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:
Nov. 30, 1999
Filed:
Mar. 09, 1998
Applicant:
Inventors:
Hiroshi Oishi, Annaka, JP;
Keiichiro Asakawa, Annaka, JP;
Assignee:
Primary Examiner:
Int. Cl.
CPC ...
B28B / ;
U.S. Cl.
CPC ...
451 41 ; 451 44 ; 451 54 ; 451 69 ; 451 70 ; 125 1302 ;
Abstract
A shallow notch 1 as a tentative mark is engraved on a periphery of an ingot at a position corresponding to a predetermined crystal orientation in the step of grinding the periphery of the ingot. After the ingot is sliced to wafers, a mark 2 for indication of a crystal orientation is carved on a sliced wafer at a position determined on the basis of the notch 1 by laser marking. Thereafter, the wafer is chamfered to a round shape, and the notch 1 is removed by the chamfering. Since a part where the mark 2 shall be carved is determined on the basis of the notch 1, the mark 2 is efficiently carved on the wafer without the necessity of subjecting each wafer to an X-ray analyzer.