Ac etching of aluminum capacitor foil
CA 1213560 A · Owner: Sprague Electric Company · Inventors: Mcpherson, Allan B.; Nguyen, Trung H.; Randall, John J. Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure In the AC etching of aluminum foil in a hydrochloric acid electrolyte containing at least one additive the presence of 200 to 500 ppm sulfate permits etching thicker foil for higher voltage use than is possible without the sulfate. The additive is chosen from phosphoric nitric, and tartaric acids or salts. The presence of the relatively small amount of sulfate yields a foil with higher capacitance and generally allows lower temperatures and frequencies to be used during the etching process.
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 November 4, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 4, 2003.
- 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.