(711a) Lead-Free Nanosolders and Their Application for Nanowire Assembly and Joining

Due to the requirements for high-performance interconnects in advanced packaging, the development of nanotechnology has to meet the dramatic scaling down of the electronics packaging size from micron-scale to nanoscale. Solder-based connections have great potential and provide ample opportunities to form robust joints between individual nanocomponents and integrate them into a nanosystem with desired functionality and geometry for device applications. Prior study has shown that nanosolders can be used to assemble and join various metallic and metal oxide nanowires. In this study, the approach of nanosoldering is shown to be useful for the construction of functional nanostructures from nanomaterials by utilizing conventional reflow process with proper flux selection and utilization. The interaction between lead-free tin-based nanosolders onto metallic nanowires and reactive substrates such as copper are studied. The melting and wetting behavior of nanosolders on a reactive surface provide primary model of nanoscale joining formed on 2-dimensional planar. Such 1-D cylindrical nanowire structure provides the critical information to process the joining techniques in micro/nano electronics packaging to devices in a much smaller scale.