Polarization Structure Light Shielding for LTPS Array Substrates
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Solution Overview
Problem
Existing n-type metal oxide semiconductor low temperature polysilicon-liquid crystal display (LTPS-LCD) manufacturing processes face issues with abnormal discharge phenomena due to the formation of metal light shield layers on entire base substrates, which require multiple patterning processes and result in thickness and slope angle issues affecting active layer crystallization.
Innovation Solution
The use of a first polarization structure, formed by a polarization layer, is implemented on the array substrate, with its projection overlapping the active layer projection on the base substrate, providing a light shield effect perpendicular to the polarization plate direction to prevent backlight irradiation and eliminate abnormal discharge, thereby reducing the need for conventional metal light shield layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a metal light shield layer is formed on the entire surface of the base substrate, then the light shield function is achieved, but abnormal discharge phenomenon occurs and manufacturing complexity increases
Solution Approach 1:
The patent divides the light shield layer into multiple segments: a first light shield layer formed only in the active pixel region, and a second light shield layer formed in the common electrode region. This segmentation eliminates the abnormal discharge phenomenon caused by continuous metal layers while maintaining light shielding effectiveness in both regions.
Solution Approach 2:
The patent applies different light shielding structures to different regions of the substrate. The active pixel region receives a first light shield layer with specific properties, while the common electrode region receives a second light shield layer with different properties, optimizing performance for each region's specific requirements and avoiding discharge issues.
2Object-affected harmful factors
If a metal light shield layer is formed on the entire surface of the base substrate, then the light shield function is achieved, but the number of patterning processes increases
Solution Approach 1:
The patent combines the formation of the first light shield layer and the active layer into a single patterning process. By using the same mask pattern for both structures, the number of patterning steps is reduced while still achieving the required light shielding function in the active pixel region.
Solution Approach 2:
The first light shield layer serves multiple functions: it provides light shielding for the active pixel region and simultaneously serves as a mask layer for subsequent processing steps. This multi-functionality reduces the need for separate dedicated mask layers, simplifying the overall manufacturing process.
3Object-affected harmful factors
If a metal light shield layer is formed on the entire surface of the base substrate, then the light shield function is achieved, but thickness and slope angle issues affect active layer crystallization
Solution Approach 1:
The patent applies different light shielding structures to different regions: the first light shield layer in the active pixel region is designed with optimized thickness and profile to avoid affecting active layer crystallization, while the second light shield layer in the common electrode region has different characteristics suited for that region's requirements.
Solution Approach 2:
The patent introduces an organic insulating layer between the metal light shield layers and the active layer. This intermediary layer prevents direct contact between the metal and the active layer, eliminating the harmful effects of metal-induced discharge and preventing interference with active layer crystallization while maintaining light shielding effectiveness.
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 solution effectively avoids photogenerated leakage currents, enhances yield rates, and simplifies the manufacturing process by reducing the number of patterning steps required, while maintaining the light shield function without the thickness and slope angle issues associated with traditional metal light shield layers.
Implementation Method 1
a light absorbing layer positioned to absorb light reflected by the metal pattern
Data Source
Figure 1~2c
Figure 2d~3
Figure 4~5c
AI summary
An array substrate and a manufacturing method thereof, and a display device are provided. The array substrate includes: a base substrate (101), an active layer (102), and a first polarization structure (104). The active layer (102) is disposed on the base substrate (101); the first polarization structure (104) is disposed on a side of the active layer (102) facing the base substrate (101), and an orthographic projection of the first polarization structure (104) on the base substrate (101) is at least partially overlapped with an orthographic projection of the active layer (102) on the base substrate (101). The first polarization structure substitutes a conventional metal light shield layer, which can effectively avoid an abnormal discharge phenomenon caused by a first polarization structure having the light shield function.