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. 02, 2001
Filed:
Jun. 28, 2000
Applicant:
Inventor:
Tetsuro Nishimura, Suita, JP;
Assignee:
Nihon Superior Sha Co., Ltd., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C22C 1/300 ; B23K 3/526 ; H05K 3/34 ;
U.S. Cl.
CPC ...
C22C 1/300 ; B23K 3/526 ; H05K 3/34 ;
Abstract
A lead-free solder characterized as comprising 0.1 to 2 wt % of Cu, 0.002 to 1 wt % of Ni with the residue being Sn. The solder preferably contains Cu in an amount of 0.3 to 0.7 wt %, and more preferably it contains Cu in an amount of 0.3 to 0.7 wt % and Ni in an amount of 0.04 to 0.1 wt %. The solder can be prepared by adding Ni to a molten mother alloy of Sn—Cu, or by adding Cu to a molten mother alloy of Sn—Ni. A lead-free solder which further comprises 0.001 to 1 wt % of Ga is also disclosed. The lead-free solder can form a solder joint having a high strength and stability comparable to those of a conventional Sn—Pb eutectic solder.