Abstract
Among many factors that influence whisker nucleation and growth in electroplated tin, it is now well established that small additions of Pb leads to whisker mitigation. To date, a good non-toxic elemental alternative to Pb that would mitigate whiskers remains elusive. In this work, a 50–100 nm In electroplated layer was incorporated into a 1-μm-thick electroplated Sn on a pure Cu substrate. In order to permit diffusion of In into Sn, heat treatments (HTs) between 125°C and 160°C were performed. The diffusion profile of In was altered by varying the dwell times of the HT and by utilizing two variants of In layer deposition, namely, (1) electroplating In at the top of the Sn plating, and (2) by sandwiching the In plating between two Sn layers, each approximately 500 nm thick. Appropriate control samples of pure Sn were utilized to permit valid data on the influence of In on whisker mitigation. Indium additions reduced whisker growth by at least two orders of magnitude following the 160°C treatment, independent of the location of the In layer. X-ray microanalysis of a focused ion beam cross section of the sandwich plating confirmed that In had indeed diffused into the Sn through the 160°C HT and was a likely reason for the mitigation of Sn whiskers.
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G.T. Galyon, SMTAI International Conference, Chicago, IL (2004), p. 26.
K.G. Compton, A. Mendizza, and S.M. Arnold, Corrosion 7, 327 (1951).
European Union, Off. J. L 037, 19 (2003).
R.M. Fisher, L.S. Darken, and K.G. Carroll, Acta Metall. 2, 368 (1954).
J.R. Black, Proceeding of the IEEE, Vol. 57 (1969), p. 1587.
K.N. Tu, Phys. Rev. B 49, 2030 (1994).
A.T. Wu and Y.C. Ding, Microelectron. Reliab. 49, 318 (2009).
W.J. Boettinger, C.E. Johnson, and L.A. Bendersky, Acta Mater. 53, 5033 (2005).
F. Pei, N. Jadhav, and E. Chason, JOM 64, 1176 (2012).
L. Succo, J. Esposito, and M. Cleeves, J. Vac. Sci. Technol. A 7, 814 (1989).
K.N. Tu, Acta Metall. 21, 347 (1973).
B.-Z. Lee and D.N. Lee, Acta Metall. 46, 3701 (1998).
K.N. Tu and J.C.M. Li, Mater. Sci. Eng. A 409, 131 (2005).
C. Xu, Y. Zhang, C. Fan, and J.A. Abys, IEEE Trans. Electron. Packag. Manuf. 28, 31 (2005).
N. Jadhav, M. Williams, F. Pei, G. Stafford, and E. Chason, J. Electron. Mater. 42, 312 (2013).
E. Sandnes, M.E. Williams, M.D. Vaudin, and G.R. Stafford, J. Electron. Mater. 37, 490 (2008).
E. Chason, N. Jadhav, and F. Pei, Prog. Surf. Sci. 88, 103 (2013).
I. Dutta, M. Burkard, S. Kuwano, T. Fujita, and M.W. Chen, J. Mater. Sci. 45, 3367 (2010).
W.J. Choi, T.Y. Lee, K.N. Tu, N. Tamura, R.S. Celestre, A.A. MacDowell, Y.Y. Bong, and L. Nguyen, Acta Mater. 51, 6253 (2003).
M. Sobiech, M. Wohlschlogel, U. Welzel, E.J. Mittemeijer, W. Hugel, A. Seekamp, W. Liu, and G.E. Ice, Appl. Phys. Lett. 94, 22 (2009).
M. Sobiech, U. Welzel, E.J. Mittemeijer, W. Hugel, and A. Seekamp, Appl. Phys. Lett. 93, 1 (2008).
S.M. Arnold, Proceedings of the IEEE Electrical Components Conference (1959), p. 75.
K.W. Moon, C.E. Johnson, M.E. Williams, O. Kongstein, G.R. Stafford, C.A. Handwerker, and W.J. Boettinger, J. Electron. Mater. 34, L31 (2005).
T.A. Woodrow and E.A. Ledbury, Proceedings of SMTA International Conference, Rosemont, IL (2006), p. 1.
E.A. Brandes and G.B. Brook, Smithells Metals Reference Book, 7th ed. (Oxford: Butterworth-Heinemann Ltd, 1992), p. 13.
S.M. Miller, U. Sahayam, and M.G. Norton, Mater. Metall. Trans. A 41A, 3386 (2010).
M. Schlesinger and M. Paunovic, Modern Electroplating, 5th ed. (New York: Wiley, 2014), p. 147.
T. Kakeshita, R. Kawanaka, and T. Hasegawa, J. Mater. Sci. 17, 2560 (1982).
K.N. Tu, J. Suh, A.T.C. Wu, N. Tamura, and C.H. Tung, Mater. Trans. 46, 2300 (2005).
J.A. Brusse, G.J. Ewell, and J.P. Siplon, “Tin Whiskers: Attributes and Mitigation”, 22nd Capacitor and Resistor Technology Symposium (2002), p. 67.
B.E. Deal and A.S. Grove, J. Appl. Phys. 36, 3770 (1965).
M.S. Sellars, A.J. Schultz, C. Basaran, and D.A. Kofke, J. Appl. Phys. 110, 1 (2011).
P.C. Millet, R.P. Selvam, and A. Saxena, Mater. Sci. Eng. A 431, 92 (2006).
Acknowledgement
This work was supported by the National Science Foundation (CMMI-1335199/1335491). The authors acknowledge the use of the Franceschi Microscopy and Imaging Center (FMIC) for the microscopy work. The contribution of some of the FIB results by Andrea Buckel, BS/MS student at New Mexico Tech, is gratefully acknowledged.
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Meinshausen, L., Bhassyvasantha, S., Majumdar, B.S. et al. Influence of Indium Addition on Whisker Mitigation in Electroplated Tin Coatings on Copper Substrates. J. Electron. Mater. 45, 791–801 (2016). https://doi.org/10.1007/s11664-015-4204-8
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DOI: https://doi.org/10.1007/s11664-015-4204-8