Stacked TFT Switching Element with Shared Electrode
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods to increase the on-state current of switching elements in liquid crystal display technology, such as increasing the width-to-length ratio, result in reduced aperture ratios due to occupied space, which hinders the ability to rapidly charge and discharge pixel electrodes.
Innovation Solution
A switching element design featuring two thin-film transistors (TFTs) arranged in parallel up and down, sharing a source-drain electrode, which increases on-state current while minimizing space occupation and simplifying the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the width-to-length ratio of the switching element is increased to increase on-state current, then the on-state current increases, but the area occupied by the switching element increases, reducing the aperture ratio
Solution Approach 1:
The patent transitions from a single-plane TFT arrangement to a three-dimensional stacked configuration where multiple TFTs are arranged vertically across different substrate layers. This spatial reorganization allows current paths to be stacked in the vertical dimension while maintaining a compact horizontal footprint, thereby increasing on-state current without sacrificing aperture ratio.
Solution Approach 2:
The switching element is divided into multiple independent TFT units (first TFT, second TFT, third TFT) that can be independently controlled. By segmenting the single TFT into multiple parallel-connected units across different layers, the total current capacity is distributed across segments, achieving higher aggregate current while each segment maintains a compact size.
2Power
If multiple switching elements are connected in parallel to increase on-state current, then the on-state current increases, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
Multiple TFTs across different layers share common source and drain electrodes, merging the electrical connection infrastructure. This shared electrode structure reduces the total number of discrete components and interconnections required, simplifying the manufacturing process while maintaining the parallel current paths needed for high on-state current.
Solution Approach 2:
The source and drain electrodes serve multiple functions: they act as common electrical connections for multiple TFTs across different layers, serve as current collection points for parallel-connected units, and provide structural support for the stacked configuration. This multi-functionality reduces overall device complexity.
Data Source
AI summary
A switching element, a manufacturing method thereof, an array substrate and a display device are provided. The switching element includes: a base substrate; a first thin-film transistor (TFT), disposed on the base substrate; and a second TFT, disposed on the first TFT, wherein the first TFT includes a first electrode and a second electrode, and the first TFT and the second TFT share the first electrode and the second electrode.