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Nickel-gold (Ni/Au) Electroplating on PCBs

I am a new application engineer in PCB industry. I want to know what is the industrial recommended thickness for Ni/Au electroplating for surface mount devices of size 0603,0402 and 0201. Can any one out there advise me?

Thanks,

Karhock
- Penang, Malaysia
2002

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Karhock:

You mean with all those plating guys in Bayan Lepas Free Trade Zone you can't find anyone to help you? Half the engineers employed there run plating lines! Anyway the answers to all your questions are in the literature. Begin with the IPC, JEDEC, and free MIL SPEC websites. They have standards which call out thicknesses for every application. Try MIL-C-14550 [link is to free spec spec at Defense Logistics Agency, dla.mil] for Copper, MIL-G-45204 [link is to free spec spec at Defense Logistics Agency, dla.mil] for Gold, and FED-QQN-290 (replaced by AMSQQN290) for Nickel. As you read these specs, print them out and start making your own binder of specs. They will constantly come in handy. Then there are books. One of my favorites is Understanding and Using Surface Mount and Fine Pitch Technology [affil link on Amazon] by Hutchins. There are many more. You can find most of the links you need here at this fine website.

Dave Kinghorn
Chemical Engineer
SUNNYvale, California
2002

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Dear K,

Ni plating is to stop copper migration to the gold and normally it requires 5-12 micron thickness. Your customers may insists you plate it thicker. There are two type of gold. One is to flash it (about 0.05 -0.1 micron) and the other type is to have a thicker for abrasion purpose, like gold fingers. They are usually hard gold. Soft gold is for bonding purposes. The thickness depends from customer requirement. The function of gold plating is normally conductivity and decorative. Your PCB chemical suppliers should be able to furnish these info. If they cannot change the supplier.

Regards,

Ang T T
- Kajang, Malaysia
2002