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:
Mar. 31, 1992
Filed:
Jun. 21, 1990
Makoto Kitano, Ibaraki, JP;
Chikako Kitabayashi, Ibaraki, JP;
Asao Nishimura, Ushiku, JP;
Hideo Miura, Ibaraki, JP;
Akihiro Yaguchi, Ibaraki, JP;
Sueo Kawai, Ibaraki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a plastic encapsulated semiconductor device, a part of wire piece may break down due to thermal fatigue, which positioned adjacent to a bonding portion of the wire piece connected to a chip. This is caused by that wire piece moves relative to plastic encapsulating the chip and the wire piece, and a strain in the wire piece due to thermal deformation of the device concentrates on one portion of the wire piece. Accordingly, a rugged portion is formed on a surface of a part of wire piece subjected to a breakdown to thermal fatigue. The plastic bites recesses of the rugged portion to prevent the wire piece from moving relative to the plastic, thereby preventing the wire piece from breaking down due to thermal fatigue.