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:
Jun. 09, 1998
Filed:
Jul. 17, 1995
Sungho Jin, Millington, NJ (US);
Mark Thomas McCormack, Summit, NJ (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
A high-strength Pb-free solder alloy, based on the Sn--Ag--Zn system, is disclosed. The Pb-free solder alloy contains, in weight percent, 0.2-0.6% Zn, 1-6% Ag, one or both 0.2-0.6% In and 0.2-0.6% Bi, and the balance Sn. The addition of Zn significantly improves the mechanical strength and creep resistance of e.g., Sn--3.5% Ag eutectic solder while maintaining substantially the same level of ductility. The increase in strength is as much as 48% over that of the Sn--3.5% Ag alloy. This strengthening from the Zn additions is attributed to a uniform solidification structure and a substantial refinement of the precipitates in the alloy. Essentially all of the added Zn resides in the more corrosion-resistant, Ag-based, intermetallic precipitates, leaving the Sn-rich matrix primarily free of Zn in solid solution.