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How to stop hydrogen pitting in tin plating

Hi, I am working on bright tin plating. However, my deposit always has hydrogen pitting, and I tried to lower the wetter but I could not remove those pits. I appreciate any help provided.

Thanks

Bryne Wang
product designer - NY, USA
August 12, 2009

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Hi, Bryne. If you have tried agitation and wetter and the pits remain, I would suspect the parts are not fully clean and tiny spots of organics are precipitating the hydrogen generation.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
August 12, 2009

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First of two simultaneous responses --

The proper amount of wetting agent, stronger agitation, cleaner parts that do not have micro pits in the surface and it will not pit. Find the problem and fix it.

James Watts
- Navarre, Florida
August 13, 2009

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Second of two simultaneous responses --

Dear Ted,
Thanks for the advise. I have tried increasing the wetter and agitation speed, and I am pretty sure that parts and HC panel used are clean. However, the pits remain. Raising temperature can remove them, but this is for electroplating bright tin, nobody works above room temperature. I am not sure that whether it is additive related, or just some particular components. I am wondering whether there is any anti-pitter used in tin electroplating. Thanks for any advise

Bryne Wang
product designer - NY, USA
August 13, 2009

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To any one who like to help,

Hi, My name is Bryne, I am working on bright tin electroplating process development. My Hull cell panels always have pitting in the hight current density area. I have tried increasing surfactant level and agitation speed, but the pits remain. My Hull cell panels are cleaned pretty well each time before plating. I really do know how to solve this issue. Any advise or help are greatly appreciated.

Bryne Wang
product designer - NY, USA
August 14, 2009

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Read James Watts' reply again. He has told you everything you need to know. On a Hull Cell panel, you may have excessive current density at the high end, higher than you will see on actual plated parts.

Jeffrey Holmes, CEF
Spartanburg, South Carolina
August 18, 2009