Metal finishing Q&As since 1989

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Bright Nickel

At my printed circuit shop we have a Boric Acid Nickel Bath which we use to put a gold finish on certain boards. We use a Cyanide Gold Bath to put the gold finish on over the Nickel. Our problem is that we can never seem to get a 'bright' finish on the Nickel. And without a 'bright' nickel finish it is impossible to obtain a 'bright' gold finish. Both baths are kept to spec as I am the Chemist for the shop. Brightener levels are kept to spec as well.

Any ideas how to obtain a 'bright' finish from the Nickel Bath?

Chris Snead
- NY, New York
2001

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Assuming the nickel you are using is meant to product a bright nickel deposit, I would be consulting with my supplier of additives as well as running some hull cell panels. Note: some additives are meant to produce a semi-bright deposit.

If the hull cell panel shows a dull or semi-bright deposit or a patchy appearance (semi bright mingle with bright) this is a strong indication that the solution is contaminated and you should look at an activated carbon treatment. There are a host of organic contaminants that can produce dull deposits in a bright nickel and most can be removed with activated carbon.

Most bright nickels use 2 - 3 additives plus an anti-pit. These additives could be out of balance.

If the hull cell panel is bright and the work is dull, you have a problem on your line or with your substrate. You should then concentrate your troubleshooting on the line and or substrate.

Ken Lemke
Burlington, Ontario, Canada
2001