Hybrid solder joints: the effect of nanosized ZrO particles on morphology of as-reflowed and thermally aged Sn-3.5Ag solder joints.

The main number of current researches has been focused on the microstructure and mechanical properties of the Sn-based Sn-Ag-Cu-based solders, while various kinds of nanosized particles have been added. The synthesis and handling of ceramic nanosized powder are much easier than of metal nanoparticles. In addition, metal nanoparticles solved in solder joints during the soldering process or by thermal aging could behave as an alloying element similar to bulk metal additions, while ceramic nanoparticles retain their chemically inactive behavior in various thermal, thermo-mechanical, and electrical constraints.