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:
Apr. 20, 2004
Filed:
Dec. 13, 2001
Ebara Corporation, Tokyo, JP;
Abstract
An abrasive liquid feed apparatus comprises a supply tank for storing an abrasive liquid having a predetermined concentration, an abrasive liquid pipe for transferring the abrasive liquid from the tank to a polishing means and an additive feed means which feeds an additive having a predetermined concentration to the tank. It further comprises an additive concentration measurement means which measures a concentration of the additive in the abrasive liquid in the supply tank, a measurement means which measures an amount of the abrasive liquid in the tank and a control which calculates an amount of the additive to be supplemented to the tank, based on the concentration of the additive measured by the additive concentration measurement means and the amount of the abrasive liquid measured by the metering means. To maintain the concentration of aqueous hydrogen peroxide in the abrasive liquid.