Emissive Display Partition Structure for Dark Dot Prevention
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Solution Overview
Problem
Emissive display devices face defects such as dark dots due to material residue on pixel electrodes, which affect image quality and can lead to short-circuits between electrodes.
Innovation Solution
The use of a dual-partition structure, where a black first partition covers the edge of the pixel electrode and a transparent second partition protrudes laterally to prevent material migration and aggregation, combined with a manufacturing method that forms these partitions to expose the center of the pixel electrode and prevent material contact with the upper surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a black partition is used to improve optical characteristics such as contrast ratio, then image quality is improved, but material residue remains on pixel electrode causing dark dots
Solution Approach 1:
The partition is divided into two distinct parts: a first partition containing black pigment/dye for optical isolation and contrast enhancement, and a second partition free of black materials that extends over the pixel electrode to prevent material migration. This segmentation allows each part to fulfill its specific function without causing defects.
Solution Approach 2:
The second partition acts as an intermediary barrier between the pixel electrode and external contaminants. It prevents metal particles and material residue from reaching the pixel electrode while allowing the first partition to maintain optical isolation functions.
2Illumination intensity
If partition material is used to cover pixel electrode edge, then optical characteristics are improved, but material migration causes short-circuits between electrodes
Solution Approach 1:
The partition structure is segmented into a first partition for optical isolation and a second partition for physical protection. The second partition extends laterally over the pixel electrode to prevent material migration that could cause short-circuits, while the first partition maintains optical characteristics.
Solution Approach 2:
The second partition extends in a lateral dimension over the pixel electrode surface, creating a protective overlay that prevents material migration from reaching the electrode while maintaining the functional integrity of the display structure.
3Device complexity
If a single partition structure is used, then device complexity is reduced, but it cannot simultaneously prevent material migration and maintain optical characteristics
Solution Approach 1:
The partition is divided into two functional segments: the first partition with black materials for optical isolation and contrast enhancement, and the second partition without black materials for preventing material migration. This segmentation enables simultaneous achievement of optical performance and defect prevention.
Solution Approach 2:
Different regions of the partition have different material compositions and functions. The first partition region contains black pigment/dye for optical isolation, while the second partition region is free of black materials to prevent contamination of the pixel electrode, with each region optimized for its specific purpose.
Data Source
AI summary
An emissive display device according to an embodiment includes: a substrate; a transistor disposed on the substrate; an insulating layer disposed on the transistor; a pixel electrode disposed on the insulating layer and electrically connected to the transistor; and a partition disposed on the insulating layer and covering at least an edge of the pixel electrode to expose a center of the pixel electrode. The partition includes a first partition in contact with a side surface of the pixel electrode, and a second partition in contact with an upper surface of the pixel electrode.