Enhanced Self-Propagating Exothermic Reaction Bonding with Nanostructured Cu/Sn Interlayer

Self-propagating exothermic reaction (SPER) binding is becoming increasingly attractive for electronics packaging, as it enables the bonding of metals or alloys while maintaining the surrounding components at ambient temperature. However, the challenges of high porosity and solder bleeding hinder its broader application. In the present work, a nanostructured Cu/Sn interlayer was utilized for SPER bonding to mitigate the above-stated problems, acting as an intermediary for Cu-Cu SPER bonding through initiation and combustion of Al/Ni nanofoils. For comparison, Sn layer of the same thickness was also prepared for SPER bonding under the same conditions. Both bonded structures were examined in terms of their microstructures and mechanical properties.