Edge Bank Structure for Moisture-Resistant Light Conversion Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current display devices face challenges in effectively partitioning emission and dummy opening areas, leading to issues with light emission efficiency and reliability due to the presence of reverse tapered faces in edge banks, which can result in moisture infiltration and reliability deterioration.
Innovation Solution
The display device incorporates a substrate with a display area and a dummy area, featuring bank patterns, light-emitting elements, and edge banks with specific inclined surfaces and configurations, including a second bank that overlaps the first bank and defines emission and dummy opening areas, with a light conversion layer and insulating layers to enhance light emission and prevent moisture ingress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If edge banks have reverse tapered faces to cover inner sides of bank patterns, then manufacturing coverage is improved, but moisture infiltration increases and reliability deteriorates
Solution Approach 1:
The edge bank is designed with asymmetric inclined surfaces: the inner inclined surface (facing the display area) has a tapered face for easy coverage, while the outer inclined surface (facing the edge) has a reverse tapered face that prevents moisture infiltration. This asymmetric design allows each surface to serve its specific function optimally.
Solution Approach 2:
Different surfaces of the edge bank are given different geometric properties tailored to their local requirements. The inner surface uses a tapered face structure to ensure complete coverage of bank patterns during manufacturing, while the outer surface uses a reverse tapered face structure to create a moisture barrier at the edge region.
2Manufacturing precision
If edge banks have tapered faces for coverage, then manufacturing precision is improved, but light emission efficiency decreases due to moisture infiltration
Solution Approach 1:
The edge bank employs asymmetric inclined surfaces where the inner surface has a tapered face for precise alignment and coverage during manufacturing, while the outer surface has a reverse tapered face that prevents moisture infiltration, thereby protecting light emission efficiency.
3Reliability
If edge banks use reverse tapered faces to prevent moisture infiltration, then reliability is improved, but manufacturing coverage of bank patterns deteriorates
Solution Approach 1:
The edge bank is designed with locally optimized surfaces: the inner inclined surface facing the display area has a tapered face structure that ensures complete coverage of bank patterns during manufacturing, while the outer inclined surface facing the edge has a reverse tapered face structure that creates an effective moisture barrier.
4Device complexity
If edge banks have uniform inclined surfaces, then structural simplicity is maintained, but both coverage and moisture protection cannot be optimized simultaneously
Solution Approach 1:
The edge bank transitions from a uniform structure to an asymmetric structure with two different inclined surfaces. The inner inclined surface has a tapered face for optimal coverage, while the outer inclined surface has a reverse tapered face for optimal moisture protection, allowing both functions to be simultaneously optimized.
Data Source
AI summary
A display device includes a substrate including a display area including pixels, and a dummy area including dummy pixels, a pixel circuit layer including a transistor, and a via layer above the transistor, bank patterns above the via layer, light-emitting elements between the bank patterns in plan view, a first bank above a portion of the bank patterns, a second bank above the first bank, and including an edge bank defining an outermost boundary of the dummy area, covering an inner side of an edge bank pattern of the bank patterns overlapping the edge bank, and covering an inner side of a portion of the first bank that overlaps the edge bank, the first bank and the second bank partitioning emission areas and dummy opening areas, and a light conversion layer in the emission areas and in the dummy opening areas, which correspond to openings of the second bank.