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Nodules substances on Sn finishing

2007

Hi,

I had encountered nodule-like substances in Sn plating.
It can be found all over the plated area.
It even can occur after new make-up.

What I had is dummy plate at high current density to remove all this small nodules in the solution.
This can work.
I heard from other platers that they also had encountered this issue before.
And they had some sort of modifiers to add in to lower the amount of nodules.
But what is reason behind this?
I need to find out this cause as sometime we need to explain to customer.

please advise me.

Steven Ang kwee Yam
Process Engineer - Singapore

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I do not agree that you need to explain it to your customer, Steven; rather, you must prevent it. Nodular plating is not acceptable except perhaps in some special engineered-to-purpose context. There really isn't enough info here (are you doing immersion tin, alkaline electroplating, acid electroplating), but you may need filtration or improved addition agents. What advice does your plating process supplier offer? Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007

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2007

We are using MSA acid base Sn plating.
I normally advised to do a through cleaning of the tank, followed by HCD plating if cleaning does not solve the problem.
I explained to them that the belt or carrier stainless steel surface was not "cleaned enough", result this nodules.

Steven Ang kwee Yam
Plating - Singapore