The cost of the film switch is relatively low, and the production is very simple. But the quality of the finished products also pass suspicious attracted much attention, the thin film switch is very common in our life, each switch button is not a lot, but mark is very clear, the key role you can quickly and easily distinguish film switch. After the circuit view of film switch, can find the structure of membrane switch is composed of upper, middle and lower three floors, with the use of two layer is a conductive coating printed circuit, at the bottom of each key will have a corresponding contact, there is a layer of intermediate the isolation layer, in some of the same key is provided with a circular contact (or hollowed out), press the cap, Unicom circuit two layers of finish, generates the corresponding signal. There are two kinds of thin film switch button structure can be divided into the volcano and scissors of the two different tectonic structure, which is the most commonly used volcano planning key, it is the key to stab button on the interface, the bottom of the direct touch with silicone cap, affected by the bond length and the elastic silicone cap column in the hand, the volcano tectonic key high key cap, long process planning key, so to get outstanding reaction, it has a drawback is that the body must do some thick, the use of keys is not very stable, easy to shake the situation, click on the hand feeling is not very good.