Dissolution of metals utilizing tungsten-diol combinations
CA 1236384 A · Owner: Plastic Specialties And Technologies, Inc. · Inventors: Elias, Moenes L.; Burger, Walter L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Improved metal dissolution rates are obtained when using a solution containing sulfuric acid, hydrogen peroxide and combinations of catalytic amounts of tungsten and of certain diols. The present invention relates to the dissolution of metals in an aqueous bath containing sulfuric acid and hydrogen peroxide, and in particular to a novel bath composition capable of effecting the dissolution at high rates. In one specific aspect the invention is concerned with etching of copper in the production of printed circuit boards.
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted May 10, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 10, 2005.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.