Electronic – Galvanic action on gold plated PCB

goldpcbpcb-fabrication

It has been always said that having gold plating on a PCB has lots of advantages. Not only does it give a good clean low resistance contact, but the perfect flat surface. However based on the galvanic series table, gold and tin\lead (or even copper) placed farther apart from each other that leads to corrosion and noise voltage.

if it is true what would be better to take into account first, resistivity or corrosion (also noise voltage)?

Best Answer

Galvanic series is entirely dependent on being immersed in water, mostly sea water. It has no bearing on much of anything else.

IF you were to take into account anything what-so-ever then I would take into account corrosion. It is true that some metals don't play well together. That really isn't the case here because these metals are all layered so that you don't have to worry about that. Resistivity is of no consequence here since the resistance added by either HASL or ENIG is extremely small either way. To be honest, your solder would add more resistance than either of these processes would. mKeith is correct and the only reason you pick one over the other is a cost/benefit analysis where you take into account that ENIG will keep a board's contacts free of detrimental oxides longer than HASL would. This improves solderability.