Positive resist composition
CA 2135250 A1 · Owner: Osaki, Haruyoshi · Inventors: Uetani, Yasunori; Hashimoto, Kazuhiko; Osaki, Haruyoshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides a positive photoresist composition comprising a 1,2-naphthoquinonediazide compound and a novolac resin obtained through a condensation reaction between an aldehyde compound and a phenol compound represented by the following general formula (I):, (I), wherein R5, R6 and R7 each independently represents hydrogen atom, hydroxyl group or alkyl cycloalkyl, alkoxy or alkenyl group having 6 or less carbon atoms or aryl group, provided that at least one of R5 R6 and R7, represents a cycloalkyl group having 6 or less carbon atoms. The composition of the present invention is excellent in the balance between properties such as sensitivity, resolution, heat resistance …
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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 November 7, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 7, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 7, 2016.
- 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.