Detaching Display Modules Bonded by Liquid Optically Clear Adhesive

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Solution Overview

Problem

Conventional methods for detaching components from electronic assemblies, such as display modules, often result in mechanical damage, temperature sensitivity issues, and inefficiency due to conduction or convection heating, wire cutting, and twisting, which can lead to the degradation of valuable components.

Innovation Solution

A process utilizing an apparatus generating electromagnetic radiation (EMR) with wavelengths between 420 nm to 650 nm and intensities from 0.05 W/cm² to 5 W/cm² to heat the adhesive, allowing for the detachment of components with minimal mechanical stress by absorbing the radiation and maintaining temperatures between 50°C to 100°C, optionally followed by cooling to facilitate easy separation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If wire cutting or mechanical separation methods are used to detach components, then the detachment process can be completed, but mechanical damages occur to valuable components

Engineering Contradiction:
Improvedetachment efficiencyVSAvoidcomponent integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent replaces mechanical wire cutting and separation methods with electromagnetic radiation (laser or LED) to heat and soften the adhesive. This substitution eliminates direct mechanical contact with valuable components, preventing mechanical damages while maintaining detachment efficiency. The adhesive is heated to its softening temperature, allowing components to be separated without forceful mechanical intervention.

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

Solution Approach 2:

The patent changes the temperature parameter of the adhesive by applying electromagnetic radiation. The adhesive is heated from room temperature to its softening temperature range (typically 60-100°C), which fundamentally alters its mechanical properties from rigid to soft/pliable state. This parameter change enables easy separation without damaging components.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If conduction or convection heating methods are used to heat the adhesive, then the adhesive temperature can be increased, but temperature sensitivity issues occur in valuable components

Engineering Contradiction:
Improveadhesive temperatureVSAvoidtemperature sensitivity damage
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent applies electromagnetic radiation to heat only the adhesive layer locally, rather than heating the entire assembly through conduction or convection. The radiation penetrates through outer components and selectively heats the adhesive, which has different absorption characteristics. This localized heating achieves the required adhesive temperature while keeping the temperature exposure of sensitive components minimal and controlled.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The adhesive acts as an intermediary that absorbs electromagnetic radiation and converts it to thermal energy. The adhesive layer serves as the primary target for radiation heating, and its thermal properties are optimized to absorb radiation efficiently while protecting underlying components from excessive heat. The adhesive mediates between the radiation source and sensitive components.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If the entire module is heated up for detachment, then the adhesive becomes softer for easier separation, but damages due to temperature sensitivity of components occur

Engineering Contradiction:
Improveadhesive softnessVSAvoidthermal damage to components
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent applies localized heating through electromagnetic radiation that selectively targets the adhesive layer. The radiation parameters (wavelength, intensity, duration) are optimized to heat the adhesive to its softening point while minimizing heat transfer to sensitive components. This creates a localized thermal zone in the adhesive without uniformly heating the entire module, thus achieving adhesive softness while preventing thermal damage.

Inventive Principle:
Principle #3Local quality

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 allows for the efficient and safe detachment of components with minimal mechanical stress, avoiding damage and temperature sensitivity issues, while maintaining the integrity of reusable components, and is more efficient than conventional heating methods.

Implementation Method 1

heating the adhesive by the electromagnetic radiation via absorption of the electromagnetic radiation

Methodology Applied
Scientific EffectAbsorption of electromagnetic radiation: Absorption (EM radiation)

Implementation Method 2

heating the adhesive by the electromagnetic radiation via absorption of the electromagnetic radiation, and increasing the temperature of the adhesive

Methodology Applied
Scientific EffectPhotothermal conversion:

Data Source

PatentEP3149096B1A process and apparatus for detaching a display module bonded by a liquid optically clear adhesive
Publication Date: 2020.06.24 HENKEL KGAA
  • EP3149096B1 patent drawingFigure 1
  • EP3149096B1 patent drawingFigure 2
  • EP3149096B1 patent drawingFigure 3

AI summary

The present invention relates to a process for detaching a component from an electronic assembly.In particular,the present invention relates to a process for detaching a component bonded with a liquid optically clear adhesive (LOCA) in a display module by using electromagnetic radiation (EMR).