Dual Plate OLED Separator Using Inorganic Insulating Layers
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Solution Overview
Problem
The existing organic electroluminescent display devices suffer from shortened lifetimes due to exposure of the organic emitting material layer and outgassing of organic insulating materials, which accelerates deterioration and reduces operational reliability.
Innovation Solution
A dual plate type organic electroluminescent display device is designed with a separator having a double layer construction of inorganic insulating materials, featuring projecting parts and undercut regions to prevent exposure of the organic emitting material layer and minimize outgassing, ensuring complete coverage by the second electrode and using inorganic materials that do not outgas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single layer organic insulating material is used as separator, then the manufacturing process is simpler, but the organic insulating material outgases and accelerates deterioration of the organic emitting material layer
Solution Approach 1:
The separator is constructed as a composite structure with a first inorganic insulating material layer (silicon oxide) and a second inorganic insulating material layer (silicon nitride) having different etch rates. This composite structure prevents outgassing while enabling selective etching to form the required separator profile without complicating the manufacturing process.
2Reliability
If the separator fully covers the organic emitting material layer, then the organic material is protected from exposure, but the separator structure becomes more complex
Solution Approach 1:
The separator structure extends in the vertical dimension with an undercut configuration where the lower portion wider than the upper portion. This dimensional approach allows the separator to provide complete coverage and protection of the organic emitting material layer while maintaining a manageable structural complexity through the etching process.
3Ease of manufacture
If the separator has uniform thickness, then the manufacturing process is simpler, but it cannot provide both coverage and undercut structure to fully protect the organic material
Solution Approach 1:
The separator exhibits local quality variation with different thickness regions: a lower portion with greater thickness providing the undercut structure for complete coverage, and an upper portion with reduced thickness. This local variation is achieved through selective etching of the two-layer inorganic insulating material structure, enabling precise geometric control without complicating the overall manufacturing process.
Data Source
AI summary
An organic electroluminescent display device includes first and second substrates facing and spaced apart from each other. A first electrode resides on the first substrate and a separator having dual-layer, reciprocal L-shaped pattern resides on the first electrode. An organic emitting layer having a first thickness resides on the first electrode in a sub-pixel region and a second electrode resides on the organic emitting layer. An array element layer resides on the second substrate, the array element layer including a thin film transistor. A connection pattern electrically connects the second electrode and the thin film transistor.