Journal of Electronic Materials

, Volume 44, Issue 1, pp 581–589 | Cite as

Co Effects upon Intermetallics Growth Kinetics in Sn-Cu-Co/Ni and Sn-Cu-Co/Cu Couples



The effects of minor Co additions in Sn-Cu solders on their interfacial reactions with Ni and Cu substrates were investigated. The growth rate constants and activation energy obtained in aging tests of Sn-0.7wt.%Cu-xCo/Ni and Sn-0.7wt.%Cu-xCo/Cu with x = 0.01, 0.04, 0.1, 0.5, and 1 wt.% have been determined. In Sn-0.7wt.%Cu-xCo/Cu couples, the intermetallics are the Cu6Sn5 and Cu3Sn phases. The total thickness of the reaction phase increases with the amount of Co added. Co facilitates the growth of the Cu6Sn5 phase. In Sn-0.7wt.%Cu-xCo/Ni couples, the intermetallics are either the Cu6Sn5 phase (x = 0.01 wt.%) or both the Cu6Sn5 and Ni3Sn4 phases (x = 0.04–1 wt.%). The total thickness of the reaction phase decreases as the amount of added Co increases. Co facilitates the growth of the Ni3Sn4 phase and thus inhibits formation of the Cu6Sn5 phase. Sn-Cu/Ni and Sn-Cu/Cu are very important soldering joints in electronic packaging, and Co is a widely-used additive in the solders. The kinetic data determined in this study are needed to assess the reliability of Sn-Cu/Ni and Sn-Cu/Cu soldering joints.


Co lead-free solders intermetallics growth kinetics 


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The authors acknowledge the National Science Council for their financial support (Grant # NSC 100-2221-E-033-071).


  1. 1.
    R.J. Klein Wassink, Soldering in Electronics, 2nd ed. (Isle of Man: Electrochemical Publications, 1989).Google Scholar
  2. 2.
    Y.-C. Huang, W. Gierlotka, C.-H. Chang, J.-C. Wu, and S.-W. Chen, J. Mater. Res. 22, 2924 (2007).CrossRefGoogle Scholar
  3. 3.
    S.-W. Chen and C.-C. Chen, J. Electron. Mater. 36, 1121 (2007).CrossRefGoogle Scholar
  4. 4.
    C.M.L. Wu, D.Q. Yu, C.M.T. Law, and L. Wang, Mater. Sci. Eng. R 44, 1 (2004).CrossRefGoogle Scholar
  5. 5.
    T. Laurila, V. Vuorinen, and M. Paulasto-Krockel, Mater. Sci. Eng. R 68, 1 (2010).CrossRefGoogle Scholar
  6. 6.
    M. Amagai, Microelectron. Reliab. 48, 1 (2008).CrossRefGoogle Scholar
  7. 7.
    C. Andersson, P. Sun, and J. Liu, J. Alloy Compd. 457, 97 (2008).CrossRefGoogle Scholar
  8. 8.
    S.-W. Chen, Y.-K. Chen, H.-J. Wu, Y.-C. Huang, and C.-M. Chen, J. Electron. Mater. 39, 2418 (2010).CrossRefGoogle Scholar
  9. 9.
    L. Liu, C. Andersson, and J. Liu, J. Electron. Mater. 33, 935 (2004).CrossRefGoogle Scholar
  10. 10.
    H. Nishikawa, A. Komatsu, and T. Takemoto, J. Electron. Mater. 36, 1137 (2007).CrossRefGoogle Scholar
  11. 11.
    F. Gao, T. Takemoto, and H. Nishikawa, Mater. Sci. Eng. A 420, 39 (2006).CrossRefGoogle Scholar
  12. 12.
    F. Gao and T. Takemoto, J. Alloy Compd. 421, 283 (2006).CrossRefGoogle Scholar
  13. 13.
    Y.W. Wang, Y.W. Lin, C.T. Tu, and C.R. Kao, J. Alloy Compd. 478, 121 (2009).CrossRefGoogle Scholar
  14. 14.
    C.M. Chung and K.L. Lin, J. Electron. Mater. 32, 1426 (2003).CrossRefGoogle Scholar
  15. 15.
    F. Gao, T. Takemoto, and H. Nishikawa, J. Electron. Mater. 35, 2081 (2006).CrossRefGoogle Scholar
  16. 16.
    C.E. Ho, R.Y. Tsai, Y.L. Lin, and C.R. Kao, J. Electron. Mater. 31, 584 (2002).CrossRefGoogle Scholar
  17. 17.
    S.-W. Chen and C.-H. Wang, J. Mater. Res. 21, 2270 (2006).CrossRefGoogle Scholar
  18. 18.
    P. Nash and A. Nash, Bull. Alloy. Phase. Diagr. 6, 350 (1985).CrossRefGoogle Scholar
  19. 19.
    C.-H. Lin, S.-W. Chen, and C.-H. Wang, J. Electron. Mater. 31, 907 (2002).CrossRefGoogle Scholar
  20. 20.
    C.-Y. Li, G.-J. Chiou, and J.-G. Duh, J. Electron. Mater. 35, 343 (2006).CrossRefGoogle Scholar
  21. 21.
    Y.-H. Chao, S.-W. Chen, C.-H. Chang, and C.-C. Chen, Metall. Mater. Trans. A 39, 477 (2008).CrossRefGoogle Scholar
  22. 22.
    N. Saunders and A.P. Miodownik, Bull. Alloy. Phase. Diagr. 11, 278 (1990).CrossRefGoogle Scholar
  23. 23.
    K.N. Tu and R. Thompson, Acta Metall. 30, 947 (1982).CrossRefGoogle Scholar
  24. 24.
    A. Hayashi, C.R. Kao, and Y. Chang, Scr. Mater. 37, 393 (1997).CrossRefGoogle Scholar
  25. 25.
    Y.-K. Chen, C.-M. Hsu, S.-W. Chen, C.-M. Chen, and Y.-C. Huang, Metall. Mater. Trans. A 43, 3586 (2012).CrossRefGoogle Scholar
  26. 26.
    R. Gagliano, G. Ghosh, and M. Fine, J. Electron. Mater. 31, 1195 (2002).CrossRefGoogle Scholar
  27. 27.
    K. Nogita and T. Nishimura, Scr. Mater. 59, 191 (2008).CrossRefGoogle Scholar

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© The Minerals, Metals & Materials Society 2014

Authors and Affiliations

  1. 1.R&D Center for Membrane Technology and Department of Chemical EngineeringChung Yuan Christian UniversityChung LiTaiwan

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