Special-Shaped TFT Layout for Stable Parasitic Capacitance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Parasitic capacitance changes due to process variations in liquid crystal display array substrates cause screen flickers and afterimages, as the source electrode shifting affects the overlapping area with the gate electrode, leading to inconsistent feeding voltage.
Innovation Solution
A special-shaped thin-film transistor design with extension parts and compensation electrodes ensures that the overlapping area between the source electrode and the gate portion remains unchanged, maintaining constant parasitic capacitance despite process variations, through strategically positioned extension parts that overlap or stagger with the gate and compensation electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the source electrode is shifted left and right due to process variation, then the overlapping area between source electrode and gate electrode changes, but this causes parasitic capacitance to change and leads to screen flickers and afterimages
Solution Approach 1:
The source electrode is divided into multiple segments (first source electrode segment, second source electrode segment, third source electrode segment) with different overlapping areas with the gate electrode. This segmentation allows the total parasitic capacitance to remain stable even when individual segments shift due to process variation, as the capacitance changes in different segments compensate for each other.
Solution Approach 2:
Different segments of the source electrode are designed with different local properties - specifically, different overlapping areas with the gate electrode. The first segment has a larger overlapping area while the second and third segments have smaller overlapping areas. This local differentiation ensures that when process variation occurs, the overall parasitic capacitance remains stable.
2Power
If the overlapping area of source electrode and gate electrode is increased to improve transistor performance, then parasitic capacitance increases, but this causes feeding voltage to increase and may cause screen flickers
Solution Approach 1:
The source electrode is segmented into multiple parts with different overlapping areas. This allows the transistor to achieve good performance through the total overlapping area while distributing the parasitic capacitance across multiple segments, making the total parasitic capacitance more stable against process variations.
Solution Approach 2:
The invention changes the parameter distribution of overlapping areas across different source electrode segments. By having the first segment with a larger overlapping area and the second and third segments with smaller overlapping areas, the design optimizes the balance between transistor performance and parasitic capacitance stability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design stabilizes the parasitic capacitance, preventing screen flickers and afterimages by ensuring consistent voltage delivery, while also allowing for miniaturization and reduced contact resistance, thus enhancing the performance of the liquid crystal display.
Implementation Method 1
an overlapping area of the source electrode 4 and the gate electrode 1 will generate parasitic capacitance
Data Source
AI summary
A special-shaped thin-film transistor and an array substrate are provided. The special-shaped thin-film transistor includes a first gate portion, a first compensation electrode, and a first source electrode. The first compensation electrode is connected to the first gate portion. The first source electrode includes a first extension part, a first source portion, and a second extension part which are connected in sequence. Part of the first extension part overlaps the first gate portion, and part of the second extension part overlaps the first compensation electrode.