Positive resist composition
CA 2067041 A1 · Owner: Doi, Yasunori · Inventors: Osaki, Haruyoshi; Hanawa, Ryotaro; Uetani, Yasunori
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A positive resist composition containing in, admixture, an alkali-soluble resin a quinone diazide com-, pound and a mixed solvent of ethyl lactate and at least one solvent selected from the group consisting of (a) n-amyl acetate and (b) 2-heptanone in a weight ratio of 5:95 to 80:20, which composition has a good coating properties and provides an improved profile and a large depth of focus.
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
- Filed April 24, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 24, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 24, 2014.
- 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.