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:
Jan. 28, 1992
Filed:
Oct. 23, 1989
Asaaki Yamashita, Kitakatsushika, JP;
Kiyoto Mori, Kasukabe, JP;
Tsugio Saito, Fujisawa, JP;
Shiro Shimauchi, Tokyo, JP;
Kanto Kagaku Kabushiki Kaisha, Tokyo, JP;
Abstract
The present invention relates to a process for recovering and reusing a resist composition which comprises the steps of (a) collecting resin composition scattered from a spinner during application of the resist composition onto silicon wafers and otherwise no longer used and to be disposed of as waste liquid; (b) introducing the resist composition into a recovery tank; (c) introducing, while measuring the viscosity of the resist composition in the recovery tank, a solvent into the recovery tank in accordance with the measured viscosity until the resist composition shows a predetermined viscosity; (d) discontinuing the solvent supply when the viscosity of the resist composition has reached a predetermined value; (e) transferring the resist composition with the predetermined viscosity to a storage tank; and (f) taking out, whenever necessary, the resist composition from the storage tank for reuse.