Cleavable Adhesive Tape for Permeate-Sensitive Surfaces

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Solution Overview

Problem

Current adhesive tapes for encapsulating permeate-sensitive surfaces, such as electronic components, face challenges in achieving storage and transportability while maintaining effective bonding and barrier properties against oxygen and water vapor, as conventional release liners cause significant adhesion issues and gelled prepregs require cooling to prevent curing.

Innovation Solution

A cleavable adhesive tape section with a settable liquid adhesive layer of low viscosity, allowing for split and reduced layer thickness, is used, featuring a carrier layer and a cover layer, enabling flexible bonding and encapsulation without the need for cooling and with improved wetting and barrier properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional release liners are used to cover the liquid adhesive layer, then storage and transportability is improved, but significant adhesion occurs between the liquid adhesive and the liner when the liner is removed

Engineering Contradiction:
Improvestorage and transportabilityVSAvoidadhesion to liner
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

A release layer is introduced as an intermediary between the liquid adhesive layer and the release liner. This release layer has controlled adhesion properties that prevent significant adhesion to the liner while allowing the adhesive to be transferred to the substrate. The release layer acts as a mediator that resolves the conflict between storage stability and clean release.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The adhesion parameters of the adhesive system are modified by adding the release layer with specific adhesion characteristics. The release layer has lower adhesion to the liner compared to the adhesive-substrate interface, creating a controlled adhesion gradient that enables clean release while maintaining bonding performance.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If gelled prepregs are used to ensure storage and transportability, then handling is improved, but the curing reaction must be continuously prevented by cooling

Engineering Contradiction:
Improvestorage and transportabilityVSAvoidcooling requirement
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The adhesive is prepared in a liquid state with appropriate viscosity for application, and the release layer is pre-applied to the liner. This preliminary preparation allows the adhesive to be applied and transferred before any curing reaction occurs, eliminating the need for continuous cooling during storage and transport.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The viscosity parameter of the adhesive is optimized for liquid application state, and the release layer introduces controlled adhesion parameters that enable storage without gelation. This parameter optimization allows the adhesive to remain in a usable liquid state during storage and transport without requiring temperature control.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If the adhesive layer is applied with high viscosity, then storage stability is improved, but wetting ability of the substrate surface during bonding is reduced

Engineering Contradiction:
Improvestorage stabilityVSAvoidwetting ability
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The release layer serves as an intermediary that decouples the viscosity requirements for storage stability from the wetting requirements for bonding. The liquid adhesive with optimized viscosity can be applied and transferred through the release layer to the substrate, achieving both storage stability and good wetting performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The viscosity parameter of the liquid adhesive is optimized within a specific range (10-1000 mPa·s) that balances storage stability and wetting ability. The release layer introduces adhesion parameters that enable the adhesive to maintain its liquid state during storage while effectively wetting the substrate during application.

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If liquid adhesive with low viscosity is used, then wetting and flowability are improved, but storage and transportability becomes difficult

Engineering Contradiction:
Improvewetting and flowabilityVSAvoidstorage and transportability
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The viscosity parameter is optimized to a specific range (10-1000 mPa·s) that provides sufficient flowability for wetting while maintaining storage stability. The release layer introduces adhesion parameters that prevent the adhesive from spreading uncontrollably during storage, enabling low-viscosity adhesives to be stored and transported effectively.

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

The method allows for multiple uses of the adhesive tape section, ensuring effective bonding and encapsulation of permeate-sensitive surfaces with reduced water vapor permeation, maintaining adhesive properties and preventing permeation of oxygen and water vapor.

Implementation Method 1

a liquid adhesive layer (iii) with a complex viscosity of less than or equal to 10 5

Methodology Applied
Scientific EffectViscosity:

Implementation Method 2

A low flow capacity on the (opto-)electronic arrangement can reduce the barrier effect at the interfaces due to incomplete wetting of the respective surface

Methodology Applied
Scientific EffectWetting: Wetting

Implementation Method 3

EP 1 518 912 A1 teaches an adhesive for encapsulating an electroluminescent element that contains a photocationically curable compound and a photocationic initiator as well as an epoxy-based adhesive

Methodology Applied
Scientific EffectChemical Bonding: Chemical Bonding

Implementation Method 4

Such barrier adhesive tapes for inorganic and/or organic (opto)electronics, in particular for organic (opto)electronics, must enable flexible bonding, which at the same time represents a permeation barrier for permeates, such as oxygen and/or water vapor

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP3137566B1Method for producing an adhesion on permeate-sensitive surfaces
Publication Date: 2021.07.28 TESA SE
  • EP3137566B1 patent drawingFigure 1
  • EP3137566B1 patent drawingFigure 2a~2c
  • EP3137566B1 patent drawingFigure 3

AI summary

The invention relates to the field of adhesive tapes, and particularly to adhesive tapes which can be split, for the purpose of the adhesion and the encapsulation of surfaces that are sensitive to permeate. In particular, the invention relates to a method for producing an adhesion using an adhesive tape section that can be split and, in particular, stored, and comprises (iii) at least one adhesive layer that can be split, is provided on at least some sections of the surface, and has a complex viscosity of less than or equal to 105 Pa s measured according to ISO6721-10 at 23°C and a frequency of 1 rad/s, and that comprises at least one settable liquid adhesive. The aforementioned splittable adhesive tape section, the adhesive tape section that has been split at least once and comprises an adhesive layer split at least once and reduced in layer thickness, and said adhesive layer that has been split at least once, are all provided for the purpose of the multiple adhesion and encapsulation of permeate-sensitive surfaces, preferably, for example, those of optoelectronic arrangements. The invention also relates to a method for producing a barrier layer.