Membrane switches have a variety of circuits: such as flexible circuits, rigid circuits. Flexible circuits are mainly used in the connection of electronic products. The functional areas of the flexible circuit board can be divided into four types: lead lines, printed circuits, connectors, and multi-function integrated systems. Its representative flexible substrate is PET. The challenge for the flexible circuit industry is to use its technical advantages to keep pace with the development of computers, telecommunications, consumer demand and the market.