1. It can prevent copper from forming “patina” in a humid environment to increase contact resistance and overheat the contact surface. After the surface of copper is plated with a layer of tin, it can prevent the oxidation of copper.
2. Tin oxide conducts electricity well and will not cause increased contact resistance or overheating of the contact surface.
3. The tin material is relatively soft, which can ensure close contact between the contact surfaces during bolt connection.

The material of the terminal plating is usually tin plating. Due to its low price, the connector is used when the environment is not strict, and tin plating terminals are the first choice. Tin material is easily oxidized in the air, and a very thin oxide film will be formed on the surface of the tin material. This oxide film is very brittle. When the male and female terminals are mated, the oxidation film on the surface is easily destroyed. The tin oxide film is The connector will be squeezed and replaced due to mechanical damage during the mating process. At this time, the load of the positive force of the terminal is transferred to the tin-plated layer. Since the tin-plated layer has low hardness and good ductility, the cracks in the oxide film widen, and the inner layer of tin is extruded from the cracks, thus forming the metal contact interface required for electrical performance.