In this work, varying weight percentages of Ni-coated CNTs (Ni-CNTs) were incorporated into the Sn-Ag-Cu matrix to develop composite solders. The samples were extruded and characterized in terms of their thermal, wettability, microstructural, tensile and nano-mechanical properties. Our characterization results established that the composite technology coupled with nanotechnology in electronic solders can lead to 8% improvement in mechanical performance (in terms of 0.2% yield strength), 12% increase in the ultimate tensile strength and better creep behavior. With the addition of Ni-CNTs, there is no compromise on the melting point of the solder alloy and in fact a better wettability of the nanocomposite solders was observed. Thus, such a Ni-coated CNT filler in Sn-Ag-Cu solder provides a promising interconnect materials for microelectronics assembly and packaging industry.