The long and short golden finger encapsulation is designed to have a power-on timing difference when the PCB board is plugged and unplugged. For example, when the golden finger is removed, the short finger will cut off the power supply first to play a protective role. Generally, when the golden finger is inserted, if the short finger is not inserted in place, the power supply will not supply power to avoid the power surge damaging the golden finger product.

There are also some devices, for example, the length of the four pins of the USB interface is also different. One of the two long golden fingers on the left and right is connected to the power supply and the other is grounded. The two short fingers in the middle are responsible for data transmission. In this way, when the U disk is inserted into the machine, ensure that the power is turned on before data can be transmitted, which is also for the normal access and protection of the equipment. If the long and short golden fingers are made into equal-length golden fingers, the protective effect will be lost and reliability problems will occur.