GVP has been manufacturing high-performance, high-quality, and highly durable Capacitive Circuits for the medical device, military, automotive, marine, and OEM industries for decades.
What is a Capacitive Circuit?
A Capacitive Circuit, which is a variation on a standard tactile Membrane Switch, is an electrical switch that is used to activate and de-activate an electrical circuit, turning it on or off. They are typically used to communicate a user’s command to the electronic device in order to perform a desired function. The circuit actuation is usually performed by pressing a specific location on the user interface, otherwise known as the Graphic Overlay, thus closing the circuit within the printed electronics below. When the membrane switch key is released, the circuit poles separate, and the circuit returns back to an open state. The Capacitive Circuit uses capacitive sensing technology to perform the functions of a traditional membrane switch with a simple, light touch. Capacitive touch membrane switches offer greater design flexibility and durability from a traditional tactile circuit.
Our standard construction is comprised of thin film membrane layers. This film is typically made using a Polyester material, although there are a wide range of other material options that can provide added benefits for more extreme environments. The circuitry is constructed using a series of printed conductive inks and a specialized capacitive active area. This created an active electrical field in this location. When the active area is pressed with a finger, the capacitance in this location changes and is recognized by the logic control board in the device, which activates the output of the key. It is within this process that provides a more robust and longer lasting circuit. With no moving parts, the circuit doesn’t contain the same potential failure point over time with excessive wear. The capacitive approach also provides a greater cost advantage as well as reduced development and lead time from a traditional tactile circuit. Low profile construction design provides more enhanced form fit and function as well as user feedback options.
Capacitive Circuit Industries and Applications:
- Household appliances (i.e., air conditioner control panel, TV remote control, microwave oven panel, etc.)
- Medical equipment
- Control panel-oriented industrial and manufacturing equipment
- Military equipment
- Aerospace applications
- Automotive controls and panels
- Retail and consumer-related equipment or machines (i.e., exercise equipment, vending machines, gasoline pumps, etc.)
Key Benefits for a Capacitive Circuits:
Light Touch Activation:
One of the main advantages of capacitive touch membrane switches is that there are no moving mechanical components to wear out like metal domes. This drastically extends the life of the product and makes it much more durable than its traditional tactile membrane switches alternative.
Customized User Interface Options:
As our Capacitive Circuits are built to order, as opposed to an off the shelf option, you have the ability to tailor the interface to meet your needs.
Capacitive Circuits can include a wide range of graphic options including custom logos, textures, and multi-color specialized graphics.
Low profile construction provides a greater space saving design option.
We are able to provide a fully sealed construction that can hold up to an IP65 rating.
Easy to Replace:
As this is a surface laminated component, a Capacitive Circuit provides a faster low-cost option for field and refurbish replacements. Since the Capacitive Circuit is all contained in one package, it provides a drop-in place option without the costly replacement of the circuit boards contained inside the unit.
Lower Cost and Lead Time:
When compared to mechanical sensors, a printed Capacitive Circuit offers a greater cost reduction with respects to the upfront tooling costs and lead time.
Components of a Capacitive Circuit:
- Graphic Overlay
- Overlay adhesive/gasket
- ESD shielding layer (optional)
- Surface mounted components (optional)
- Circuit layer
- Rear adhesive layer (with liner)
- Back panel
Optional Capacitive Circuit Features:
- Custom printed graphics and logos (Graphic Overlay portion)
- Custom shapes
- Multi-layer/sided construction through conductive vias
- Surface texture materials (Graphic Overlay portion)
- Embossing (Graphic Overlay portion)
- Customizable connector styles
- Window lens coating (Graphic Overlay portion)
- Moisture and dust-resistant sealing
- LED/resistor embedding
- Options for EMI/ESD/RFI shielding
- Other options available for custom Capacitive Circuits upon request
Contact GVP For Custom Capacitive Circuits:
At GVP, our Capacitive Circuits are custom designed to provide a durable and robust construction to meet your projects requirements. If you are looking to add a light touch user interface to your device, then Contact our team of engineers today and see how we can assist you with your latest custom printed Capacitive Circuits!