Process for desmearing and etching of plastics layers in holes drilled in basic material of printed circuit boards
CA 1267826 C · Owner: Grapentin, Hans-Joachim · Inventors: Schaar, Detlef; Grapentin, Hans-Joachim
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a process for the reliable desmearing and etching as well as crack-free roughening of plastic layers in holes drilled in basic material of printed circuit boards for highly adhesive metal-coating of the same with the use of sulfuric-acid solutions characterized in that the holes are treated with a solution containing sulfuric acid and nitrate anions the process, being suitable for manufacturing printed circuit boards and/or through-plated circuit boards.
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 April 17, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 17, 2007.
- 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.