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:
Sep. 11, 2001
Filed:
Dec. 02, 1998
NEC Corporation, Tokyo, JP;
Abstract
The concentrations of predetermined components of a chemical solution,present in a cleaning bath,are measured by a measurement unit,. From the results are calculated the concentrations of various chemical species. From the concentrations calculated and an experimentally obtained rate equation is calculated the treating ability of the chemical solution,before supplementation of said components. Then, the treating abilities of chemical solution when the components and ultrapure water are supplemented, are calculated for various cases of amounts supplemented. From these cases is determined a case of amounts supplemented in which the treating ability of chemical solution is maintained at a required level and the amounts supplemented are minimized. Next, the components and ultrapure water are supplemented in respective determined amounts via feeding pumps,and