Overpressure-protected, polysilicon, capacitive differential pressure sensor and method of making the same
CA 2095783 A1 · Owner: Fung, Clifford D. · Inventors: Fung, Clifford D.; Chau, Kevin H.-L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A capacitive differential pressure sensing device with pressure overrange protection and a method of making the same are described. The device employs a doped polysilicon diaphragm overlying a cavity in a doped single crystal silicon wafer having a port extending into the cavity from the opposite side. The cavity floor serves as an overrange protector.
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 May 7, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 7, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 7, 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.