Display Substrate Light-Blocking Layer Opening for Short Circuit Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In liquid crystal display (LCD) substrates, the rough surface of data metal due to etching processes can lead to short circuits between the data metal and the pixel electrode, caused by the light-blocking layer's thickness reduction in photolithography, resulting in deteriorated step coverage of protective layers.
Innovation Solution
A display substrate design with a light-blocking layer having a first opening portion under the storage capacitor region, which prevents exposure of the data metal during etching, and a pixel electrode configuration with specific width and insulation layers to enhance step coverage and prevent short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a light-blocking layer is formed under the storage capacitor to maintain pixel voltage, then the storage capacitor function is improved, but the thickness of the upper photoresist is reduced causing data metal surface roughness and short circuits
Solution Approach 1:
The light-blocking layer is selectively formed only in the storage capacitor region rather than uniformly across the entire substrate. This localized formation maintains the storage capacitor function where needed while preserving sufficient photoresist thickness in other regions, preventing data metal surface roughness and short circuits.
Solution Approach 2:
The light-blocking layer is divided into a first portion and a second portion with different thicknesses. The first portion is formed thicker to ensure adequate photoresist thickness and prevent short circuits, while the second portion maintains the storage capacitor function. This segmented structure resolves the contradiction between reliability and manufacturing precision.
2Ease of manufacture
If the light-blocking layer thickness is reduced to improve photolithography, then the photolithography process is improved, but the data metal surface becomes rough leading to short circuits
Solution Approach 1:
Different regions of the light-blocking layer have different thicknesses optimized for their specific functions. The first portion has sufficient thickness to maintain photoresist integrity and prevent short circuits, while the second portion is optimized for photolithography performance, resolving the contradiction between ease of manufacture and reliability.
Solution Approach 2:
The light-blocking layer thickness is varied across different regions rather than being uniform. By changing the thickness parameter locally, the patent achieves both good photolithography results and reliable short circuit prevention, resolving the contradiction between ease of manufacture and reliability.
3Productivity
If the data metal surface becomes rough from etching, then the etching process is completed, but the step coverage of protective layers deteriorates causing short circuits
Solution Approach 1:
The light-blocking layer is formed beforehand to cushion and protect the data metal surface during the etching process. This pre-formed layer prevents direct exposure of the data metal to etchant, maintaining surface smoothness and ensuring good step coverage of subsequent protective layers, thus resolving the contradiction between productivity and manufacturing precision.
Solution Approach 2:
The light-blocking layer acts as an intermediary between the etching process and the data metal surface. It mediates the etching process by providing a protective interface that allows etching completion while preventing surface roughness, thereby ensuring both productivity and protective layer step coverage.
Data Source
AI summary
A display substrate in accordance with one or more embodiments includes a first line pattern, a first insulation layer, a second line pattern, a color filter layer and a pixel electrode, which are formed on a substrate. The first line pattern includes a gate line and a light-blocking layer. The light-blocking layer has a first opening portion formed in a storage capacitor region. The first insulation layer is formed on the substrate having the first line pattern. The second line pattern is formed on the first insulation layer. The color filter layer is formed on the substrate having the second line pattern, and has a second opening portion overlapping with the storage electrode. The pixel electrode is formed on the substrate having the color filter layer. Thus, short circuits between the storage electrode and the pixel electrode may be prevented.