Optical Adhesive Layer Net Structure for Stretchable Display Edge Fracture
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Solution Overview
Problem
In stretchable display devices, stress concentration at the edge leads to fracture due to differing elastic moduli of the flexible display substrate, Optical Clear Adhesive (OCA) layer, and backing film, while the interior does not deform significantly, limiting the stretching ratio.
Innovation Solution
An optical adhesive layer with a net-like structure of connection ribs and block regions is designed, where the ribs connect the edge region to block regions in a hollow portion, distributing tension forces uniformly across the block regions to prevent edge fractures and allow interior deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional OCA layer structure is used to protect the flexible display substrate, then the substrate is protected, but stress concentration occurs at the edge during stretching, leading to fracture
Solution Approach 1:
The OCA layer is segmented into multiple independent adhesive blocks distributed across the substrate surface, rather than forming a continuous layer. This segmentation allows each block to independently manage local stress, preventing stress concentration at edges while maintaining overall substrate protection.
Solution Approach 2:
The adhesive blocks are strategically positioned at specific locations where stress distribution is needed, creating localized adhesive regions rather than uniform coverage. This local quality approach ensures protection where needed while allowing stress dissipation in critical edge regions.
2Adaptability or versatility
If the OCA layer has high flexibility (smallest elastic modulus) to accommodate deformation, then it can deform easily, but this causes excessive deformation and rubbing at the stretched edge
Solution Approach 1:
By segmenting the OCA layer into discrete blocks, the patent allows localized deformation within each block while preventing excessive edge deformation. The segmented structure distributes deformation across multiple points rather than concentrating it at the edges.
Solution Approach 2:
The patent extracts the adhesive function from the edge regions and concentrates it in internal adhesive blocks. This removal of adhesive material from critical edge zones eliminates the source of edge deformation and rubbing problems.
3Reliability
If the OCA layer is made continuous to ensure uniform adhesion, then adhesion is uniform, but the interior region does not stretch and deform, limiting the stretching ratio
Solution Approach 1:
The continuous OCA layer is divided into multiple discrete adhesive blocks, creating gaps between them. This segmentation allows the interior regions to stretch and deform independently while maintaining adhesion at block locations, thereby increasing the overall stretching ratio.
Solution Approach 2:
The segmented OCA structure creates a porous or discontinuous adhesive distribution pattern. This porous arrangement provides space for deformation and stretching in the interior regions while maintaining sufficient adhesion through the distributed blocks.
Data Source
AI summary
The present disclosure provides an optical adhesive layer, a stretchable display device and a preparing method for the optical adhesive layer. The optical adhesive layer includes: an edge region enclosing a hollow portion; a plurality of block regions distributed in the hollow portion along a first direction and a second direction; and connection ribs connecting the block regions to the edge region, wherein the connection ribs are distributed in the hollow portion in a net form, and the connection ribs include a plurality of first ribs, second ribs, and third ribs connecting the block regions with the first and second ribs.