Multilayer Adhesive Tape Step Coverage

Solution Overview

Problem

Existing adhesive tapes used in electronic devices face challenges with white turbidity and reworkability, particularly in minimizing residue and achieving excellent step coverage during reconstruction.

Innovation Solution

A multilayer adhesive tape is designed with a first outer adhesive layer, an intermediate adhesive layer containing a polymerization unit of an alkyl group-containing (meth)acrylate monomer, a carboxyl group-containing monomer, and an acrylamide-based monomer, and a second outer adhesive layer, which enhances reworkability and step coverage while minimizing white turbidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single-layer adhesive tape is used, then the structure is simple, but white turbidity occurs and reworkability is poor

Engineering Contradiction:

Improveadhesive tape structureVSAvoidwhite turbidity

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The adhesive tape is divided into three distinct layers: a first outer adhesive layer, an intermediate adhesive layer, and a second outer adhesive layer. Each layer has different composition and function, with the intermediate layer containing specific polymers (acrylic polymer, polyurethane polymer, and polyvinyl acetate polymer) to prevent white turbidity while outer layers provide adhesion and reworkability

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The intermediate adhesive layer uses a composite of three different polymer types (acrylic polymer with specific Tg range, polyurethane polymer, and polyvinyl acetate polymer) to achieve the dual function of preventing white turbidity through appropriate cohesive force while maintaining optical transparency

Inventive Principle:

Principle #40Composite materials

2Device complexity

If a single-layer adhesive tape is used, then the structure is simple, but reworkability is poor with residue remaining

Engineering Contradiction:

Improveadhesive tape structureVSAvoidreworkability

Core Design Contradiction:

Device complexityVSEase of operation

Solution Approach 1:

The adhesive tape is divided into three distinct layers: a first outer adhesive layer, an intermediate adhesive layer, and a second outer adhesive layer. Each layer has different composition and function, with the intermediate layer containing specific polymers (acrylic polymer, polyurethane polymer, and polyvinyl acetate polymer) to prevent white turbidity while outer layers provide adhesion and reworkability

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The outer adhesive layers use polymers with low glass transition temperatures (Tg ≤ 0°C) to provide low viscosity and high fluidity, enabling the adhesive to flow and conform during application while maintaining ease of removal during rework, contrasting with the intermediate layer's higher Tg polymers that provide cohesive strength

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If outer adhesive layers with low Tg are used, then fluidity and step coverage are improved, but cohesive force may be reduced

Engineering Contradiction:

Improvestep coverageVSAvoidcohesive force

Core Design Contradiction:

Manufacturing precisionVSStrength

Solution Approach 1:

The adhesive tape is divided into three distinct layers: a first outer adhesive layer, an intermediate adhesive layer, and a second outer adhesive layer. Each layer has different composition and function, with the intermediate layer containing specific polymers (acrylic polymer, polyurethane polymer, and polyvinyl acetate polymer) to prevent white turbidity while outer layers provide adhesion and reworkability

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The outer adhesive layers use polymers with low glass transition temperatures (Tg ≤ 0°C) to provide low viscosity and high fluidity, enabling the adhesive to flow and conform during application while maintaining ease of removal during rework, contrasting with the intermediate layer's higher Tg polymers that provide cohesive strength

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11725126B2Multilayer adhesive tape

Publication Date: 2023.08.15 KOZA NOVEL MATERIALS KOREA CO LTD

AI summary

Provided is a multilayer adhesive tape having excellent step coverage and reworkability. The multilayer adhesive tape sequentially includes: a first outer adhesive layer; an intermediate adhesive layer; and a second outer adhesive layer, in which the intermediate adhesive layer includes an intermediate adhesive polymer including: a polymerization unit of an alkyl group-containing (meth)acrylate monomer; a polymerization unit of a carboxyl group-containing monomer; and a polymerization unit of an acrylamide-based monomer.