Touch Sensor Module Supporting Structure for Flexible Displays

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Solution Overview

Problem

Existing touch sensor modules face challenges in maintaining electrical and mechanical reliability, especially when subjected to bending or folding, which can lead to delamination and damage to sensing electrodes and traces in flexible display devices.

Innovation Solution

A touch sensor module design featuring a supporting structure that partially covers the touch sensor layer and flexible circuit board, along with an optical layer and filling layer, which enhances adhesion and flexibility, preventing delamination and damage during bending by adjusting the tensile modulus and adhesion forces of the supporting structure and filling layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the touch sensor module is made flexible to enable bending, then adaptability is improved, but mechanical reliability deteriorates due to delamination and damage to sensing electrodes and traces

Engineering Contradiction:

ImproveflexibilityVSAvoidmechanical reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent employs a multi-layer composite structure consisting of a touch sensor layer, flexible circuit board, and supporting structure. Each layer is made of materials with specific mechanical properties that complement each other, creating a composite system that maintains structural integrity during bending while enabling flexibility. The supporting structure provides mechanical reinforcement without compromising the flexible nature of the overall module.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The supporting structure is designed to cover and protect vulnerable areas of the touch sensor layer and flexible circuit board before bending occurs. This preemptive protective measure prevents delamination and damage to sensing electrodes and traces by providing mechanical support in advance, addressing the reliability issue while maintaining flexibility.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If the supporting structure is made rigid to prevent delamination, then mechanical reliability is improved, but flexibility deteriorates

Engineering Contradiction:

Improvemechanical reliabilityVSAvoidflexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The supporting structure is designed with spatially varying properties - it provides rigid support in areas where structural integrity is critical (preventing delamination) while allowing flexibility in areas where bending is required. This localized differentiation of mechanical properties resolves the contradiction between reliability and flexibility.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent optimizes the mechanical parameters of the supporting structure, including its thickness, material composition, and attachment method, to achieve a balance between rigidity for delamination prevention and flexibility for bending capability. By carefully controlling these parameters, both reliability and flexibility are maintained.

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 proposed design significantly improves the mechanical reliability and flexibility of touch sensor modules, preventing delamination and damage to sensing electrodes and traces, even under extreme bending conditions, while maintaining effective touch sensing functionality.

Implementation Method 1

a supporting structure commonly and partially covering the flexible circuit board and the touch sensor layer

Methodology Applied

Scientific EffectAdhesion: Adhesive

Implementation Method 2

a filling layer at least partially filling the gap

Methodology Applied

Scientific EffectViscoelasticity: Viscoelasticity

Data Source

PatentUS11182032B2Touch sensor module, window stack structure including the same and image display device including the same

Publication Date: 2021.11.23 DONGWOO FINE CHEM CO LTD

AI summary

A touch sensor module according to an embodiment of the present invention includes a touch sensor layer including sensing electrodes and traces branching from the sensing electrodes, a flexible circuit board electrically connected to the traces at one end portion of the touch sensor layer, and a supporting structure commonly and partially covering the flexible circuit board and the touch sensor layer. Damages and delamination of electrodes and wirings included in the flexible circuit board and the touch sensor layer is prevented by the supporting structure.