Growth kinetics of bismuth nickel intermetallics
- 53 Downloads
Bismuth (Bi)-based systems are of great interest as it is considered to potentially replace high lead (Pb)-content solders used in high temperature electronics. In particular, molten Bi strongly reacts with Ni to form higher melting point intermetallic compounds (IMCs) via transient liquid phase (TLP), which can offer a joining method alternative to the traditional solder approach. A fundamental understanding of nucleation and growth of intermetallic phases is crucial to create a reliable joint. Two intermetallic phases form between Bi and Ni (Bi3Ni, BiNi). In this study, growth kinetics for Bi3Ni and BiNi was investigated, both of which show a parabolic growth behavior. Bi3Ni exhibits rapid growth and apparent activation energy of 65.5 kJ/mol at lower temperatures (from 160 to 240 °C) and of 132.9 kJ/mol at higher temperatures (> 240 °C), where the transition is likely due to a viscous-flow nature near melting temperature of Bi. On the other hand, BiNi grows at a later stage with a slower rate with the apparent activation energy of 125.6 kJ/mol (from 260 to 340 °C). In addition, based on the formation sequence and growth direction of these IMCs, interdiffusion coefficients for each of these IMCs were determined. Micro-hardness tests show that Bi3Ni is softer and more brittle than BiNi.
This project was financially supported by Integrated Electronics Engineering Center (IEEC) of Binghamton University (State University of New York). In addition, we used the equipment facilities at Analytical and Diagnostics Laboratory (ADL) of Small Scale Systems Integration and Packaging (S3IP) Center for some of materials characterization data presented here. We also thank Liang Yin, David Shaddock, Kaustubh Nagarkar and Arun Gowda from GE for their support on this project. Furthermore, the assistance provided by Sandeep Mallampati, a former member of our group, is greatly appreciated.
- 8.J. Cho, R. Sheikhi, S. Mallampati, L. Yin, D. Shaddock, Bismuth-based transient liquid phase (TLP) bonding as high-temperature lead-free solder alternatives. in 2017 IEEE 67th Electronic Components and Technology Conference (ECTC), 2017, pp. 1553–1559Google Scholar
- 9.J. Cho, S. Mallampati, R. Tobias, H. Schoeller, L. Yin, D. Shaddock, Exploring bismuth as a new Pb-free alternative for high temperature electronics. in 2016 IEEE 66th Electronic Components and Technology Conference (ECTC) (2016), pp. 432–438Google Scholar
- 10.J. Cho, S. Mallampati, H. Schoeller, L. Yin, D. Shaddock, Developments of Bi–Sb–Cu alloys as a high-temperature Pb-free solder. in 2015 IEEE 65th Electronic Components and Technology Conference (ECTC) (2015), pp. 1251–1256Google Scholar
- 11.H.-T. Lee, M.-H. Chen, H.-M. Jao, T.-L. Liao, Influence of interfacial intermetallic compound on fracture behavior of solder joints. Mater. Sci. Eng. A, 358(1–2), 134–141 (2003)Google Scholar
- 19.S. Bader, W. Gust, H. Hieber, Rapid formation of intermetallic compounds interdiffusion in the CuSn and NiSn systems. Acta Metall. Mater. 43(1), 329–337 (1995)Google Scholar