Polysiloxane Adhesive Debonding for Semiconductor Wafer Processing

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Solution Overview

Problem

Current temporary wafer bonding methods in the semiconductor industry face challenges such as low yield, low productivity, and complexity due to the need for high-temperature processing, harsh solvent cleaning, and the use of UV or laser sources, which are costly and difficult to manage, especially when handling thin, fragile patterned wafers for 3-D packaging and LED applications.

Innovation Solution

A method involving the application of a silsesquioxane-based release layer and a polysiloxane-based adhesive, which are immiscible and can be thermally or UV-activated for bonding, allowing for debonding by solvent dissolution, thereby simplifying the process and reducing manufacturing costs and downtime.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If high-temperature processing (285°C) and harsh solvent cleaning are used for debonding, then the bonding strength is maintained, but yield and productivity decrease

Engineering Contradiction:
Improvebonding strengthVSAvoidthroughput
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The patent changes the chemical parameters of the adhesive layer by using a polysiloxane-based adhesive that can be selectively dissolved by organic solvents. This allows debonding to occur through solvent dissolution rather than high-temperature processing, dramatically improving throughput while maintaining bonding strength during processing

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the thermal-mechanical debonding system (high-temperature sliding) with a chemical dissolution system. The adhesive layer is designed to be soluble in organic solvents, allowing gentle chemical debonding instead of harsh mechanical sliding, which improves both yield and productivity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If UV or laser sources are used for debonding, then the bonding can be released, but cost and operational complexity increase

Engineering Contradiction:
Improvedebonding capabilityVSAvoidprocess complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces complex UV or laser debonding systems with a simple organic solvent dissolution system. The adhesive layer is specifically designed to be soluble in common organic solvents, allowing debonding through simple chemical浸泡 instead of expensive and complex UV or laser equipment

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses a disposable adhesive layer made of polysiloxane-based material that is inexpensive and designed to be dissolved by organic solvents. This replaces expensive and complex UV or laser debonding systems with a simple, low-cost chemical dissolution approach

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Strength

If plasma treatment is applied to improve surface compatibility, then adhesion is enhanced, but process complexity and cost increase

Engineering Contradiction:
Improveadhesion strengthVSAvoidprocess complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent changes the chemical parameters of the adhesive composition itself by using a polysiloxane-based adhesive with inherent compatibility for silicon wafer surfaces. This eliminates the need for plasma treatment while maintaining strong adhesion, simplifying the process and reducing costs

Inventive Principle:
Principle #35Parameter changes

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 approach enhances wafer handling and processing efficiency, improves throughput, and reduces manufacturing costs by enabling easy debonding and cleaning with organic solvents, while maintaining the integrity of the wafers during grinding and TSV processing.

Implementation Method 1

a silsesquioxane-based release layer and a polysiloxane-based adhesive, which are immiscible and can be thermally or UV-activated for bonding

Methodology Applied
Scientific EffectThermal activation: Heating

Implementation Method 2

allowing for debonding by solvent dissolution

Methodology Applied
Scientific EffectSolvent dissolution: Solvation

Implementation Method 3

a silsesquioxane-based release layer and a polysiloxane-based adhesive, which are immiscible and can be thermally or UV-activated for bonding

Methodology Applied
Scientific EffectUV activation: Photopolymerisation

Data Source

PatentEP2681762B1Wafer bonding system and method for bonding and debonding thereof
Publication Date: 2017.04.26 DOW SILICONES CORP
  • EP2681762B1 patent drawingFigure 1
  • EP2681762B1 patent drawingFigure 2
  • EP2681762B1 patent drawingFigure 3

AI summary

A method of treating the surface of a semiconductor wafer through the formation of a bonding system is provided in order to enhance the handling of the wafer during subsequent processing operations. The method generally comprises the steps of applying a release layer (10) and an adhesive (15) to different wafers (5, 20); bonding the wafers together to form a bonded wafer system; performing at least one wafer processing operation (e.g., wafer grinding, etc.) to form a thin processed wafer; debonding the wafers; and then cleaning the surface of the processed wafer with an organic solvent that is capable of dissolving the release layer or any residue thereof. The adhesive includes a vinyl - functionalized polysiloxane oligomeric resin, a Si-H functional polysiloxane oligomeric resin, a catalyst, and optionally an inhibitor, while the release layer is comprised of either a silsesquioxane -based resin or a thermoplastic resin.