Resin Sheet with Surface Irregularities for Residue-Free Wafer Fixing

Solution Overview

Problem

The existing methods for processing semiconductor wafers using resin sheets often result in adhesive residue left on the wafer surface due to the strong adhesive power of the resin, particularly when dealing with wafers that have bumps or need to be divided into small device chips.

Innovation Solution

A method involving a resin sheet with a layered structure, where surface irregularities are formed on the base material layer opposite the adhesive layer, allowing the wafer to be fixed to the resin sheet without using adhesive, thereby preventing residue from remaining on the wafer during processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If an adhesive layer with strong adhesive power is used to firmly secure the resin sheet to the wafer, then the resin sheet can be firmly secured to the workpiece, but adhesive residue remains on the face side of the wafer after peeling off the resin sheet

Engineering Contradiction:

Improveadhesive strengthVSAvoidadhesive residue

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

The adhesive layer is extracted from the resin sheet structure that contacts the wafer. The resin sheet is applied without an adhesive layer facing the wafer, eliminating the source of adhesive residue while maintaining resin sheet attachment through van der Waals forces and surface irregularities.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

A release sheet serves as an intermediary between the adhesive layer and the wafer. The release sheet prevents direct contact between the adhesive and the wafer surface, allowing the resin sheet to be applied and removed without leaving adhesive residue on the wafer.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the resin sheet is peeled off from the wafer after processing, then the wafer can be accessed, but adhesive residue is left on the face side of the wafer

Engineering Contradiction:

Improveresin sheet removalVSAvoidadhesive residue

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The adhesive layer is extracted from the resin sheet structure that contacts the wafer. The resin sheet is applied without an adhesive layer facing the wafer, eliminating the source of adhesive residue while maintaining resin sheet attachment through van der Waals forces and surface irregularities.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The resin sheet with release sheet is designed as a disposable protective covering that is applied and then removed after serving its protective function during processing. The release sheet enables easy removal without adhesive residue, making the system suitable for single-use applications.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Object-affected harmful factors

If a resin sheet with adhesive layer is used to protect devices on the face side of the wafer, then device protection is achieved, but the adhesive creates contamination risk on the wafer surface

Engineering Contradiction:

Improvedevice protectionVSAvoidcontamination

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The adhesive layer is extracted from the resin sheet structure that contacts the wafer. The resin sheet is applied without an adhesive layer facing the wafer, eliminating the source of adhesive residue while maintaining resin sheet attachment through van der Waals forces and surface irregularities.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

A release sheet serves as an intermediary between the adhesive layer and the wafer. The release sheet prevents direct contact between the adhesive and the wafer surface, allowing the resin sheet to be applied and removed without leaving adhesive residue on the wafer.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 ensures that no adhesive residue is left on the wafer after processing, allowing for efficient and residue-free handling of wafers, and enables the use of a cost-effective protective tape without permanent adhesion.

Implementation Method 1

bringing the workpiece into intimate contact with the resin sheet to fix the workpiece to the resin sheet

Methodology Applied

Scientific EffectVan der Waals force: Van der Waals Force

Data Source

PatentUS11508607B2Method of processing workpiece and resin sheet unit

Publication Date: 2022.11.22 DISCO CORP

AI summary

A method of processing a workpiece includes sticking an adhesive layer side of a resin sheet having a layered structure that includes an adhesive layer and a base material layer, to an annular frame having an opening in covering relation to the opening, forming surface irregularities on a face side of the base material layer that is opposite the adhesive layer, placing the face side of the workpiece and the face side of the base material layer in facing relation to each other and pressing the workpiece against the resin sheet or pressing the resin sheet against the workpiece, thereby bringing the workpiece into intimate contact with the resin sheet to fix the workpiece to the resin sheet, holding the face side of the workpiece fixed to the resin sheet on a holding surface of a chuck table, and grinding the reverse side of the workpiece with a grinding stone.