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:
Oct. 22, 2002
Filed:
May. 30, 2001
Seiji Ichikawa, Tokyo, JP;
Tatsuo Tokue, Tokyo, JP;
Nobuo Nagano, Tokyo, JP;
Fumie Ogihara, Tokyo, JP;
Taku Sato, Tokyo, JP;
NEC Corporation, , JP;
Abstract
A method of producing a semiconductor device of the present invention is applicable to a multilayer wafer for leadless chip carrier packages and breaks it on a package basis. The method begins with a step of forming a generally V-shaped groove in one major surfaces of the wafer in the direction of thickness of the wafer. A weak, cleaving portion is formed in the other major surface of the wafer in alignment with the groove. A cleaving force is exerted on the wafer to thereby form a break in the cleaving portion, so that the wafer is caused to break from the groove toward the cleaving portion in the direction of thickness of the wafer. The cleaving portion may be replaced with a strong, non-cleaving portion, in which case the break is formed in the interface between the non-cleaving portion and the wafer due to a difference in cleaving force.