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. 15, 1994
Filed:
Jul. 12, 1991
Katsuyuki Toyofuku, Tokyo, JP;
Ichiro Nagamatsu, Tokyo, JP;
Shinji Shirakawa, Tokyo, JP;
Hiroto Iga, Tokyo, JP;
Takeshi Kujiraoka, Tokyo, JP;
Kensei Murakami, Tokyo, JP;
Tanaka Denshi Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A clad bonding wire for electrically connecting the bonding pad of a semiconductor device to an external lead comprises a core wire formed on one of high-purity Pd or a Pd alloy, high-purity Au or a Au alloy, high-purity Pt or a Pt alloy, and high-purity Ag or a Ag alloy, and a cladding cladding the core wire and formed of another one of the foregoing materials other than that forming the core wire. The wire-to-cladding diameter ratio D.sub.2 /D.sub.1 is in the range of 15% to 60% or 85% to 99. When the tip of the clad bonding wire is heated to form a ball, part of the core wire and part of the cladding in a neck formed behind the ball diffuse into each other to form an alloy of the materials forming the core wire and the cladding between the core wire and the cladding to enhance the mechanical strength of the neck beyond that of other portion of the clad bonding wire.