Hostname: page-component-84b7d79bbc-dwq4g Total loading time: 0 Render date: 2024-07-30T07:28:27.006Z Has data issue: false hasContentIssue false

Numerical Simulations of Microstructural Evolution of Lamellar Alloys: Applications to Pb-Sn Solder

Published online by Cambridge University Press:  01 February 2011

Rifa J. El-Khozondar
Affiliation:
Department of Physics, New Mexico State University, P.O.Box 3001, Las Cruces, NM 88003, U.S.A.
Vitcheslav S. Solomatov
Affiliation:
Department of Physics, New Mexico State University, P.O.Box 3001, Las Cruces, NM 88003, U.S.A.
Veena Tikare
Affiliation:
Materials Modeling and Simulation, Sandia National Laboratories, MS 1405, Albuquerque, NM 87185, U.S.A.
Get access

Abstract

Understanding the morphological changes of Pb-Sn solder alloys helps to improve their performance in electronic applications. The focus of our study is degeneration of lamellar structures at high temperatures. Microstructural evolution of the Pb-Sn eutectic lamellar structure is modeled numerically using Monte Carlo Potts approach. The initial structure consists of alternating layers of Pb-rich and Sn-rich phases, simulating the lamellar array in a near eutectic system. Faults are introduced to destabilize the system. After a short incubation period the shape of lamellae become irregular. The perturbations grow with time and eventually break the lamellae into nearly equiaxed grains. The grain size of the degenerated structure is 2-3 times the original lamellar spacing weakly depending on the spacing between the faults. This is consistent with the experimental observation of degeneration of Pb-62 wt% Sn solder. The duration of degeneration processes is comparable with the time it would take Ostwald ripening to produce grains of the same size. Eventually grain growth reaches the asymptotic regime of coarsening described by a power-law function of time.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Hacke, P. L., Sprecher, A. F. and Conrad, H., “Thermal Stress and Strain in microelectronics packaging,” Thermodynamic Fatigue of 63Sn-37Pb Solder Joints, ed. Lau, J. H. (Van Nostrand Reinhold, 1993) pp. 467499.Google Scholar
2. Frear, D., Grivas, D. and Morris, J. W., J. Elec. Mat. 17, 171180 (1988).Google Scholar
3. Shen, Y. L., Li, W. and Fang, H. E., Trans. ASME 123, 7478 (2001).Google Scholar
4. Gupta, D., Vieregge, K. and Gust, W., Acta mater. 47, 512 (1999).Google Scholar
5. Anderson, M. P., Srolovitz, D. J., Grest, G. S., Sahni, P. S., Acta Metall. 32, 783791 (1984).Google Scholar
6. Anderson, M. P., Grest, G. S., Srolovitz, D. J., Phil. Mag. 59B, 293329 (1989).Google Scholar
7. Tikare, V., Gawley, J. D., J. Am. Ceram. Soc. 81, 485491 (1998a).Google Scholar
8. Tikare, V., Gawley, J. D., Act Mater. 46, 13431356 (1998b).Google Scholar
9. Tikare, V., Holm, E. A., Fan, D., Chen, L. Q., Act Mater 47, 363371.Google Scholar
10. Solomatov, V. S., El-Khozondar, R., Tikare, V., Phys. Earth Planet. Inter. 129,265282 (2002).Google Scholar
11. Lin, L. Y., Country, T. H. and Ralls, K. M., Acta Metall. 25, 99106 (1977).Google Scholar
12. Graham, L. D. and Kraft, R. W., Trans. Metall. Soc. AIME 236, 94102 (1966).Google Scholar