Journal of Electronic Materials

, Volume 43, Issue 12, pp 4435–4441 | Cite as

Significance of Nucleation Kinetics in Sn Whisker Formation

  • E. Chason
  • F. Pei
  • C. L. Briant
  • H. Kesari
  • A. F. Bower
Article

Abstract

Sn whiskers are believed to form in response to stress in layers used as protective coatings. However, what makes them form at specific sites on the surface is not known. We have used thermal expansion mismatch to induce stress and observe the resulting whisker formation. Cross-sectional measurements of the region around whiskers show that there are oblique grain boundaries under the whiskers that are not seen in the as-deposited columnar structure. The kinetics also suggest that the whiskering sites may be formed by a nucleation process. Based on these results, we propose a nucleation mechanism in which the boundaries of the surrounding grains migrate due to strain energy differences and create oblique boundaries at which whiskers can form. A simple model is developed to predict the stress-dependence of the nucleation rate.

Keywords

Pb-free manufacturing tin whiskers thermal cycling 

References

  1. 1.
    NASA, Multiple examples of whisker-induced failures are documented on the NASA website. http://nepp.nasa.gov/whisker/
  2. 2.
    G.T. Galyon, IEEE Trans. Electron. Packag. Manuf. 28, 1 (2005).CrossRefGoogle Scholar
  3. 3.
    S.M. Arnold, Plating 53, 1 (1966).Google Scholar
  4. 4.
    E. Chason, N. Jadhav, F. Pei, E. Buchovecky, and A. Bower, Prog. Surf. Sci. 88, 2 (2013).CrossRefGoogle Scholar
  5. 5.
    B.Z. Lee and D.N. Lee, Acta Mater. 46, 10 (1998).Google Scholar
  6. 6.
    W.J. Boettinger, C.E. Johnson, L.A. Bendersky, K.W. Moon, M.E. Williams, and G.R. Stafford, Acta Mater. 53, 19 (2005).Google Scholar
  7. 7.
    E. Chason, N. Jadhav, W.L. Chan, L. Reinbold, and K.S. Kumar, Appl. Phys. Lett. 92, 17 (2008).CrossRefGoogle Scholar
  8. 8.
    K.N. Tu, Phys. Rev. B 49, 3 (1994).Google Scholar
  9. 9.
    N. Jadhav, E. Buchovecky, E. Chason, and A. Bower, JOM 62, 7 (2010).CrossRefGoogle Scholar
  10. 10.
    C.-H. Su, H. Chen, H.-Y. Lee, and A.T. Wu, Appl. Phys. Lett. 99, 13 (2011).Google Scholar
  11. 11.
    P. Snugovsky, S. Meschter, Z. Bagheri, E. Kosiba, M. Romansky, and J. Kennedy, J. Electron. Mater. 41, 2 (2012).CrossRefGoogle Scholar
  12. 12.
    F. Pei, N. Jadhav, and E. Chason, JOM 64, 10 (2012).CrossRefGoogle Scholar
  13. 13.
    P. Sarobol, A.E. Pedigo, P. Su, J.E. Blendell, and C.A. Handwerker, IEEE Trans. Electron. Packag. Manuf. 33, 3 (2010).CrossRefGoogle Scholar
  14. 14.
    F. Pei, N. Jadhav, and E. Chason, Appl. Phys. Lett. 100, 22 (2012).Google Scholar
  15. 15.
    P. Sarobol, W.-H. Chen, A.E. Pedigo, P. Su, J.E. Blendell, and C.A. Handwerker, J. Mater. Res. 28, 05 (2013).Google Scholar
  16. 16.
    J. Smetana, IEEE Trans. Electron. Packag. Manuf. 30, 1 (2007).CrossRefGoogle Scholar
  17. 17.
    N. Jadhav, M. Williams, F. Pei, G. Stafford, and E. Chason, J. Electron. Mater. 42, 2 (2013).CrossRefGoogle Scholar
  18. 18.
    P. Sarobol, J.E. Blendell, and C.A. Handwerker, Acta Mater. 61, 6 (2013).CrossRefGoogle Scholar
  19. 19.
    P.T. Vianco and J.A. Rejent, J. Electron. Mater. 38, 9 (2009).Google Scholar
  20. 20.
    P.A. Beck and P.R. Sperry, J. Appl. Phys. 21, 2 (1950).Google Scholar
  21. 21.
    S.P. Bellier and R.D. Doherty, Acta Metall. 25, 5 (1977).Google Scholar
  22. 22.
    J.E. Bailey and P.B. Hirsch, Philos. Mag. 5, 53 (1960).Google Scholar
  23. 23.
    F. Pei and E. Chason, J. Electron. Mater. 43, 1 (2014).CrossRefGoogle Scholar
  24. 24.
    E. Chason, Thin Solid Films 526, (2012).Google Scholar
  25. 25.
    F. Pei, A. F. Bower, and E. Chason, unpublished (2014).Google Scholar
  26. 26.
    F. Pei, C.L. Briant, H. Kesari, A.F. Bower, and E. Chason, Scripta Mater. (2014). doi:10.1016/j.scriptamat.2014.08.019.
  27. 27.
    F.J. Humphreys and M. Hatherly, Recrystallization and Related Annealing Phenomena (Oxford: Pergamon, 1995), pp. 207–209.Google Scholar
  28. 28.
    L. Nicola, E.V. Giessen, and A. Needleman, J. Mater. Res. 19, 04 (2004).CrossRefGoogle Scholar
  29. 29.
    K.S. Kumar, L. Reinbold, A.F. Bower, and E. Chason, J. Mater. Res. 23, 11 (2008).Google Scholar

Copyright information

© The Minerals, Metals & Materials Society 2014

Authors and Affiliations

  • E. Chason
    • 1
  • F. Pei
    • 1
  • C. L. Briant
    • 1
  • H. Kesari
    • 1
  • A. F. Bower
    • 1
  1. 1.School of EngineeringBrown UniversityProvidenceUSA

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