Patterned Spacers for LCD Cell Gap Uniformity
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Solution Overview
Problem
The existing liquid crystal display (LCD) devices using ball spacers face issues with non-uniform cell gap maintenance, light leakage, and the ripple phenomenon, especially in large-sized displays, due to the random distribution and elastic nature of ball spacers, which affect display quality and manufacturing costs.
Innovation Solution
The use of patterned spacers formed in non-pixel regions between substrates, which are fixed and precisely controlled to maintain a uniform cell gap, reducing light leakage and improving contrast ratio, and are fabricated using a reduced number of mask processes to lower production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If ball spacers are used to maintain cell gap, then the manufacturing process is simple, but the cell gap uniformity deteriorates and light leakage occurs
Solution Approach 1:
The invention divides the spacer function into two distinct components: columnar spacers that define fixed vertical positions for maintaining cell gap uniformity, and ball spacers that fill horizontal gaps between columns. This segmentation allows each component to specialize in its optimal function, with columnar spacers providing precise positional control and ball spacers providing flexible gap filling, thereby resolving the contradiction between manufacturing simplicity and cell gap uniformity.
2Ease of manufacture
If ball spacers are randomly distributed, then the manufacturing process is simple, but the ripple phenomenon occurs and display quality deteriorates
Solution Approach 1:
The invention applies local quality by creating regions with different spacer characteristics: columnar spacers are positioned at specific locations (pixel regions and non-pixel regions) to provide fixed structural support and prevent ripple phenomenon, while ball spacers are allowed to randomly distribute in other regions to maintain manufacturing simplicity. This localized differentiation resolves the contradiction between manufacturing simplicity and display quality by applying the appropriate spacer type in the appropriate location.
3Manufacturing precision
If patterned spacers are formed using multiple mask processes, then the cell gap uniformity is improved, but the manufacturing cost increases
Solution Approach 1:
The invention merges the formation of columnar and ball spacers into a single integrated process. Columnar spacers are formed first through photolithography and etching to create the fixed positional framework. Then ball spacers are deposited as a coating layer that automatically fills the gaps between columnar spacers. This merging of processes achieves uniform cell gap control through the combined action of both spacer types while avoiding the need for multiple separate mask processes, thereby resolving the contradiction between manufacturing precision and device complexity.
Data Source
AI summary
A liquid crystal display device includes first and second substrates, a black matrix on the second substrate, the black matrix including a plurality of open portions corresponding to pixel regions and a plurality of holes disposed adjacent to the plurality of open portions, color filter layers on the black matrix, and a plurality of patterned spacers corresponding to each of the plurality of holes between the first and the second substrates.