Properties of the SAC solder paste with different nanoparticles

Our research objective is trying to modify the SAC solder paste properties by addition a different nanoparticles. It is continuation of our previous work on including to the SAC solder paste the silver nanoparticles with different grain sizes. Improvement of the wetting results of investigated "nano solder pastes" on copper substrate depends especially for the 4% silver nanopowders. It forced us to enlarge our work on nickel and copper nanoparticles. The SAC "nanopastes" were obtained by adding from 0.05 to 4% of Ni, Cu and Ag nanoparticles. The results were compared with previously obtained for SAC with silver nanoparticles. We measured spreading, wettability, solder ball and slump of the "nanopastes". We obtained contrary results of wettability for nNi and nCu addition than for the silver nanoparticles addition. Wetting of the SAC solder paste with nNi and nCu decreases with increasing of the nanoparticles addition. Using SEM and EDS spectroscopy we measure the "nanosolder" pastes microstructure for establishing the differences between type of nanoparticles and their amount added to SAC solder paste. The microstructure of the cross-sectional solder joints as well as creates the IMC scallop or rod layers with different thickness after reflow process will be presented.