Array Substrate Light Blocking Layer for TFT-LCD Dark Current Reduction
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Solution Overview
Problem
In TFT-LCDs, the reflection of light from non-transparent metal films used in the black matrix can cause dark current, leading to reduced pixel charge retention and image flickering due to light radiation on semiconductor layers, affecting display quality.
Innovation Solution
A light blocking layer is formed on the TFT array substrate to prevent light from reaching the semiconductor layers, comprising a gate light blocking portion and a scanning line light blocking portion, with a gap between them, and a gate electrode connected via a via hole filled with conductive material, forming a double-channel TFT structure to improve conductivity and block light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a non-transparent metal film is used for the black matrix, then light reflection is enhanced, but dark current increases due to light radiation on semiconductor layers
Solution Approach 1:
The invention divides the light blocking function into multiple components: the black matrix on the color filter substrate and a newly introduced light blocking layer on the TFT array substrate. This segmentation allows the light blocking function to be distributed, reducing the harmful light radiation effect on semiconductor layers while maintaining overall light reflection performance.
Solution Approach 2:
The light blocking layer acts as an intermediary element between the black matrix and the semiconductor layers. It intercepts and blocks light before it reaches the semiconductor layers, preventing the generation of dark current while allowing the black matrix to maintain its light reflection function.
2Object-affected harmful factors
If the light blocking layer is formed covering the data scanning line, then light blocking performance is improved, but manufacturing complexity increases due to additional process steps
Solution Approach 1:
The invention merges the light blocking layer formation process with existing manufacturing steps. The light blocking layer is formed using the same photolithography and etching processes as the data scanning line, combining multiple functions into a single integrated structure rather than adding separate process steps.
Solution Approach 2:
The light blocking layer serves multiple functions: it blocks light from reaching semiconductor layers, provides structural support, and can be integrated with the data scanning line formation process. This multi-functionality reduces the need for additional dedicated process steps.
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
The light blocking layer effectively prevents light from radiating onto the semiconductor layers, reducing dark current and maintaining pixel charge retention, thereby enhancing the display quality and electrical properties of TFT-LCDs.
Implementation Method 1
a light blocking layer, formed on the base substrate and corresponding to the thin film transistor and the data scanning line
Data Source
AI summary
An array substrate comprises: a base substrate; a gate scanning line, a data scanning line, a pixel electrode and a thin film transistor, formed on the base substrate; and a light blocking layer, formed on the base substrate and corresponding to the thin film transistor and the data scanning line.