Via-Hole Conductive Layer for Array Substrate Light Reflection
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Solution Overview
Problem
In thin film transistor liquid crystal display devices, the formation of a black matrix on the array substrate to prevent light leakage results in reduced contrast ratio and color purity due to reflection of ambient light by the drain electrode at the via hole, which is not shielded by the black matrix.
Innovation Solution
A fabrication method for an array substrate involving the formation of a via-hole conductive layer with lower reflectivity than the drain electrode, connected to the drain electrode through a via hole in the passivation layer, to reduce light reflection and improve display quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the black matrix is formed on the array substrate to prevent light leakage, then light leakage is reduced, but the contrast ratio and color purity are reduced due to reflection from the drain electrode at the via hole
Solution Approach 1:
The patent introduces an intermediary substance (black matrix material or reflective layer) to fill the via hole, which mediates between the drain electrode and the external environment. This intermediary prevents direct light reflection from the drain electrode while maintaining the electrical connection, thus resolving the contradiction between preventing light leakage and maintaining contrast ratio
Solution Approach 2:
The patent applies different properties to different parts of the via hole structure. The via hole is filled with a material that has specific optical properties (black matrix material or reflective layer) that differ from the surrounding passivation layer. This local differentiation allows the via hole to prevent light leakage in specific directions while maintaining overall display quality
2Object-affected harmful factors
If the black matrix is formed on the array substrate to prevent light leakage, then light leakage is reduced, but the color purity is reduced due to reflection from the drain electrode
Solution Approach 1:
The intermediary material filled in the via hole acts as a mediator that prevents ambient light from reflecting off the drain electrode and entering the pixel region. This eliminates the harmful reflection that would otherwise contaminate the color output, thereby maintaining color purity while still preventing light leakage
Solution Approach 2:
The patent converts the potentially harmful reflective surface of the drain electrode into a beneficial structure by filling it with appropriate material. The via hole, which initially creates a reflective problem, is transformed into a light-blocking or light-managing feature that actually improves display quality by preventing unwanted reflections
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 method effectively reduces light reflection from the drain electrode, enhancing the contrast ratio and color purity of the display device by ensuring the via-hole conductive layer has lower reflectivity than the drain electrode, thereby improving overall display quality.
Implementation Method 1
the drain electrode at the via hole will reflect the ambient light, resulting in reduction of contrast ratio and color purity
Data Source
AI summary
Embodiments of the disclosure provide an array substrate having via-hole conductive layer and display device. The array substrate includes: a thin film transistor; a passivation layer, covering the thin film transistor, the passivation layer having a via hole and the via hole exposing at least a portion of a drain electrode of the thin film transistor; a via-hole conductive layer, covering the portion of the drain electrode exposed at the via hole and connected to the drain electrode, and a reflectivity of the via-hole conductive layer being lower than a reflectivity of the drain electrode; and a pixel electrode, connected with the drain electrode through the via-hole conductive layer.