OLED Encapsulation Layer Thickness Distribution for Sealing and Flexibility
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Solution Overview
Problem
The existing organic light emitting displays face challenges in achieving a balance between flexibility and hermetic sealing due to the complexity and low productivity of the multi-layered encapsulation process, which requires at least 10 layers of alternately deposited inorganic and organic films, leading to decreased flexibility and increased manufacturing complexity.
Innovation Solution
The encapsulation layer is structured with an organic layer uniformly covering both light emitting and bank portions, and an inorganic layer that is thicker on the light emitting areas than on the bank portions, comprising a first inorganic film uniformly deposited on the organic layer and a second inorganic film selectively formed only on the light emitting areas, enhancing sealing while maintaining flexibility by reducing the number of layers needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If at least 10 layers of inorganic and organic films are alternately deposited to achieve hermetic sealing, then the sealing protection improves, but the flexibility is drastically decreased
Solution Approach 1:
The encapsulation layer structure is designed with different thicknesses in different regions: the inorganic layer is thicker on the light emitting area to provide hermetic sealing, while the organic layer is thicker on the bank portion to provide flexibility. This local differentiation allows each region to optimize its function without compromising the other.
Solution Approach 2:
The encapsulation layer is divided into functionally distinct regions: a first region covering the light emitting area with enhanced inorganic layer thickness for sealing, and a second region covering the bank portion with enhanced organic layer thickness for flexibility. This segmentation resolves the contradiction by assigning different structural characteristics to different functional zones.
2Reliability
If at least 10 layers of inorganic and organic films are alternately deposited to achieve hermetic sealing, then the sealing protection improves, but the manufacturing process becomes very complicated
Solution Approach 1:
The patent merges the sealing function and flexibility function into a single integrated encapsulation layer structure, rather than requiring separate multi-layer stacks. The inorganic and organic layers are formed in a simplified sequence where the inorganic layer is deposited first, followed by the organic layer that is selectively thicker on the bank portion, achieving both sealing and flexibility in one structure.
Solution Approach 2:
The encapsulation layer structure is designed with different thicknesses in different regions: the inorganic layer is thicker on the light emitting area to provide hermetic sealing, while the organic layer is thicker on the bank portion to provide flexibility. This local differentiation allows each region to optimize its function without compromising the other.
3Reliability
If at least 10 layers of inorganic and organic films are alternately deposited to achieve hermetic sealing, then the sealing protection improves, but the productivity is low
Solution Approach 1:
The patent merges the sealing function and flexibility function into a single integrated encapsulation layer structure, rather than requiring separate multi-layer stacks. The inorganic and organic layers are formed in a simplified sequence where the inorganic layer is deposited first, followed by the organic layer that is selectively thicker on the bank portion, achieving both sealing and flexibility in one structure.
Solution Approach 2:
The inorganic layer is formed first as a base layer with uniform thickness, and then the organic layer is formed with selective thickness variation. This preliminary formation of the inorganic layer simplifies the overall process by establishing the sealing foundation before adding the flexibility-enhancing organic layer in a single subsequent step.
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 approach simplifies the manufacturing process, improves productivity, and maintains both flexibility and effective sealing by focusing the inorganic layer's thickness on the light emitting areas for sealing and minimizing it on the bank portions for flexibility, thereby reducing the overall complexity and enhancing the display's performance.
Implementation Method 1
the inorganic film 32 prevents the penetration of oxygen and moisture and the organic film 31 provides flexibility
Implementation Method 2
The organic film 31 can be composed of either of acrylic, methacrylic, polyester, polyethylene terephthalate, polyethylene, or polypropylene, etc.
Data Source
AI summary
An organic light emitting display and a manufacturing method thereof include an improved encapsulation layer. The encapsulation layer of the organic light emitting display includes an organic layer uniformly covering bank portions and light emitting areas on a substrate; and an inorganic layer formed thicker on the light emitting areas than on the bank portions. In the organic light emitting display, the inorganic layer is thick on the light emitting area in which a sealing ability is required and the bank portion is thin in order to provide flexibility. Therefore, the encapsulation layer can be formed more easily compared to an encapsulation layer on a device in which the organic layer and inorganic layer are alternately formed at least 10 times.