A PCB membrane switch is a type of membrane switch that uses a printed circuit board (PCB) as the circuit layer. The PCB is made of a rigid material such as fiberglass or epoxy resin and contains conductive traces that connect the switch's contacts.
The switch is composed of multiple layers of materials, including a graphic overlay, a spacer layer, and the PCB. The graphic overlay is the top layer of the switch and contains the printed design that represents the user interface. The spacer layer is a dielectric layer that separates the graphic overlay and the PCB. The PCB contains the circuitry, which is connected to the switch's contacts.