摘要： Various microstructural zones were observed in the solidified solder of flip-chip solder joints with three metal bond-pad configurations (Cu/Sn/Cu, Ni/Sn/Cu, and Cu/Sn/Ni). The developed microstructures of the solidified flip-chip solder joints were strongly related to the associated metal bond pad. A hypoeutectic microstructure always developed near the Ni bond pad, and a eutectic or hypereutectic microstructure formed near the Cu pad. The effect of the metal bond pads on the solder microstructure alters the Cu solubility in the molten solder. The Cu content (solubility) in the molten Sn(Cu) solder eventually leads to the development of particular microstructures. In addition to the effect of the associated metal bond pads, the developed microstructure of the flip-chip solder joint depends on the configuration of the metal bond pads. A hypereutectic microstructure formed near the bottom Cu pad, and a eutectic microstructure formed near the top Cu pad. Directional cooling in the flip-chip solder joint during the solidification process causes the effects of the metal bond-pad configuration. Directional cooling causes the Cu content to vary in the liquid Sn(Cu) phase, resulting in the formation of distinct microstructural zones in the developed microstructure of the flip-chip solder joint. 其他題名： Journal of Elec Materi 出版者： Boston: Springer US 出版日期： 2014-01 出處： Journal of electronic materials, 2014-01, Vol.43 (1), p.170-175 資源來源： EBSCOhost OmniFile Full Text Select 版權： TMS 2013 版權： TMS 2014 識別號： ISSN: 0361-5235 識別號： EISSN: 1543-186X 識別號： DOI: 10.1007/s11664-013-2784-8 識別號： CODEN: JECMA5
