Display Cathode Auxiliary Electrode Structure for Dense Pixel Integration
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Solution Overview
Problem
High-resolution display devices face challenges with high pixel integration, leading to narrowed spacing between light emitting elements, which can result in cathode electrode disconnection defects during the formation of multiple light emitting layers using photo lithography.
Innovation Solution
A display device design that includes a substrate with an anode electrode, a pixel defining layer, a first auxiliary electrode, a light emitting layer, a cathode electrode, a cathode capping layer, spacers, and a second auxiliary electrode, which helps to lower cathode electrode resistance and prevent disconnection by spacing apart the light emitting layers and using transparent conducting oxide for the cathode capping layer and second auxiliary electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photo lithography method is used to form multiple light emitting layers with high pixel integration, then manufacturing precision is improved, but cathode electrode disconnection defects occur due to narrowed spacing between light emitting elements
Solution Approach 1:
The patent introduces a first auxiliary electrode as an intermediary component between the light emitting layers and the cathode electrode. This auxiliary electrode serves as a mediator that maintains electrical connection across the narrowed spacing gap, preventing direct disconnection while allowing the photo lithography process to achieve high pixel integration precision
Solution Approach 2:
The cathode electrode structure is segmented into multiple portions (first cathode electrode portion and second cathode electrode portion) separated by spacers. This segmentation allows each portion to be independently positioned and connected to the first auxiliary electrode, ensuring reliable electrical connection even with narrowed spacing between light emitting elements
2Productivity
If spacing between light emitting elements is narrowed to achieve high pixel integration, then productivity is improved, but cathode electrode resistance increases due to disconnection defects
Solution Approach 1:
The first auxiliary electrode acts as a conductive intermediary that bridges the gap between light emitting elements with narrowed spacing. By providing an additional conductive path through the auxiliary electrode and spacers, the overall resistance of the cathode electrode structure is reduced despite the reduced spacing between light emitting elements
Solution Approach 2:
The patent merges the cathode electrode structure with the first auxiliary electrode and spacers to form an integrated conductive network. This combination creates multiple parallel conductive paths, effectively reducing the total resistance while maintaining high pixel integration density
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 design effectively reduces cathode electrode resistance and prevents disconnection defects, ensuring stable operation of high-resolution display devices by flattening level differences and electrically connecting auxiliary electrodes through the cathode capping layer.
Implementation Method 1
using transparent conducting oxide for the cathode capping layer and second auxiliary electrode
Data Source
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AI summary
A display device includes: a substrate including a light emitting area and a non-light emitting area; an anode electrode on the light emitting area of the substrate; a pixel defining layer on the non-light emitting area of the substrate and defining a first opening; a first auxiliary electrode on the pixel defining layer; a light emitting layer on the anode electrode and spaced apart from the first auxiliary electrode; a cathode electrode on the light emitting layer and the first auxiliary electrode; a cathode capping layer on the cathode electrode; a spacer on the cathode capping layer and defining a second opening; and a second auxiliary electrode on the cathode capping layer and the spacer.