1. Prevent oxidation of bare copper surface

Copper is easy to oxidize in the air, resulting in the PCB solder pad is not conductive or reduce the weldability, by placing tin on the copper surface, the copper surface can be effectively isolated from the gas, maintaining the conductivity and weldability of the PCB.

2, keep the solder

Other surface treatment methods include: hot melt, organic protective film OSP, chemical tin, chemical silver, chemical nickel gold, electroplating nickel gold and so on; But in order to spray tin plate cost-effective best spray tin PCB board process characteristics of spray tin plate including copper tin two layers of metal can adapt to the poor environment conditions and solder performance is better in high temperature and corrosive environment is more suitable. This board is widely used in industrial control equipment communication products and military equipment products tin-sprayed PCB advantages: in the usual PCB surface treatment, tin-sprayed process is known as the best solderability, because there is tin on the pad, when soldering tin, with gold plate or rosin and OSP process, it is easier. This is very easy for us to solder manually, welding is not very easy.