Common micro fuses are glass tube fuses and sheet fuses in automobiles. As a protective component of electronic equipment, glass tube fuse has been used for a long time, but because of its large size, fragile, unable to achieve automatic installation and other shortcomings, the demand for micro fuse is growing. Traditional fuses are generally designed to protect the input part of the power supply. Nowadays, some changes have taken place. Many new uses have been derived from fuses, such as the protection of PCB and IC inside the equipment, the protection of input and output circuits, etc. This also makes the use of micro fuses increase year by year. The micro fuse has the characteristics of small size, high sensitivity and quick protection. Usually used in switching power supply, charger, small household appliances control board.