Method of forming a multilayer printed circuit board and product thereof
CA 2090099 C · Owner: Tran, William Luong-Gia · Inventors: Tran, William Luong-Gia; Rath, James; Flynn, Kathy M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a process for fabricating a multilayer printed circuit board with permanent innerlayers of photoresist the photo-, imageable composition used to form the hard permanent layer comprises a polymerizable acrylate monomer; an oligomer formed by the reaction of an epoxy resin and an acrylic or methacrylic acid; a photosensitive, free radical generating initiator for polymerization of the acrylic monomer and oligomer; a curable epoxy resin; a curing agent for the epoxy resin; and optionally, a crosslinking agent reactive with hydroxyl groups. After exposure and development of a layer of the photoimageable composition and etching of the underlying metal layer on a board the resultant …
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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
- Filed February 22, 1993 and granted January 14, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 22, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 22, 2015.
- 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.