Abstract
Stress is believed to provide the driving force for growth of Sn whiskers, so stress relaxation in the Sn layer plays a key role in their formation. To understand and enhance stress relaxation in Sn-based films, the effects of Pb alloying and microstructure on their mechanical properties have been studied by observing the relaxation of thermal expansion-induced strain. The relaxation rate is found to increase with film thickness and grain size in pure Sn films, and it depends on the microstructure in Pb-alloyed Sn films. Measurements of multilayered structures (Sn on Pb-Sn and Pb-Sn on Sn) show that changing the surface layer alone is not sufficient to enhance the relaxation, indicating that the Pb enhances relaxation in the bulk of the film and not by surface modification. Implications of our results for whisker mitigation strategies are discussed.
Article PDF
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.Avoid common mistakes on your manuscript.
References
S.B. Lyon, Shreir’s Corrosion, ed. J.A.R. Tony (Oxford: Elsevier, 2010), p. 2068.
G.T. Galyon, IEEE Trans. Electron. Packag. Manuf. 28, 94 (2005).
S. Herat, CLEAN-Soil Air Water 36, 145 (2008).
B. Hampshire and L. Hymes, Circuits Assembly (2000), p. 50.
B. D. Dunn, European Space Agency (ESA) STR-223 (1987).
N. Jadhav, E. Buchovecky, E. Chason, and A. Bower, JOM 62, 30 (2010).
NASA.
K.G. Compton, A. Mendizza, and S.M. Arnold, Corrosion 7, 327 (1951).
S.M. Arnold (Presented at the IEEE Electronic Components Technology Conference, unpublished, 1959).
B.Z. Lee and D.N. Lee, Acta Mater. 46, 3701 (1998).
K.N. Tu, Phys. Rev. B 49, 2030 (1994).
E. Chason, N. Jadhav, W.L. Chan, L. Reinbold, and K.S. Kumar, Appl. Phys. Lett. 92, 171901 (2008).
W. Zhang and F. Schwager, J. Electrochem. Soc. 153, C337 (2006).
W.J. Boettinger, C.E. Johnson, L.A. Bendersky, K.W. Moon, M.E. Williams, and G.R. Stafford, Acta Mater. 53, 5033 (2005).
C.-F. Yu, C.-M. Chan, and K.-C. Hsieh, Microelectron. Reliab. 50, 1146 (2010).
E. Chason, N. Jadhav, and F. Pei, JOM 63, 62 (2011).
J. Liang, Z.-H. Xu, and X. Li, J. Mater. Sci.: Mater. Electron. 18, 599 (2007).
Y. Sun, E.N. Hoffman, P.-S. Lam, and X. Li, Scripta Mater. 65, 388 (2011).
M. Sobiech, M. Wohlschlogel, U. Welzel, E.J. Mittemeijer, W. Hugel, A. Seekamp, W. Liu, and G.E. Ice, Appl. Phys. Lett. 94, 221901 (2009).
E. Chason and J.A. Floro, Measurements of Stress Evolution During Thin Film Deposition (1996).
J. Smetana, IEEE Trans. Electron. Packag. Manuf. 30, 11 (2007).
M. Dittes, P. Obemdorff, and L. Petit (Presented at the Electronic Components and Technology Conference, Proceedings. 53rd, unpublished, 2003).
C. Xu, Y. Zhang, C. Fan, J. Abys, L. Hopkins, and F. Stevie, CircuiTree 94–105 (2002).
N. Jadhav, E.J. Buchovecky, L. Reinbold, S. Kumar, A.F. Bower, and E. Chason, IEEE Trans. Electron. Packag. Manuf. 33, 183 (2010).
K. Tsuji, (Presented at the IPC/JEDEC 4th International Conference on Lead-Free Electronic Components and Assemblies, Frankfurt, Germany, unpublished, 2003).
Y. Choi and S. Suresh, Acta Mater. 50, 1881 (2002).
R.-M. Keller, S.P. Baker, and E. Arzt, J. Mater. Res. 13, 1307 (1998).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Jadhav, N., Wasserman, J., Pei, F. et al. Stress Relaxation in Sn-Based Films: Effects of Pb Alloying, Grain Size, and Microstructure. J. Electron. Mater. 41, 588–595 (2012). https://doi.org/10.1007/s11664-011-1829-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11664-011-1829-0