Silver-Inclusive Transparent Conductive Coating for Touch Panels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing process of projected capacitive touch panels is burdensome and costly due to the need for multiple photolithography steps and the high sheet resistance of indium tin oxide (ITO) layers, which limits their use in large format touch panels.
Innovation Solution
A projected capacitive touch panel with a silver-inclusive transparent conductive layer sandwiched between dielectric layers, allowing for a matrix of row and column electrodes and traces to be formed on a single plane with reduced photolithography steps, using a silver-inclusive transparent conductive coating that includes layers such as silicon nitride, titanium oxide, zinc oxide, and silver, resulting in lower sheet resistance and higher transparency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple photolithography steps are used to pattern ITO layers, then conductor and insulator patterns can be formed, but the manufacturing process becomes burdensome and costly
Solution Approach 1:
The patent combines the conductor layer and insulator layer into a single multi-functional layer. This layer contains both conductive material (ITO) and insulating material (such as silicon nitride) in different regions, allowing both conductors and insulators to be formed in one deposition and patterning step, thereby eliminating multiple photolithography steps and reducing manufacturing complexity
Solution Approach 2:
The patent uses a composite layer structure where conductive and insulating materials are integrated into a single layer. This composite approach allows the layer to serve dual functions: providing conductive paths in some areas and insulating barriers in other areas, simplifying the overall manufacturing process by reducing the number of separate layers and patterning steps required
2Illumination intensity
If ITO layers are used for conductors, then transparent conductive coating can be achieved, but sheet resistance is high which limits use in large format touch panels
Solution Approach 1:
The patent applies different materials or compositions to different regions of the conductive layer. Specifically, the multi-functional layer uses ITO in regions requiring conductivity while using insulating material in regions requiring isolation. This local differentiation allows optimization of electrical properties in conductive regions while maintaining transparency, and eliminates the need for thick ITO layers that would compromise transparency
Solution Approach 2:
The patent changes the material composition parameters of the conductive layer by integrating multiple materials with different properties. By adjusting the ratio and distribution of conductive (ITO) and insulating materials in the multi-functional layer, the patent achieves low sheet resistance in conductive regions while maintaining high transparency, overcoming the limitations of pure ITO layers
3Manufacturing precision
If three deposition steps and three photolithography processes are used, then conductors and insulators can be formed, but production efficiency decreases and costs increase
Solution Approach 1:
The patent merges multiple deposition steps into a single deposition process that creates a multi-functional layer containing both conductive and insulating materials. This consolidation reduces the number of deposition steps from three to one, and similarly reduces photolithography processes from three to one or two, thereby significantly improving production efficiency and reducing manufacturing costs while maintaining the required patterning precision
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 production costs and increases efficiency by allowing the formation of long narrow traces with low sheet resistance, enabling the use of silver-inclusive coatings in larger touch panels while maintaining high transparency and conductivity.
Implementation Method 1
a silver-inclusive transparent conductive coating supported by the substrate and including, in order moving away from the substrate: a first silicon-based layer, a first dielectric layer, a second dielectric layer, a silver-based conductive layer, an upper contact layer, a second dielectric layer, and a second silicon-based layer
Implementation Method 2
silver-inclusive transparent conductive coating... resulting in lower sheet resistance and higher transparency
Implementation Method 3
a silver-inclusive transparent conductive coating supported by the substrate and including, in order moving away from the substrate: a first silicon-based layer, a first dielectric layer, a second dielectric layer, a silver-based conductive layer, an upper contact layer, a second dielectric layer, and a second silicon-based layer
Data Source
AI summary
A projected capacitive touch panel, including a substrate, a silver-inclusive transparent conductive coating which forms a plurality of row electrodes, a plurality of column electrodes, and a plurality of conductive traces, and a signal processor which sequentially measures a capacitance between each of row electrodes and an adjacent column electrode. The row electrodes, the plurality of column electrodes, and the plurality of traces are on a plane substantially parallel to the substrate. Each of the row electrodes is electrically connected to the signal processor by one of the plurality of conductive traces. The plurality of traces are at least partially substantially parallel to the column electrodes.