The difference between PCB gold plating process and immersion gold process
PCBA board production is a very important part of PCBA processing. There are also many process requirements for PCB boards. For example, customers often need gold plating and immersion techniques, both of which are commonly used for PBC boards. In the process, the feeling of listening to names is almost the same, but in reality there are big differences, and many customers usually cannot distinguish the difference between the two processes. Xinda introduced these two different processes to everyone.
Gold plating: mainly through electroplating, gold particles are attached to the pcb circuit board, because the gold plating adhesion is strong, also known as hard gold, the gold finger of the memory strip is hard gold, high hardness and wear resistance.
Immersion gold: This is a chemical redox reaction to form a coating. The gold particles crystallized and adhered to the pcb pad. It is also known as soft gold due to its weak adhesion.
The difference between gold plating and immersion gold:
1. The gold plating process in SMT processing is completed before the solder mask is executed. The green oil cleaning may not be clean and is not easily applied to the tin; and the immersion gold process is completed after the solder mask is performed, and the patch is easily tinned.
2. Before the gold plating process, it is usually necessary to plate a layer of nickel and then plate a layer of gold. The metal layer is copper nickel gold. Since nickel is magnetic, it has the function of shielding electromagnetic. The immersion gold process directly deposits gold on the copper skin, the metal layer is copper gold, there is no nickel, and there is no magnetic shielding.
3. The gold plating and immersion gold processes are different, and the crystal structure formed is different. Dip gold plating is easier to weld than gold plating and does not cause poor soldering. Moreover, immersion gold is denser than gold plating and is less prone to oxidation.
4. The plate is not as flat as gold after gold plating. For more demanding boards, the flatness is better. Usually, immersion gold is used. Immersion gold is usually not displayed as a black mat after assembly.