TFT Array Substrate Repair Patterns and Shield Lines
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Solution Overview
Problem
Conventional liquid crystal display (LCD) modules face issues with defects in lead lines during manufacturing, leading to image quality problems and light leakage due to non-uniform sealant radiation and lack of effective shielding, resulting in low yield and poor displaying quality.
Innovation Solution
A thin film transistor (TFT) array substrate with repair patterns and shield lines is introduced, where repair patterns are strategically placed between lead lines and the substrate to isolate and reconnect defective areas, and shield lines are used to prevent light leakage by overlapping with lead lines, with connections having smaller widths than gaps to avoid shorts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If shield lines are added between lead lines to prevent light leakage, then light leakage is reduced, but the risk of short circuits increases due to particle contamination or static discharge at overlap areas
Solution Approach 1:
The shield line is divided into multiple segments that are electrically isolated from each other. Each shield line segment is positioned between adjacent lead lines to provide light shielding, but the segments themselves are electrically isolated to prevent short circuits. This is achieved by creating gaps or insulating barriers between consecutive shield line segments.
Solution Approach 2:
The shield line structure is optimized locally at different positions. At areas where light leakage is most problematic, shield lines are densely placed. At areas prone to particle contamination or static discharge, the shield line structure is modified to reduce electrical conductivity or increase spacing, thereby reducing short circuit risk while maintaining light shielding effectiveness.
2Ease of repair
If repair patterns are introduced to fix lead line defects, then defect repair capability is improved, but device complexity increases
Solution Approach 1:
Repair patterns are pre-formed as part of the standard manufacturing process, positioned at strategic locations where lead line defects most commonly occur. These repair patterns are prepared in advance during the fabrication stages, so when defects are detected, the repair structures are already in place and ready for activation, eliminating the need for complex post-manufacturing repairs.
Solution Approach 2:
The repair pattern acts as an intermediary structure between the defective lead line and the functional circuit. When a lead line defect is detected, the repair pattern provides an alternative conductive path that bridges the gap or bypasses the defective area, restoring electrical connectivity without requiring direct modification of the original lead line or complex rework procedures.
3Ease of repair
If the inner area is added between pixel region and outer area, then lead line defects can be repaired, but manufacturing complexity increases
Solution Approach 1:
The inner area is merged with the existing peripheral circuit region structure, combining the repair functionality with the existing lead line routing and shielding structures. The inner area shares common manufacturing steps with other regions of the substrate, using the same deposition, patterning, and bonding processes, thereby minimizing the increase in manufacturing complexity while providing the desired repair capability.
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
The solution enhances the yield and displaying quality of LCDs by effectively repairing defects in lead lines and preventing light leakage, ensuring proper signal transmission and improved contrast.
Implementation Method 1
the first lead line and the second repair pattern thereabove are welded through the second pre-repair area such that the two parts of the first lead line are electrically connected with the second repair pattern
Implementation Method 2
each of the first shield lines is disposed between two adjacent second lead lines for preventing lights pass through gaps between the second lead lines
Data Source
AI summary
A TFT array substrate comprising a substrate has a pixel region and a peripheral circuit region surrounding the pixel region, a TFT array, first lead lines, second lead lines, and first repair patterns is provided. The peripheral circuit region has an outer area and an inner area. The inner area is disposed between the pixel region and the outer area. The TFT array disposed in the pixel region includes a first conducting layer and a second conducting layer. The first lead lines and the second lead lines disposed in the peripheral circuit region are on the same layer of the first conducting layer and the second conducting layer respectively. The first repair patterns disposed in the inner area are sandwiched between the second lead lines and the substrate. At least a first pre-repair area is at a region where the second lead lines and the first repair patterns are overlapped.