Keypad Terminology A-D

Rubber Switch Actuation Force: The force required to collapse the membrane of a rubber switch.

Rubber Keypad Air Channel: Air paths on the bottom of rubber keypads and switches that
allow for air passage (venting) when the switch is actuated. Switches must be vented on at least two sides.

Silicone Rubber Keypad Alignment Hole: Through hole in rubber keypad that is used to position keypad. Used in an enclosure when overall keypad size exceeds three inches in either length or width.

Base: Silicone sheet material that joins all keys/switches on a rubber keypad. It is also known as an “apron.”

Bezel: The faceplate (cover) typically made of either plastic or metal. The bezel is used to secure a keypad to a printed circuit board. The bezel also aligns the keypad during the final assembly and protects the keypad-base material from contact with human hands.

Bosses: Small posts used for positive alignment of rubber keypad in bezels or assemblies.

Breakdown Voltage: Voltage at which an insulator or dielectric ruptures. Breakdown voltage is also known as dielectric strength.

Silicone rubber compression set: The measurement of a material’s ability to recover its original size and shape after compression under prescribed conditions. It is usually expressed as a recovery percentage (fraction) of the compression condition.

Conductive Rubber Switch: Mechanical switch made of silicone rubber with either direct or indirect contact.

Contact: The current-carrying area under each rubber switch (conductive pill or carbon-inked surface). The “contact” that makes an electrical connection with the electrode on a printed circuit board when the switch is actuated.

Rubber switch contact force: The force required to maintain rubber switch contact closure force/stroke curve with a printed circuit board.

Contact Rating: The electric power handling capability for rubber contacts under strictly controlled laboratory conditions.

Draft Angle: The amount of taper for molded or cast parts perpendicular to the parting line.

Dual Durometer: Silicone rubber keypads manufactured using a two-shot molding process and two-material hardness.

Durometer: Durometer is one of the several measures of the hardness of a material. Hardness may be defined as a material’s resistance to permanent indentation.