TFT Array Substrate Source Wiring and Pixel Electrode Short Circuit Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The FFS liquid crystal display device faces issues with point defects due to short circuits between the source wiring and pixel electrode, caused by pattern residue during manufacturing, leading to decreased quality and yield, and requiring costly equipment for defect detection and repair.
Innovation Solution
A TFT array substrate is designed with the source wiring and pixel electrode formed from the same transparent conductive material layer, where the end faces of the source wiring and silicon film are overlapped and of identical width, preventing short circuits by maintaining a sharp taper angle and avoiding pattern residue accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the source wiring and pixel electrode are formed from the same transparent conductive material layer to reduce manufacturing complexity, then the number of masks and manufacturing steps are reduced, but pattern residue may cause short circuits between the source wiring and pixel electrode
Solution Approach 1:
The patent segments the transparent conductive material layer into distinct regions: a source wiring formation region and a pixel electrode formation region. By applying different patterning conditions (different resist patterns, etching conditions, or deposition parameters) to these regions, the source wiring and pixel electrode are formed with different shapes and positions, preventing pattern residue from causing short circuits while maintaining the benefit of using a single material layer
Solution Approach 2:
The patent applies different formation conditions to different regions of the transparent conductive material layer. The source wiring region and pixel electrode region are treated differently during patterning, creating local variations in the conductive layer's properties (such as thickness, shape, or connectivity) that prevent short circuits while maintaining overall manufacturing simplicity
2Reliability
If the source wiring and pixel electrode are formed at a constant interval to prevent contact, then short circuits are avoided, but manufacturing precision requirements increase due to pattern residue sensitivity
Solution Approach 1:
By segmenting the formation process into distinct source wiring and pixel electrode regions with different patterning parameters, the patent creates inherent spatial separation that is more robust to manufacturing variations than a simple constant interval approach, reducing the sensitivity to pattern residue
Solution Approach 2:
The patent performs preliminary patterning actions that establish the source wiring and pixel electrode shapes before final assembly, ensuring that their spatial relationship is predetermined by the segmentation strategy rather than relying solely on maintaining a constant interval throughout manufacturing, thereby reducing precision requirements
Data Source
AI summary
A TFT array substrate includes: a pixel electrode, which is arranged in a pixel region formed in a matrix shape by a gate wiring and a source wiring on an insulating substrate; a switching element, which is disposed at an intersection of the gate wiring and the source wiring; a counter electrode, which is formed on the pixel electrode with interposing an insulating film; and a silicon film is formed on a lower layer so as to face the source wiring, wherein the source wiring and the pixel electrode are formed of the same transparent conductive material layer, and the source wiring and the silicon film are formed so that end faces of the source wiring and the silicon film are overlapped and a width of the source wiring is identical to a width of the silicon film, in a plan view.