TFT Substrate Shared Doping Region for High PPI Layout
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Solution Overview
Problem
Traditional circuit designs for AMOLEDs, which require two TFTs with a metal bridge transferring layer, occupy significant layout space, making it difficult to achieve higher Pixels per Inch (PPI) as the industry demands.
Innovation Solution
The design incorporates a TFT substrate with a first TFT structure and a second TFT structure where the first doping region of the first TFT extends and functions as the gate pattern for the second TFT, allowing for a more compact layout by overlapping conductive channels and doping regions, thereby saving space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional circuit design with two TFTs and a metal bridge transferring layer is used, then the circuit structure is complete and functional, but the layout space is significantly occupied, making it difficult to achieve higher PPI
Solution Approach 1:
The patent merges the gate electrode of the second TFT with the drain electrode of the first TFT by forming them as a continuous conductive structure. This eliminates the need for a separate metal bridge transferring layer, thereby reducing layout space while maintaining the complete circuit structure and functionality of both TFTs
Solution Approach 2:
The conductive structure serving as the drain of the first TFT simultaneously functions as the gate electrode of the second TFT. This multi-functional design reduces the number of separate components needed, optimizing layout space utilization while ensuring both TFTs operate correctly
Data Source
AI summary
A TFT substrate, a display device and a manufacturing method are disclosed. The TFT substrate includes a substrate and a first TFT structure and a second TFT structure formed on the substrate. The first TFT structure includes a first gate pattern and a first semiconductor pattern. The first semiconductor pattern is divided into a first channel region, and a first doping region and a second doping region located at two sides of the first channel region. The first channel region is disposed corresponding to the first gate pattern to form a first conductive channel under the function of first gate pattern. The first doping region is extended inside the second TFT structure as a second gate pattern of the second TFT structure. The present invention uses doping drain of a switching TFT as gate of a driving TFT to save layout space, and beneficial for realization of higher PPI.