Senju Metal Industry Co., Ltd.

Miyazaki Prefecture

Hoshiro Takahashi

Masahiro Watanabe

Ryoichi Kurata

Masataka Shimizu

Kiyoshi Torigoe

Kenji Yamamoto

Mitsuhiro Mizozoe

Tomohide Suzuki

Motohiro Murase

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

Minute copper balls having a high sphericity which are suitable for use as the cores of copper core solder balls are manufactured by heating small pieces comprising an alloy of 0.5-40 wt % of Zn and a remainder of Cu to at least the melting point of Cu without the pieces contacting each other to give them a spherical shape and cooling the resulting spheres to form solid balls. The minute copper balls which are obtained comprises 0.01-0.5 wt % of Zn and a remainder of Cu and have a spherical shape with a diameter in the range of 50-1000 &mgr;m.

Minute copper balls and a method for their manufacture

An automatic soldering apparatus includes a conveyor for conveying a printed circuit board along a predetermined path, a heater located below the conveyor and adapted to heat the lower surface of the printed circuit board on which leads of chips and other electronic parts are to be electrically connected to circuits as printed, a flux applicator located downstream of the heater and arranged to apply a molten flux to the surface of the printed circuit board, and a supply of solder located downstream of the flux applicator and arranged to solder the leads to the circuits. The flux applicator includes a supply of flux for feeding flux in solid form at room temperature, a heater for heating the flux to a temperature above its melting point to provide a molten flux, and a spray nozzle for spraying the molten flux to the surface of the substrate. A supply of hot air is operatively associated with the spray nozzle and adapted to supply hot air under pressure to the spray nozzle, whereby a mist of the molten flux is sprayed onto the surface of the printed circuit board.

Soldering apparatus and method

Growing community of inventors

Mouka, Japan

Hoshiro Takahashi