Organic EL Display Blocking Structure for Moisture Sealing
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Solution Overview
Problem
Existing organic EL display devices suffer from moisture ingress through the display area due to insufficient sealing, particularly when foreign matter adheres to the vapor deposition mask during the formation of the sealing film, leading to potential display failures.
Innovation Solution
Incorporating a blocking area with a first blocking area made of inorganic material between the display and peripheral circuit areas, and a second blocking area including a light-emitting organic layer, to prevent moisture entry from the peripheral circuit area into the display area, while using an evaporation mask that does not contact the display area during deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing film is formed to cover the overall surface including peripheral circuit area, then sealing coverage is improved, but foreign matter transfer risk increases
Solution Approach 1:
The patent divides the surface into distinct deposition regions: a first deposition region for the display area and a second deposition region for the peripheral circuit area. By using separate vapor deposition masks for each region, foreign matter transferred to one mask cannot contaminate the other region, thus maintaining sealing coverage while preventing foreign matter transfer.
Solution Approach 2:
The patent introduces an intermediate structure (protrusion and recess configuration) between the display area and peripheral circuit area. The protrusion on the substrate and corresponding recess on the mask create a physical barrier that prevents foreign matter on the mask from being transferred to the display area during deposition.
2Manufacturing precision
If vapor deposition mask contacts peripheral circuit area, then deposition coverage is improved, but moisture entry risk increases
Solution Approach 1:
The patent segments the deposition process into two separate operations: first depositing the organic insulating layer in the display area, then depositing the light emitting organic layer in the peripheral circuit area using a second mask. This segmentation ensures that the mask only contacts the peripheral circuit area during the second deposition, maintaining both deposition coverage and moisture sealing.
Solution Approach 2:
The patent applies different masking strategies to different regions: the display area receives deposition without mask contact to ensure moisture sealing, while the peripheral circuit area receives deposition with mask contact to ensure proper layer formation. This local quality approach optimizes both deposition coverage and sealing reliability.
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 effectively prevents moisture ingress, thereby maintaining long-term display quality by blocking foreign matter transfer and ensuring proper sealing, thus reducing display failures.
Implementation Method 1
a first blocking area configured by only one or a plurality of layers made of inorganic material between an insulating substrate made of a base material and an electrode layer which covers the display area
Implementation Method 2
In particular, in a deposition process before the sealing film is formed, the foreign matter that has adhered to a vapor deposition mask may be transferred to the TFT substrate side during the deposition process
Data Source
AI summary
A light-emitting element display device includes: a display area which has an organic insulating layer that is made of an organic insulating material; a peripheral circuit area which is disposed around the display area and which has the organic insulating layer; and a blocking area that is formed between the display area and the peripheral circuit area. The blocking area includes: a first blocking area configured by only one or a plurality of inorganic material layers between an insulating base substrate and an electrode layer which covers the display area and is formed continuously from the display area, and which configures one of two electrodes for allowing the light emitting area to emit the light; and a second blocking area including a plurality of layers configuring the first blocking area, and a light emitting organic layer.