TY - JOUR
T1 - Evolution of the Microstructure of Sn58Bi Solder Paste with Sn-3.0Ag-0.5Cu Addition During Isothermal Aging
AU - Xu, Ruisheng
AU - Liu, Yang
AU - Zhang, Hao
AU - Li, Zhao
AU - Sun, Fenglian
AU - Zhang, Guoqi
PY - 2019
Y1 - 2019
N2 - Eutectic Sn58Bi (SnBi) solder paste mixed with 0 wt.%, 3 wt.%, 5 wt.%, 8 wt.% and 15 wt.% of Sn-3.0Ag-0.5Cu (SAC) paste was prepared by mechanical mixing. The effects of SAC paste additions on the microstructure evolution of SnBi-SAC/Cu composite solder joints during isothermal aging were investigated. The results indicated that the number of large Bi-rich phases decreased and the relative areas of β-Sn increased with increasing SAC content. Moreover, 1-μm Bi-rich particles were found near the Bi-rich phases. During the isothermal aging process, the diameter of the 1-μm Bi-rich particles in the solder bulk increased by about 50% with aging time by Ostwald ripening. The thickness of the interfacial intermetallic compound in all the solder joints increased slightly during the aging process. The formation of Cu6Sn5 was suppressed by the Bi-rich phases above the Cu6Sn5 layer with the aging time increasing. In addition, the solder bulk showed many cracks along the β-Sn grain boundaries after isothermal aging when the content of SAC paste was 5 wt.%. With 8 wt.% or 15 wt.% SAC, fractures were more obvious near the interface than away from the interface.
AB - Eutectic Sn58Bi (SnBi) solder paste mixed with 0 wt.%, 3 wt.%, 5 wt.%, 8 wt.% and 15 wt.% of Sn-3.0Ag-0.5Cu (SAC) paste was prepared by mechanical mixing. The effects of SAC paste additions on the microstructure evolution of SnBi-SAC/Cu composite solder joints during isothermal aging were investigated. The results indicated that the number of large Bi-rich phases decreased and the relative areas of β-Sn increased with increasing SAC content. Moreover, 1-μm Bi-rich particles were found near the Bi-rich phases. During the isothermal aging process, the diameter of the 1-μm Bi-rich particles in the solder bulk increased by about 50% with aging time by Ostwald ripening. The thickness of the interfacial intermetallic compound in all the solder joints increased slightly during the aging process. The formation of Cu6Sn5 was suppressed by the Bi-rich phases above the Cu6Sn5 layer with the aging time increasing. In addition, the solder bulk showed many cracks along the β-Sn grain boundaries after isothermal aging when the content of SAC paste was 5 wt.%. With 8 wt.% or 15 wt.% SAC, fractures were more obvious near the interface than away from the interface.
KW - IMC
KW - isothermal aging
KW - microstructure
KW - SAC
KW - SnBi
UR - http://www.scopus.com/inward/record.url?scp=85058846069&partnerID=8YFLogxK
U2 - 10.1007/s11664-018-06865-1
DO - 10.1007/s11664-018-06865-1
M3 - Article
AN - SCOPUS:85058846069
SN - 0361-5235
VL - 48
SP - 1758
EP - 1765
JO - Journal of Electronic Materials
JF - Journal of Electronic Materials
IS - 3
ER -