What are non-tactile membrane switches?

To understand non-tactile membrane switches, it’s first important to examine how membrane switches work as a whole.

·         Membrane switches are comprised of several different layers, including:

·         The graphics overlay

·         Adhesive layers

·         The circuit layer (generally a flexible printed circuit printed circuit board)

The function of a membrane switch is to provide a user interface onto which graphics like icons, instructions, and logos can be easily printed. When a user presses a button, the switch is activated, and the user receives feedback. 

The sleek, thin profile of the membrane switch means it can be incorporated into any number of electronic devices. The membrane switch fits seamlessly into the final product, drastically reducing the risk of contamination.

All user interfaces must provide feedback to users—membrane switches are no exception. The core difference between a tactile and non-tactile membrane switch is in how they provide feedback when a switch is activated:

Tactile switches offer a tactile response—users can feel when the switch is activated

Non-tactile switches must offer other forms of feedback—usually auditory and visual feedback

At first glance, it may seem like a tactile membrane switch is the best option, given that they offer an extra form of feedback. The tactile vs. non-tactile switch dichotomy is not quite so simple, however. There are many advantages to non-tactile switches.

Shielding

Many options are available for shielding membrane switches.

Printed Shield

Either carbon or silver can be printed over the top of the circuit to act as a shield or aluminum foil can be used. Carbon shields are less expensive than silver. A printed grid pattern is normally used to reduce cost and can be terminated to the circuit tail.

Aluminum

Aluminum foil material is the most conductive shield available but the most expensive. A foil shield adds an additional layer to the membrane switch construction. The foil termination requires a separate tail for ground connection.

Top Surface Shielding

Graphic overlay ESD material can be another option. Contact 

Qianshenglong  for termination requirements.

Additional Options

ITO coated polyester can be used to provide a conductive surface for clear window areas. ITO is transparent and is used with other shielding options.

Design of the shield on a membrane switch depends greatly on your requirements. Termination options can use an electrical termination, aluminum ground tail or by using conductive PSA.

Sealed Gaskets

Dust, harsh chemicals, water or other contaminants can cause failure in your membrane switch. We  offers solutions to prevent malfunction and ensure longevity in your switch.

Preventing failure starts with the proper design. Our engineering team can assist you with design recommendations providing you with the most efficient, cost-effective solution. Your circuit tail exit point is the most vulnerable point of your membrane switch. In a typical membrane switch design, there is usually a “tail filler” area. This is a piece applied separately to the back of your overlay which is equal to the stack up of your membrane switch. This is exactly where moisture and other contaminants can get through.

A membrane switch gasket design can solve this issue because it does not have the tail filler, so there is no pathway for contaminants. The custom-built gasket is the same thickness as your membrane switch and the B.O.M. will meet or exceed your requirements for your membrane switch. Gaskets can be more expensive, but failure is not an option.

There are two types of classification rating systems: NEMA (National Electronic Manufacturers Association) and IP (Ingress Protection). The two systems use different test parameters, are not directly comparable or easily converted. It is important to identify the enclosure rating necessary for your application. Contact us to discuss your protection options.