Multi-Layer Adhesive System for Flexible Display Crack Prevention
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Solution Overview
Problem
During the manufacturing process of flexible display devices using bent window members, stress applied to the display module can cause cracks, leading to damage and reduced reliability.
Innovation Solution
A display device structure is developed, featuring a display module with a flexible display panel, input sensing circuit, and a multi-layer adhesive system comprising an acrylic-based first adhesive member and a polyurethane-based or other high-strength second adhesive member, which is applied in a specific configuration to prevent stress-induced cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a bent window member is used in flexible display devices, then adaptability to various shapes is improved, but stress concentration occurs causing cracks in the display module
Solution Approach 1:
The adhesive layer is divided into multiple sub-layers with different material properties. The first sub-layer (acrylic-based) provides initial bonding and stress distribution, while the second sub-layer (polyurethane-based or other high-strength material) provides enhanced crack resistance and mechanical strength. This segmentation allows each sub-layer to perform its specific function optimally in managing stress during bending.
Solution Approach 2:
The invention uses a composite adhesive structure combining acrylic-based material and polyurethane-based material (or alternative high-strength materials like polyethersulfone, polyamide, or ethylene-vinyl acetate). This composite material approach leverages the complementary properties of different materials to achieve both flexibility and crack resistance, resolving the contradiction between adaptability and reliability.
2Ease of manufacture
If stress is applied to the display module during manufacturing, then assembly processability is improved, but cracks occur reducing product reliability
Solution Approach 1:
The multi-layer adhesive structure is applied beforehand to cushion and distribute stress before cracks can occur. The first adhesive sub-layer absorbs initial stress through its acrylic-based properties, while the second adhesive sub-layer provides additional stress distribution and crack prevention through its high-strength material properties, protecting the display module during manufacturing processes.
Solution Approach 2:
The invention changes the material parameters of the adhesive layer by using different material compositions in different sub-layers. The first sub-layer uses acrylic-based material with specific viscosity and bonding characteristics, while the second sub-layer uses polyurethane-based or other high-strength materials with different mechanical properties. This parameter change allows the adhesive to withstand manufacturing stresses without causing cracks.
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 solution effectively prevents or significantly reduces the occurrence of cracks in the display module during manufacturing, enhancing the reliability and durability of the display device.
Implementation Method 1
a first adhesive member on the first display surface, the second display surface, and the third display surface, the first adhesive member including an acrylic-based material
Implementation Method 2
a second adhesive member on the first adhesive member, and including at least one of a polyurethane-based material, a polyethersulfone-based material, a polyamide-based material, or an ethylene-vinyl acetate-based material
Data Source
AI summary
A display device includes: a display module including: a display panel including a first display surface having a first side and a second side opposite the first side, a second display surface extending from the first side at an angle with respect to the first display surface, and a third display surface extending from the second side at an angle with respect to the first display surface; and an input sensing circuit on the display panel; a first adhesive member on the first display surface, the second display surface, and the third display surface, the first adhesive member including an acrylic-based material; a second adhesive member on the first adhesive member, and including at least one of a polyurethane-based material, a polyethersulfone-based material, a polyamide-based material, or an ethylene-vinyl acetate-based material; and a window member on the second adhesive member.