OLED Encapsulation Structure With Valley Barrier Against Moisture Ingress
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic light-emitting display apparatuses face image quality deterioration due to infiltration of impurities like gas or moisture from external sources or generated within the device, which affects the performance and longevity of the OLEDs.
Innovation Solution
The design incorporates a substrate with a display area and a periphery area, featuring a first organic insulating layer with a valley portion, a second organic insulating layer with specific openings, and a capping layer, along with a common electrode that covers the valley portion and extends to prevent impurities from entering the display area, and an encapsulation member comprising organic and inorganic films to protect the OLEDs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If organic light-emitting devices are used in display apparatus, then the display can be driven at low voltage, be light-weight and thin, have excellent viewing angle, high contrast ratio, and high response speed, but image quality deteriorates due to infiltration of impurities such as gas or moisture
Solution Approach 1:
The encapsulation structure is divided into multiple functional layers: first and second organic insulating layers, inorganic encapsulation layers, and a capping layer. Each layer serves specific protective functions, creating a multi-barrier system that effectively blocks impurity infiltration while maintaining OLED performance
Solution Approach 2:
The patent employs a composite encapsulation structure combining organic insulating materials and inorganic encapsulation materials. This composite approach leverages the advantages of both material types: organic layers provide flexibility and stress relief, while inorganic layers provide superior moisture and gas barrier properties
2Reliability
If the organic insulating layer is disposed across the entire substrate including periphery area, then it provides continuous protection, but impurities can still infiltrate through the periphery area affecting OLED performance
Solution Approach 1:
The patent implements local quality enhancement by extending the first organic insulating layer into a valley portion in the periphery area, and by positioning the inorganic encapsulation layer to specifically cover the valley portion. This localized reinforcement prevents impurity infiltration at the critical periphery interface without compromising the overall protective function
Solution Approach 2:
The patent introduces a vertical dimension solution by creating a valley portion structure where the encapsulation layers extend downward into the periphery area. This three-dimensional configuration provides enhanced barrier protection against impurity infiltration from the periphery region
Data Source
AI summary
An organic light-emitting display apparatus includes a substrate having a display area displaying an image and a periphery area. The periphery area is located next to the display area. A first organic insulating layer is disposed on the substrate. The first organic insulating layer includes a valley portion separating the first organic insulating layer from the periphery area. A plurality of organic light-emitting devices is disposed on the substrate. Each of the organic light-emitting devices includes a first electrode, an emission layer, and a second electrode, sequentially disposed over the first organic insulating layer. The second electrode covers the emission layer and the valley portion. A second organic insulating layer is disposed over the first organic insulating layer and incudes a first opening exposing a center portion of the first electrode and a second opening overlapping the valley portion. A capping layer covers the second electrode.