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Selective stripping of electroless copper

2003

I am trying to metallize alumina substrate using electroless Copper and I etch the Electroless copper in selective area and Electroplate (acid bath) rest of the pattern with copper. The problem is I am not able to completely remove the seeding (Pd/Tin), it starts to grow (Spread) when it gets to Cu plating. I have tried using different etchants and it has not been successful. This doesn't happen in all area, but only in few area where the pattern is quite close to each other.

How do I completely remove the seeding? How can I stop spreading during Cu plating. Your help will be appreciated.

Karthik Thambidurai
electronic components - Norwood, Massachusetts

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Try a weak HBF4 dip to undercut the chloride.

James Totter, CEF
- Tallahassee, Florida
2003

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James,

Thanks for your input. I tried HBF4, it doesn't help. After stripping I see a thin layer of loosely held smut on the surface and HBF4 doesn't do any help to remove this smut. But physically this smut can be removed by wiping or with pressure spray. Also the physical method is not much effective, sometimes it fails to remove the smut and this smut serves as a seeding during copper plating. I am trying a chemical means that could get rid of it in one single stripping process. Your help will be appreciated.

Karthik Thambidurai
electronic components - Norwood, Massachusetts
2003

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Hmm...

Rinse your material in potassium dichromate added with boric acid before the next plating...

monggoluton
- malaysia
November 18, 2009