Analysis and control of Cu6Sn5 preferred nucleation on single crystal (0 0 1)Cu

Abstract Fully oriented-intermetallic interconnects (FOI) of high melting point and service performance have highly considerable potential application in the current generation of 3D electronic packaging. The primary process of fabrication of this structure is the Cu6Sn5 preferred nucleation. In this article, the orientations of 59 successive Cu6Sn5 grains along the radius of (0 0 1)Cu/Sn-3.0Ag solder interface were investigated. Finally, an analysis and control model of Cu6Sn5 preferred nucleation determined by chemical potential gradient of Cu migration was established and applied to address and manage the orientation growth of Cu6Sn5 under different reflow temperatures and solder compositions. The results pave the way for orientation controlling of interfacial intermetallics in 3D packaging technologies.