Double-Sided Wafer Polishing Pad Adhesive for Flatness Control
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Solution Overview
Problem
Conventional polishing pads experience peeling due to insufficient adhesive strength, particularly at slurry supply ports on the upper turn table, leading to wafer flatness deterioration during double-side polishing, and thick adhesive layers cause creep deformation.
Innovation Solution
A polishing pad with a double-sided tape having a 90° peeling adhesive strength of 2000 g/cm or more and a ratio of 1.05 or more to 180° peeling adhesive strength, with total adhesive layer thickness of 80 μm or less, to prevent peeling and creep deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the adhesive layer thickness is increased to improve adhesive strength, then the 90° peeling adhesive strength improves, but creep deformation occurs leading to wafer flatness deterioration
Solution Approach 1:
The invention changes the chemical composition parameters of the adhesive layer by incorporating specific rubber components (natural rubber 20-80 parts by weight, synthetic rubber 20-80 parts by weight) and tackifying resin (5-30 parts by weight) to achieve high 90° peeling adhesive strength (2000 g/cm or more) while maintaining adhesive layer thickness at 80 μm or less, thereby preventing both peeling and creep deformation that would deteriorate wafer flatness
Solution Approach 2:
The invention uses a composite adhesive layer formulation combining multiple rubber types (natural rubber and synthetic rubber) with tackifying resin to create a multi-component adhesive system that provides both high 90° peeling adhesive strength and resistance to creep deformation, resolving the contradiction between strength and dimensional stability
2Strength
If a conventional double-sided tape with adequate 180° peeling adhesive strength is used, then the polishing pad can be attached to the turn table, but the 90° peeling adhesive strength is insufficient causing peeling at slurry supply ports
Solution Approach 1:
The invention shifts the adhesive strength parameter balance by formulating an adhesive layer that achieves 90° peeling adhesive strength of 2000 g/cm or more (with 90°/180° ratio of 1.05 or more), reversing the conventional priority where 180° peeling strength was emphasized but 90° peeling strength was insufficient, thereby preventing peeling at slurry supply ports under gravitational force
Solution Approach 2:
The invention converts the previously harmful effect of gravity causing peeling into a manageable factor by designing an adhesive layer with specifically engineered 90° peeling adhesive strength that exceeds the peeling force generated by gravity, transforming the gravitational challenge into a solved attachment reliability issue
3Manufacturing precision
If the adhesive layer is made thin to prevent creep deformation, then wafer flatness is maintained, but adhesive strength may be insufficient
Solution Approach 1:
The invention changes the adhesive strength parameters through chemical composition optimization rather than thickness increase, achieving 90° peeling adhesive strength of 2000 g/cm or more with the specified rubber and resin formulation, allowing the adhesive layer thickness to be kept at 80 μm or less while maintaining both high strength and prevention of creep deformation
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
Prevents peeling of the polishing pad and suppresses creep deformation, maintaining wafer flatness by ensuring strong adhesive strength and minimizing adhesive layer thickness.
Implementation Method 1
a double-sided tape for attaching the polishing layer to an upper turn table
Implementation Method 2
polishing slurry permeates into these portions
Data Source
AI summary
The present invention is a polishing pad having a polishing layer for polishing surface of a wafer and a double-sided tape for attaching the polishing layer to an upper turn table of a double-side polishing apparatus, wherein, the double-sided tape has a 90° peeling adhesive strength A of 2000 g/cm or more, and a ratio A/B of the 90° peeling adhesive strength A to a 180° peeling adhesive strength B of 1.05 or more, the double-sided tape has a base material, a polishing-layer-side adhesive layer to be attached to the polishing layer, and an upper-turn-table-side adhesive layer to be attached to the upper turn table, and total thickness of the polishing-layer-side adhesive layer and the upper-turn-table-side adhesive layer is 80 μm or less. This provides a polishing pad capable of suppressing deterioration of flatness of the wafer when performing double-side polishing of the wafer.