Study of microstructure evolution in novel SnZn/Cu bi-layer and Cu/SnZn/Cu sandwich structures with nanoscale thickness for 3D packaging interconnection
Soldering of sub-micron scale solder thickness Cu/SnZn/Cu and SnZn/Cu were studied. The Cu6Sn5 concumption based Cu3Sn growth and Zn diffusion were discussed. Fast formation of Kirkendall voids in these structures were observed and studied.
microstructure evolution 3d packaging kirkendall voids intermetallic compounds ultra-thin solder