FFS LCD Array Substrate Eliminating Semiconductor Protrusions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fringe field switching (FFS) mode liquid crystal display (LCD) devices face issues with wavy noise and photo leakage current due to the protrusion of semiconductor layers beyond source and drain electrodes, leading to signal coupling and reduced aperture ratio.
Innovation Solution
The array substrate design includes a gate line, gate electrode, gate insulating layer, semiconductor layer, source and drain electrodes with sub-layers, a data line with a double-layered structure, and a pixel electrode extending from the drain electrode, all fabricated using a five-mask process without protrusions, preventing photo leakage and wavy noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the semiconductor layer protrudes beyond the source and drain electrodes in FFS mode LCD fabrication, then the five-mask process can be used to reduce production costs, but wavy noise and photo leakage current problems occur
Solution Approach 1:
The invention extracts and removes the protruding portions of the semiconductor layer that extend beyond the source and drain electrodes. By selectively eliminating these problematic protrusions through etching processes, the patent resolves the wavy noise and photo leakage current issues while maintaining the cost-effective five-mask fabrication process.
Solution Approach 2:
The invention applies preliminary anti-action by pre-defining the semiconductor layer boundaries to align with the source and drain electrode edges before final assembly. This preventive approach ensures that no protrusions are formed in the first place, thereby avoiding wavy noise and photo leakage current problems while maintaining manufacturing efficiency.
2Device complexity
If the semiconductor layer protrudes beyond the source and drain electrodes, then fabrication can be simplified, but aperture ratio is reduced
Solution Approach 1:
The invention extracts and removes the protruding semiconductor layer portions that would otherwise reduce the aperture ratio. By eliminating these excess portions, the active display area is maximized while the fabrication process remains simplified through the five-mask process.
3Ease of manufacture
If the semiconductor layer protrudes beyond the source and drain electrodes, then the five-mask process can be used, but photo leakage current increases
Solution Approach 1:
The invention extracts and removes the protruding semiconductor layer portions that generate photo leakage current. By eliminating these protrusions, the harmful photo leakage effect is prevented while the cost-effective five-mask fabrication process is maintained.
Solution Approach 2:
The invention converts the potential harm of protruding semiconductor layers into a benefit by using the same five-mask fabrication process to precisely control and define the boundaries, then removing any excess portions. This transforms a potentially harmful situation into a controlled process that eliminates photo leakage current while maintaining manufacturing simplicity.
Data Source
AI summary
An array substrate for a fringe field switching mode liquid crystal display device comprises a gate line on a substrate; a gate electrode connected to the gate line; a gate insulating layer on the gate line and the gate electrode; a semiconductor layer on the gate insulating layer and corresponding to the gate electrode; source and drain electrodes on the semiconductor layer and spaced apart from each other, the source electrode having first and second sub-source layers, the drain electrode having first and second sub-drain layers. Also disclosed in a method of fabricating a fringe field switching mode liquid crystal display device.