Nanolead-free solder alloys for electronic packaging and integration

Synthesis of metal nanoparticles with specific properties is a newly established research area attracting a great deal of attention. Several methods have been put forward for synthesis of these materials, namely chemical vapor condensation, arc discharge, hydrogen plasma-etal reaction, and laser pyrolysis in the vapor phase, microemulsion hydrothermal, sol-gel, sonochemical. Nanoscale lead-free soldrs (i.e., Sn-xAg [x 0 0, 20, 40, 60, 0, 100(wt%)], Sn-3.0Ag-0.5Cu, Sn-3.5Ag-0.5Cu, Sn-3.5Ag-xZn (x = 0.5 to 3.5wt%) and Sn-0.7Cu) have been investigated. For Sn-3.5Ag and Sn-3.5Ag-0.5Cu nanoparticles, the melting temperature with average size of 30nm was 210 degr. C. and 201 degr. C., much lower than that of bulk alloy. Also, Sn-Ag-Cu nanopowders showed good wttability with contact angles less than 30 degr. The peak melting temperatures of the 21nm, 18nm and 14nm Sn-0.7Cu nanoparticles were 212.9 degr. C, 207.9 degr. C and 205.2 degr. C, respectively. In this paper, the fundamentals of synthesis of nanolead-free solder materials including their characterization and their use in microelectronic packaging are reviewed.     «

Synthesis of metal nanoparticles with specific properties is a newly established research area attracting a great deal of attention. Several methods have been put forward for synthesis of these materials, namely chemical vapor condensation, arc discharge, hydrogen plasma-etal reaction, and laser pyrolysis in the vapor phase, microemulsion hydrothermal, sol-gel, sonochemical. Nanoscale lead-free soldrs (i.e., Sn-xAg [x 0 0, 20, 40, 60, 0, 100(wt%)], Sn-3.0Ag-0.5Cu, Sn-3.5Ag-0.5Cu, Sn-3.5Ag-xZn (x...     »