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:
Aug. 22, 1989
Filed:
Oct. 17, 1988
Tsutomu Ogawa, Machida, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A vacuum chuck apparatus operable in both gas and liquid includes a liquid-gas separating membrane which allows passage of gas molecules but prevents passage of liquid. The liquid-gas separating membrane is disposed between an inlet hole of the chuck and a manifold which is connected to a pneumatic system. The pneumatic system includes an aspirator, a compressor and a switching valve. The vacuum chuck is immersed into a liquid, compressed gas purges the liquid in the inlet hole, then the switching valve is switched to the aspirator. An object, such as a semiconductor wafer, is vacuumed quickly to the chuck, and the inlet hole is closed by the object. If a small quantity of liquid intrudes into the chuck, it is stopped by the liquid-gas separating membrane.