Orientation relationships among Sn/Cu6Sn5/Cu3Sn/(111)Cu in the eutectic SnBi/(111)Cu solder joint

摘要

TEM (transmission electron microscope) observations and precise SAED (selected area electron diffraction) analysis were used to character the growth of IMCs (intermetallic compounds) between eutectic SnBi solder and Cu(111) substrate after reflowing. The results indicated that after reflowing the interface between eutectic SnBi solder and Cu(111) substrate is made up by four groups of neighboring phases: Cu(111)/Cu6Sn5, Cu(111)/Cu3Sn, Cu3Sn/Cu6Sn5, Cu6Sn5/Sn. The precise SAED analysis revealed during nucleation and growth process of interfacial IMCs the neighboring phases kept perfect orientation relationships in order to decrease the nucleation driving force of IMCs.