Display Substrate Electrode Layout to Prevent Auxiliary Electrode Shorts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In LED displays driven by thin-film transistors, the high sensitivity of the drive current to voltage drops across auxiliary electrodes leads to the need for large-area VDD and VSS auxiliary electrodes, which can result in short circuits and affect product yield and reliability.
Innovation Solution
A displaying substrate is designed with a flexible base plate, a first metal layer containing a first auxiliary electrode connected to a power cord, and a pixel unit with thin-film transistors, an insulation layer, and a second auxiliary electrode connected to another power cord. The first auxiliary electrode is positioned on one side of the flexible base plate away from the second auxiliary electrode, increasing the distance between them and reducing the risk of short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If large-area auxiliary electrodes are used to reduce resistance and voltage drop, then the drive current stability is improved, but the risk of short circuit between auxiliary electrodes increases
Solution Approach 1:
The patent applies dimensionality change by moving the first auxiliary electrode from the same plane as the second auxiliary electrode to the back side of the substrate. This spatial reconfiguration in three-dimensional space allows both electrodes to maintain large areas for low resistance while eliminating planar overlap that causes short circuits. The first auxiliary electrode is positioned on the rear surface of the substrate, connected to the VDD power supply, while the second auxiliary electrode remains on the front surface, creating vertical separation that prevents harmful electrical interaction.
2Object-affected harmful factors
If the distance between auxiliary electrodes is increased to prevent short circuit, then the short circuit risk is reduced, but the manufacturing complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the substrate into distinct functional layers: the front surface containing the second auxiliary electrode and pixel structures, and the back surface containing the first auxiliary electrode. This segmentation separates the electrode systems into independent domains, reducing the risk of short circuits while maintaining manufacturing feasibility through standard multi-layer fabrication processes. The substrate itself acts as an insulating barrier between the segmented electrode systems.
3Reliability
If large-area auxiliary electrodes are manufactured, then the voltage drop is reduced, but the manufacturing precision requirements increase
Solution Approach 1:
By relocating the first auxiliary electrode to the back side of the substrate, the patent eliminates the need for precise lateral positioning between the first and second auxiliary electrodes. The large-area electrodes can be manufactured with relaxed precision requirements on the front surface, while the back-side electrode is positioned independently. This dimensional separation decouples the positioning constraints, allowing large electrode areas without stringent manufacturing precision requirements.
Data Source
AI summary
A displaying substrate and a displaying device. The displaying substrate comprises a flexible base plate; a first auxiliary electrode arranged on one side of the flexible base plate, the first auxiliary electrode being connected with a first power cord; a pixel unit arranged on a side of the flexible base plate away from a first metal layer, the pixel unit comprising: thin-film transistors arranged on the side of the flexible base plate away from the first metal layer, an insulation layer and a second auxiliary electrode, the second auxiliary electrode being connected with a second power cord, wherein the plurality of thin-film transistors comprise a drive transistor, the drive transistor has a source connected with the first auxiliary electrode and a drain connected with a first electrode of a light emitting device, a second electrode of the light emitting device is connected with the second auxiliary electrode.