The materials used in the flexible circuit of membrane switch are insulating film, adhesive and conductor. The insulating film forms the base layer of the circuit, and the adhesive adheres the copper foil to the insulating layer. In multilayer design, it is bonded with the inner layer.

　　They are also used as protective coverings to insulate the circuit from dust and moisture, and to reduce stress during flexing. Copper foil forms a conductive layer. Data structure of membrane switch (flexible circuit) in some membrane switches, rigid components made of aluminum or stainless steel are adopted, which can provide dimensional fluctuation, provide physical support for the placement of components and wires, and release stress.

　　The adhesive binds the rigid component and the flexible circuit together. Another kind of material is sometimes used in flexible circuits. It is adhesive layer, which is composed of two sides of insulating film coated with adhesive. Bonding layer provides protection and electronic insulation function, and can eliminate a layer of film, and has the ability to bond a few layers. There are many kinds of insulating film materials, but the most commonly used materials are polyimide and polyester materials.