Capacitive Touch Sensor Structure Using Inboard Vias and Plastic Substrates
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Solution Overview
Problem
Existing touch screen manufacturing processes involve high-temperature curing stages, which can be costly and inefficient, and traditional capacitive touch screens are prone to breakage due to the use of rigid glass substrates, limiting durability and flexibility.
Innovation Solution
A capacitive touch screen design featuring a plastic substrate coated with indium tin oxide (ITO) and a low-temperature silver ink pattern, laminated with ultra-thin antiglare glass, and incorporating passageways or vias for electrical connectivity without surface-mounted connectors, enhancing durability and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-temperature curing stages are used in traditional touch screen manufacturing, then electrical conductivity and coating stability are improved, but manufacturing cost and process complexity increase
Solution Approach 1:
The patent changes the temperature parameter from high-temperature (510°C for ATO, 480°C for silver epoxy, 520°C for hardcoat) to low-temperature processing. This is achieved by substituting traditional high-temperature materials with low-temperature alternatives that achieve comparable or superior performance without requiring extreme thermal conditions, thereby simplifying the manufacturing process and reducing complexity.
Solution Approach 2:
The patent employs disposable low-temperature silver ink that can be applied and cured at lower temperatures, replacing expensive, temperature-sensitive traditional silver epoxy materials. This approach allows for simpler, more cost-effective manufacturing while maintaining electrical conductivity requirements.
2Strength
If rigid glass substrates are used in traditional capacitive touch screens, then structural strength is improved, but durability and flexibility deteriorate due to breakage risks
Solution Approach 1:
The patent replaces rigid glass substrates with flexible plastic substrates that have been coated with conductive layers. This substitution maintains the necessary structural integrity while dramatically improving flexibility and resistance to breakage. The plastic substrate can bend and flex without shattering, making the touch screen suitable for applications requiring durability and flexibility.
Solution Approach 2:
The patent creates a composite structure by coating plastic substrate with transparent conductive coatings (such as ITO or ATO) and silver ink patterns. This composite material combines the flexibility and impact resistance of plastic with the electrical conductivity and optical properties of thin film coatings, achieving both durability and functional performance.
3Manufacturing precision
If traditional multi-step high-temperature manufacturing processes are used, then coating performance is improved, but manufacturing efficiency and cost-effectiveness worsen
Solution Approach 1:
The patent fundamentally changes the temperature parameter from high-temperature (requiring multiple curing stages at 480-520°C) to low-temperature processing. This enables faster cycle times, reduced energy consumption, and simplified equipment requirements, directly improving manufacturing efficiency and cost-effectiveness while maintaining coating quality through carefully selected low-temperature materials.
4Reliability
If transparent conductive coatings are fired at high temperatures, then electrical conductivity and transparency are improved, but energy consumption and manufacturing cost increase
Solution Approach 1:
The patent changes the thermal processing parameter from high-temperature firing (510°C or higher) to low-temperature curing. This is achieved by selecting conductive coating materials that achieve optimal electrical conductivity and transparency at lower temperatures, thereby significantly reducing energy consumption while maintaining or improving coating performance.
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 solution provides a more durable, lightweight, and cost-effective touch screen with reduced breakage risks, suitable for various applications, including vandal-proof and flush-mounted installations, while maintaining optimal electrical conductivity and optical properties.
Implementation Method 1
capacitive sensor or touch screen includes a substrate coated with a conductive coating and with a pattern of electrodes disposed thereon
Implementation Method 2
a low temperature silver ink, and an antiglare (AG) coated thin glass
Implementation Method 3
laminated with ultra-thin antiglare glass
Data Source
AI summary
A touch sensor, such as a capacitive touch sensor, includes a substrate having at least one passageway established therethrough. A first conductive coating is established at a first surface of the substrate, and a conductive element is disposed at the substrate and at least partially through the passageway. The conductive element establishes conductive continuity between the first surface and second or opposite surface of the substrate. The passageway may comprise multiple passageways and is/are established inboard of a perimeter edge of the substrate. The conductive element may include a first conductive material disposed at the first surface and partially into the passageway and a second conductive material disposed at the second surface and partially into the passageway, whereby the conductive materials contact one another in the passageway to establish conductive continuity between the first and second surfaces of the substrate.