Dual-Gate TFT Design for Display Bright and Dark Spot Elimination
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Solution Overview
Problem
Display panels using thin-film transistors (TFTs) often suffer from bright and dark spots due to component failures, such as broken gate electrodes or active layers, leading to increased production costs and reduced aperture ratios, as existing methods like laser cutting or duplicating TFTs in subpixel units either fail to eliminate defects or compromise display effectiveness.
Innovation Solution
A TFT design featuring a dual-gate electrode configuration where both gate electrodes are electrically connected in parallel, allowing one to function normally if the other fails, and an array substrate structure that includes capacitors to enhance liquid crystal pixel potential retention, reducing bright and dark spots and improving display performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single gate electrode configuration is used in TFT, then the device structure is simple, but bright and dark spots occur due to component failures
Solution Approach 1:
The gate electrode is divided into two separate gate electrodes (first gate electrode and second gate electrode) that are respectively overlapped with first and second channel regions. This segmentation allows independent functionality of each gate electrode, so if one fails, the other can still maintain TFT operation, thereby eliminating bright and dark spots while improving reliability.
Solution Approach 2:
Different gate electrodes are positioned over different channel regions with distinct source/drain areas. The first gate electrode controls the first channel region with first source/drain areas, while the second gate electrode controls the second channel region with second source/drain areas. This local differentiation enables localized functionality, ensuring that failure in one region does not affect the other.
2Reliability
If laser cutting is used to eliminate bright and dark spots, then display defects are reduced, but production costs increase
Solution Approach 1:
The dual gate electrode configuration is built into the TFT structure during manufacturing, providing built-in redundancy before defects occur. This preliminary design prevents bright and dark spots from forming in the first place, eliminating the need for costly post-manufacturing laser cutting processes while maintaining high display quality.
3Productivity
If TFT aperture ratio is increased, then display effectiveness improves, but production costs increase due to defect elimination measures
Solution Approach 1:
The dual gate electrode structure provides built-in redundancy that cushions against potential failures. By having two independent gate electrodes with separate source/drain areas, the system can tolerate failure of one electrode without performance degradation, thereby maintaining high aperture ratio and display effectiveness without incurring additional costs for defect elimination.
Data Source
AI summary
A thin-film transistor (TFT), an array substrate, a manufacturing method thereof and a display device are provided. The TFT includes an active layer, a gate electrode, a first source/drain electrode and a second source/drain electrode. The active layer includes a first channel region and a second channel region, a first source/drain area between the first channel region and the second channel region, and a second source/drain area opposite to the first source/drain area through the first channel region or the second channel region. The gate electrode includes a first gate electrode and a second gate electrode which are respectively overlapped with the first channel region and the second channel region. The first source/drain electrode and the second source/drain electrode are respectively electrically connected with the first source/drain area and the second source/drain area of the active layer.