OLED Encapsulation Layer Height Variation for Moisture Barrier
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Solution Overview
Problem
Organic light-emitting display apparatuses are vulnerable to external moisture and oxygen, which can lead to deterioration, and existing thin film encapsulation methods may not adequately prevent the intrusion of contaminants, especially at the side surfaces.
Innovation Solution
An organic light-emitting display apparatus with a substrate having side walls and an encapsulation layer that includes a first inorganic layer, a first organic layer, and a second inorganic layer, where the height of the encapsulation layer's outer end portion and a barrier part are less than the side walls, effectively sealing the display unit and preventing moisture and gas intrusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a thin film encapsulation layer is used to make the display apparatus thin and flexible, then the device thickness and flexibility are improved, but the side-surface barrier characteristics deteriorate
Solution Approach 1:
The encapsulation layer is designed with different height levels: a first height for the central region and a second height (lower than the first) for the outer end portion. This dimensional variation allows the encapsulation layer to provide adequate barrier protection at the side surfaces while maintaining overall thinness and flexibility of the display apparatus.
Solution Approach 2:
The encapsulation layer has non-uniform thickness distribution, with the central region having a greater height than the outer end portion. This local quality variation optimizes the barrier characteristics at critical areas (side surfaces) while keeping other areas thin, thus resolving the contradiction between overall thinness and localized protection.
2Reliability
If the encapsulation layer height is increased to improve barrier characteristics, then the side-surface protection is improved, but the display apparatus thickness increases
Solution Approach 1:
The encapsulation layer is segmented into different height regions: a central region with greater height and an outer end portion with lesser height. This segmentation allows the side surfaces to receive adequate protection from the taller central region while the overall device thickness is controlled by the shorter outer end portion.
Solution Approach 2:
By introducing vertical dimension variation within the encapsulation layer structure, the patent achieves different protection levels at different locations without uniformly increasing the overall device thickness.
3Ease of manufacture
If a simple single-layer encapsulation is used, then the manufacturing process is simplified, but the barrier effectiveness against moisture and oxygen deteriorates
Solution Approach 1:
The encapsulation layer comprises multiple material layers (first and second inorganic layers, first and second organic layers) with different properties. This composite structure provides enhanced barrier effectiveness against moisture and oxygen penetration while maintaining a relatively simple deposition process.
Solution Approach 2:
The encapsulation is divided into multiple functional layers with different heights and materials, where inorganic layers provide barrier properties and organic layers provide flexibility and stress relief, achieving both protection and manufacturability.
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
The solution enhances the side-surface barrier characteristics, effectively preventing the intrusion of external moisture and gases, thereby improving the durability and reliability of the organic light-emitting display apparatus.
Implementation Method 1
an encapsulation layer which is deposited over the display unit and contacts each of the one or more side walls
Data Source
AI summary
Provided is an organic light-emitting display apparatus including: a substrate having one or more side walls; a display unit positioned on the substrate; and an encapsulation layer deposited over the display unit and contacting each of the one or more side walls, wherein a height of an outer end portion of the encapsulation layer is less than that of each of the side walls.