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:
Sep. 25, 2001
Filed:
Feb. 07, 2000
Shigeo Sasaki, Chigasaki, JP;
Shinya Takyu, Saitama-ken, JP;
Keisuke Tokubuchi, Yokohama, JP;
Koichi Yazima, Chigasaki, JP;
Hideo Nakayoshi, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
Grooves are formed in a surface of a wafer, on which semiconductor elements are formed, along dicing lines or chip parting lines on the wafer. The grooves are deeper than the thickness of a finished chip, and each of them has a curved bottom surface. A holding sheet is attached on the surface of the wafer on which the semiconductor elements are formed. Subsequently, the rear surface of the wafer is lapped and polished to the thickness of the finished chip, thereby dividing the wafer into chips. Even after the wafer is divided into the chips, the lapping and polishing is continued until the thickness of the wafer becomes equal to the thickness of the finished chip. The lapping and polishing amount required to attain the thickness of the finished chip after the lapped face of the wafer reaches the bottom surface of the groove, and a depth of a region of the curved bottom surface of the groove define a ratio of not less than 0.3.