OLED Display Substrate Pixel Separating Pattern Corrosion Protection
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Solution Overview
Problem
Top emission type OLED display devices face reliability issues due to corrosion of the cathode electrode, which affects the overall performance and longevity of the device.
Innovation Solution
A display substrate design that includes a pixel portion with a light generation region and a pixel separating region, featuring a thin film transistor, an insulating pattern, and a pixel separating pattern with a first and second pixel separating portion, which reduces the exposure and corrosion of the first electrode by forming it naturally using the pixel separating pattern and allowing the organic emission layer and second electrode to be formed inside a vacuum chamber, minimizing external exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a patterned cathode electrode is formed using a conductive material having a corrosion characteristic, then the aperture ratio can be increased and various driving devices can be designed, but the cathode electrode is easily corroded and reliability is reduced
Solution Approach 1:
The patent introduces an intermediary substance (encapsulation layer or protective coating) between the conductive cathode electrode and the external environment. This intermediary layer prevents direct contact between the corrosive environment and the cathode electrode, thereby maintaining the corrosion-prone conductive material's electrical properties while protecting it from degradation, thus preserving both the aperture ratio benefits and driving device design flexibility without sacrificing reliability
Solution Approach 2:
The patent creates an inert or protected environment around the cathode electrode through encapsulation structures that exclude moisture and oxygen. By maintaining an inert atmosphere at the cathode electrode interface, the corrosive reactions are prevented while allowing the use of conductive materials with good electrical properties, thus resolving the contradiction between corrosion resistance and electrical performance
2Ease of manufacture
If the cathode electrode is exposed to the external environment, then the manufacturing process is simpler, but the corrosion occurs and reliability reduces
Solution Approach 1:
The patent applies preliminary protective action by forming encapsulation layers or protective coatings on the cathode electrode during the manufacturing process, before the device is exposed to the external environment. This preliminary protection is integrated into the manufacturing steps, adding minimal complexity while ensuring the cathode electrode is protected from corrosion throughout the device's operational life, thus maintaining ease of manufacture while improving reliability
3Manufacturing precision
If a separate photolithography process is used for patterning, then the manufacturing precision is improved, but the device complexity and manufacturing time increase
Solution Approach 1:
The patent merges the patterning process with the existing manufacturing steps by using the same photolithography and etching processes that are already employed for forming other device structures. By combining the cathode electrode patterning with previously performed patterning operations, the manufacturing precision is maintained while avoiding additional separate photolithography processes, thus reducing device complexity and manufacturing time
Data Source
AI summary
A display substrate, an organic light emitting diode display device having the same, and a manufacturing method thereof are disclosed. The display substrate includes a first pixel separating portion and a second pixel separating portion extending from the pixel separating portion and disposed around a pixel portion. Therefore, the number of processes for forming the organic light emitting diode display device can be reduced, and corrosion of a first electrode of the organic light emitting diode display device can be prevented.