IPS LCD Electrode Width Reduction via Insulation Masking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In-plane switching mode liquid crystal display devices have a low transmittance due to the narrow widths of pixel and common electrodes, which limits the aperture ratio and viewing angle, as the current photolithography techniques cannot further reduce the electrode widths.
Innovation Solution
A method is developed to form pixel and common electrodes with significantly reduced widths by using a process involving a first insulation layer, an electrode layer, and a second insulation layer, where the second insulation layer is etched to remain on the sides of the first insulation layer, allowing the electrode layer to be etched further, resulting in electrodes with widths ranging from 0.1 μm to 2 μm, thereby increasing the aperture ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photolithography techniques are used to form pixel and common electrodes, then the manufacturing process is simple and reliable, but the electrode widths cannot be reduced below a certain limit, resulting in low aperture ratio and transmittance
Solution Approach 1:
The patent segments the electrode formation process into multiple steps using different insulation layers (first insulation layer 110, second insulation layer 130) as masks at different stages. This allows the electrode width to be controlled by the thickness of the insulation layers rather than being limited by photolithography resolution, achieving sub-micron electrode widths while maintaining manufacturing simplicity.
Solution Approach 2:
The patent transitions from controlling electrode width in the planar dimension (via photolithography) to controlling it in the vertical dimension (via insulation layer thickness). By forming the second insulation layer 130 with controlled thickness on sides of the first insulation layer 110, the electrode width is determined by vertical layer dimensions rather than lateral patterning, enabling precise width control at sub-micron scales.
2Area of stationary object
If electrode widths are reduced to increase aperture ratio, then transmittance and viewing angle improve, but the manufacturing precision requirements exceed current photolithography capabilities
Solution Approach 1:
The patent performs preliminary action by forming the first insulation layer 110 and second insulation layer 130 with predetermined thicknesses and patterns before forming the electrodes. These insulation layers are prepared in advance as self-aligned masks, ensuring that the subsequent electrode formation automatically achieves the desired narrow width without requiring high-precision photolithography alignment.
Solution Approach 2:
The patent introduces insulation layers (first insulation layer 110 and second insulation layer 130) as intermediary elements that mediate between the substrate and the electrodes. These intermediaries serve as self-aligned masks that define the electrode width, transferring the dimensional control from the photolithography process to the insulation layer formation process, thereby achieving precise width control.
3Ease of manufacture
If wider electrodes are used, then manufacturing is easier with current photolithography, but the aperture ratio and transmittance are reduced
Solution Approach 1:
The patent segments the masking function across multiple insulation layers, allowing the electrode width to be determined by the combined thickness of the first insulation layer 110 and second insulation layer 130 rather than requiring a single thick mask layer. This segmentation enables narrow electrode widths that increase aperture ratio while maintaining ease of manufacture through standard thin-film deposition processes.
Data Source
AI summary
A method of manufacturing an IPS switching mode liquid crystal display device includes forming a first insulation layer on a substrate, forming an electrode layer on the substrate containing the first insulation layer, forming a second insulation layer on the electrode layer, etching the second insulation layer such that the second insulation layer remains on sides of the first insulation layer, and etching the electrode layer using the remaining second insulation layer as a mask to form a plurality of electrodes. The plurality of electrodes are formed to have widths of about 0.1 μm to 2 μm, thus aperture ratio and transmittance are increased.