Pixel Define Layer for OLED Displays via Dual-Layer Etching
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Solution Overview
Problem
Existing methods for manufacturing pixel define layers in OLED/PLED displays require multiple patterning processes and masks, increasing manufacturing costs and complexity, particularly due to the need for precise control over liquid luminescent material distribution within small pixel regions.
Innovation Solution
A method involving sequential formation of a first and second transparent define layers with different etch rates, where the second define layer is hydrophobic and the first is hydrophilic, allowing for wider openings at the bottom and narrower openings at the top, facilitating accurate luminescent material distribution within pixel regions without adjacent spilling, and reducing the need for multiple photolithography masks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a double-film pixel define layer structure is used to control liquid luminescent material distribution, then manufacturing precision of pixel regions is improved, but device complexity and manufacturing cost increase due to requiring two separate patterning processes and multiple masks
Solution Approach 1:
The patent combines two separate patterning processes into one by using a dual-layer photosensitive resin structure. The first photosensitive resin layer forms a base pattern, and the second photosensitive resin layer forms the final pixel define pattern. Both layers are exposed and developed in sequence within a single patterning workflow, eliminating the need for separate mask processes while achieving the precision of a double-film structure.
Solution Approach 2:
The pixel define layer is segmented into two functional parts: a first photosensitive resin layer that provides the base structure and wider openings, and a second photosensitive resin layer that provides the final precise pattern with narrower openings. This segmentation allows each layer to perform its specific function while being manufactured together, reducing overall process complexity.
2Ease of manufacture
If wider openings are formed in the lower-layer film to ensure liquid drops spread within pixel regions, then ease of manufacture is improved, but harmful factors increase due to risk of liquid drops flowing to adjacent pixels
Solution Approach 1:
The patent uses a nested structure where the second photosensitive resin layer is formed on top of the first photosensitive resin layer. The first layer creates wider openings that facilitate liquid spreading, while the second layer is patterned with narrower openings that contain the liquid within pixel boundaries. The second layer effectively nests within the structure provided by the first layer, combining the benefits of both wide and narrow openings.
Solution Approach 2:
Different regions of the pixel define layer have different opening widths tailored to specific functional requirements. The first photosensitive resin layer provides wider openings in regions where liquid spreading is needed, while the second photosensitive resin layer provides narrower openings in regions where liquid containment is critical. This local variation in opening quality optimizes both spreading and containment performance.
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 ensures accurate spreading and containment of luminescent material within pixel regions, reduces manufacturing costs by minimizing mask usage, and enhances light-emitting quality by preventing defects like RGB color crosstalk and Mura, while simplifying the manufacturing process.
Implementation Method 1
the second define layer is hydrophobic and the first is hydrophilic, allowing for wider openings at the bottom and narrower openings at the top, facilitating accurate luminescent material distribution within pixel regions without adjacent spilling
Implementation Method 2
the second define layer is hydrophobic and the first is hydrophilic, allowing for wider openings at the bottom and narrower openings at the top, facilitating accurate luminescent material distribution within pixel regions without adjacent spilling
Implementation Method 3
performing etching, so as to form openings corresponding to respective pixels in both the uncovered second define layer and said first define layer below the second define layer, wherein, during etching, etch rate at which said second define layer is etched is lower than etch rate at which said first define layer is etched
Data Source
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AI summary
The present invention discloses a light-emitting display backplane, a display device and a manufacturing method of a pixel define layer, relates to a field of display, and can ensure that the liquid drops of the luminescent material, which is formed by printing, can be spread within pixel regions, and a situation that the liquid drops may flow into an adjacent pixel region is avoid. A light-emitting display backplane according to the present invention comprises: a substrate (10) and a pixel define layer (11) provided thereon, wherein said pixel define layer comprises: a first photosensitive resin layer (111), a first transparent define layer (112) and a second transparent define layer (113) sequentially provided on said substrate (10) from bottom to top, each of the first photosensitive resin layer (111), the first define layer (112)and the second define layer (113) is provided with openings corresponding to respective pixels, and the openings in said second define layer (l) are smaller than those (L) in both said first define layer and said first photosensitive resin layer, so as to form luminescent material filling regions which are wider at bottom and narrower at top. The present invention is used to improve techniques of forming films by printing, so that the liquid drops of the luminescent material can be spread within the pixel region, and light-emitting quality of the light-emitting display backplane is thus improved.