An Introduction to Silicone Rubber Keypads and How They Work
Have you heard of silicone rubber keypads? Also known as elastomeric keypads, they've become a popular alternative to traditional plastic keypads. You can find silicone rubber keypads in ATMs, medical machines, human machine interfaces (HMIs), point-of-sale (POS) systems, microwaves and other devices. For a better understanding of silicone rubber keypads and how they work, keep reading.
What Are Silicone Rubber Keypads?
Silicone rubber keypads are switch devices that live up to their namesake by featuring a silicone rubber construction. Like all switch devices, they consist of controllable circuits. You can press a key on a silicone rubber keypad to open or close the respective circuit. Silicone rubber keypads are simply made of silicone rubber.
How Silicone Rubber Keypads Work
As shown in the photo above, silicone rubber keypads look like ordinary keypads. They feature keys with letters, numbers and/or characters on them. Pressing one of these keys will open or close the circuit with which the key is used.
Most silicone rubber keypads rely on printed circuit board (PCB) contacts to control their circuits. There's a PCB below all of the keys. On the bottom of the keys is a conductive contact, such as a gold pill. By default, the PCB and the keys are separated by air. Pressing a key will then push it down so that the key's conductive contact is exposed to the PCB. Exposure to the PCB will engage the circuit.
Silicone rubber keypads are designed to "bounce back" when pressure is removed from their keys. When you release your finger from a key, for instance, the key will spring up to its original position. This is due to the fact that silicone rubber keypads are made of molded silicone rubber, which is naturally elastic.
