Multi-layer Film with Intervention Layer for Foldable Display Stress Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional display panels face issues when folded due to stress on inorganic layers, which can lead to cracking under tension or compression, as they typically have uniform multi-film structures in flexible and rigid areas, causing neutral planes to coincide and resulting in structural instability.
Innovation Solution
A multi-layer film with distinct regions, including a first region with a bonding layer and planarization layer, and a second region with a bonding layer, planarization layer, and an intervention layer, where the second bonding layer is irradiated with UV light, and a second support layer is added to enhance interfacial bonding strength, allowing for a more balanced stress distribution when folded.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a uniform multi-film structure is used in flexible and rigid areas, then the manufacturing process is simple, but the neutral planes coincide causing structural instability when folded
Solution Approach 1:
The display panel is divided into a first area (flexible region) and a second area (rigid region) with different multi-film structures. The first area includes a first flexible substrate with first bonding layer and first planarization layer, while the second area includes a second rigid substrate with second bonding layer and second planarization layer. This segmentation allows each region to have optimized stress distribution characteristics, preventing neutral plane coincidence and resulting cracks when folded.
Solution Approach 2:
Different regions of the display panel are given different structural properties tailored to their specific functional requirements. The flexible area uses a flexible substrate configuration suitable for bending, while the rigid area uses a rigid substrate configuration for stability. This local quality approach ensures that each region handles stress appropriately during folding operations.
2Adaptability or versatility
If the display panel is folded, then flexibility and adaptability are improved, but stress on inorganic layers causes cracking
Solution Approach 1:
The display panel structure is segmented into flexible and rigid areas with distinct multi-film configurations. The first area with flexible substrate and the second area with rigid substrate are positioned at different locations, creating separate neutral planes that do not coincide during folding. This prevents stress concentration and cracking in the inorganic layers while maintaining foldability.
Solution Approach 2:
Organic bonding layers are introduced as intermediary layers between the flexible substrate and planarization layers, and between the rigid substrate and its planarization layers. These bonding layers act as stress buffers that reduce the direct transmission of mechanical stress to the inorganic layers during folding, thereby preventing cracks while enabling flexibility.
3Strength
If thicker bonding layers are used to increase interfacial bonding strength, then bonding reliability is improved, but the neutral plane position shifts causing stress concentration
Solution Approach 1:
The bonding layer thickness is optimized differently for the flexible and rigid areas based on their specific stress requirements. The first bonding layer in the flexible area and the second bonding layer in the rigid area have thicknesses designed to achieve appropriate interfacial bonding strength while maintaining proper neutral plane positioning for each region, preventing stress concentration.
Solution Approach 2:
The thickness parameters of the bonding layers are carefully controlled within specific ranges to balance two competing requirements: providing sufficient interfacial bonding strength to prevent delamination, while keeping the layers thin enough to maintain proper neutral plane positioning and avoid stress concentration in the inorganic layers.
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 configuration allows the display panel to maintain structural integrity when folded by relocating neutral planes to different layers, reducing the risk of cracking and enabling flexible and rigid areas to handle stress more effectively, thus enhancing the durability of the display panel.
Implementation Method 1
the second bonding layer is irradiated by UV light, and a second support layer is added to enhance interfacial bonding strength
Data Source
AI summary
The present disclosure relates to a multi-layer film. The multi-layer film may include a first region and a second region. The first region may include a first bonding layer and a first planarization layer directly contacted with each other. The second region includes a second bonding layer, a second planarization layer, and an intervention layer between the second bonding layer and the second planarization layer.