OLED Substrate Pixel Definition Layer Via Hole Cleaning
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Solution Overview
Problem
The existing OLED substrates face difficulties in cleaning up organic light-emitting material that falls into via holes during the manufacturing process, making it challenging to prevent material accumulation in these areas.
Innovation Solution
The OLED substrate design features a pixel definition layer with successively arranged first and second patterns, where the protrusion portion of the first pattern corresponds to the groove portion of the second pattern, allowing for continuous printing of the light emitting material layer without entering the groove portions, thus avoiding material accumulation under the via holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the passivation layer has via holes in cathode contact regions, then electrical connection is achieved, but organic light emitting material accumulates in via hole positions and is difficult to clean
Solution Approach 1:
The pixel definition layer is designed with protrusion portions positioned exactly where via holes will be formed in the passivation layer. This preliminary structural arrangement ensures that when organic light emitting material is deposited, it naturally accumulates on the protrusion portions rather than falling into the via hole positions, eliminating the need for subsequent cleaning operations.
Solution Approach 2:
The pixel definition layer is not uniform but features localized protrusion portions at specific positions corresponding to via hole locations. This local structural variation creates different surface properties in different areas: protrusion portions that receive material and flat/groove portions that prevent material accumulation, thereby solving the cleaning difficulty while maintaining electrical connection through via holes.
2Productivity
If continuous printing is used to form light emitting material layer, then production efficiency is improved, but material accumulates in via hole positions requiring cleaning
Solution Approach 1:
Before continuous printing of the light emitting material layer, the pixel definition layer is pre-formed with protrusion portions at via hole positions. This preliminary action guides the continuous printing process to deposit material on protrusion portions while preventing accumulation in via hole areas, maintaining high production efficiency without requiring post-printing cleaning.
Solution Approach 2:
The protrusion portions of the pixel definition layer automatically guide and confine the organic light emitting material during continuous printing, causing material to self-assemble on protrusion portions without manual intervention. The structure itself performs the function of material positioning, eliminating the need for cleaning operations while maintaining continuous printing efficiency.
Data Source
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AI summary
The present invention provides an OLED substrate, a manufacturing method thereof and a display device, which can solve the problem that it is difficult for the existing OLED substrate to clean up the light emitting material. The OLED substrate of embodiments of the present invention is divided into a display area and peripheral area. The peripheral area has a plurality of cathode contact regions. The OLED substrate comprises: a base substrate; a source-drain metal extending portion arranged on the base substrate; a passivation layer having a plurality of via holes at positions corresponding to the cathode contact regions; an anode metal extending portion being electrically connected with the source-drain metal extending portion through the via holes; a pixel definition layer having a plurality of first patterns at positions corresponding to the display area, each of the first patterns having a protrusion portion and a groove portion; the pixel definition layer having a plurality of second patterns at positions corresponding to the cathode contact regions, each of the second pattern having a protrusion portion and a groove portion. The protrusion portion of the first pattern corresponds to the groove portion of the second pattern, and the groove portion of the first pattern corresponds to the protrusion portion of the second pattern.