The materials used in membrane switches are insulating films, adhesives and conductors. The insulating film forms the base layer of the circuit, and the adhesive bonds the copper foil to the insulating layer. In the multi-layer design of the membrane switch, it is then bonded to the inner layer. They are also used as a protective cover to insulate the circuit from dust and moisture and to reduce stress during flexing, and the copper foil forms a conductive layer.
Membrane switch design uses rigid members made of aluminum or stainless steel, which can provide dimensional stability, physical support for the placement of components and wires, and stress relief. Membrane switch adhesives bond rigid components and flexible circuits together.
In addition, another material is sometimes used in membrane switches (flexible circuits). It is an adhesive layer, which is formed by coating adhesive on both sides of an insulating film. The adhesive layer sheet provides environmental protection and electrical insulation functions, and can eliminate a layer of film, and has the ability to bond multiple layers with a small number of layers. There are many types of insulating film materials, but polyimide and polyester materials are commonly used.