Spontaneous Tin Whisker Growth: Mechanism and Prevention

  • King-Ning Tu
Part of the Springer Series in Materials Science book series (SSMATERIALS, volume 117)


Whisker growth on beta-tin (β-Sn) is a surface relief phenomenon of creep [1–16]. It is driven by a compressive stress gradient and occurs at room temperature. Spontaneous Sn whiskers are known to grow on matte Sn finish on Cu. Today, due to the wide application of Pb-free solders on Cu conductors used in the packaging of consumer electronic products, Sn whisker growth has become a serious reliability issue because the Sn-based Pb-free solders are very rich in Sn. The matrix of most Sn-based Pb-free solders is almost pure Sn. The well-known phenomena of tin such as tin-cry, tin-pest, and tin-whisker are receiving attention again.


Stress Gradient Whisker Growth Consumer Electronic Product Laue Pattern Deviatoric Strain Tensor 
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  1. C. Herring and J. K. Galt, Phys. Rev. 85, 1060 (1952).CrossRefGoogle Scholar
  2. J. D. Eshelby, Phys. Rev., 91, 755 (1953).CrossRefGoogle Scholar
  3. F. C. Frank, Philos. Mag., 44, 854 (1953).Google Scholar
  4. G. W. Sears, Acta Metall., 3, 367 (1955).CrossRefGoogle Scholar
  5. S. Amelinckx, W. Bontinck, W. Dekeyser, and F. Seitz, Philos. Mag., 2, 355 (1957).CrossRefGoogle Scholar
  6. W. C. Ellis, D. F. Gibbons, and R. C. Treuting, “Growth of metal whiskers from the solid,” in “Growth and Perfection of Crystals,” R. H. Doremus, B. W. Roberts, and D. Turnbull (Eds.), John Wiley, New York, pp. 102–120 (1958).Google Scholar
  7. A. P. Levitt, in “Whisker Technology,” Wiley–Interscience, New York (1970).Google Scholar
  8. U. Lindborg, “Observations on the growth of whisker crystals from zinc electroplate,” Metall. Trans. A, 6, 1581–1586 (1975).CrossRefGoogle Scholar
  9. I. A. Blech, P. M. Petroff, K. L. Tai, and V. Kumar, “Whisker growth in Al thin-films,” J. Cryst. Growth, 32, 161–169 (1975).CrossRefGoogle Scholar
  10. N. Furuta and K. Hamamura, “Growth mechanism of proper tin-whisker,” Jpn. J. Appl. Phys., 8, 1404–1410 (1969).CrossRefGoogle Scholar
  11. R. Kawanaka, K. Fujiwara, S. Nango, and T. Hasegawa, “Influence of impurities on the growth of tin whiskers,” Jpn. J. Appl. Phys. Part I, 22, 917–922 (1983).CrossRefGoogle Scholar
  12. K. N. Tu, “Interdiffusion and reaction in bimetallic Cu-Sn thin films,” Acta Metall., 21, 347–354 (1973).CrossRefGoogle Scholar
  13. K. N. Tu, “Irreversible processes of spontaneous whisker growth in bimetallic Cu-Sn thin film reactions,” Phys. Rev. B, 49, 2030–2034 (1994).CrossRefGoogle Scholar
  14. G. T. T. Sheng, C. F. Hu, W. J. Choi, K. N. Tu, Y. Y. Bong, and L. Nguyen,“Tin whiskers studied by focused ion beam imaging and transmission electron microscopy,” J. Appl. Phys., 92, 64–69 (2002).CrossRefGoogle Scholar
  15. W. J. Choi, T. Y. Lee, K. N. Tu, N. Tamura, R. S. Celestre, A. A. MacDowell, Y. Y. Bong, and L. Nguyen, “Tin whiskers studied by synchrotron radiation micro-diffraction,” Acta Mater., 51, 6253–6261 (2003).CrossRefGoogle Scholar
  16. W.J. Boettinger, C.E. Johnson, L. A. Bendersky, K.-W. Moon, M.E. Williams, and G.R. Stafford, Whisker and hillock formation in Sn, Sn-Cu, and Sn-Pb lectrodeposists; Acta Mater., 53, 5033–5050 (2005).CrossRefGoogle Scholar
  17. I. Amato, “Tin whiskers: The next Y2K problem?” Fortune magazine, vol. 151, issue 1, p.27 (2005).Google Scholar
  18. R. Spiegel, “Threat of tin whiskers haunts rush to lead-free,” Electronic News, 03/17/2005.Google Scholar
  19. W. J. Choi, G. Galyon, K. N. Tu, and T. Y. Lee, “The structure and kinetics of tin whisker formation and growth on high tin content finishes,” in “Handbook of Lead-Free Solder Technology for Microelectronic Assemblies,” K. J. Puttlitz and K. A. Stalter (Eds.), Marcel Dekker, New York (2004).Google Scholar
  20. P. G. Shewmon, “Diffusion in Solids,” McGraw–Hill, New York (1963).Google Scholar
  21. D. A Porter and K. E. Easterling, “Phase Transformations in Metals and Alloys,” Chapman & Hall, London (1992).Google Scholar
  22. K. Zeng, R. Stierman, T.-C. Chiu, D. Edwards, K. Ano, and K. N. Tu, “Kirkendall void formation in SnPb solder joints on bare Cu and its effect on joint reliability,” J. Appl. Phys., 97, 024508-1 to –8 (2005).Google Scholar
  23. B.-Z. Lee and D. N. Lee, “Spontaneous growth mechanism of tin whiskers,” Acta Mater., 46, 3701–3714 (1998).CrossRefGoogle Scholar
  24. C. Y. Chang and R. W. Vook, “The effect of surface aluminum oxide film on thermally induced hillock formation,” Thin Solid Films, 228, 205–209 (1993).CrossRefGoogle Scholar
  25. K. N. Tu and J. C. M. Li, “Spontaneous whisker growth on lead-free solder finishes,” Mater. Sci. and Eng. A, 409, 131–139 (2005).CrossRefGoogle Scholar
  26. C. Y. Liu, C. Chen, and K. N. Tu, “Electromigration of thin stripes of SnPb solder as a function of composition,” J. Appl. Phys., 80, 5703–5709 (2000).CrossRefGoogle Scholar
  27. S. H. Liu, C. Chen, P. C. Liu, and T. Chou, “Tin whisker growth driven by electrical currents,” J. Appl. Phys., 95, 7742 (2004).CrossRefGoogle Scholar

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© Springer 2007

Authors and Affiliations

  • King-Ning Tu
    • 1
  1. 1.Department of Materials Science and EngineeringUniversity of California at Los AngelesLos AngelesUSA

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