Rubber Keypads

Membrane switches incorporate silicone-rubber keypads to improve the aesthetic look and feel of a switch. Designs have a large variety of effects from embossed and debossed features, printed text, painted icons, backlighting and even rockertoggle actuators. Polyurethane, epoxy and UV coatings available can protect keypads from the environment and abuse.
The keypad utilizes a variety of contact systems ranging from carbon pills, to gold pills, to actuating tactile metal domes in a membrane-switch assembly. Mounting methods used to apply the rubber actuator to the switch may vary. One simple method of mounting rubber actuator is double-sided pressure-sensitive silicone-rubber adhesive. This is applied to a carrier on one side, and the applicable mounting adhesive is applied to the other. Another mounting method includes a simple pull-through molded into the rubber itself. The pull-through is then “pulled” through a printed circuit board substrate, where an interference fit secures the rubber component to the assembly.