All About Silicone Rubber Keypads
Silicone Rubber keypads, known also as Rubber Keypads or Elastomeric Keypads are used extensively in defense, aerospace, consumer, and industrial electronic products.
Silicone Rubber keypads serve as the top layer of an electronic switch. This top layer is provided in a broad variety of colors, dimensional design, and surface finishes providing a durable, cost effective, customized electronic switch.
Silicon rubber is fabricated with compression molding technology that results in a three dimensional configuration. When a rubber keypad is depressed, switch webbing around the perimeter of a key (button) uniformly deforms to produce a tactile response. When pressure is removed from the switch the webbing returns to its neutral position with positive feedback. In order to complete an electric circuit, a carbon or gold pill is placed on the base of the switch center which contacts a printed circuit or polyester membrane switch base layer.
It is possible to vary the tactile response and travel of a key by changing the webbing design and/or the shore hardness of the silicone base material. Unusual key shapes can easily be accommodated as can key travel up to 3mm. Tactile forces can be as high as 500g depending on key size and shape.
By adding pigments to the natural silicone rubber it is possible to create keys in various colors which can be molded simultaneously (Flowing colors) to form a multi key keypad. Individual graphics and legends can be printed on to a key allowing full customization of the keypad for its application. Rubber keypads can also be spray painted and subsequently, legends can be laser etched through the paint coating, allowing individual key to be illuminated using LEDs placed on the printed circuit board.
Finally, contact resistance can be customized by utilizing contact pills of different resistance.
All of these design options make Silicon Rubber keypads one of the most versatile, durable, cost effective electronic switches available on the market.
