Carbon Contact Silicone Keypad

Making a Contact

In order to make a proper connection with the printed circuit board (PCB) or printed circuit, it is necessary to use a conductive carbon contact. The contact can be printed carbon or a pre-formed carbon piece known as a “pill”. Printed carbon contacts are sufficient for most constructions. A conductive carbon contact pill can also be used but adds some cost. Carbon pills are known for long life (>10 million actuations) and low resistance (<100W). Additionally, the pills come in a variety of shapes but are usually circular with diameters ranging from 1.5 - 10 mm and thickness from 0.4 0.6 mm.