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:
May. 31, 2011
Filed:
Jan. 20, 2009
Tomohiro Uno, Tokyo, JP;
Keiichi Kimura, Tokyo, JP;
Takashi Yamada, Iruma, JP;
Nippon Steel Materials Co., Ltd., Tokyo, JP;
Nippon Micrometal Corporation, Iruma, JP;
Abstract
A high-performance bonding wire that is suitable for semiconductor mounting technology, such as stacked chip bonding, thinning, and fine pitch mounting, where wire lean (leaning) at an upright position of a ball and spring failure can be suppressed and loop linearity and loop height stability are excellent. This bonding wire for a semiconductor device includes a core material made of a conductive metal, and a skin layer formed on the core material and containing a metal different from the core material as a main component; wherein a relationship between an average size (a) of crystal grains in the skin layer on a wire surface along a wire circumferential direction and an average size (b) of crystal grains in the core material on a normal cross section, the normal cross section being a cross section normal to a wire axis, satisfies an inequality of a/b≦0.7.