Spacer Alignment Mark Placement in Large LCD Color Filters
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Solution Overview
Problem
In large-size liquid crystal display panels, the inability to produce alignment marks outside the display area due to mask plate size limitations hinders precise control of spacer position accuracy, especially in supersized products where splicing exposure techniques are used, leading to potential position deviations that are difficult to detect and correct in time.
Innovation Solution
The method involves forming a black matrix layer with smaller first sub-pixel opening areas and larger second sub-pixel opening areas on a substrate, creating an alignment mark near the first sub-pixel opening areas to facilitate precise spacer alignment and position accuracy detection by calculating the position difference between the openings and the alignment mark.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If splicing exposure techniques are used for supersized products, then the display area size can be increased beyond mask plate limitations, but alignment marks cannot be produced outside the display area, resulting in loss of position accuracy control
Solution Approach 1:
The patent segments the sub-pixel opening areas into different sizes: first sub-pixel opening areas (smaller) and second sub-pixel opening areas (larger). The alignment marks are specifically formed around the first sub-pixel opening areas, which are positioned within the display area. This segmentation allows alignment marks to be produced inside the display area during splicing exposure, enabling position accuracy control even for supersized products that require splicing exposure techniques.
2Manufacturing precision
If alignment marks are produced at the periphery outside the display area, then position accuracy of each film layer can be precisely controlled, but this approach is not feasible when the display area size exceeds mask plate size
Solution Approach 1:
The patent changes the spatial dimension for placing alignment marks from the periphery (outside display area) to the interior (within display area). By positioning alignment marks around first sub-pixel opening areas that are located within the display area, the invention enables alignment mark production inside the display area during splicing exposure, thus maintaining position accuracy control capability for large-size products.
3Reliability
If position deviation occurs during fabrication, then quality may be affected, but timely detection and compensation are not possible without alignment marks
Solution Approach 1:
The patent implements a feedback mechanism by forming alignment marks around first sub-pixel opening areas within the display area. These alignment marks serve as reference points that enable detection of position deviations between different film layers (color filter, spacer layer, TFT). By having alignment marks accessible within the display area, the system can detect position deviations and implement compensation measures, thus improving product quality and reliability.
Data Source
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AI summary
The present application discloses a method for preparing an alignment mark for a spacer, a method for detecting accuracy, a color filter and a method for preparing the same. The method for preparing an alignment mark for a spacer comprises: in the fabrication of a black matrix layer of a color filter, forming at least one first sub-pixel opening area and a plurality of second sub-pixel opening areas on a substrate, wherein the size of the first sub-pixel opening area is smaller than the size of the second sub-pixel opening area; in the fabrication of a spacer layer, fabricating an alignment mark for the spacer layer at a designated position around the first sub-pixel opening area.