OLED Cathode IR Drop Mitigation via Sharp Corner Strap Electrode
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Solution Overview
Problem
Large-size OLED panels face display unevenness due to IR drops across the cathode, leading to brightness inconsistencies, which existing methods attempt to address through complex fabrication processes and costly material selection.
Innovation Solution
A method of manufacturing OLED panels involves forming a TFT substrate with an auxiliary electrode connected to the cathode via a strap electrode with a sharp corner, allowing for direct electrical connection by puncturing the electron transport and injection layers when a voltage is applied, thereby improving uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pillar with inverted trapezoid cross-section is fabricated to connect auxiliary electrode to cathode, then the connection between auxiliary electrode and cathode is achieved, but the manufacturing process becomes complicated and material selection options increase cost
Solution Approach 1:
The invention extracts the connection function from the complex inverted trapezoid pillar structure and implements it through a simple via hole penetrating the planarization layer. The strap electrode with sharp corner directly connects to the auxiliary electrode through this via hole, eliminating the need for complex isolation columns while maintaining the electrical connection between auxiliary electrode and cathode.
Solution Approach 2:
Instead of using a complex pillar structure to achieve connection, the invention inverts the approach by using a simple via hole and strap electrode configuration. The sharp corner of the strap electrode penetrating through the planarization layer provides the connection function that previously required complex isolation structures.
2Reliability
If complex isolation column fabrication is used to connect auxiliary electrode, then connection is achieved, but the manufacturing cost increases due to limited material selectivity
Solution Approach 1:
The invention extracts the essential connection function from the costly isolation column structure and implements it through a simple via hole and strap electrode. This reduces material requirements and manufacturing cost while maintaining the auxiliary electrode connection functionality.
Solution Approach 2:
The invention replaces expensive isolation column materials with a simpler strap electrode structure formed through standard via hole processes. The sharp corner configuration achieves the same connection function with less material and lower cost.
3Ease of manufacture
If standard planarization layer patterning is used, then the layer is formed, but the sharp corner area requires additional via holes for cathode connection
Solution Approach 1:
The invention performs preliminary action by forming the sharp corner on the strap electrode before final cathode deposition. The via holes are strategically positioned to expose the sharp corner area, enabling subsequent puncturing to create direct cathode connection. This sequence simplifies the overall manufacturing process.
Solution Approach 2:
The invention applies local quality by creating sharp corners at specific locations on the strap electrode where via holes will penetrate. This localized feature modification enables direct cathode connection only where needed, maintaining simplicity in other areas while achieving the required functionality.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances display uniformity by ensuring consistent signal input to the cathode, reducing the impact of IR drops and simplifying the manufacturing process by eliminating the need for complex isolation structures.
Implementation Method 1
applying a voltage between the auxiliary electrode and the cathode, so that the electron transport layer and the electron injection layer corresponding to the area of the sharp shaped corner being punctured to directly connect the cathode with the strap electrode
Data Source
AI summary
A method of manufacturing an OLED panel and an OLED panel are provided. The method includes forming an anode connected to a source of a TFT, and a strap electrode connected to an auxiliary electrode on a TFT substrate. A sharp shaped corner is formed on the strap electrode, therefore an area of the electron transport layer and the electron injection layer corresponding to the sharp shaped corner have a thinner thickness. By applying a voltage between the auxiliary electrode and the cathode, the electron transport layer and the electron injection layer corresponding to the sharp shaped corner are punctured, the cathode is directly connected to the strap electrode and further conducted to the auxiliary electrode, resulting in a signal is inputted to the cathode through the auxiliary electrode during display. The problem of uneven display of the OLED panel due to the IR drop of the cathode is improved.