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Thread 20/25

Inhibiting copper corrosion and tarnish

I have oxidation on my finish copper product surface (leadframe), my process are : etching-rinsing-stripping of photoresist by sodium hydroxide-rinsing-neutralizer by sulfuric acid-rinsing-antitarnish-DI rinsing-air blow-dry. The oxidation are 1)red dot 2)dark brown dot 3)black dot and this affect my production yield badly,any suggestion? Any help would be appreciated

Ken Chia
- Singapore
1998
publicly reply to Ken Chia

It sounds like you don't have a corrosion inhibitor that is specifically used for copper in the acids and rinses after the acids. Sherwin Williams makes one called Cobratec. The chemical name is tolytriazole. Just a little in the acid and rinses should help.

Good Luck,

Craig Burkart
- Naperville, Illinois
1998
publicly reply to Craig Burkart

The COBRATEC line of corrosion inhibitors, primarily for copper, its alloys and silver, is now part of the PMC Specialties Group, Inc.

Bruce Fredrickson
- Berlin, New Jersey
2001
publicly reply to Bruce Fredrickson

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