Regeneration of copper etch bath
CA 1309324 C · Owner: Baldauf, Walter W. Jr. · Inventors: Baldauf, Walter W. Jr.; Petraitis, Kestutis F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
of the Invention, This invention relates to a copper etching process which involves contacting the copper with an aqueous etching solution comprising sulfuric acid and a peroxide to which is added less than about 0.2% of an organic additive useful as a crystallization control agent and selected from the group comprising a low molecular weight glycol and gum arabic. With this compound present copper sulfate crystals do not adhere to the tank and removal of the crystals from the bath is facilitated.
Read the whole patent
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 October 27, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 27, 2009.
- 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.