TFT Array Substrate Via Openings Prevent Static Crack
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Solution Overview
Problem
Existing TFT array substrates are vulnerable to static electricity, which can cause cracks in the conductive layers, disrupting the connection between metallic layers and affecting the reliability and functionality of display panels.
Innovation Solution
The TFT array substrate design includes a third conductive layer connected to first and second conductive layers through specific via structures with openings that prevent cracks from extending, ensuring continuous connectivity even when struck by static electricity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional TFT array substrate structure with ITO layer and vias is used, then the display panel can be manufactured with standard processes, but the ITO layer is vulnerable to static electricity causing cracks that separate conductive layers
Solution Approach 1:
The third conductive layer is segmented into multiple sections by introducing first and second openings that divide it into separate regions. These openings are positioned such that they create discrete conductive paths through the via structures, preventing a single crack from propagating across the entire layer and causing complete disconnection.
Solution Approach 2:
The via structures serve as intermediary elements that provide alternative conductive paths. When the third conductive layer is cracked, the vias maintain electrical connection between the first, second, and third conductive layers by providing vertical conductive pathways that bypass the crack in the horizontal plane.
2Reliability
If the ITO layer is made continuous to ensure good conductivity, then electrical connection is improved, but the layer becomes more susceptible to crack propagation under static electricity stress
Solution Approach 1:
The third conductive layer is divided into multiple segments by the first and second openings. This segmentation prevents crack propagation across the entire layer while maintaining electrical connectivity through the via structures, effectively breaking the continuous path that would otherwise allow cracks to spread.
Solution Approach 2:
The opening structures are designed in advance to intercept and stop crack propagation before it can reach critical dimensions. By positioning the openings strategically, the design creates predetermined weak points that stop cracks, cushioning the overall structure against complete failure.
3Productivity
If vias are positioned close together to minimize space, then manufacturing efficiency is improved, but static electricity can still cause cracks that separate the conductive layers between vias
Solution Approach 1:
The third conductive layer is segmented by openings positioned between the vias, creating discrete conductive regions. This segmentation ensures that even when vias are closely spaced for manufacturing efficiency, each via maintains its own dedicated conductive path that cannot be compromised by cracks in adjacent regions.
Solution Approach 2:
The opening structures create local variations in the conductive layer, with each via having its own protected conductive path. This local quality enhancement ensures that connection integrity is maintained at each via location independently, preventing crack propagation from affecting multiple vias simultaneously.
Data Source
AI summary
The TFT array substrate has a third conductive layer connected to a first conductive layer and a second conductive layer through a first via and a second via, respectively. The third conductive layer further has separated first and second openings. The first opening has a vertical projection to a side of the second via and has an end extending beyond an edge of the second via adjacent to the first via. The second opening has a vertical projection to a side of the first via and has an end extending beyond an edge of the first via adjacent to the second via. As such, when the third conductive layer is stricken by static electricity, the first and second openings prevent a crack from breaking the first and second conductive layers apart, thereby enhancing the reliability of the connection between the first and second conductive layers.