The early stage soldering reaction, reflow for 5 s at 250 °C followed by a liquid nitrogen quench, of Sn-3.5Ag on an electroplated Ni substrate gives rise to a Ni dissolution zone, an amorphous Ni-Sn diffusion zone, and nuclei of NiSn intermetallic compound within the interfacial region. The nucleation of NiSn takes place at the interface between the dissolution zone and the amorphous diffusion zone as well as within the amorphous Ni-Sn diffusion zone, producing 10 nm nanocrystallites. High resolution transmission electron microscope observations indicate that NiSn is the preliminary intermetallic compound that forms during the soldering reaction.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)