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:
Feb. 24, 2015
Filed:
Mar. 09, 2004
Kunihito Takaura, Mouka-shi, Tochigi, JP;
Kaichi Tsuruta, Haga-gun, Tochigi, JP;
Hiroshi Kawanakago, Shimotsuga-gun, Tochigi, JP;
Hiroshi Takahashi, Utsunomiya-shi, Tochigi, JP;
Kunihito Takaura, Mouka-shi, Tochigi, JP;
Kaichi Tsuruta, Haga-gun, Tochigi, JP;
Hiroshi Kawanakago, Shimotsuga-gun, Tochigi, JP;
Hiroshi Takahashi, Utsunomiya-shi, Tochigi, JP;
Senju Metal Industry Co., Ltd., Tokyo, JP;
Abstract
A solder paste using a Sn—Ag base, Sn—Cu base, or similar alloy powder has a high melting point, so it causes thermal damage to electronic devices. Sn—Ag—In base lead-free solder alloys having a low melting temperature have been studied, but they are difficult to use because they cause much occurrence of chips standing up during reflow. The present invention forms a solder paste by separating a Sn—Ag—In base lead-free solder into first and second solder alloy powders for which the difference in their peak temperatures measured by differential thermal analysis is at least 10° C. and blends the mixed powders with a flux.