OLED Common Electrode Closed Curve Cut for Bright Spot Repair
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Solution Overview
Problem
Bright spot failures in OLED displays, where pixels continuously emit light regardless of data and gate signals, reduce display quality and conventional repair methods can damage peripheral components.
Innovation Solution
The formation of a closed curve electrode cut around the pixel defining layer, which includes a channel that overlaps with the electrode cut, allows for the deactivation of defective OLEDs by electrically isolating the common electrode and organic emission layer, preventing light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of repair
If a laser is used to deactivate a pixel with bright spot failure, then the defective pixel can be repaired, but peripheral data lines, common lines, and electrodes may be damaged
Solution Approach 1:
The electrode cut divides the common electrode into separate segments, creating an isolated region around the defective pixel. This segmentation allows the laser repair process to be confined to a specific area, preventing damage to peripheral data lines, common lines, and other electrodes while still effectively deactivating the defective OLED.
Solution Approach 2:
The electrode cut creates a localized modification in the electrode structure, forming a closed curve that encloses only the defective pixel area. This local structural change enables targeted repair without affecting the overall integrity and functionality of surrounding components, achieving precise control over the repair zone.
2Ease of manufacture
If the electrode cut does not form a closed curve, then the manufacturing process is simpler, but the defective pixel cannot be reliably isolated
Solution Approach 1:
The electrode cut extracts or removes a portion of the common electrode to form a closed curve structure. This extraction creates a complete isolation barrier around the defective pixel, ensuring reliable electrical separation between the defective region and the rest of the display, which cannot be achieved with open or incomplete cuts.
3Ease of manufacture
If the pixel defining layer is flat, then the manufacturing process is simpler, but the electrode cut cannot effectively isolate the defective region from surrounding structures
Solution Approach 1:
The pixel defining layer is given a three-dimensional stepped structure with different elevation levels. This dimensional change creates a physical barrier that enhances the isolation effect of the electrode cut, preventing lateral spread of defects and improving the effectiveness of the closed curve in separating the defective pixel from surrounding structures.
Data Source
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AI summary
Aspects of the present invention relate to an organic light emitting diode (OLED) display and a manufacturing method thereof. The OLED display includes: a substrate ; pixel electrodes disposed on the substrate; a pixel defining layer disposed on the substrate, having a plurality of openings that expose the pixel electrodes; an organic emission layer formed on the pixel electrodes; and a common electrode formed on the organic emission layer and the pixel defining layer. An electrode cut is formed in the common electrode, around one of the openings of the pixel defining layer, to electrically isolate a portion of the common electrode.