naa a22 4500 510803172 CHVBK 20180411083404.0 cr unu---uuuuu 180411e20131201xx s 000 0 eng 10.1007/s11664-013-2749-y doi (NATIONALLICENCE)springer-10.1007/s11664-013-2749-y Effect of Bi Segregation on the Asymmetrical Growth of Cu-Sn Intermetallic Compounds in Cu/Sn-58Bi/Cu Sandwich Solder Joints During Isothermal Aging [Elektronische Daten] [Xiaowu Hu, Yulong Li, Ke Li, Zhixian Min] An asymmetrical interfacial microstructure was observed at both top and bottom interfaces of Cu/Sn-58Bi/Cu solder joints after isothermal aging at 120°C for different times. The asymmetrical interfacial microstructure resulted from asymmetrical Bi segregation, which was attributed to the density difference between Bi and Sn atoms. Bi atoms were driven to the bottom solder/Cu interface by gravity during the liquid soldering procedure since Bi atoms are more massive than Sn atoms. With increasing aging time, Bi accumulated at the bottom Cu3Sn/Cu interface and the Bi segregation enhanced Cu6Sn5 intermetallic compound growth, blocked Sn transport to the Cu3Sn intermetallic compound, and facilitated growth of the Cu6Sn5, based on the measured thicknesses of intermetallic compounds (including Cu6Sn5 and Cu3Sn) at both bottom and top interfaces for Cu/Sn-58Bi/Cu sandwich joints under the same aging process. TMS, 2013 Lead-free solder nationallicence segregation nationallicence intermetallic compounds nationallicence microstructure nationallicence Hu Xiaowu School of Mechanical and Electrical Engineering, Nanchang University, 330031, Nanchang, China aut Li Yulong School of Mechanical and Electrical Engineering, Nanchang University, 330031, Nanchang, China aut Li Ke School of Mechanical and Electrical Engineering, Nanchang University, 330031, Nanchang, China aut Min Zhixian China Electronics Technology Group Corporation No.38 Research Institute, 230088, Hefei, China aut Journal of Electronic Materials Springer US; http://www.springer-ny.com 42/12(2013-12-01), 3567-3572 0361-5235 42:12<3567 2013 42 11664 https://doi.org/10.1007/s11664-013-2749-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11664-013-2749-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hu Xiaowu School of Mechanical and Electrical Engineering, Nanchang University, 330031, Nanchang, China aut NATIONALLICENCE 700 1- Li Yulong School of Mechanical and Electrical Engineering, Nanchang University, 330031, Nanchang, China aut NATIONALLICENCE 700 1- Li Ke School of Mechanical and Electrical Engineering, Nanchang University, 330031, Nanchang, China aut NATIONALLICENCE 700 1- Min Zhixian China Electronics Technology Group Corporation No.38 Research Institute, 230088, Hefei, China aut NATIONALLICENCE 773 0- Journal of Electronic Materials Springer US; http://www.springer-ny.com 42/12(2013-12-01), 3567-3572 0361-5235 42:12<3567 2013 42 11664 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer