OLED Spacer Etch Selectivity for Pixel Noise Reduction
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Solution Overview
Problem
Existing organic light-emitting displays face challenges in maintaining reliability due to potential noise and electrical connectivity issues between adjacent pixel regions.
Innovation Solution
The organic light-emitting display incorporates a substrate with a division region between pixel regions, featuring an insulating layer with a recess and a spacer with different etch selectivity, allowing for disconnection of charge generation layers and continuous extension of the common electrode across pixel regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If charge generation layers are continuous between adjacent pixel regions, then electrical connectivity is maintained, but noise and electrical interference increase
Solution Approach 1:
The charge generation layers are segmented and disconnected in the division region between adjacent pixel regions. The insulating layer with recess and spacer structure creates physical separation, dividing the continuous charge generation path into discrete segments that prevent electrical interference while maintaining functional operation within each pixel region.
Solution Approach 2:
The harmful electrical connectivity between adjacent pixel regions is extracted and removed by creating a discontinuity in the charge generation layers. The insulating layer structure with recess and spacer effectively extracts the unwanted electrical pathway while preserving the necessary electrical connections within individual pixel regions.
2Ease of manufacture
If insulating layer has straight-line side walls, then manufacturing is simpler, but spacer adhesion and etch selectivity are reduced
Solution Approach 1:
The insulating layer side wall is designed with a curved shape instead of a straight-line profile. This curvature increases the surface area and provides better mechanical interlocking and adhesion for the spacer material deposited on it, while still maintaining manufacturability through standard deposition and etching processes.
3Ease of manufacture
If spacer material has same etch selectivity as insulating layer, then processing is simpler, but selective removal and precision are reduced
Solution Approach 1:
The spacer material is selected to have different etch selectivity compared to the insulating layer material. This local differentiation in material properties enables selective etching processes that precisely define spacer positions and dimensions, improving manufacturing precision while maintaining reasonable processing complexity.
Data Source
AI summary
An organic light-emitting display includes a substrate including a first pixel region, a second pixel region, and a division region disposed between the first pixel region and the second pixel region, an insulating layer disposed on the substrate and including a recess disposed in the division region, the insulating layer including a first inner side wall defining a first portion of the recess and a second inner side wall extending from the first inner side wall, defining a second portion of the recess, and having a curved shape, a plurality of pixel electrodes disposed on the insulating layer, a spacer disposed on a side wall of each of the pixel electrodes and the first inner side wall, and a first organic emission layer disposed on the spacer, wherein the spacer includes a material having an etch selectivity different than an etch selectivity of the insulating layer.