PCB factory china tells you the difference between immersion gold and gold plating as following：

1. The crystal structure formed by immersion gold and gold plating is different. The thickness of immersion gold is much thicker than gold plating. Immersion gold will be golden yellow, which is more yellow than gold plating (this is one of the methods to distinguish gold plating and immersion gold).

2. Immersion gold is easier to weld than gold plating and will not cause poor welding.

3. There is only nickel and gold on the pads of the immersion gold board. The signal is transmitted on the copper layer and will be not affected.

4. The crystal structure of immersion gold is denser than gold plating and it is not easy to be oxidized.

5. Gold plating is easy to short-circuit. However, there is only nickel-gold on the pad of the immersion gold PCB, so there will be no short circuit of the gold wire.

6. There is only nickel-gold on the pads of the immersion gold board, so the combination of wire resistance and copper layer is stronger.

7. The flatness and service life of the immersion gold PCB are better than the gold plating PCB.

Gold is widely used because of its excellent conductivity in electronic products, such as key boards, gold finger boards, etc. The most fundamental difference between gold plating PCB and immersion gold PCB is that gold plating is hard gold and immersion gold is soft gold.