Electroplating can be divided into hard gold and soft gold. Hard gold electroplating is an alloy, so its hardness is relatively hard. It is suitable for use in places requiring force and friction. It is generally used as the edge contact point of PCB (commonly known as golden finger). Soft gold, On the other hand, is commonly used to connect aluminum wires On the COB (Chip On Board) or On the touch surface of mobile phone keys, and more recently, it is widely used On both sides of BGA boards. The distinction of hard gold and soft gold, it is the component of this layer of gold that goes up finally plating, when gold-plating can choose electroplate pure gold or alloy, because the hardness of pure gold is softer, so also call "soft gold".
Hard gold plating PCB has excellent electrical conductivity, wear resistance, oxidation resistance and reduced contact resistance. But gold is extremely expensive, so it is only used for topical gold plating or chemical gold on goldfinger.
Hard gold plating PCB production process: upper – grinding plate (micro erosion) – washing, activation, washing, nickel plating, washing, activation, washing, gold plated, gold recovery – water – air drying – the lower.
Hard gold plating PCB steps: adhesive tape — roller tape — automatic nickel-gold plating — tape tearing — washing and drying.