PCB Membrane Switch

A PCB (or printed circuit board)　membrane switch, is typically made of copper-clad cloth or fiber infused into a resin material. The cloth/fiber used, along with the resin material, creates a cloth-to-resin ratio to determine the laminate's type designation (FR-4, CEM-1, G-10, etc.). FR-4 is the most common material used today.

An acid-resistant solder mask is applied to the copper-clad PCB, and the exposed areas (not covered by the solder mask) are etched away using acid. The exposed copper pathways are plated with various metals to protect the copper from corrosion. Gold plating is often required on many PCBs in critical applications where corrosion and exposure to chemicals is an issue.

The PCB membrane switch construction utilizes a PCB (as described above) as the main structure/support substrate, with the membrane switch on the front of the PCB assembly, and the display (along with the other discrete components) on the back side of the PCB.

The variety of discrete components can include, but PCB memebrane switch not limited to LEDs, resistors, connectors (both SMT and though-hole), LCD and LED displays, sensors, and speakers. The addition of a daughter board can add even more design flexibility and can connect directly to the PCB membrane switch.