OLED Pixel Defining Layer Concave Sidewall Ink Climbing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In OLED display manufacturing, inkjet printing technology leads to uneven film formation in pixel regions due to a 'climbing phenomenon' where the film is thin in the middle but thick on the edges, resulting in poor uniformity.
Innovation Solution
A pixel defining layer with a concave wall portion on its sidewall, made of hydrophilic materials like silica or silicon nitride, which inhibits ink climbing and ensures uniform film formation by blocking ink flow, combined with a hydrophobic second layer to prevent overflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If inkjet printing technology is used for film formation in pixel regions, then manufacturing simplicity and cost are improved, but film uniformity deteriorates due to climbing phenomenon causing thin middle and thick edges
Solution Approach 1:
The pixel partition wall is designed with a concave wall portion that creates different surface properties at different locations. The concave structure specifically modifies the local geometry at the wall edges to inhibit capillary action and ink climbing, while maintaining the overall simplicity of the inkjet printing process. This local structural modification addresses the film uniformity issue without complicating the manufacturing process.
Solution Approach 2:
The sidewall of the pixel partition wall incorporates a concave curved portion instead of a straight vertical wall. This curvature is specifically designed to prevent ink from climbing along the wall edges during the drying process. The curved geometry changes the capillary action characteristics, thereby improving film uniformity across the pixel region while maintaining manufacturing simplicity.
2Device complexity
If a vertical sidewall structure is used in the pixel partition wall, then device complexity is reduced, but film formation uniformity deteriorates due to uncontrolled ink climbing on edges
Solution Approach 1:
The pixel partition wall incorporates a concave curved portion in its sidewall, replacing the traditional straight vertical structure. This curvature is specifically engineered to inhibit capillary action and prevent ink from climbing along the wall edges during the drying process. The curved geometry maintains relatively simple device structure while effectively improving film thickness uniformity across the pixel region.
3Ease of manufacture
If the pixel partition wall has a straight sidewall, then manufacturing process is simplified, but ink climbing occurs causing non-uniform film thickness with thick edges and thin middle
Solution Approach 1:
The pixel partition wall is designed with a concave curved portion in its sidewall instead of a straight vertical wall. This curved geometry specifically targets and inhibits the capillary action that causes ink to climb along the wall edges during drying. The modification maintains process simplicity while achieving better film thickness control and uniformity across the pixel region.
Solution Approach 2:
The concave curved portion is strategically positioned in the sidewall of the pixel partition wall to create localized surface geometry that prevents ink climbing. This local structural modification addresses the film uniformity issue at the critical wall-edge regions without requiring changes to the overall manufacturing process, thereby maintaining ease of manufacture while improving film thickness control.
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 concave wall portion effectively reduces the thickness difference between the film's edges and middle, enhancing the uniformity of film formation and preventing uneven luminescence, thereby improving the overall display quality.
Implementation Method 1
a sidewall of the first layer has a concave wall portion concave inward towards the pixel partition wall
Implementation Method 2
the second layer is made of a hydrophobic material
Data Source
AI summary
This disclosure provides a pixel defining layer, a display panel and a display device. The pixel defining layer comprises a pixel partition wall, wherein the pixel partition wall encloses a plurality of openings; wherein the pixel partition wall comprises a first layer, wherein the first layer is disposed on a base substrate, and wherein a sidewall of the first layer has a concave wall portion concave inward towards the pixel partition wall.