ENIG (Electroless Nickel Immersion Gold) is a surface finish used in the production of printed circuit boards (PCBs). It involves depositing a thin layer of nickel onto the copper pads and traces of the PCB, followed by a layer of immersion gold. (4 Layer ENIG PCB Board) The main advantage of ENIG is its flat surface, which makes it suitable for fine-pitch surface mount technology (SMT) components...