OLED Sealing Layer Valley Structure for Moisture Protection
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Solution Overview
Problem
Existing organic light emitting display devices face challenges in effectively protecting the organic light emitting diodes (OLEDs) from contamination and moisture ingress, which can lead to defects and reduced lifespan.
Innovation Solution
A display device structure incorporating a sealing layer with a combination of inorganic and organic materials, where the inorganic materials are used at the edges to prevent moisture intrusion and the organic materials are used to cover the inorganic layers to prevent cracking, while also forming a valley in the non-display area to reduce residual layers and enhance protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing layer is used to protect OLEDs from contamination and moisture, then reliability is improved, but device complexity increases due to the need for multiple material layers
Solution Approach 1:
The sealing layer is constructed as a composite structure comprising an inorganic layer and an organic layer. The inorganic layer (e.g., silicon oxide, silicon nitride) provides moisture and oxygen barrier properties, while the organic layer (e.g., acrylic, epoxide) covers the inorganic layer to prevent cracking and provide mechanical flexibility. This composite material approach resolves the contradiction by combining materials with complementary properties to achieve both protection and structural integrity.
Solution Approach 2:
The sealing layer is divided into functionally distinct segments: the inorganic layer segment that provides chemical barrier properties against moisture and oxygen, and the organic layer segment that provides mechanical protection and crack prevention. This segmentation allows each layer to optimize its specific function, improving overall reliability while maintaining a manageable structural complexity through clear functional division.
2Object-affected harmful factors
If inorganic materials are used at the edges to prevent moisture intrusion, then protection effectiveness is improved, but manufacturing difficulty increases due to precise patterning requirements
Solution Approach 1:
The inorganic layer is selectively formed at the edges and peripheral regions of the substrate where moisture intrusion is most critical, rather than covering the entire surface uniformly. This local quality approach concentrates the moisture barrier function where it is most needed, improving protection effectiveness while reducing the overall manufacturing complexity by limiting the patterning requirements to specific critical areas.
3Strength
If organic materials cover the inorganic layers, then cracking is prevented, but productivity decreases due to additional coating steps
Solution Approach 1:
The organic layer is formed to cover and integrate with the inorganic layer in a unified sealing structure, where the two layers work together as a single protective system. This merging allows the organic material to provide crack prevention and mechanical flexibility while the inorganic layer provides the barrier function, achieving both strength and protection in one integrated structure that can be manufactured efficiently.
Data Source
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AI summary
A display device includes a substrate including a display configured to display an image and a non-display area disposed on at least one side of the display area. A plurality of pixels is disposed in the display area. An organic insulating layer is disposed on the substrate. A pixel defining layer is disposed on the organic insulating layer. A sealing layer at least partially covers the display area and the non-display area and includes an inorganic material. The organic insulating layer and the pixel defining layer have a valley disposed therein. The valley is formed by removing portions of the organic insulating layer and the pixel defining layer along a circumference of the display area.