Color Filter Substrate Backside Exposure Planarization
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Solution Overview
Problem
The conventional manufacturing process of color filter substrates for liquid crystal displays is complex and prone to defects, leading to high manufacturing costs and risks due to the need for multiple processes and inconsistent film thicknesses.
Innovation Solution
A simplified manufacturing method involving back side and front side exposure of a negative photoresist resin layer to form a planarization layer and post spacers, using a halftone mask to create main and sub post spacers, which simplifies the operation flow and reduces manufacturing costs and risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional manufacturing process with multiple sequential layers (black matrix, red filter layer, green filter layer, blue filter layer, planarization layer, sub post spacer layer, main post spacer layer) is used, then the color filter substrate can be manufactured with required functional layers, but the manufacturing process becomes highly complicated with seven processes and high risk of defects
Solution Approach 1:
The patent merges multiple separate manufacturing steps into a single integrated process. Specifically, the color filter layers and planarization layer are formed simultaneously in one coating operation rather than sequentially. The photoresist layer is exposed through the substrate from the back side to cure both the color filter layers and form the planarization layer in a single exposure step, eliminating the need for separate processing steps for each layer and significantly reducing process complexity.
Solution Approach 2:
The photoresist layer serves multiple functions simultaneously: it acts as the color filter layer (red, green, blue filters), the planarization layer, and the post spacer layer. By using a single material layer with differentially controlled curing through selective exposure, the patent eliminates the need for multiple separate layers and processes, reducing both manufacturing complexity and defect risk while maintaining all required functionalities.
2Manufacturing precision
If multiple separate layers are formed sequentially to ensure planarization and proper cell gap, then the structural requirements are met, but the manufacturing time and cycle are extended
Solution Approach 1:
The patent performs preliminary curing of the photoresist layer by exposing it through the substrate from the back side before final pattern formation. This preliminary action creates the planarization layer and color filter layers with appropriate thickness and uniformity, which then serves as the foundation for the final post spacer pattern formation in a single subsequent exposure step, ensuring precision while maintaining speed.
Solution Approach 2:
The patent combines the formation of color filter layers, planarization layer, and post spacers into a single photoresist layer processed in one exposure-development cycle. The selective exposure through the substrate from the back side enables differential curing that simultaneously achieves planarization and creates the required layer structures, eliminating multiple sequential processing steps and significantly improving manufacturing efficiency.
3Ease of manufacture
If seven separate manufacturing processes are used to form each layer sequentially, then complete functional layers are achieved, but the manufacturing cost increases due to high facility investment and process complexity
Solution Approach 1:
The patent merges seven separate manufacturing processes into a single integrated process where all color filter layers and the planarization layer are formed simultaneously in one coating and exposure operation. This eliminates the need for multiple separate coating, drying, and exposure equipment and processes, significantly reducing facility investment and manufacturing cost while simplifying the manufacturing procedure.
Solution Approach 2:
The patent uses a single photoresist material layer to fulfill multiple functional roles (color filters and planarization layer) that traditionally required seven separate material layers and processing steps. This multi-functionality approach reduces material costs, processing costs, and facility requirements while achieving the same functional outcomes.
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 method significantly simplifies the manufacturing process, reduces facility investment, lowers the risk of defects, and shortens the product manufacturing cycle while ensuring a planarized surface for the color filter substrate.
Implementation Method 1
conducting back side exposure on the photoresist layer from an underside of the backing plate such that exposure light transmits through the backing plate and the color filter layer to irradiate on the photoresist layer to cure a portion of the photoresist layer
Data Source
AI summary
The present invention provides a manufacturing method of a color filter substrate, in which a layer of photoresist layer of a negative photoresist resin material is first formed on the color filter film layer; then, back side exposure is conducted on the photoresist layer from the underside of the backing plate so that a part of the photoresist layer that is adjacent to the backing plate gets cured for subsequently forming a planarization layer; afterwards, a mask is used to conduct front side exposure on the photoresist layer from the backing plate to form post spacers; and finally, the photoresist layer that has been subjected to exposure twice is subjected to development to remove a portion of the photoresist layer that has not been cured so as to form, simultaneously, a planarization layer and post spacers located on the planarization layer. This, when compared to an existing manufacturing method of a color filter substrate, can greatly simplify operation flow and thus greatly reduce investment on manufacturing line facility and lower down manufacturing costs of products and potential risks of unexpected problems occurring in the manufacturing process and shortening product manufacturing cycle.