OLED Encapsulation Layout Using Multi-Height Dams for Moisture Sealing
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Solution Overview
Problem
OLED displays are susceptible to degradation due to environmental factors like moisture and oxygen, which can compromise their performance and longevity.
Innovation Solution
The implementation of a thin film encapsulation layer with a dam unit and a metal layer, where the dam unit includes multiple dams with varying heights and is formed on the same layer as the planarization and pixel-defining layers, and the metal layer is integrated with the voltage lines to enhance sealing and prevent organic material flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a thin film encapsulation layer is used to seal the OLED display, then the device can be kept light and thin, but the sealing effectiveness may be insufficient against environmental factors like moisture and oxygen
Solution Approach 1:
The encapsulation structure is segmented into multiple components: a thin film encapsulation layer for basic sealing, a dam unit with multiple dams at different positions for enhanced barrier protection, and a metal layer for additional sealing reinforcement. This segmentation allows each component to contribute to the overall sealing effectiveness while maintaining the light and thin characteristics of the display.
Solution Approach 2:
The encapsulation system uses composite materials including organic thin film layers, inorganic metal layers, and polymer-based dam units. This composite approach combines the advantages of different materials: the flexibility and light weight of organic films with the barrier properties of inorganic metals and the structural integrity of polymer dams, achieving effective sealing without compromising the display's lightweight nature.
2Ease of manufacture
If the dam unit is formed on the same layer as the planarization and pixel-defining layers, then the manufacturing process is simplified, but the adhesive strength and sealing effectiveness may be reduced
Solution Approach 1:
The dam unit is merged with the planarization and pixel-defining layers, forming an integrated structure that simplifies the manufacturing process. This merging allows the dam unit to be formed simultaneously with other critical layers, reducing the number of fabrication steps. The adhesive strength is maintained through proper material selection and interface design at the merged layers.
Solution Approach 2:
While the dam unit is formed on the same layer as other structures, local quality variations are introduced through the metal layer positioned at specific locations to enhance adhesive strength and sealing effectiveness at critical areas. This allows the overall structure to benefit from simplified manufacturing while maintaining high strength where needed.
3Reliability
If multiple dams with varying heights are used in the dam unit, then the sealing effectiveness is improved, but the device complexity increases
Solution Approach 1:
The dam unit is segmented into multiple dams with varying heights positioned at different locations around the display area. This segmentation creates a multi-level sealing barrier that effectively prevents moisture and oxygen penetration. The varying heights are strategically designed to provide enhanced protection at critical areas while maintaining overall structural simplicity through the integration with other layers.
Data Source
AI summary
An organic light-emitting diode display is disclosed. In one aspect, the display includes a display unit located on the substrate and including a display area and a non-display area surrounding the display area, and a thin film encapsulation layer sealing the display unit. The display also includes a voltage line formed in the non-display area and surrounding the display area, a metal layer formed of the same material as the voltage line, and a dam surrounding the display area and contacting the voltage line. The voltage line includes a first voltage line disposed in one side of the display area. The first voltage line includes a pair of first end portions and a pair of first connectors respectively connected to the pair of first end portions and extending away from the display area. The metal layer is disposed between the pair of first connectors. The dam contacts the metal layer.