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:
Dec. 23, 1997
Filed:
Jul. 29, 1996
Fumihiko Hasegawa, Nishishirakawa-gun, JP;
Makoto Kobayashi, Nishishirakawa-gun, JP;
Tameyoshi Hirano, Hiroshima, JP;
Shin-Etsu Handotai Co., Ltd., Tokyo, JP;
Abstract
The invention features flattening a sliced wafer in a thin disc-like form, and chamfered if necessary, through simultaneous double side grinding by passing the wafer through between paired cylindrical grinding rolls supported at both ends in bearings, and subsequently single side polishing or double side polishing the flattened wafer to obtain a polished wafer. A lapping step and an etching step in the related art thus can be dispensed with to curtail the process time. The grinding is done by simultaneous double side grinding, so that it is free from slice mark transfer due to vacuum suction of wafer to hold the wafer, or unlike a wax mounting system it does not involve complicated operation. Furthermore, instead of batch grinding, continuous grinding can be readily made. The process is thus free from working stock removal fluctuations and permits high flatness and stable thickness to be obtained by the grinding.