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:
May. 21, 2002
Filed:
Oct. 04, 2001
Senju Metal Industry Co., Ltd., Tokyo, JP;
Abstract
A solder paste comprises a lead-free solder alloy powder and a flux and is suitable for use in reflow soldering of electronic parts at a soldering temperature of 230° C. or below with minimized damage to the electronic parts to form soldered joints of good bond strength. The solder alloy powder is a mixture of from 10 to 30 vol % of a first powder of an Sn—Bi alloy consisting essentially of 10-45 wt % of Bi and a balance of Sn and from 70 to 90 vol % of a second powder of an Sn—Zn alloy consisting essentially of 9-15 wt % of Zn and a balance of Sn. The mixture gives an alloy having a composition upon melting which consists essentially of 7-11 wt % of Zn, 1-5 wt % of Bi, and a balance of Sn.