The electronics industry has been abruptly advanced in recent years. On interconnecting microelectronics components with circuit board, solder paste has been used for surface mounted devices to achieve the extreme fineness of the detail of the assemblage.
The more complex the surface mounting, the finer solder powder is needed for the paste. On the other hand the finer powder is more easily surface-oxidized. Because surface oxidation of powder prevent sound soldering, finer powder of specific particle size (40 micron under) is usually removed by classification. On considering productivity, it is necessary that solder powder should have particle size in the same range as possible on atomization.
In this parper, an investigation has been made of relationship between centrifugal atomization conditions of eutectic solder and its morphologies. The results are summarized below.
(1) As atomization disk revolution rate is lowered, particle size distribution becomes narrower.
(2) As atomization disk diameter is smaller, particle size distribution becomes narrower.
(3) Atomization disk is water-cooled and then particle size distribution becomes narrower.
