TY - JOUR
T1 - Microstructural study of interfacial reactions between liquid Sn and electroless Fe-Ni alloys
AU - Zhou, Haifei
AU - Guo, Jingdong
AU - Shang, Jian Ku
N1 - Funding Information:
This study was supported by the National Basic Research Program of China, Grant No. 2010CB631006 and the Natural Science Foundation of Liaoning Province, China, Grant No. 20092076. Thanks go to Dr. C.H. Lei for his help with the English of this paper. Thanks go to Miss B. Wu for her help with the figures of this paper.
PY - 2012/11
Y1 - 2012/11
N2 - Interfacial reactions between liquid Sn and electroless xFeNiP alloys (where x is the at.% of Fe) were investigated to determine the suitability of electroless Fe-Ni films as a potential under-bump metallization in solder interconnections. It was found that the interfacial reactions depended strongly on the Fe percentage in the electroless Fe-Ni alloys. The FeSn 2 compound layer was observed at the interface of alloys with high atomic percentage of Fe, such as 55 at.% and 75 at.%, while both FeSn 2 and Ni 3Sn 4 layers were found at the interface at low Fe concentration such as 25 at.%. The growth rate of interfacial intermetallic compounds and the amount of intermetallic whiskers grown on the FeNiP coatings decreased with increasing Fe percentage. The presence of FeSn 2 phase in Fe-Ni alloys at different Fe concentrations was believed to result from the lower Gibbs free energy for FeSn2 formation in the Sn/FeNiP system, while the variation in the growth rate of the intermetallic layer with Fe concentration was related to the different growth rates of FeSn 2 and Ni 3Sn 4 compounds.
AB - Interfacial reactions between liquid Sn and electroless xFeNiP alloys (where x is the at.% of Fe) were investigated to determine the suitability of electroless Fe-Ni films as a potential under-bump metallization in solder interconnections. It was found that the interfacial reactions depended strongly on the Fe percentage in the electroless Fe-Ni alloys. The FeSn 2 compound layer was observed at the interface of alloys with high atomic percentage of Fe, such as 55 at.% and 75 at.%, while both FeSn 2 and Ni 3Sn 4 layers were found at the interface at low Fe concentration such as 25 at.%. The growth rate of interfacial intermetallic compounds and the amount of intermetallic whiskers grown on the FeNiP coatings decreased with increasing Fe percentage. The presence of FeSn 2 phase in Fe-Ni alloys at different Fe concentrations was believed to result from the lower Gibbs free energy for FeSn2 formation in the Sn/FeNiP system, while the variation in the growth rate of the intermetallic layer with Fe concentration was related to the different growth rates of FeSn 2 and Ni 3Sn 4 compounds.
KW - Electroless Fe-Ni
KW - Interfacial reaction
KW - Under-bump metallization
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U2 - 10.1007/s11664-012-2199-y
DO - 10.1007/s11664-012-2199-y
M3 - Article
AN - SCOPUS:84868543742
SN - 0361-5235
VL - 41
SP - 3161
EP - 3168
JO - Journal of Electronic Materials
JF - Journal of Electronic Materials
IS - 11
ER -