Cathode Isolation Retaining Wall for OLED Patterning
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Solution Overview
Problem
In the manufacturing of organic light emitting diode array panels, the existing methods for forming cathode isolation retaining walls using positive or negative photoresists result in poor patterning effects due to the formation of integrally connected cathode structures, which are difficult to separate, and are not cost-effective for mass production.
Innovation Solution
A method involving the use of positive photoresist layers to create a cathode isolation retaining wall structure with specific surface area and height configurations, where the first isolation retaining wall portion is disposed on the anode layer and the second isolation retaining wall portion is stacked on top, allowing for the separation of cathode layers during vapor deposition, improving patterning effects and reducing production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If positive photoresist is used to form cathode isolation retaining wall by photolithography, then the manufacturing process is suitable for mass production and cost-effective, but the light absorption during exposure results in insufficient light intensity at the bottom of the photoresist, forming a trapezoidal shape that prevents effective cathode separation
Solution Approach 1:
The cathode isolation retaining wall is divided into two separate formation steps: first forming a base retaining wall structure, then forming an additional retaining wall structure on top. This segmentation allows each part to be optimized independently - the base provides structural support while the additional structure provides the necessary overhang for cathode separation, resolving the contradiction between manufacturability and patterning precision.
Solution Approach 2:
The base retaining wall structure is formed first as a preliminary structure before forming the additional retaining wall structure. This preliminary action creates a foundation that supports the subsequent structure, enabling the formation of the desired inverted trapezoidal shape with proper overhang that achieves both manufacturability and cathode separation precision.
2Manufacturing precision
If negative photoresist is used to form inverted trapezoidal cathode isolation retaining wall, then cathode separation is achieved, but the method is difficult to apply in mass production and cost will be high
Solution Approach 1:
Instead of using negative photoresist to directly form the inverted trapezoidal shape, the invention uses positive photoresist with a dual-layer approach where the additional retaining wall structure is formed on top of the base structure. This inverts the conventional approach while achieving the same functional result using cost-effective positive photoresist suitable for mass production.
Solution Approach 2:
The solution moves from a single-layer photoresist approach to a two-layer structure (base retaining wall + additional retaining wall). This dimensional change in the photoresist structure allows the formation of the inverted trapezoidal profile using positive photoresist, achieving both cathode separation precision and mass production suitability.
3Stability of the object's composition
If trapezoidal shaped cathode isolation retaining wall is formed with narrow top and wide bottom, then the structure is stable, but the cathode layer forms an integral structure that cannot be separated into multiple cathode strips
Solution Approach 1:
The retaining wall is segmented into two functional parts: the base retaining wall structure that provides stability with its wider bottom, and the additional retaining wall structure that creates the overhang necessary for cathode separation. This segmentation allows each part to fulfill its specific function without compromising the other.
Solution Approach 2:
The additional retaining wall structure is nested on top of the base retaining wall structure, with the orthographic projection of the first top surface falling within the orthographic projection of the second bottom surface. This nested configuration creates the inverted trapezoidal shape that maintains stability while enabling cathode separation.
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
The method enables the separation of cathode layers on the cathode isolation retaining walls and the anode layer, enhancing the cathode patterning effect and reducing production costs by utilizing positive photoresist, which is more suitable for mass production compared to negative photoresist.
Implementation Method 1
when light propagates from the top of the photoresist to the bottom of the photoresist, it is gradually absorbed
Data Source
AI summary
The disclosure provides a method for manufacturing cathode isolation retaining walls, display panel and manufacturing method thereof. A method for manufacturing a cathode isolation retaining wall, including exposing a first photoresist layer formed on an anode layer to obtain a first isolation retaining wall portion. The method includes forming a second photoresist layer on a side of the first photoresist layer away from the anode layer. After exposing the second photoresist layer, a second isolation retaining wall portion at least partially stacked with the first isolation retaining wall portion is obtained. The method includes developing the first photoresist layer and the second photoresist layer to obtain a cathode isolation retaining wall composed of the first isolation retaining wall portion and the second isolation retaining wall portion.