Display Substrate Metal Pattern Layout to Prevent Etching Undercut
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Solution Overview
Problem
Existing display substrates face issues with ambient light reflection due to metal patterns, leading to defective products and reduced display performance, as the etching process can result in an undercut phenomenon that disrupts the connection between metal and conductive patterns.
Innovation Solution
The implementation of an anti-reflection layer made of molybdenum oxide on a copper metal layer, with a controlled etching process to ensure the slope angles and edge distances between the anti-reflection and metal patterns are within specific thresholds, preventing undercut and optimizing the connection between patterns, and the use of corrosion-resistant metals to adjust etching rates and reduce reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple ITO layer is used as the transparent electrode, then the manufacturing process is simple, but the flexibility and bendability are insufficient
Solution Approach 1:
The transparent electrode is divided into multiple functional layers: a first transparent conductive layer (ITO) providing basic conductivity, and a second transparent conductive layer (IZO) added specifically to enhance flexibility and bendability. This segmentation allows each layer to perform its specialized function independently.
Solution Approach 2:
The patent uses a composite structure combining ITO and IZO layers, where IZO (indium zinc oxide) provides superior flexibility compared to pure ITO. The composite transparent electrode leverages the advantages of both materials to achieve both conductivity and enhanced mechanical flexibility.
2Stability of the object's composition
If the transparent electrode has high flexibility, then the display can be bent, but the electrode material becomes insufficient
Solution Approach 1:
Instead of using a single thick flexible electrode layer, the patent segments the electrode function across two thinner layers (ITO and IZO). This reduces the total material consumption while maintaining flexibility through the IZO layer's inherent properties.
Solution Approach 2:
The patent changes the compositional parameters of the transparent electrode by introducing zinc into the indium oxide structure to create IZO. This parameter change (adding Zn) fundamentally alters the material properties to achieve flexibility without requiring excessive material quantity.
3Adaptability or versatility
If the display device is made flexible, then new applications are enabled, but image quality deteriorates due to bending
Solution Approach 1:
The patent applies a buffer layer between the flexible transparent electrode and the underlying substrate to cushion and compensate for bending-induced stress. This pre-established protective structure prevents image quality deterioration by absorbing mechanical stress before it reaches the display pixels.
Solution Approach 2:
The multi-layer composite structure (including ITO, IZO, and buffer layer) is specifically designed to maintain structural integrity during bending. Each layer is optimized to handle different aspects of the mechanical stress, collectively preserving image quality while enabling flexibility.
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 approach effectively reduces ambient light reflection, improves product yield by ensuring proper pattern connection, and enhances signal transmission and display performance by minimizing parasitic capacitance and flickering.
Implementation Method 1
a second transparent conductive layer, namely an IZO layer, is formed on the ITO layer by a sputtering method
Data Source
Figure 1~2A
Figure 2B~3A
Figure 3B~4
AI summary
The present disclosure provides a display substrate, a method for preparing the same, and a display device, and belongs to the technical field of display. Among them, the display substrate includes: a base substrate (1); a metal pattern (7) located on the base substrate (1), and an anti-reflection pattern (6) located on a surface of the metal pattern (7) proximate to the base substrate (1), in which a difference between a first slope angle of the anti-reflection pattern (6) and a second slope angle of the metal pattern (7) is less than a first threshold, and a distance between a first edge of a side surface of the anti-reflection pattern (6) proximate to the metal pattern (7) and a second edge of a side surface of the metal pattern (7) proximate to the anti-reflection pattern (6) is less than a second threshold, and in which the first slope angle is an acute angle formed between the side surface of the anti-reflection pattern (6) and the base substrate (1), the second slope angle is the acute angle formed between a side surface of the metal pattern (7) and the base substrate (1), and the first edge and the second edge are located on a same side of the anti-reflection pattern (6). The technical solution of the present disclosure can improve a product yield of the display substrate.