Electroless Nickel Immersion Gold (often referred to as "ENIG" or simply "immersion gold") and electroplated gold for PCB surface finishing are frequently confused, but they serve entirely different purposes.
 
- Electroless Nickel Immersion Gold (ENIG): It uses a chemical process to deposit a nickel + gold layer on copper. Its advantages include a flat surface and excellent oxidation resistance. It is particularly suitable for high-density packages like BGA and QFN, ensuring reliable soldering, but the cost is relatively higher.
- Electroplated Gold: Mostly applied via an electroplating process, it features a thick gold layer with high hardness and strong wear resistance. It is commonly used on gold fingers and connectors to ensure stable performance during repeated plugging and unplugging. However, its process is complex, making it unsuitable for large-area applications.
 
How to Choose?
 
- Prioritize soldering stability → Choose Electroless Nickel Immersion Gold (ENIG).
- Prioritize wear resistance and durability → Choose Electroplated Gold.
 
In short, opt for Electroless Nickel Immersion Gold (ENIG) when soldering reliability is key, and choose Electroplated Gold when wear resistance is the main concern.