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. 26, 1988
Filed:
Oct. 16, 1987
Masayuki Ochiai, Kawasaki, JP;
Fujitsu Limited, Kanagawa, JP;
Abstract
A soldering method using a solder paste composed of solder alloy powder and soldering flux comprising rosin, thixotropic agent, activator, organic solvent and azobis compound such as 1,1'-azobis (cyclohexane-1-carbonitrile) as a free radical generator. The 1,1'-azobis (cyclohexane-1-carbonitrile) generates free radicals of cychlohexane-1-carbonitrile when heated in soldering, and the generated free radicals urge the activator to liberate hydrogen halide which enhances a removing effect of oxide film over a metal surface to be soldered. The azobis compound contributes to diminish the amount of activator and, consequently, hydrogen halide in the flux. The viscosity of the solder paste does not vary for a long time, which results in allowing the solder paste have a long shelf life. Since generation of the free radical is not decreased even though a soldering temperature decreased, which results in increasing solderability for low temperature soldering.