Journal of Electronic Materials

, Volume 43, Issue 1, pp 259–269 | Cite as

Investigation of Sn Whisker Growth in Electroplated Sn and Sn-Ag as a Function of Plating Variables and Storage Conditions

  • Jaewon Chang
  • Sung K. Kang
  • Jae-Ho Lee
  • Keun-Soo Kim
  • Hyuck Mo LeeEmail author


Sn whiskers are becoming a serious reliability issue in Pb-free electronic packaging applications. Among the numerous Sn whisker mitigation strategies, minor alloying additions to Sn have been proven effective. In this study, several commercial Sn and Sn-Ag baths of low-whisker formulations are evaluated to develop optimum mitigation strategies for electroplated Sn and Sn-Ag. The effects of plating variables and storage conditions, including plating thickness and current density, on Sn whisker growth are investigated for matte Sn, matte Sn-Ag, and bright Sn-Ag electroplated on a Si substrate. Two different storage conditions are applied: an ambient condition (30°C, dry air) and a high-temperature/high-humidity condition (55°C, 85% relative humidity). Scanning electron microscopy is employed to record the Sn whisker growth history of each sample up to 4000 h. Transmission electron microscopy, x-ray diffraction, and focused ion beam techniques are used to understand the microstructure, the formation of intermetallic compounds (IMCs), oxidation, the Sn whisker growth mechanism, and other features. In this study, it is found that whiskers are observed only under ambient conditions for both thin and thick samples regardless of the current density variations for matte Sn. However, whiskers are not observed on Sn-Ag-plated surfaces due to the equiaxed grains and fine Ag3Sn IMCs located at grain boundaries. In addition, Sn whiskers can be suppressed under the high-temperature/high-humidity conditions due to the random growth of IMCs and the formation of thick oxide layers.


Sn whiskers electroplating minor alloying 


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  1. 1.
    J. Smetana, IEEE Trans. Electron. Packag. Manuf. 30, 11 (2007).CrossRefGoogle Scholar
  2. 2.
    J. Chang, S.-K. Seo, M.G. Cho, D.-N. Lee, K.-S. Kang, and H.M. Lee, J. Mater. Res. 27, 1877 (2012).CrossRefGoogle Scholar
  3. 3.
    H. Leidecker, and J. Brusse, Tin whiskers: a history of documented electrical system failures, Accessed 30 September 2013.
  4. 4.
    N. Jadhav, J. Wasserman, F. Pei, and E. Chason, J. Electron. Mater. 41, 588 (2012).CrossRefGoogle Scholar
  5. 5.
    European Union, Directive 2002/96/EC of the European parliament and of the council of 27 January 2003 on WEEE, Off. J. Eur. Union, L37/24-38 (2003).Google Scholar
  6. 6.
    K.G. Compton, A. Mendizza, and S.M. Arnold, Corrosion 7, 327 (1951).Google Scholar
  7. 7.
    M.W. Barsoum, E.N. Hoffman, R.D. Doherty, S. Gupta, and A. Zavaliangos, Phys. Rev. Lett. 93, 206104 (2004).CrossRefGoogle Scholar
  8. 8.
    K.N. Tu and J.C.M. Li, Mater. Sci. Eng. A 406, 131 (2005).CrossRefGoogle Scholar
  9. 9.
    G.T. Galyon and L. Palmer, IEEE Trans. Electron. Packag. Manuf. 28, 17 (2005).CrossRefGoogle Scholar
  10. 10.
    B.-Z. Lee and D.-N. Lee, Acta Mater. 46, 3701 (1998).CrossRefGoogle Scholar
  11. 11.
    W.J. Boettinger, C.E. Johnson, L.A. Bendersky, K.-W. Moon, M.E. Williams, and G.R. Stafford, Acta Mater. 53, 5033 (2005).CrossRefGoogle Scholar
  12. 12.
    K.N. Tu, Acta Metall. 21, 347 (1973).CrossRefGoogle Scholar
  13. 13.
    T. Shibutani, Q. Yu, T. Yamashita, and M. Shiratori, IEEE Trans. Electron. Packag. Manuf. 29, 259 (2006).CrossRefGoogle Scholar
  14. 14.
    H. Moriuchi, Y. Tadokoro, M. Sato, T. Furusawa, and N. Suzuki, J. Electron. Mater. 36, 220 (2007).CrossRefGoogle Scholar
  15. 15.
    J.W. Shin and E. Chason, J. Mater. Res. 24, 1522 (2009).CrossRefGoogle Scholar
  16. 16.
    K.-S. Kim, C.-H. Yu, and J.-M. Yang, Thin Solid Films 504, 350 (2006).CrossRefGoogle Scholar
  17. 17.
    A. Dimitrovska and R. Kovacevic, J. Electron. Mater. 38, 2726 (2009).CrossRefGoogle Scholar
  18. 18.
    H.J. Kao, W.C. Wu, S.T. Tsai, and C.Y. Liu, J. Electron. Mater. 35, 1885 (2006).CrossRefGoogle Scholar
  19. 19.
    K.-S. Kim, S.-S. Kim, Y. Yorikado, K. Suganuma, M. Tsujimoto, and I. Yanada, J. Alloy Compd. 558, 125 (2013).CrossRefGoogle Scholar
  20. 20.
    S.-K. Lin, Y. Yorikado, J. Jiang, K.-S. Kim, K. Suganuma, S.-W. Chen, M. Tsujimoto, and I. Yanada, J. Mater. Res. 22, 1975 (2007).CrossRefGoogle Scholar
  21. 21.
    S.-K. Lin, Y. Yorikado, J. Jiang, K.-S. Kim, K. Suganuma, S.-W. Chen, M. Tsujimoto, and I. Yanada, J. Electron. Mater. 36, 1732 (2007).CrossRefGoogle Scholar
  22. 22.
    T. Kakeshita, K. Shimizu, R. Kawanaka, and T. Hasegawa, J. Mater. Sci. 17, 2560 (1982).CrossRefGoogle Scholar
  23. 23.
    K.-S. Kim, W.-O. Han, and S.-W. Han, J. Electron. Mater. 34, 1579 (2005).CrossRefGoogle Scholar
  24. 24.
    Y. Fukuda, M. Osterman, and M. Pecht, Microelectron. Reliab. 47, 88 (2007).CrossRefGoogle Scholar
  25. 25.
    A. Baated, K. Hamasaki, S.S. Kim, K.-S. Kim, and K. Suganuma, J. Electron. Mater. 40, 2278 (2011).CrossRefGoogle Scholar
  26. 26.
    S. Arai and T. Watanabe, Mater. Trans. 39, 439 (1998).Google Scholar
  27. 27.
    C.W. Fairhurst and J.B. Cohen, Acta Crystallogr. Sect. B Struct. Sci. 28, 371 (1972).Google Scholar

Copyright information

© TMS 2013

Authors and Affiliations

  • Jaewon Chang
    • 1
  • Sung K. Kang
    • 2
  • Jae-Ho Lee
    • 3
  • Keun-Soo Kim
    • 4
  • Hyuck Mo Lee
    • 1
    Email author
  1. 1.Department of Materials Science and EngineeringKAISTTaejonRepublic of Korea
  2. 2.IBM T.J. Watson Research CenterNew YorkUSA
  3. 3.Department of Materials Science and EngineeringHongik UniversitySeoulRepublic of Korea
  4. 4.Fusion Technology LabHoseo UniversityAsanRepublic of Korea

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