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. 20, 2018
Filed:
Oct. 10, 2014
Applicant:
Mitsubishi Electric Corporation, Tokyo, JP;
Inventors:
Assignee:
Mitsubishi Electric Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 23/48 (2006.01); H01L 21/02 (2006.01); B24D 3/00 (2006.01); H01L 21/301 (2006.01); B24B 1/00 (2006.01); H01L 21/304 (2006.01); H01L 21/306 (2006.01); H01L 21/683 (2006.01); H01L 21/66 (2006.01); B24B 27/00 (2006.01); B24B 49/12 (2006.01); B24B 7/22 (2006.01);
U.S. Cl.
CPC ...
H01L 21/304 (2013.01); B24B 7/228 (2013.01); B24B 27/0023 (2013.01); B24B 49/12 (2013.01); H01L 21/30604 (2013.01); H01L 21/6836 (2013.01); H01L 22/20 (2013.01); H01L 22/12 (2013.01); H01L 2221/6834 (2013.01); H01L 2221/68327 (2013.01);
Abstract
As a first grinding step, a peripheral portion of a back surface of a wafer () is ground with a first grindstone () to form a fractured layer () in the peripheral portion. Subsequently, as a second grinding step, a central portion of the back surface of the wafer () is ground with the first grindstone () to form a recess () while the peripheral portion in which the fractured layer () is formed is left as a rib (). Subsequently, as a third grinding step, a bottom surface of the recess () is ground with a second grindstone () of an abrasive grain size smaller than that of the first grindstone () to reduce a thickness of the wafer ().