Silicone rubber keypads have become a common switching solution. Also known as an elastomeric switch, they are characterized by the use of silicone rubber webbing. As you may know, silicone rubber is soft and elastic, resulting in unique qualities that aren’t found in other switching solutions. In this post, we’re going to take a closer look at silicone rubber keypads.

What Is a Silicone Rubber Keypad?

A silicone rubber keypad is an electrical switch that features a soft webbing made of silicone rubber. This webbing plays an important role in the keypad’s functionality. In its default state, the webbing remains erect and upright. When the button is pressed, on the other hand, the webbing deforms, at which point a conductive-coated pill makes contact with an underlying printed circuit board (PCB), thereby completing the circuit.

How Does a Silicone Rubber Keypad Work?

As previously mentioned, silicone rubber keypads rely on silicone rubber webbing material that’s placed around an electrical switch. Underneath the webbing is a conductive-coated pill. Below this pill is air, followed by a PCB. In its default state, the conductive-coated pill doesn’t touch the PCB. As a result, the switch remains in an open state. When you press the button, however, you’ll deform the silicone rubber webbing until it makes contact with the PCB, at which point the circuit will be complete.

Do Silicone Rubber Keypads Support Backlighting?

You’ll often find silicone rubber keypads featuring backlighting. This versatile type of switching solution supports a wide range of backlights, including light guides, light-emitting diodes (LEDs), fiber optic and even electroluminescent (EL). By adding backlights to a silicone rubber keypad, users can achieve higher input accuracy by reducing the risk of erroneous commands, especially in low-light conditions.

Can Silicone Rubber Keypads Be Laser Etched?

Laser etching is often used in conjunction with backlights to create a superior level of aesthetics and visibility for silicone rubber keypads. What is laser etching exactly? Basically, laser etching is a finishing process that involves the application of a high-powered laser to selectively remove some of the paint on the surface of a silicone rubber keypad. With the paint removed, the backlight is able to illuminate the silicone rubber keypad from underneath.

After reading this post, you should have a better understanding of silicone rubber keypads and how they work. Just remember that all silicone rubber keypads feature a soft webbing made of silicone rubber around a center switch.