Method of manufacturing a capacitive humidity sensor
CA 2048904 C · Owner: Kallfass, Traugott · Inventors: Hegner, Frank; Kallfass, Traugott
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This method comprises the following steps which are com-, patible with thin-film technology: forming a bottom electrode (2) on an insulating substrate (1), depositing a humidity-sensitive polymer layer (5) of uniform thickness on the bottom electrode (2) leaving contact areas (3a, 3b) uncovered acti-, vating surface bonds of the polymer layer (5) apply-, ing a colloidal dispersion of SiO2 or Al2O3 particles (6) of uniform grain size as a thin layer to the polymer layer (5) and subsequently drying it depositing a, cover electrode (7) on the particles (6) still evenly distributed on the polymer layer (5) after the drying of the dispersion, and removing the particles (6) together with the …
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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 August 9, 1991 and granted September 13, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 9, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 9, 2013.
- 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.