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Au plating on Kovar and Mo carrier

2007

Dear Sir,
I am a R&D engneer and trying to figure out some problems in plated materials. I sometimes find Au film peeling problems in Kovar and Mo carriers after 380C alloy. The vendors used to implement Ni electroless plating on Kovar and Mo carriers before Au electrolytic plating. However, I wonder if there are surface clean issues on Kovar and Mo carriers or thermo-expansion issues resulting from lattice mistaching effects. Please help to suggest the surface clean methods and Au plating solutions for Kovar and Mo carriers. Thank you very much.

Best regards,

Wu

Chang-Luen Wu
product designer - Tainan County, Taiwan, R.O.C.

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First of two simultaneous responses --

I think reading responses to letter #28980 may help you.

Mark Baker
Process Engineer - Syracuse, New York
2007

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Second of two simultaneous responses --

Surely you want a nickel barrier betwen the Kovar and gold. The Kovar (becasue it has been heated and possesses a tenacious oxide) should be activated in strong Hydrochloric Acid followed without rinsing into a Nickel Chloride Strike (2 pounds per gallon nickel chloride, two quarts per gallon Hydrochloric acid, 100 amps per square foot. Then follow that with about 0.0003 inch of regular plated nickel, rinse, do not stop to look, gold strike, gold plate.

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina

2007