Display Device Dummy Pattern for Uniform Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display devices face issues with non-uniform pattern densities between the internal and outer boundary regions of the pixel array, leading to critical dimension deviations and disconnection of wiring lines, which affect screen uniformity and the exposure process during photolithography.
Innovation Solution
A display device with a dummy pattern formed in the non-display area adjacent to the pixel array, parallel to the outermost pixel pattern, and connected to ground or power wiring lines to act as a static electricity shielding circuit, which helps in uniformizing pattern densities and reducing critical dimension deviations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pattern density is increased in the outer boundary region to match internal region density, then manufacturing precision improves, but device complexity increases due to additional dummy patterns
Solution Approach 1:
The patent applies the copying principle by creating dummy patterns that replicate the structure of actual pixel patterns in the outer boundary region. These dummy patterns are copies of the pixel patterns (including gate electrodes, source/drain regions, and contact holes) that allow the outer boundary area to have the same pattern density as the internal region, thereby improving manufacturing precision without requiring fundamental structural changes to the display device.
2Manufacturing precision
If dummy patterns are added to uniformize pattern density, then manufacturing precision improves, but the exposure process complexity increases
Solution Approach 1:
The patent applies the merging principle by integrating the dummy patterns into the existing photolithography exposure process. The dummy patterns are designed to be exposed simultaneously with the actual pixel patterns using the same photolithography steps and conditions. This merging of processes ensures that the dummy patterns and pixel patterns receive identical exposure treatment, thereby improving critical dimension deviation without adding separate exposure process complexity.
3Manufacturing precision
If the dummy pattern is placed closer to the pixel array to maximize density uniformization, then manufacturing precision improves, but the non-display area size increases
Solution Approach 1:
The patent applies the local quality principle by placing dummy patterns specifically in the outer boundary region where pattern density uniformization is most needed, rather than uniformly distributing dummy patterns throughout the entire non-display area. The dummy patterns are localized adjacent to the pixel array in the row and column direction, providing targeted density uniformization only where critical dimension deviation occurs, thereby minimizing the overall non-display area size while maintaining manufacturing precision.
Data Source
AI summary
A display device includes a plurality of signal lines formed in a display area, a pixel array connected to the plurality of signal lines and including a plurality of pixels arranged in a matrix, a scan driving circuit and a data driving circuit formed in a non-display area and electrically connected to the plurality of signal lines, and a dummy pattern formed in the non-display area in a position adjacent to the pixel array along an outer boundary of the pixel array. The dummy pattern is formed to be parallel to a first pixel in a position spaced apart from the first pixel located at an edge of the pixel array in the non-display area by a predetermined distance.