The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 01, 2020
Filed:
Apr. 11, 2018
Screen Holdings Co., Ltd., Kyoto, JP;
Taiki Hinode, Kyoto, JP;
Abstract
When a silicon concentration of a phosphoric acid aqueous solution inside a tank reaches an upper limit value of a specified concentration range, the phosphoric acid aqueous solution is drawn off from the tank and/or an amount of the phosphoric acid aqueous solution returning to the tank is decreased to decrease a liquid amount inside the tank to a value not more than a lower limit value of a specified liquid amount range. When the liquid amount inside the tank decreases to the value not more than the lower limit value of the specified liquid amount range, the phosphoric acid aqueous solution is replenished to the tank to increase the liquid amount inside the tank to a value within the specified liquid amount range and decrease the silicon concentration of the phosphoric acid aqueous solution inside the tank to a value within the specified concentration range.