OLED Electrode Taper Control to Prevent Cathode Disconnection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display devices, particularly those used in high-resolution applications like head-mounted displays for virtual and augmented reality, suffer from cathode electrode disconnections due to uneven taper angles of anode electrodes, leading to device failure.
Innovation Solution
The display device is designed with a first electrode having a taper angle of 45 degrees or less, reducing the step difference of the pixel defining film and preventing cathode electrode disconnections through a manufacturing method involving an insulating film, first electrode layer, sacrificial layer, and photoresist pattern to form a more even anode electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the anode electrode has a large taper angle to facilitate manufacturing, then the manufacturing process is easier, but the pixel defining film exhibits significant step difference causing cathode electrode disconnection
Solution Approach 1:
The patent changes the geometric parameter of the anode electrode by controlling its taper angle to be 45 degrees or less. This parameter modification reduces the step difference of the pixel defining film formed on the anode electrode, preventing cathode electrode disconnection while maintaining manufacturability through standard fabrication processes
Solution Approach 2:
The patent applies preliminary anti-action by pre-controlling the anode electrode's taper angle during fabrication to prevent the future problem of cathode electrode disconnection. By establishing the correct geometric configuration early in the manufacturing process, the patent prevents stress concentration and disconnection risks before they occur
2Reliability
If the anode electrode has a small taper angle to reduce step difference, then cathode electrode disconnection is prevented, but the manufacturing precision requirement increases
Solution Approach 1:
The patent specifies a quantitative parameter range (taper angle ≤ 45 degrees) that balances reliability improvement with manufacturing feasibility. This parameter setting is achievable through conventional fabrication techniques while effectively reducing step difference and preventing cathode electrode disconnection
Data Source
AI summary
A display device, an optical device and an electronic device each including the display device, and a method of manufacturing a display device are provided. The display device includes: a substrate; a first electrode on the substrate; a pixel defining film on the first electrode and defining an emission area; a light emitting stack on the first electrode; and a second electrode on the light emitting stack and the pixel defining film, wherein a taper angle of the first electrode is less than or equal to about 45 degrees.