Trench Capacitance Electrode for High-Definition LCD
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-definition liquid crystal display devices face challenges in maintaining sufficient electric capacitance with reduced pixel size, leading to potential display unevenness and defects due to the limited capacity of existing capacitance elements.
Innovation Solution
The electro-optical device incorporates a capacitance element with a trench structure that includes a first and second insulating layer, where the second layer protrudes like an eave within the trench, increasing the effective capacitance by positioning capacitance electrodes and insulating films on both the inner side and surface of the trench, and utilizing a conductive layer for simplified wiring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the pixel size is reduced to increase the number of pixels for high-definition display, then the display resolution is improved, but the electric capacitance of the capacitance element is reduced
Solution Approach 1:
The patent transitions from a planar capacitance element structure to a three-dimensional structure by forming a trench and stacking insulating layers vertically. The capacitance element utilizes both the inner side and upper surface of the trench, effectively adding a vertical dimension to the capacitance formation area. This dimensional change allows the capacitance element to maintain sufficient electric capacitance even when the pixel size is reduced for high-definition display.
Solution Approach 2:
The patent implements a nested structure where the second insulating layer is positioned within the trench formed in the first insulating layer, and the capacitance electrodes are arranged to overlap across multiple layers. This nesting approach maximizes the use of vertical space within the pixel region, increasing the effective capacitance area without expanding the planar footprint, thereby maintaining adequate capacitance in reduced pixel sizes.
2Area of moving object
If the planar size of the auxiliary capacitance electrode is reduced, then the aperture ratio of the pixel can increase, but the electric capacitance of the capacitance element is reduced
Solution Approach 1:
The patent compensates for the reduced planar area of the capacitance electrode by extending the capacitance structure vertically through multiple stacked insulating layers and utilizing the inner surface of the trench. This vertical extension increases the effective capacitance area without increasing the planar footprint, allowing the aperture ratio to be improved while maintaining sufficient electric capacitance.
Solution Approach 2:
The capacitance element is segmented into multiple functional layers (first insulating layer with trench, second insulating layer with aperture, capacitance electrodes) that work together to provide the required capacitance. This segmentation allows the capacitance to be distributed across multiple surfaces and layers, maintaining adequate total capacitance even when each individual layer has a reduced planar area.
3Device complexity
If a simple trench structure is used for the capacitance element, then the device complexity is reduced, but the electric capacitance is insufficient
Solution Approach 1:
The patent enhances the simple trench structure by adding vertical stacking of insulating layers and positioning capacitance electrodes to utilize both the inner side and upper surface of the trench. This maintains relative structural simplicity while dramatically increasing the effective capacitance area through three-dimensional configuration, achieving high capacitance without proportionally increasing device complexity.
Solution Approach 2:
The trench structure serves multiple functions: it provides mechanical support, defines the capacitance electrode positioning, creates overlapping surfaces for capacitance formation, and enables vertical stacking of insulating layers. This multi-functionality allows the same structural element to contribute to both mechanical integrity and electrical performance, achieving high capacitance without adding separate complex components.
Data Source
AI summary
A liquid crystal device as an electro-optical device includes a first insulating layer as a first layer with an insulating property stacked on a base member as a substrate, a trench provided in the first insulating layer for each pixel, a second insulating layer as a second layer stacked on the first insulating layer and having an aperture communicating with the trench, and a retention capacitor as a capacitance element including a first capacitance electrode, a first capacitance insulating film, and a second capacitance electrode which are provided on at least an inner side the trench and the aperture. A layer thickness of the first insulating layer is larger than a layer thickness of the second insulating layer, and a width of the trench is larger than a width of the aperture in the X direction as a first direction.