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:
Feb. 13, 2001
Filed:
Mar. 15, 1999
Hiroshi Tanaka, Kurume, JP;
Yasuhiro Chouno, Tosu, JP;
Takashi Terada, Kumamoto, JP;
Satoshi Nakashima, Tamana-gun, JP;
Tokyo Electron Limited, Tokyo, JP;
Abstract
In a pneumatically driven liquid supply apparatus comprising a circulation pump,or constant-volume pump,for supplying a washing liquid or chemical to a washing tank,for semiconductor wafers used during the fabrication of semiconductor devices; an electromagnetic switching valve,and a pressure regulator,that configure an air-pressure adjustment means,are connected to an air source,; and air supply pipelines,, and,are each connected to the air-pressure adjustment means,, the circulation pump,and the constant-volume pump,. A leakage sensor,is interposed within each of the air supply pipelines,, and,between the air-pressure adjustment means,and the circulation pump,or constant-volume pump,, so that any liquid that flows backward through the circulation pump,or the constant-volume pump,and into the air supply pipeline,, or,is detected by the leakage sensor,. This makes it possible to prevent damage or halting of the functions of the air-pressure adjustment means due to liquid flowing into the air supply pipelines via one of the pumps.