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:
Jul. 06, 1999
Filed:
Jan. 31, 1997
Atsushi Yamaguchi, Moriguchi, JP;
Tetsuo Fukushima, Katano, JP;
Abstract
The present invention relates to a soldering alloy composed mainly of Sn and free from lead which is a toxic substance. An addition of a small quantity of Ag to the soldering alloy can fine the alloy structure, minimize structural changes of the alloy and increase thermal fatigue resistance thereof. An addition of a small quantity of Bi to the soldering alloy lowers the melting point and improves the wettability thereof. Further, an addition of a small quantity of Cu restrains the growth of intermetallic compounds in the bonding interface between a copper land and the solder. Furthermore, an addition of a small quantity of In improves the elongation property and thermal fatigue resistance of the alloy.