Nanosized samarium oxide (Sm2O3) particles suppressed the IMC phases and enhanced the shear strength of environmental-friendly Sn–Ag–Cu material

Abstract

Environmental-friendly Sn–Ag–Cu-based composite material was prepared through evenly mixing of similar density nonreacting samarium oxide (Sm2O3) nanoparticles into Sn–3Ag–0.5Cu (wt%) powders. Further, the interfacial structural morphology and strength on various surface-finished e.g., Cu, Au/Ni-plated and Ag-plated Cu pads were studied on aging period with different temperatures. At low-temperature aging, a layer-type Cu6Sn5 intermetallic compound (IMC) phase was detected on Cu and Ag-plated Cu pad surface. Further, a thin film-type Cu3Sn IMC phase was grown during the aging treatment. Moreover, in Au/Ni-plated Cu substrate, a (Cu, Ni)6Sn5 IMC phase was grown at the pad surface. However, these IMC layers become thicker with the aging temperature and time. Additionally, in the solder matrix, a spherical-shape Cu6Sn5 and needle-shape Ag3Sn IMC phases were evenly dispersed in β-Sn matrix. However, it was worthy noted that these IMC particles and layers growth nature of interconnection made by composite material was slower than that of reference solder systems. This phenomenon was occurred due to set the surface-active Sm2O3 nanoparticles on IMC phase. Moreover, nanoparticles doped composite material ensured the higher shear strength due to reduce the growth rate of IMC thickness, control the IMC particles and evenly distributed of Sm2O3 nanoparticles in the solder matrix.