Flexible Display Adhesive Thickness Ratio for Crack Prevention
Solution Overview
Problem
Bended and flexible display devices face defects such as cracks in the electrode and wiring patterns of capacitive touch panels, which affect their durability and lifespan.
Innovation Solution
A display device structure featuring a display panel, a touch module, a cover film, and adhesive layers with specific thickness ratios to absorb folding stress and prevent cracks, with the first and second adhesive layers comprising optically clear adhesives and applied to both sides for enhanced attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a capacitive touch panel is used to improve durability and lifespan, then reliability is improved, but cracks occur in the electrode pattern and wiring pattern when bended
Solution Approach 1:
A buffer layer is introduced between the touch panel and the display panel to absorb and distribute folding stress before it reaches the electrode and wiring patterns. This cushioning layer prevents stress concentration that would otherwise cause cracks, thereby maintaining the structural integrity and reliability of the capacitive touch panel during bending operations
2Adaptability or versatility
If the touch panel is made flexible to enable bended display devices, then adaptability is improved, but defects occur due to generation of cracks
Solution Approach 1:
The display device employs a composite structure comprising multiple layers including the touch panel, buffer layer, and display panel. Each layer is designed with specific material properties that collectively provide both flexibility for bending and resistance to crack formation, enabling the device to adapt to various form factors while maintaining reliability
3Strength
If adhesive layers with specific thickness ratio are used to prevent cracks, then strength is improved, but device complexity increases
Solution Approach 1:
The invention specifies precise thickness ratios for the adhesive layers (first adhesive layer thickness: 1/4 to 1/2 of the display panel thickness, second adhesive layer thickness: 1/8 to 1/4 of the display panel thickness). By controlling these dimensional parameters, the structure achieves optimal stress distribution and crack prevention without requiring complex additional components, thus balancing strength enhancement with structural simplicity
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 structure effectively prevents cracks and maintains assembly stability even with curvature, ensuring the display device's durability and longevity by controlling folding stress within safe limits.
Implementation Method 1
a first adhesive layer located between the display panel and the touch module, and a second adhesive layer located between the touch module and the cover film, wherein a thickness ratio of the first adhesive layer and the second adhesive layer with respect to a thickness of the display device is in a range of 7% to 40%
Data Source
AI summary
A display device according to an embodiment includes a display panel, a touch module located on the display panel, a cover film located on the touch module, a first adhesive layer located between the display panel and the touch module, and a second adhesive layer located between the touch module and the cover film, wherein a thickness ratio of the first adhesive layer and the second adhesive layer with respect to a thickness of the display device is in a range of 7% to 40%.