Method for removing boron from metallurgical grade silicon and apparatus
CA 2227693 C · Owner: Saito, Kenji · Inventors: Nakamura, Naomichi; Yuge, Noriyoshi; Aratani, Fukuo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Method and apparatus for refining metallurgical grade silicon to carry out deboronization rapidly in production of silicon for solar cells, by blowing a mixed gas of water vapor and inert gas on a surface of molten silicon, and wherein a reducing gas is further applied to the molten metal surface, and including the further step of controlling mix ratios of water vapor and reducing gas, the angle of blowing of the gas, and the deboronization parameters.
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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 January 22, 1998 and granted July 10, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 22, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 22, 2020.
- 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.