Display Substrate Groove Design for Spacer Stability
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Solution Overview
Problem
Liquid crystal display devices face issues with spacers gliding out of grooves due to external forces, leading to alignment defects and manufacturing inefficiencies, such as light leakage and color unevenness, which increase costs and process time.
Innovation Solution
A display substrate with grooves formed by photoresist in the photolithography process, where the bottom surface of the grooves exceeds the pixel area height, allowing spacers to be securely embedded and preventing gliding, thus avoiding alignment film scratches and additional processing steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If spacers are placed on the substrate surface without grooves, then the fabrication process is simple, but the spacers glide out under external forces causing alignment defects
Solution Approach 1:
The groove is formed in advance on the substrate surface at the designated spacer position before spacer placement. This preliminary structural preparation ensures that when spacers are placed, they are mechanically constrained within the groove, preventing gliding under external forces during subsequent manufacturing processes.
Solution Approach 2:
The groove structure provides localized mechanical constraint only at the spacer position, while the rest of the substrate surface maintains its original properties. This localized modification ensures spacer stability without affecting other areas of the substrate, balancing manufacturing simplicity with reliability.
2Reliability
If grooves are formed by additional photolithography processes, then spacer position stability is improved, but manufacturing cost and process time increase
Solution Approach 1:
The groove formation process is merged with the existing photolithography process used for forming the transparent electrode. By integrating the groove patterning into the same photolithography step (using the same photoresist coating, exposure, and development processes), no additional process time is required, and manufacturing efficiency is maintained while achieving improved spacer stability.
Solution Approach 2:
The photolithography process serves multiple functions: it forms the transparent electrode pattern and simultaneously creates the groove structure for spacer positioning. This multi-functionality eliminates the need for separate groove formation processes, reducing both time and cost while maintaining reliability.
3Reliability
If grooves are formed by additional photolithography processes, then spacer position stability is improved, but manufacturing cost increases
Solution Approach 1:
The groove formation is combined with the transparent electrode formation in a single photolithography process. The same photoresist layer is used to define both the electrode pattern and the groove locations, eliminating the need for additional process steps, materials, and equipment, thereby avoiding increased manufacturing cost and complexity.
Solution Approach 2:
The photolithography process is designed to perform multiple functions simultaneously: creating the transparent electrode pattern and forming the groove structures. This universal approach uses existing process capabilities to achieve additional functionality without increasing device complexity or manufacturing cost.
4Ease of manufacture
If the groove bottom surface is below the pixel area height, then the fabrication process is easier, but alignment film scratches occur when spacers glide out
Solution Approach 1:
The groove depth is designed in advance to extend below the pixel area height level. This preliminary structural design ensures that when spacers are constrained within the groove, any potential gliding motion is stopped by the groove walls before the spacers can scratch the alignment film on the pixel area surface, preventing harmful effects.
Solution Approach 2:
The groove structure acts as a protective cushioning mechanism by providing mechanical constraint below the pixel area. This beforehand protection prevents the harmful effect of spacer gliding from reaching and damaging the alignment film, even if external forces are applied during manufacturing.
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 solution effectively prevents spacer gliding and alignment defects, maintaining image quality and reducing manufacturing costs by integrating groove formation into existing photolithography processes without extra steps.
Implementation Method 1
The groove is formed by photoresist used in a last photolithography process in a fabrication process of the display substrate
Data Source
AI summary
A display substrate, a method of fabricating the same and a display device are provided. The display substrate includes a substrate and a groove formed on the substrate. The groove is formed by photoresist and the bottom surface of the groove exceeds a height of a pixel area.