Color Filter Spacer Height Control via Photoresist Thickness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for manufacturing color filter substrates are costly and limited in achieving a significant height difference between main and secondary spacers due to the high cost of halftone or gray-tone masks and the difficulty in controlling the size and homogeneity of secondary spacers using photolithographic processes.
Innovation Solution
A color filter substrate design where spacers are formed using a common mask, with secondary spacers created in the same photolithographic process as the color photoresist patterns, allowing for continuous strip-like patterns that enable the formation of main and secondary spacers with adjustable heights, reducing production costs and improving spacer homogeneity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If halftone mask or gray-tone mask is used to control light intensity during exposure, then the height difference between main spacer and secondary spacer can be adjusted, but the manufacturing cost increases significantly
Solution Approach 1:
The patent extracts the height difference control function from the mask design and transfers it to the photoresist layer thickness control. By using a common mask with uniform exposure zones and controlling the thickness of the photoresist layer during the photolithographic process, the height difference between main and secondary spacers is achieved without requiring expensive halftone or gray-tone masks. This separates the masking function from the height control function, allowing standard masks to be used while still achieving precise height differences through photoresist thickness management.
2Manufacturing precision
If the exposure zone size in the mask is controlled strictly to achieve suitable secondary spacer height, then the height difference can be realized, but the manufacturing precision and homogeneity become difficult to ensure
Solution Approach 1:
Instead of controlling the exposure zone size in the mask to achieve the desired spacer height, the patent inverts the approach by controlling the photoresist layer thickness during the photolithographic process. The mask uses uniform exposure zones with standard sizes, and the height difference is achieved by controlling how thick the photoresist layer becomes during exposure and development. This inversion simplifies mask design and exposure zone control while maintaining precise height difference control through photoresist thickness management.
3Manufacturing precision
If the cross-sectional dimension of the top of the formed spacer is kept small to realize height difference, then the height difference can be achieved, but the spacer homogeneity and application range are limited
Solution Approach 1:
The patent changes the controlling parameter from exposure zone size to photoresist layer thickness. By controlling the thickness of the photoresist layer during the photolithographic process, the height difference between main and secondary spacers can be achieved while allowing the top cross-sectional dimension of the spacers to be larger. This parameter change enables better spacer homogeneity and expands the application range, as the spacers can maintain sufficient structural integrity and uniformity across different sizes and applications.
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 allows for a larger and more homogeneous height difference between main and secondary spacers, enhancing the manufacturing efficiency and reducing costs by eliminating the need for specialized masks, while maintaining the structural integrity of the liquid crystal display.
Implementation Method 1
forming a color filter layer including color photoresist patterns with N different colors arranged cyclically in discontinuous sub-pixel areas in adjacent N rows/columns
Data Source
AI summary
A color filter substrate, a manufacturing method thereof and a display device are provided. The color filter substrate includes a substrate; a black matrix dividing the substrate into a plurality of sub-pixel areas arranged in matrix; a color filter layer including color photoresist patterns with N different colors, N≧3, arranged cyclically in discontinuous sub-pixel areas in adjacent N rows/columns, the color photoresist patterns in M adjacent sub-pixel areas of a single color in at least one line/column in the color filter layer extending to regions over the black matrix corresponding to regions between adjacent sub-pixel areas, to form continuous strip-like color photoresist patterns, wherein M≧2; and spacers including main spacers disposed over regions between adjacent discontinuous color photoresist patterns corresponding to the black matrix and secondary spacers disposed over regions of the continuous strip-like color photoresist patterns corresponding to the black matrix.