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:
Apr. 16, 2002
Filed:
Feb. 19, 1999
Applicant:
Inventors:
Atsushi Yamaguchi, Moriquichi, JP;
Tetsuo Fukushima, Katano, JP;
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B23K 2/800 ; C22C 1/300 ;
U.S. Cl.
CPC ...
B23K 2/800 ; C22C 1/300 ;
Abstract
The present invention relates to a soldering alloy composed mainly of Sn and free from lead, a toxic substance. Adding a small quantity of Ag to the soldering alloy can make the alloy structure fine, minimize structural changes of the alloy and increase its thermal fatigue resistance. Adding a small quantity of Bi to the soldering alloy lowers the melting point and improves the alloy's wettability. Further, adding a small quantity of Cu restrains the growth of intermetallic compounds in the bonding interface between a copper land and the solder. Furthermore, addition of a small quantity of In improves the elongation property and thermal fatigue resistance of the alloy.