METHOD AND APPARATUS FOR PRODUCING METALLIC SPHERICAL PARTICLE AND METALLIC SPHERICAL PARTICLE OBTAINED BY THE PRODUCTION METHOD AND APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a method for producing metallic spherical particles such as solder balls of high quality with high efficiency with the incidence of defective products remarkably reduced.;SOLUTION: Molten metal 3 is charged to a vessel 1 for molten metal where the group of small pores 2 having diameters at which the molten metal 3 does not flow off in a stationary state by its surface tension is formed at the lower part. The vessel 1 is vibrated to allow the molten metal 3 to fall from the small pores 2 into an inert gas atmosphere G drop by drop. In the process of the falling, the dropped body 3a is sphered by its surface tension. The sphered metallic particles 3b are further cooled and solidified in the process of the falling. The solidified metallic particles 3c are allowed to fall onto an inclined soft face material 4. The particles rolled down the slope 5 of the soft face material 4 are sorted to obtain uniform metallic spherical particles 3d having surface luster with high efficiency.;COPYRIGHT: (C)2002,JPO