The easiest way to understand what a membrane switch is, is to reference an all-time favorite device-the microwave.  The membrane switch on the microwave is the buttons—the human interface layer—that communicates to the microwave that you’d like to reheat your food for one minute.

A membrane switch consists of various layers laminated together. The layers of a basic membrane switch construction include: a membrane overlay, spacer, printer circuit, rear adhesive, and tail filler. Depending on the environment and requirements of the application into which the membrane switch plugs into, the construction can vary. For example, if shielding is necessary, a two-circuit membrane switch design would be a better construction choice.

For more stringent environmental requirements, the printed silver circuit can be replaced with a copper and polyimide construction. These construction designs are often called “Kapton” circuits and offer advantage with regard to current carrying capacity and better resistance to moisture. You can explore more construction possibilities by downloading our membrane switch design guide or contacting us for support.