to achieve the desired balance. This parameter optimization ensures sufficient viscosity for good applicability while maintaining the molecular weight necessary for strong high-temperature adhesiveness.
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 maintains strong adhesiveness in high temperatures and allows easy peeling without residue, suitable for semiconductor wafer processing, ensuring fragile wafers are not damaged and facilitating efficient laminate production.
Implementation Method 1
when the temporary adhesive as will be described below is subjected to a heat treatment, the molecular weight of its resin components increases by more than or equal to 1.2 times as compared with that before the heat treatment
Implementation Method 2
the molecular weight of resin components contained in a heat-treated product formed by heating the temporary adhesive at 230° C. for 5 minutes is 1.2 times or more the weight average molecular weight of the resin components contained in the temporary adhesive
Data Source
AI summary
Provided is a temporary adhesive that has good applicability and adhesiveness and allows an adherend to be easily peeled off by a slide peeling method or a blade peeling method. The temporary adhesive of the present disclosure contains, as resin components, a polyvalent vinyl ether compound (A), a polymer (B) having a plurality of hydroxy groups and/or carboxy groups as pendant groups, and a thermoplastic resin (C). The polymer (B) has a weight average molecular weight from 1500 to 7000, the thermoplastic resin (C) has a weight average molecular weight greater than 7000, and the resin components contained in the temporary adhesive have a weight average molecular weight less than or equal to 100000. A weight average molecular weight of the resin components contained in a heat-treated product formed by heating the temporary adhesive at 230° C. for 5 minutes is more than or equal to 1.2 times as great as the weight average molecular weight of the resin components contained in the temporary adhesive, the heat-treated product has a Tg higher than or equal to 100° C. and lower than 200° C., and the heat-treated product has a viscosity, at 200° C. and a frequency of 10 Hz, of less than or equal to 100 cP.