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Adhesion failure of Electroless Nickel over Sulfamate Nickel

We are experiencing serious problem of Electroless Nickel (Mid Phosphorous 5-9%) plated over sulfamate Nickel. The base material is mild steel stamped(LeadFrame).

Sulfamate Nickel is plated over cyanide copper flash. Electroless Nickel is plated on line without any delay. Even installing different activation steps prior to ENP like Acid Dip, dry acid salts etc did not prove any results. Also virgin sulfamate electrolyte without any additive/grain refiner also tried but unsuccessfully.

It is also tried that this ENP over Copper or directly on to the base material did not fail adhesion. Also that the sulfamate Ni deposit have good adhesion with the Tin plating (MSA Acid based)

Please suggest means to overcome the problem

K M M Abubacker
process engineer - Bangalore, Karnataka, India
November 10, 2009

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You want to make sure you are using the highest purity Ni sulfamate concentrate. I have seen cases where this chemical was of poor quality, and peeling occurred. We had to make up a new batch without any stress reducers or wetters and add a few carbon packs to the filter chamber before plating our first run. This practice did solve the problem. The chemical contained unwanted organics.
Some Ni bath suppliers will state in the tech data sheet that a carbon treatment should be performed on the new Ni sulfamate concentrate before production. Rinsing practices and water quality could be the culprit as well. It sounds like you have done everything else to prevent passivation of the Ni surface. Good Luck!

Mark Baker
Fellow Plater - Syracuse, NY, USA
November 18, 2009

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IN PLACE OF NICKEL SULFAMATE YOU CAN TRY A NICKEL STRIKE SOLUTION 1 MIN AT HIGH AMP, NORMALLY THERE IS NO PROBLEM OF ADHESION OF ELECTROLESS ON NICKEL STRIKE

Ricardo Burstein
Bnei Berak, Israel
November 27, 2009

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My dear Ricardo who once was my student, is right.
Nickel strike is the right way but it does not have to be instead of the sulfamate, it can be on top of the sulfamate.

Sara Michaeli
Tel-Aviv-Yafo, Israel
December 24, 2009