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Yellow and white passivation conductivity

Dear Sir,

Recently we have received a part with white passivation. Already the we have received the same part with yellow passivation.

We are not facing any issues with yellow passivation. But we have faced some contact problems with white passivation.

Can you please tell me whether there will be any difference of electrical conductivity of white and yellow passivation ? Is there any detailed information on this subject ?

With best regards

Sasikumar
MTL Instruments Pvt Ltd - India
2005

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A couple of years ago this was an easy question: the thinner the chromate (i.e., the clearer), the better the conductivity. But since RoHS standards and other efforts to eliminate hexavalent chromate, that doesn't hold. To meet corrosion resistance requirements the trivalent chromates usually receive a topcoat which can interfere greatly with conductivity. Unfortunately your plater has to give you the full details and proprietary names of his chromates and sealers or it is impossible to hazard a guess as to their conductivity any more.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005