Membrane or foil keypads are a very popular technological solution, valued for its durability, slimness, as well as favourable price and attractive design. Thanks to their small size, they can be easily fitted in the device enclosure. They are used in industry (also in machines operating in extremally polluted environment), automotive industry, as well as as switches in building automation systems.
Membrane keypad design
A membrane keypad consists of multiple layers of foil. The outer layer – made of polyester or polycarbonate – is designed to protect the interior from environmental influences. The print with icons, letters or numbers is located on the inside, thanks to which it does not get damaged due to intensive use. Conductive paths and contact pads are printed on the polyester foil contact. The signal flows after a key is pressed, and, depending on the construction, it starts as a result of contact between the printed layers of foil or a metal element and the foil – then, a galvanic short circuit of the system occurs. The individual layers are joined by means of fixing and distance foils covered with glue. This design ensures resistance to mechanical damage, weather conditions, dust, water and many chemical compounds. Membrane keyboards work well in places where standard mechanical keyboards get damaged easily. These products are available in versions with or without tactile “clicks” (the former have a longer service life).
Foil keypads in TME offer
In the TME catalogue, you will find membrane keypads manufactured by LC Elektronik and QWERTY. They are available in 12-, 13-,16-, and 20-button versions with flexible flat output cables.