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Stripping of Copper Leaving Nickel unchanged

2005

I am interested in preferentially stripping copper without affecting any nickel that has been electroplated on the copper. Basically I have a copper foil stuck on a board sheet (similar to the type used by Printed Circuit Board Manufacturers) with nickel plating done on the copper side in parts. I need to know how to strip the exposed copper leaving the nickel plating unaffected.

Thank you in advance.

Sumeet Mehta
Plating - Mumbai, Maharashtra, India

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2005

Copper complexes much more strongly than nickel.
Especially with cyanide ion. Soaking your boards in a shallow bath of buffered cyanide (neutral or mildly basic) for a long time, might work. Oxygen from air will be providing the oxidizing power. It can only diffuse in there slowly. Electrolyzing with a very low voltage (~1 v) or limited current might help it along.

James Swenson
- Los Angeles, California, USA

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2005

Dear sir,
I am stuck with one problem
We have manufacturing finned tubes, which is used in various industries, in finned tubes contact in between fin & tube is very critical, our finned tubes is rejected due to contact in between fin tubes is not 100% & both material is carbon steel, tube inside there is fuel gases & temp. is 500 deg.C, we have tried out in hot dip (melting temp is 40 °C). What is electrolysing nickel? please guide us,
thanking you & awaiting your response accordingly.

SUDHAKAR ANCHAN
HEFT ENGINEERS - Mumbai, Maharashtra, India

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2005

I am not implying that I am confident that electroless nickel is a suitable answer to your problem, but electroless nickel is a plating solution that will deposit a nickel coating on properly prepared steel components. Typical thicknesses would be up to about 0.001" and because electrolytic current is not involved, the thickness of deposit is quite uniform.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey