OLED Substrate Conductive Layer Reduces IR Drop
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Solution Overview
Problem
Conventional OLED display devices face issues with non-uniform image display due to high IR drop in the first electrode, which requires additional space for a cathode auxiliary line, reducing the aperture ratio and complicating the manufacturing process with the need for a fine metal mask.
Innovation Solution
An organic light emitting diode array substrate with a pixel definition layer comprising a first insulating layer, a conductive layer, and a second insulating layer, where the conductive layer is sandwiched and insulated within the display region, reducing IR drop without sacrificing aperture ratio and simplifying the manufacturing process by eliminating the need for a fine metal mask.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the first electrode is made as a very thin layer to achieve high transmission rate, then the transmission rate is improved, but the resistance increases resulting in large IR drop and non-uniform image display
Solution Approach 1:
The invention divides the first electrode into two separate electrodes: a first electrode (anode) and a second electrode (cathode). The first electrode maintains high transmission rate while the second electrode provides low resistance and is connected to a conductive layer that reduces IR drop, thereby resolving the contradiction between transmission rate and image uniformity
Solution Approach 2:
A conductive layer is introduced as an intermediary between the second electrode and the organic light emitting layer. This conductive layer has low resistance and reduces the overall IR drop of the first electrode structure, enabling uniform image display while maintaining high transmission rate through the first electrode
2Reliability
If a cathode auxiliary line is added to reduce IR drop, then the image uniformity is improved, but the aperture ratio is reduced due to additional space requirement
Solution Approach 1:
Instead of adding a cathode auxiliary line in the planar dimension which reduces aperture ratio, the invention introduces a conductive layer in a different dimensional configuration - sandwiched between insulating layers within the pixel structure. This three-dimensional arrangement reduces IR drop without occupying additional planar space, thereby maintaining high aperture ratio
3Reliability
If a fine metal mask is used in the manufacturing process to accommodate the cathode auxiliary line, then the image uniformity is improved, but the manufacturing complexity increases
Solution Approach 1:
The invention extracts and eliminates the need for the fine metal mask and cathode auxiliary line from the manufacturing process. By using a conductive layer sandwiched between insulating layers, the structure can be manufactured using standard semiconductor fabrication processes without requiring the complex fine metal mask alignment steps, thereby reducing manufacturing complexity while maintaining image uniformity
Data Source
AI summary
The present application discloses an organic light emitting diode array substrate comprising a base substrate; a first electrode; a second electrode; and a pixel definition layer. The pixel definition layer comprises a first insulating layer comprising a plurality of first insulating units; a second insulating layer comprising a plurality of second insulating units; and a conductive layer comprising a plurality of interconnected conductive units sandwiched by the first insulating layer and the second insulating layer.