UV-Curable Structural Adhesives With Electrical Debonding

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Solution Overview

Problem

Existing adhesives used in electronic devices fail to provide sufficient adhesive strength under traumatic conditions and are not easily removable for recycling or repair, limiting the reuse and recyclability of electronic components.

Innovation Solution

A curable composition containing a (meth)acrylic-based multiblock copolymer, statistical (meth)acrylic-based copolymer, epoxy resin, photoacid generator, and ionic liquid, which can be cured with UV radiation and debonded using a direct current electric potential, providing structural adhesion and enabling separation of bonded substrates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional adhesives are used to bond components in electronic devices, then adhesive strength is provided under normal conditions, but adhesive strength is insufficient under traumatic conditions (impact/drop)

Engineering Contradiction:
Improveadhesive strengthVSAvoidadhesive reliability under trauma
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent uses a composite adhesive system combining acrylic-based polymers (for toughness and impact resistance) with epoxy resins (for strong bonding). This composite formulation provides both high adhesive strength under normal conditions and superior resistance to traumatic forces, resolving the contradiction between常规 adhesive strength and trauma reliability.

Inventive Principle:
Principle #40Composite materials

2Strength

If permanent adhesives are used to ensure strong bonding, then component attachment is secure, but component removal and recycling become difficult

Engineering Contradiction:
Improvebonding strengthVSAvoidcomponent removability
Core Design Contradiction:
StrengthVSEase of repair

Solution Approach 1:

The patent employs a reversible bonding mechanism where the adhesive's bond strength can be dynamically changed. During normal operation, the adhesive provides strong permanent bonding. When removal is needed, applying an electric field or heat reversibly weakens the bond, allowing clean component separation. This dynamic property resolves the contradiction between permanent attachment and ease of removal.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The adhesive system allows changing its bonding parameters (strength, reversibility) based on external conditions. By controlling factors such as electric field application, temperature, or moisture exposure, the adhesive transitions between strongly bonded and easily separable states, enabling both secure attachment and controlled removal.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If strong adhesives are used for structural bonding, then impact resistance is improved, but adhesive removal for recycling becomes problematic

Engineering Contradiction:
Improveimpact and drop resistanceVSAvoidadhesive residue after removal
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent replaces traditional mechanical or chemical adhesive removal methods with an electric field-based removal mechanism. The conductive or semi-conductive adhesive contains embedded particles that respond to applied electric fields, enabling controlled debonding without mechanical force that would cause residue or damage. This substitution resolves the contradiction between strong structural bonding and clean removal for recycling.

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

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

The solution offers high adhesive strength under impact and drop resistance while allowing for easy separation and reuse of components, enhancing recyclability and repairability of electronic devices.

Implementation Method 1

The curable composition can be cured with UV radiation

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

an ionic liquid that has a melting point less than 100 degrees Celsius and that has an anion selected from SbF6-

Methodology Applied
Scientific EffectIon migration: Electrophoresis

Data Source

PatentEP4602109B1Electrically debondable UV activated adhesives
Publication Date: 2026.03.04 3M INNOVATIVE PROPERTIES CO
  • EP4602109B1 patent drawingFigure 1A~1C
  • EP4602109B1 patent drawingFigure 2A~2B
  • EP4602109B1 patent drawingFigure 3

AI summary

Curable and cured compositions as well as articles containing the curable or cured compositions are provided. The cured compositions are typically a semi-structural or structural adhesive. Advantageously, the cured compositions can be removed (e.g., de-bonded) from the various surfaces of the articles after the useful lifetime of the articles, to correct misplacement of a part during manufacturing, or to repair the electronic device. The separation step occurs using a direct current electric potential across the cured composition.