Color Filter Stack Eliminates Black Matrix in LCD Manufacturing
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Solution Overview
Problem
The manufacturing process of liquid crystal displays (LCDs) with a COT structure is complex and costly due to the need for additional masking processes to form the black matrix, which can lead to misalignment and lower picture quality.
Innovation Solution
The black matrix is omitted by forming color filter layers in a stack structure on the TFT substrate, where the color filter layers serve as a light shielding layer, reducing the number of masks required and simplifying the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a separate black matrix is formed on the TFT substrate using additional masking processes, then light shielding is achieved, but the manufacturing process becomes complex and costly with increased risk of misalignment
Solution Approach 1:
The invention merges the black matrix function with the color filter layers by forming the color filter layers directly on the TFT substrate at regions where the black matrix would traditionally be formed. This integration eliminates the need for a separate black matrix formation process, reducing manufacturing complexity while maintaining light shielding functionality through the stacked color filter structure.
Solution Approach 2:
The color filter layers are given multiple functions: they serve both as color filters for displaying red, green, and blue colors and as the light shielding layer (black matrix) when stacked. This multi-functionality eliminates the need for a dedicated black matrix layer, simplifying the manufacturing process while achieving both color display and light shielding requirements.
2Adaptability or versatility
If color filter layers and pixel arrays are formed on separate substrates, then manufacturing flexibility is maintained, but the manufacturing process becomes complicated requiring multiple masking processes
Solution Approach 1:
The invention merges the formation of color filter layers and pixel arrays into a single manufacturing process on the same TFT substrate. The color filter layers are formed directly on the substrate at the same time as the pixel array structures, eliminating the need for separate substrate processing and multiple masking steps while maintaining manufacturing flexibility.
3Object-affected harmful factors
If a separate black matrix is formed, then light shielding is provided, but misalignment during substrate attachment occurs resulting in lower picture quality
Solution Approach 1:
By merging the black matrix function into the color filter layer structure formed directly on the TFT substrate, the invention eliminates the separate black matrix layer that would require precise alignment during substrate attachment. The integrated structure removes the alignment precision requirement entirely, as there is no separate layer to align.
Data Source
AI summary
A method for manufacturing a liquid crystal display includes forming a plurality of gate lines and data lines on a substrate, the plurality of gate and data lines cross each other and defining a plurality of unit pixel regions displaying red, green, and blue colors, forming a plurality of thin film transistors in each unit pixel regions, forming a passivation layer on the substrate, forming a green color filter layer on the substrate within a unit pixel region displaying the green color, forming one of a red color filter layer and a blue color filter layer within a unit adjacent to the unit pixel region displaying the green color, and within a portion of the green color filter layer overlapping the thin film transistor, depositing an organic insulating layer on the substrate and forming a contact hole, and forming a plurality of pixel electrodes corresponding to each unit pixel region.