The outer surface of the circuit board usually has three colors: gold, silver, and light red. Gold is the most expensive, silver is cheaper, and light red is the cheapest. So, how to distinguish the pcb manufacturer China surface treatment process by color?

1.Gold
Gold is real gold. Although there is only a thin layer, it accounts for nearly 10% of the cost of the circuit board. The purpose of using gold is to facilitate welding and to prevent corrosion. The gold-plated layer is widely used in the component pads, gold fingers, and connector shrapnel of the circuit board.

2.Silver
The silver circuit board is called spray tin board. Spray a layer of tin on the outer layer of the copper circuit to help soldering. The tin-sprayed board has no effect on the components that have been soldered, but the reliability of the pads exposed to the air for a long time is not enough, and the long-term use is easy to oxidize and rust, resulting in poor contact.

3. Light red
OSP, organic soldering film, is organic and not metal. The price is cheaper than the tin spraying process. The only function is to ensure that the inner copper foil will not be oxidized before soldering. When the welding is heated, this layer of film evaporates. OSP can weld copper wires and components together when soldering, but it is not corrosion resistant. If an OSP quick turn PCB Assembly circuit board is exposed to the air for ten days, the components cannot be soldered.