Miyazaki Prefecture

Senju Metal Industry Co., Ltd.

Kenji Yamamoto

Masataka Shimizu

Hoshiro Takahashi

Kiyoshi Torigoe

Mitsuhiro Mizozoe

Shingo Hamayama

Tomohide Suzuki

Motohiro Murase

Provided is a method suitable for industrial-scale production of a dispersion in which nano-sized particles are dispersed. Specifically, a method for producing a nanoparticle-in-oil dispersion in which fine particles made up of a solid component, an aqueous liquid component or a mixture thereof are dispersed in an oil phase, includes: (1) a step of preparing a W/O emulsion-type precursor in which an aqueous phase in the form of droplets of an aqueous solution having a water-soluble substance dissolved therein is dispersed in an oil phase; and (2) a step of boiling the aqueous phase of the W/O emulsion-type precursor, to obtain a nanoparticle-in-oil dispersion in which the fine particles are dispersed in the oil phase.

Method of producing nanoparticle-in-oil dispersion

In a solder paste which is a mixture of a flux and low melting point metal particles, low melting point metal fine particles manufactured by a conventional method or apparatus therefor include particles having widely varying particle diameters. Accordingly, the solder paste could not completely fill the minute holes in a mask for application to minute solder portions by printing, or mask removability was poor. According to the present invention, a mixture of a heat resistant continuous phase liquid and coarse metal particles in molten state is passed through a porous membrane to form the coarse low melting point metal particles into fine particles with a predetermined diameter. An apparatus according to the present invention comprise a porous membrane between a heating and dispersing mechanism and a cooling mechanism, and a pressure vessel connected to the heating and dispersing mechanism for applying a high pressure to the heating and dispersing mechanism.

Method and apparatus for manufacturing low melting point metal fine particles

Growing community of inventors

Miyazaki, Japan

Kenji Yamamoto