Fabrication of Lead Free Micro Solder Powder by Melts Dispersion Technique
A new process, melts dispersion technique, was developed to fabricate the solder powder in oil surroundings by forming molten metal’s droplets. The main parameters of the technique on shape and size of powders were investigated in the present paper. It is shown that a cooling rate of the melts and viscosity of oil for isolation of droplets affect the shape and the size. The cooling rate is a very important parameter, and there is a critical cooling rate at given conditions. Although the melts were dispersed perfectly in oil, fine droplets were merged and coalesced during solidification without rapid cooling. The shape of powder has an influence mainly on oil viscosity and was altered into a sphere from an irregular shape with increasing oil viscosity.
Hyung Sun Kim, Yu Bao Li and Soo Wohn Lee
J. I. Youn et al., "Fabrication of Lead Free Micro Solder Powder by Melts Dispersion Technique", Materials Science Forum, Vols. 510-511, pp. 570-573, 2006