Thin Wafer Bonding Without Carbon Black for Clean Support Reuse

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Solution Overview

Problem

Existing methods for manufacturing thin wafers using a photothermal conversion layer with carbon black result in scattering during support reuse and cleaning, which is undesirable in semiconductor manufacturing due to the need for a clean environment.

Innovation Solution

A method involving a composition for temporary fixing without carbon black, using a polymerizable component, photoradical polymerization initiator, and ultraviolet absorber with a polymerizable functional group, allows for peeling the thin wafer from an optically transparent support member by specific light irradiation, followed by cleaning without scattering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a photothermal conversion layer containing carbon black is used to enable laser peeling, then the thin wafer can be separated from the support, but carbon black scatters during support reuse and cleaning

Engineering Contradiction:

Improvepeeling easeVSAvoidcarbon black scattering

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent removes carbon black from the photothermal conversion layer, extracting the harmful scattering component while retaining the essential peeling function through alternative photothermal materials that do not scatter

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the compositional parameters of the photothermal conversion layer by replacing carbon black with alternative materials having different optical and thermal properties, achieving peeling without scattering

Inventive Principle:

Principle #35Parameter changes

2Productivity

If carbon black is included in the photothermal conversion layer, then laser peeling efficiency is improved, but cleaning of the support member becomes difficult

Engineering Contradiction:

Improvepeeling speedVSAvoidcleaning ease

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The patent extracts carbon black from the system to eliminate cleaning difficulties while maintaining peeling productivity through alternative photothermal conversion mechanisms

Inventive Principle:

Principle #2Taking out (Extraction)

3Object-affected harmful factors

If a protective tape made of organic resin film is used, then flexibility is provided, but strength and heat resistance are insufficient for high temperature steps

Engineering Contradiction:

Improvecrack preventionVSAvoidheat resistance

Core Design Contradiction:

Object-affected harmful factorsVSTemperature

Solution Approach 1:

The patent uses a composite structure combining the organic resin film protective tape with an inorganic photothermal conversion layer, where the inorganic layer provides heat resistance while the organic layer provides flexibility and crack prevention

Inventive Principle:

Principle #40Composite materials

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

Enables clean and efficient production of multiple thin wafers by preventing carbon black scattering and facilitating easy cleaning of the support member, ensuring high productivity and cleanliness in semiconductor manufacturing.

Implementation Method 1

a photothermal conversion layer between the semiconductor chip and a light transmissive support. The photothermal conversion layer is decomposed by irradiation with radiant energy such as laser light

Methodology Applied

Scientific EffectPhotothermal conversion: Absorption (EM radiation)

Implementation Method 2

a step (2) of irradiating light having a wavelength of 350 nm to 700 nm from the support member side to cure the composition for temporary fixing to form an adhesive layer

Methodology Applied

Scientific EffectPhotoradical polymerization: Photopolymerisation

Implementation Method 3

ultraviolet absorber having a polymerizable functional group

Methodology Applied

Scientific EffectUV absorption and polymerization: Photopolymerisation

Data Source

PatentEP4661057A1Method for manufacturing plurality of thin wafers

Publication Date: 2025.12.10 DENKA CO LTD

AI summary

An object of the present invention is to provide a method for manufacturing a plurality of thin wafers, the method being capable of cleaning a support member without providing a layer containing carbon black. The object can be solved by a method for manufacturing a plurality of thin wafers, the method including: a step (1) of bonding a substrate of a thin wafer and an optically transparent support member via a composition containing (A) polymerizable component containing (meth)acrylate, (B) photoradical polymerization initiator, and (C) ultraviolet absorber having a polymerizable functional group; a step (2) of irradiating light having a wavelength of 350 nm to 700 nm from the support member side to cure the composition to form an adhesive layer, and bonding the substrate and the support member; a step (3) of processing a surface of the substrate to form a thin wafer; a step (4) of irradiating light having a wavelength of 385 nm or less from the support member side to decompose the adhesive layer and peel the thin wafer from the support member; a step (5) of cleaning the support member for use in manufacturing a next thin wafer; and a step (6) of repeating the steps (1) to (5) at least once, in which in the step (1), a layer containing carbon black is not interposed between the substrate and the support member.