Electrode Contact: surface/design on a printed circuit board that conducts current when rubber switch is actuated and switch closure occurs.
Key Height: The measured distance from the bottom of a keypad (base) to the top surface of a key. Expressed in 1/100 mm.
Legend: Some type of printed graphic (symbol, number or letter) on the top of the key surface.
Life The number of switch actuations realized before the switch membrane ruptures or over stresses.
Membrane: The non-conductive hinge that permits a rubber key to flex, and is responsible for the tactile feel realized.
Negative-Image Graphics: Graphics that allow switch color or switch masking color to be seen through top-surface printing on keypad.
Overstroke: Additional travel experienced with a rubber switch after initial switch closure has been realized. Rubber switches with overstroke require a double-cone or double-bell shaped membrane.
Positive Image Graphics: Single or multicolor printing on top of key surface.
Return Force: Force created by switch membrane as it returns the key to a non-actuated position.
Reversed-Out Graphics: Graphics that allow rubber color or masking color to be seen through top surface printing on keypad.
Shore A: The Durometer “Shore A” is designed to measure the penetration hardness of rubber, elastomers. It also includes other rubber-like substances such as neoprene, silicone, and vinyl. It can also be used for soft plastics, felt, leather and similar materials.
Snap Ratio: Represents the difference between the actuation force and the contact force of a switch divided by the actuation force.
Stroke: Distance from the contact surface on a rubber switch to an electrode pattern on a printed circuit board.
Tactile Feel: The response of rubber while depressing. For tactile rubber keypads, it is a critical function of the diaphragm web geometry.
Tear Strength: The tear strength is a measure of the resistance of rubber to tear forces. The tear strength is calculated by dividing the maximum force load by the thickness of the rubber.
Wear or abrasion resistance: The resistance of a particular ink or coating to manual wearing. The testing process is usually a Norman tester with the number of cycles legends can perform before wear is noticeable.