In the PCBA chip processing, PCB board production is a very important aspect. There are many technological requirements for pcb. For example, customers require gold plating and immersion gold (ENIG) processes. Both of them are commonly technology for PCB. But they are very different. A lot of people will confuse them. So, what is the difference between gold plating and Immersion gold?
Profile of gold plating and ENIG:
Gold plating: Gold particles are mainly attached to the PCB by plating. Because of the strong adhesion of gold plating, so it also called hard gold. The memory of the gold finger is hard gold with high hardness and wear-resistant.
ENIG: It is through chemical redox reaction to generate a layer of gold particles crystal coating, attached to the pcb pad. It also called soft gold because of the weak adhesion.
The difference between gold plating and ENIG:
1. The crystal structure formed by Immersion gold and Gold Plated is different, The gold thickness of Immersion Gold is much thicker than Gold Plated, and Immersion Gold shows the colour of golden yellow, it looks more yellow and customers are more satisfied.
2. The Immersion Gold PCB has better solderability than Gold Plated PCB, it won’t easy to cause defect on soldering, however, the immersion gold is soft compared with plated gold, so the gold finger PCB with immersion gold wear not so well.
3. the nickel-gold is only on Pads for immersion gold, it doesn’t affect the signal since the signal transmission is on copper.
4. Compared with plated gold, the crystal structure of immersion gold is more compact, and not easily to be oxidized.
5. As the wiring density is increased, wiring short is easy to happen on plating gold, but it won’t happen on immersion gold since only Pads have nickel-gold.
6. Immersion gold is normally used for PCB board with high requirements and good flatness, The flatness and working life of immersion gold is as good as gold plating.