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Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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Activation of tungsten (W) for non-cyanide Copper or Acid copper plating?
Q. Greetings,
My name is Rocco Basilica, process engineer for ODIS, Inc. I would like to plate approx. 1 micron copper onto some refractory metal (tungsten) features (smallest feature about 3 microns) for heat sinking purposes . I would be using standard microelectronic photoresists to mask the features. I would like to use non-cyanide copper plating solution. I understand I need to activate the tungsten before plating. I have some experience in pulse plating Au onto micro features on Au. Does anyone have any experience/suggestions that might help me.
Thank you
process engineer - Storrs, Connecticut, USA
November 30, 2009
A. Hi, Rocco. It is very difficult to plate onto refractory metals because they quickly form very stable oxides on their surfaces. ASM Metals Handbook, Vol. 5, Surface Engineering has a whole chapter on the prep cycles for tungsten and refractory metals. It is possible that you'll need multiple layers of plating such as, for example, starting with a nickel strike. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
December 3, 2009
A. When electroplating looks difficult one could look for PVD. Copper coating is easy with cathodic arc as well as sputtering. Masking material and technique may need some attention.
H.R. Prabhakara - ConsultantBangalore Plasmatek - Bangalore Karnataka India
December 4, 2009
Q. Hi all,
we need to electroplate tungsten part with a deposition of copper.
We already have acid copper plating bath, in order to do copper electroforming deposition on mechanical parts of copper.
What do we need in order to do a deposition of copper on parts of tungsten?
Regards
Alfredo
- GUIDONIA MONTECELIO - ROME - ITALY
June 14, 2016
August 31, 2021
A. You have to activate Tungsten in Potassium ferric cyanide solution. The solution should be at 55 °C.
After this you have to Dip in Potassium Hydroxide solution 10%
After that you have to Dip in 10% HCl
Rinse in water
You can plate copper now or nickel.
For silver you have to plate copper first and then silver.
For more details please refer ASM handbook Surface finishing.
CTO - Vapi Gujarat, India
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