Light Shielding Layer for Array Substrate IR Drop and Data Loss
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Solution Overview
Problem
Display apparatuses using metal oxide or metal oxynitride thin film transistors face issues with light sensitivity leading to threshold voltage drift and data loss, as well as current-resistance (IR) drop in power supply lines due to insufficient light shielding.
Innovation Solution
An array substrate with a light shielding layer electrically connected to power supply lines is introduced, which shields the active layers of thin film transistors from light irradiation, reducing current-resistance drop and data loss by forming additional capacitance between the light shielding layer and gate electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a light shielding layer is added to protect the active layer from light irradiation, then the threshold voltage stability is improved, but the device complexity increases
Solution Approach 1:
The light shielding layer is designed to serve dual functions: (1) shielding the active layer from light irradiation to prevent threshold voltage drift, and (2) acting as an additional power supply line to reduce IR drop. By making the light shielding layer electrically connected to power supply lines, it simultaneously provides light shielding and electrical connection functions, thereby reducing device complexity despite adding a structural layer.
Solution Approach 2:
The invention merges the light shielding function with the power supply function by electrically connecting the light shielding layer to the power supply lines. This combination allows the light shielding layer to contribute to both protecting the active layer and reducing IR drop, effectively addressing multiple problems with a single integrated solution.
2Loss of energy
If the light shielding layer is electrically connected to power supply lines, then the current-resistance drop is reduced, but the manufacturing complexity increases
Solution Approach 1:
The light shielding layer is integrated with the power supply lines through electrical connection, merging two functional elements into a unified structure. This integration allows the light shielding layer to serve as both a protective element and an electrical conductor, reducing IR drop while maintaining manufacturing efficiency by combining processes rather than adding separate steps.
3Object-affected harmful factors
If the orthographic projection of the light shielding layer substantially covers the orthographic projection of the first active layer, then the light shielding effectiveness is improved, but the area occupied increases
Solution Approach 1:
The light shielding layer is designed to substantially cover the active layer area, providing effective light shielding. By electrically connecting this covering layer to power supply lines, it simultaneously functions as a power distribution network, reducing IR drop without requiring additional separate power lines, thus optimizing area utilization.
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 shielding layer effectively reduces data loss and current-resistance (IR) drop in power supply lines, enhancing the performance and reliability of display apparatuses by minimizing the impact of light on thin film transistors.
Implementation Method 1
a light shielding layer configured to shield light from irradiating on the first active layer
Implementation Method 2
forming additional capacitance between the light shielding layer and gate electrodes
Data Source
AI summary
The present application provides an array substrate. The array substrate includes a base substrate; a plurality of light emitting elements on the base substrate; a plurality of driving thin film transistors for driving light emission of the plurality of light emitting elements, each of the plurality of driving thin film transistors including a first active layer; one or more power supply lines configured to supply a driving current respectively to the plurality of light emitting elements; and a light shielding layer configured to shield light from irradiating on the first active layer, the light shielding layer being electrically connected to at least one of the one or more power supply lines.