Conductive Sheet with Dual-Surface Lattice Electrodes for Capacitive Touch Panels
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Solution Overview
Problem
Conventional projected capacitive touch panels face issues with finger position detection accuracy, visibility, and production complexity due to electrode array configurations and high resistance of ITO electrodes, which become problematic when scaling to larger devices.
Innovation Solution
A conductive sheet design featuring conductive patterns with small and medium lattices on opposing substrate surfaces, connected by thin metal wires, with specific lattice arrangements and insulations to reduce resistance and improve visibility, suitable for large-sized projected capacitive touch panels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gaps are formed between first and second electrode arrays on one main surface to prevent short circuit, then electrical isolation is achieved, but finger position detection accuracy deteriorates
Solution Approach 1:
The patent transitions from a planar electrode arrangement on a single surface to a three-dimensional configuration where first electrode arrays are formed on one main surface and second electrode arrays are formed on the other main surface of the substrate. This dimensional change allows electrical isolation through the substrate thickness while maintaining detection accuracy through the matrix arrangement of electrodes on opposing surfaces.
Solution Approach 2:
The patent segments the electrode arrays into first electrode arrays on one surface and second electrode arrays on the other surface, with each array containing multiple electrodes arranged in specific patterns. This segmentation allows independent optimization of each electrode array while maintaining overall system functionality and detection accuracy.
2Reliability
If insulation layers are formed between electrode connections to prevent short circuit at intersections, then electrical isolation is achieved, but visibility deteriorates due to local black points
Solution Approach 1:
Instead of forming insulation layers in the plane of the electrode connections, the patent uses the third dimension (substrate thickness) to achieve electrical isolation. The first and second electrode arrays are positioned on opposing surfaces, and insulation is provided through the substrate material and intermediate layers between surfaces, eliminating the need for visible insulation layers at intersections.
Solution Approach 2:
The patent extracts the insulation function from the planar electrode connection layer and relocates it to the vertical dimension through substrate thickness and intermediate insulation layers. This removes the harmful visual effect of insulation layers at intersections while maintaining electrical isolation.
3Reliability
If mask patterns are used to form insulation layers and electrode connections, then electrical isolation is achieved, but production process complexity increases
Solution Approach 1:
The patent eliminates the need for complex mask patterns by forming electrode arrays and connections through sequential deposition processes on opposing substrate surfaces. The first electrode arrays are formed on one surface, then the substrate is processed to form second electrode arrays on the other surface, reducing the need for repeated masking operations.
Solution Approach 2:
The patent performs preliminary formation of first electrode arrays and their connections on one substrate surface before processing the other surface. This preliminary action establishes the electrical isolation structure early in the process, simplifying subsequent steps and reducing overall process complexity.
4Reliability
If ITO electrodes are used in conventional projected capacitive touch panels, then capacitive detection is achieved, but response speed deteriorates due to high resistance
Solution Approach 1:
The patent employs composite conductive structures combining ITO with additional conductive materials such as metal wires or conductive polymers. This composite approach maintains the capacitive detection functionality of ITO while improving overall electrical conductivity to reduce resistance and enhance response speed.
Solution Approach 2:
The patent changes the electrical resistance parameter of the conductive paths by using multiple conductive materials with different resistance characteristics. By combining ITO with lower-resistance materials in the electrode arrays and connections, the overall resistance is reduced, improving response speed while maintaining detection capability.
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 design achieves lower electrical resistance, enhanced visibility, and improved response speed, enabling effective multi-touch detection and scalability to larger touch panel sizes.
Implementation Method 1
a conductive sheet, a method for using a conductive sheet, and a capacitive touch panel... the conductive sheet can have a low-resistance conductive pattern on a substrate
Implementation Method 2
capacitive touch panels are position input devices capable of detecting a human finger touch position based on an electrostatic capacitance change between the finger and a conductive film
Data Source
AI summary
A conductive Sheet, a method for using conductive sheet, and a capacitive touch panel are provided. A first conductive sheet contains two or more conductive first sense pads and a first connection for electrically connecting the adjacent first sense pads on a first transparent substrate. The first sense pads each contain a combination of two or more small lattices, the first connection contains one or more medium lattices (a first medium lattice to a fourth medium lattice), and the pitch of the medium lattices is n times larger than that of the small lattices (in which n is a real number larger than 1).