Using Nanoparticles and Carbon Nanotubes to Enhance the Properties of a Lead-free Solder

In the present study, using the powder metallurgy route, varying amount of nano-sized Y2O3 particulates and Nicoated carbon nanotubes (Ni-CNTs) were intentionally incorporated into the Sn-3.5Ag-0.7Cu solder to develop two nanocomposite solder systems. The samples were extruded and characterized in terms of their wettability, thermal, microstructural and tensile properties. Characterization results established that composite technology coupled with nanotechnology in electronic solders can lead to improvement in mechanical performance (in terms of better 0.2% yield strength (up to 13% increase) and better ultimate tensile strength (up to 17% increase). With the addition of reinforcements, better wettability of the nanocomposite solders was also observed and with no compromise on the melting temperature. These advanced interconnect materials will hence benefit the microelectronics packaging and assembly industry. An attempt is also made in this study to correlate the properties of the resultant nanocomposite solders with the increasing presence of reinforcements.