Stretchable Display Encapsulation Structure for Crack Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display devices experience defects such as cracks due to elongation, particularly in inorganic layers, which limits their elongation rate and structural integrity during bending or stretching.
Innovation Solution
The display device incorporates a substrate with specific bank layers and encapsulation layers, including sub-bank layers with tips and multiple encapsulation layers, to enhance elongation rate by dispersing stress and preventing cracks, while using conductive and insulating materials to maintain electrical connectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the display device is elongated to achieve flexible forms, then adaptability is improved, but cracks occur in inorganic layers reducing reliability
Solution Approach 1:
The inorganic encapsulation layer is divided into multiple segments separated by organic insulating layers. These segmented inorganic layers are connected through conductive layers that extend into the second area, allowing independent movement of each segment during elongation while maintaining electrical connectivity, thus preventing crack formation
Solution Approach 2:
Organic insulating layers are introduced as intermediary layers between adjacent inorganic encapsulation layers. These organic layers act as flexible buffers that can accommodate deformation during elongation, preventing stress concentration and crack propagation between the rigid inorganic layers
2Adaptability or versatility
If the elongation rate is increased to enhance flexibility, then adaptability is improved, but structural integrity deteriorates
Solution Approach 1:
The encapsulation structure is segmented into multiple inorganic layers separated by organic insulating layers. This segmentation allows each layer to deform independently during elongation, distributing mechanical stress and preventing catastrophic failure, thereby maintaining structural integrity at higher elongation rates
Solution Approach 2:
The patent changes the physical and chemical parameters of the encapsulation layers by using different material compositions (inorganic vs. organic) with different mechanical properties. The organic insulating layers have higher flexibility parameters that allow greater elongation, while the inorganic layers provide protective barriers, achieving both high elongation rate and structural integrity
3Reliability
If conductive layers are added to maintain electrical connectivity across segmented areas, then reliability is improved, but device complexity increases
Solution Approach 1:
The conductive layers serve multiple functions: they provide electrical connectivity between adjacent first areas, act as bridging elements between segmented inorganic encapsulation layers, and extend into the second area to maintain circuit continuity during deformation. This multi-functionality reduces the need for separate components, thereby limiting the increase in device complexity
Data Source
AI summary
A display device includes a substrate including a first area and a second area surrounding the first area, a first electrode disposed in the first area, a first bank layer disposed on the first electrode and defining a first opening that overlaps the first electrode and a second opening that overlaps the second area, an intermediate layer disposed on the first electrode, a second electrode disposed on the intermediate layer, and an encapsulation layer disposed on the second electrode and defining a third opening that overlaps the second area, wherein the first bank layer includes a first sub-bank layer and a second sub-bank layer, the second sub-bank layer being disposed on the first-sub bank layer and including a first tip extending toward the first opening and a second tip extending toward the second opening.