Capacitive Touch Panel Dual Resistive ITO Layers
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Solution Overview
Problem
Existing capacitive touch screen technologies face challenges in achieving high accuracy and reducing manufacturing complexity and costs, particularly due to the high resistance of indium tin oxide (ITO) conductive layers and the need for metal traces, which can obstruct display visibility and increase environmental pollution.
Innovation Solution
The use of dual non-metallic conductive layers with different surface resistivities, where a lower resistivity layer forms traces and a higher resistivity layer forms electrodes, eliminating the need for metal traces and enhancing transparency, is implemented in a touch screen sensor assembly. This involves depositing and patterning ITO layers with specific resistivity values on substrates to create a patterned substrate for capacitive touch screens.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal traces are used to couple conductive layers, then electrical connection is achieved, but display visibility is obstructed and environmental pollution increases
Solution Approach 1:
The patent replaces metal traces with a transparent conductive material layer that has a resistivity gradient. The first region has higher resistivity and forms the trace pattern, while the second region has lower resistivity and provides electrical connection, eliminating the need for opaque metal traces and improving display visibility.
Solution Approach 2:
The patent changes the resistivity parameter of the transparent conductive material by creating a gradient from the first region to the second region. This parameter change allows the same material to serve dual functions: forming electrical traces in the high-resistivity region and providing low-resistance electrical connections in the low-resistivity region.
2Illumination intensity
If ITO conductive layer is used, then transparency is achieved, but resistance is relatively high requiring metal traces
Solution Approach 1:
The patent modifies the resistivity parameter of the ITO layer by creating distinct regions with different resistivity values. The first region has higher resistivity for trace formation, while the second region has lower resistivity for electrical connection, eliminating the need for metal traces while maintaining transparency.
Solution Approach 2:
The patent segments the ITO conductive layer into two functional regions: a first region with higher resistivity for forming trace patterns and a second region with lower resistivity for providing electrical connections. This segmentation allows the single transparent conductive layer to perform multiple functions without requiring additional metal layers.
3Measurement precision
If dual patterned conductive layers are used, then touch accuracy is improved, but manufacturing complexity increases
Solution Approach 1:
The patent combines the functions of multiple conductive layers into a single transparent conductive material layer with a resistivity gradient. The layer is patterned to form both electrodes and traces in different regions, eliminating the need for separate conductive layers and reducing manufacturing complexity while maintaining touch accuracy.
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
This approach reduces manufacturing complexity and costs, enhances transparency by minimizing trace width and height, and improves touch accuracy by eliminating the need for metal traces, thereby addressing the limitations of previous designs.
Implementation Method 1
a lower resistivity non-metallic conductive layer, both of which are disposed on the substrate
Implementation Method 2
depositing and patterning ITO layers with specific resistivity values on substrates
Data Source
AI summary
A patterned substrate for a touch screen sensor assembly that includes a plurality of electrodes that are formed from a first transparent conductive layer that has a first surface resistivity. The substrate also has a plurality of traces that may be used to couple the electrodes controller associated with the touch screen sensor assembly. The traces are formed from a second conductive layer that has a second surface resistivity that is less than the surface resistivity of the first conductive layer. The first and second conductive layers may be formed from indium tin oxide (ITO) having different surface resistivities. A second, similarly configured substrate can be provided and may be spaced apart from the first substrate by a dielectric spacer.