Laser-Etched Touch Sensor Tracks for Accurate Capacitance Sensing
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Solution Overview
Problem
Current touch sensors, particularly capacitive touch screens, face challenges in accurately detecting the presence and location of touches or proximity due to variations in electrode materials and configurations, which can affect capacitance measurements and overall user interaction.
Innovation Solution
The implementation of laser-etched conductive tracks on a touch sensor substrate that electrically couple drive and sense electrodes to connection pads, allowing for precise capacitance measurements and improved touch detection, using materials like copper or silver with specific thickness and width configurations, and potentially incorporating indium tin oxide (ITO) for enhanced conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional electrode materials and configurations are used in capacitive touch screens, then manufacturing processes are simpler, but touch detection accuracy and capacitance measurement reliability deteriorate due to material variations
Solution Approach 1:
The patent changes the physical parameters of the electrode configuration by etching conductive tracks directly into the substrate material. This transforms the electrode structure from separate deposited layers to integrated substrate features, achieving more consistent electrical properties and improved touch detection accuracy through controlled track geometry (width, depth, spacing) rather than relying on material deposition variations
Solution Approach 2:
The patent employs composite material structures by combining the substrate material with etched conductive regions. The conductive tracks are formed as integral parts of the substrate through selective etching, creating a composite structure that leverages both the substrate's mechanical properties and the enhanced electrical conductivity of the etched regions, thereby improving measurement precision
2Reliability
If laser etching is used to create conductive tracks on the substrate, then electrical coupling between electrodes is improved, but manufacturing process complexity increases
Solution Approach 1:
The patent replaces traditional mechanical electrode deposition processes with laser-based etching. Instead of depositing conductive materials through complex multi-layer fabrication, the laser directly etches conductive tracks into the substrate, substituting a thermal/optical process for mechanical deposition and achieving more reliable electrical coupling with fewer manufacturing steps
Solution Approach 2:
The laser etching process enables precise control of track parameters (width, depth, shape) through adjustable laser parameters such as power, speed, and pulse duration. This parameter control allows optimization of electrical coupling characteristics while maintaining manufacturing efficiency, as the same laser system can produce varying track geometries without changing physical tooling or materials
3Reliability
If multiple materials like copper, silver, and ITO are used for conductive tracks, then conductivity is enhanced, but manufacturing complexity and cost increase
Solution Approach 1:
The patent applies local quality by selectively etching conductive tracks in specific regions of the substrate where high conductivity is needed for electrode connections. Rather than making the entire substrate highly conductive or using expensive materials everywhere, the laser etching creates localized conductive paths only where electrical coupling is required, optimizing conductivity where needed while maintaining manufacturing simplicity in other areas
Solution Approach 2:
The patent achieves enhanced conductivity through parameter changes in the etching process rather than material changes. By controlling laser parameters to create tracks with optimal width, depth, and cross-sectional geometry, the substrate's inherent conductivity is maximized in the track regions, eliminating the need for additional copper, silver, or ITO material layers and their associated complex deposition processes
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 solution enhances the accuracy and reliability of touch detection by ensuring consistent and efficient electrical coupling between electrodes, thereby improving user interaction and reducing manufacturing costs through simplified design changes and production processes.
Implementation Method 1
paths laser etched into the sensor substrate
Data Source
AI summary
In one embodiment, a method includes receiving a touch sensor substrate associated with a plurality of electrodes and a plurality of connection pads. The plurality of electrodes is configured to detect a touch. The plurality of connection pads are configured to be electrically coupled with a touch controller. The method further includes laser etching a plurality of paths. The method also includes filling the plurality of paths with an electrically conductive material to form a plurality of tracks. Each track is configured to electrically couple at least one connection pad of the plurality of connection pads with at least one electrode of the plurality of electrodes.