Alignment Electrode Openings to Prevent Display Bright Spots
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Solution Overview
Problem
Display devices often suffer from bright spot defects, which compromise their reliability and performance, particularly due to issues with sub-pixel alignment and insulation layers in the non-emission areas.
Innovation Solution
A display device design featuring first, second, and third sub-pixels with specific electrode configurations, insulating layers, and openings to prevent bright spot defects, including a first insulating layer with openings, a second insulating layer with through holes, and a third insulating layer with contact holes, along with a method to separate exposed alignment electrodes to enhance reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If insulating layers are continuously formed over alignment electrodes in non-emission areas, then insulation is improved, but bright spot defects occur due to electrical discharge paths
Solution Approach 1:
The continuous insulating layer is segmented by forming openings and through-holes at specific locations. The first insulating layer has openings exposing the first alignment electrode, and the second insulating layer has through-holes corresponding to these openings. This segmentation prevents electrical discharge paths that would otherwise occur through continuous insulating layers, thereby eliminating bright spot defects while maintaining insulation reliability in other areas.
Solution Approach 2:
Different regions of the insulating structure are given different properties: the first insulating layer has openings in non-emission areas to prevent discharge, while the emission areas maintain continuous insulation. The second insulating layer has through-holes only in non-emission areas, and the third insulating layer has contact holes positioned strategically. This local differentiation allows the structure to prevent bright spot defects in non-emission areas while maintaining proper insulation in emission areas.
2Object-affected harmful factors
If alignment electrodes are exposed in non-emission areas, then electrical discharge paths are prevented, but electrode misalignment and insulation issues occur
Solution Approach 1:
The first insulating layer acts as an intermediary between the first alignment electrode and the second alignment electrode. It has openings that expose the first alignment electrode to prevent discharge paths, while the second insulating layer with through-holes provides a controlled interface. The third insulating layer with contact holes further mediates the electrical connection. This multi-layer intermediary structure prevents direct contact between opposing electrodes in non-emission areas, eliminating discharge paths while maintaining manufacturing precision through controlled opening positions.
3Object-affected harmful factors
If multiple insulating layers with openings and through-holes are formed, then bright spot defects are prevented, but device complexity increases
Solution Approach 1:
Multiple insulating layers (first, second, and third insulating layers) are merged into a unified structure where openings, through-holes, and contact holes are positioned to serve multiple functions simultaneously. The same structural features prevent bright spot defects while providing electrical connections and insulation. This merging reduces the need for separate components and simplifies the overall manufacturing process despite the multi-layer structure.
Solution Approach 2:
The insulating layers are designed with multi-functionality: the first insulating layer provides insulation and defines opening positions; the second insulating layer provides additional insulation and creates through-holes for electrical connections; the third insulating layer provides final insulation and contact holes. Each layer performs multiple functions (insulation, structural support, electrical connection definition) thereby reducing the need for additional dedicated components and simplifying the overall device structure.
Data Source
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AI summary
A display device including: a first sub-pixel, a second sub-pixel, and a third sub-pixel adjacent to each other, each of the first, second, and third sub-pixels including an emission area and a non-emission area, where each of the first, second, and third sub-pixels includes: a first alignment electrode and a second alignment electrode spaced from each other; a first insulating layer on the first alignment electrode and the second alignment electrode; light emitting elements on the first insulating layer on the first alignment electrode and the second alignment electrode in the emission area; a second insulating layer on the first insulating layer and the light emitting elements; and a third insulating layer on the second insulating layer, wherein the second and the third insulating layers are not on at least one area of the first alignment electrode in at least the non-emission area.