Display Panel Cathode Layout for Uniform Brightness
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Solution Overview
Problem
Large-sized display panels experience uneven brightness due to high cathode resistance, leading to voltage drops and uneven display performance.
Innovation Solution
A display panel design featuring an auxiliary electrode with multiple conductive layers and a planarization layer, where the pixel definition layer has openings exposing the auxiliary electrode's lateral walls, allowing direct electrical connection between the first electrode and the auxiliary electrode, reducing contact resistance and voltage drops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If large-sized display panels are used, then display area is increased, but cathode resistance increases causing voltage drops and uneven brightness
Solution Approach 1:
The cathode is divided into multiple segments: the first electrode (cathode) and auxiliary electrodes are separated into distinct functional units. The auxiliary electrodes are further divided into multiple conductive layers (first, second, and third conductive layers) stacked vertically, creating a segmented structure that reduces current path length and resistance in each segment while maintaining overall large display area coverage
Solution Approach 2:
The patent transitions from a planar two-dimensional electrode structure to a three-dimensional stacked structure by introducing vertical conductive layers. The auxiliary electrode comprises multiple conductive layers stacked in the vertical dimension, with orthogonal projections overlapping on the base substrate, creating a multi-layered conductive path that reduces resistance without increasing lateral area
2Reliability
If auxiliary electrode with multiple conductive layers is added, then resistance is reduced, but device complexity increases
Solution Approach 1:
Multiple conductive layers (first, second, and third conductive layers) are merged into a single auxiliary electrode structure, combining their electrical conductivities to achieve lower overall resistance. The pixel definition layer and organic light-emitting layer are also integrated into a unified structure that simplifies the overall device architecture despite the multi-layered electrode configuration
3Reliability
If pixel definition layer has openings exposing auxiliary electrode, then contact resistance is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The pixel definition layer is designed with localized openings only at specific positions where electrical contact with the auxiliary electrode is required, rather than being uniformly open or closed. This local quality approach ensures low contact resistance only where needed while maintaining the integrity of the pixel definition layer elsewhere, reducing the overall manufacturing precision burden
Data Source
AI summary
A display panel and an electronic device are provided. In the display panel, by disposing an auxiliary electrode in a first opening of a pixel definition layer, a first electrode is electrically connected to an auxiliary electrode line through the auxiliary electrode, so as to reduce a resistance of the first electrode. Therefore, uneven display due to voltage drop is remedied, so that a problem of large cathode resistance existing in a current display panel is relieved. Meanwhile, the first opening of the pixel definition layer of the present application exposes a part of a lateral wall of the auxiliary electrode. An organic light-emitting layer is cut off at a position of the first opening exposing the at least part of the lateral wall. The first electrode is electrically connected to the at least part of the lateral wall exposed by the organic light-emitting layer.