In the PCB manufacturing process into a multi-layer circuit boards, many customers will choose to use immersion gold or gold-plated process, but the specific immersion gold or gold-plated, customers are not very clear, we are now sinking gold and gilded detail a difference, as well as their advantages shortcomings.
Immersion Gold is by chemical oxidation-reduction reaction method to generate a layer of nickel alloy or a copper pad on the gold thickness generated by this method is thicker than gold plating, and is using a deposition way to achieve the gold layer thickness, we usually referred to as immersion gold.
Difference Immersion Gold PCB multilayer circuit boards and gilded board has the following main points:
1, the crystal structure of the nickel alloy between them is not the same, gold is much thicker than gold plating on the surface, the color tends to be more yellow gold, many look beautiful, more satisfied customers. Compare whitened gold plating, gold is not so yellow.
2, due to the different crystal structure, Shen metallurgical gold is easier for electric welding, and gold-plate stress easier to control.
3, immersion gold plate on top will produce copper or nickel alloy pads, and other places will not produce the metal, so that the child will not produce interference on the signal of the copper layer in the signal transmission process.
4, Immersion Gold board more dense than gold-plated board, more antioxidant helps to protect circuit boards and copper.
5, more sophisticated circuit boards, usually around 3mil board with Immersion Gold process is more prone to nickel and gold on the pad, without causing short circuits.
6, Immersion Gold sheet metal on the pad is very smooth, this is for BGA soldering, welding or some high requirements pad is very necessary process.
7, but immersion gold process arising from nickel-gold due to the different crystal structures of the nickel layer of relatively soft gold, unlike gold plating so hard, so not suitable for use Immersion Gold Goldfinger process and selection of gold, because gold gilt over heavy resistance mill.
