The principle of patch touch switches, also known as button switches or sensitivity switches, is the same as ordinary switches. The presence or absence of a certain function can be controlled through the on/off of the internal circuit of the switch, but it is different from ordinary switches. For ordinary switches, pressing the switch once to open and then pressing the switch again to close, but for touch switches, when the switch is pressed, the internal circuit is connected to complete the specified function, After releasing the switch, the internal circuit is no longer in a connected state.

The SMT light touch switch is mainly composed of five parts: a cover plate, a button, a spring piece, a base, and pins. When the button is subjected to external pressure, it transfers the pressure to the spring piece and causes slight deformation of the spring piece. For a four foot light touch switch, the small deformation of the spring piece causes the four pins to be connected in pairs, thereby enabling the circuit to conduct and complete the specified function; When the pressure on the button disappears, the small deformation generated by the spring is restored, and the connection between the four pins of the switch is disconnected by lightly touching it, causing the circuit to disconnect.

For an electronic person, simply understanding the principle of a touch switch is not enough. Welding it is definitely unavoidable. During the welding process, there are some things to pay attention to: firstly, if a load is applied to the terminal, different conditions may cause looseness and deterioration of electrical characteristics. Secondly, when using through hole printed circuit boards, the impact of thermal stress may change, Therefore, it is necessary to fully confirm the welding conditions in advance. Finally, when conducting secondary welding on the SMT touch switch, continuous heating may cause peripheral deformation, terminal looseness, unstable performance, and other effects. Therefore, it is necessary to wait until the first welding part returns to normal before welding.