How to choose the membrane thickness of the membrane switch circuit?

2020-07-16

　Membrane switch is an operating system that integrates key functions, indicator elements, and instrument panel. It consists of four parts: panel, upper circuit, isolation layer and lower circuit. When the membrane switch is pressed, the contact of the upper circuit is deformed downward, and the contact with the polar plate of the lower circuit is conducted. After the finger is released, the contact of the upper circuit bounces back, the circuit is disconnected, and the circuit triggers a signal. Membrane switch has strict structure, beautiful appearance and good sealing. It has the characteristics of moisture resistance and long service life. Widely used in electronic communication, electronic measuring instruments, industrial control, medical equipment, automotive industry, smart toys, household appliances and other fields.
The membrane of the circuit layer in the membrane switch considers the separation of the electric shock of the switch, the rebound, and the reliability of the insertion or riveting of the lead to the connector, so the thickness of the circuit material should be selected between 0.125 mm and 0.15 mm. If it is too thin, there is no rebound force, the separation of the contacts is not agile, if it is too thick, the action is slow, and the operating force is increased. From the specific situation, the choice of film thickness is also related to the following factors:
1. The thickness of the isolation layer.
2. The shape of the key body.
3. The size of the key body.

Therefore, the thickness of the membrane switch circuit layer is preferably 0.125mm.