Journal of Electronic Materials

, Volume 37, Issue 6, pp 887–893

Electromigration of Sn-9wt.%Zn Solder


The morphological evolution of Sn-9wt.%Zn solder under electromigration at a current density of about 105 A/cm2 was examined. Sn extrusion was observed, suggesting that Sn is the dominant moving species under electromigration. In contrast, Zn appeared to be immobile. It was also found that the microstructure of the solder had a significant effect on the electromigration behavior. For the solder with fine Zn precipitates, the surface morphology of the solder was almost unchanged except for the formation of Sn extrusion sites at␣the anode side after electromigration. However, for the solder with coarse Zn precipitates, more Sn extrusion sites were observed, and they were located not only at the anode side but also within the solder. Coarse Zn precipitates appeared to block Sn migration, thus Sn migration was intercepted in front of the Zn precipitates. The Sn atoms accumulated there, which led to its extrusion. The blocking effect was found to depend strongly on the size and orientation of the Zn precipitates.


Electromigration Sn-9wt.%Zn microstructure Zn precipitates 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    S. Brandenburg and S. Yeh, Proc. Surface Mount International Conference and Exhibition, SMI 98, San Jose, CA, 23–27 August 1998 (Edina, MN: SMTA, 1998), p. 337Google Scholar
  2. 2.
    Y.L. Lin, C.W. Chang, C.M. Tsai, C.W. Lee, C.R. Kao, J. Electron. Mater. 35 (2006) 1010CrossRefGoogle Scholar
  3. 3.
    H.B. Huntington, Diffusion in Solids: Recent Developments, ed. A.S. Nowick and J.J. Burton (New York: Academic Press, 1975), pp. 303–352Google Scholar
  4. 4.
    E.C.C. Yeh, W.J. Choi, K.N. Tu, P. Elenius, H. Balkan, Appl. Phys. Lett. 80 (2002) 580CrossRefGoogle Scholar
  5. 5.
    Y.C. Hu, Y.H. Lin, C.R. Kao, K.N. Tu, J. Mater. Res. 18 (2003) 2544CrossRefGoogle Scholar
  6. 6.
    C.Y. Liu, C. Chen, C.N. Liao, K.N. Tu, Appl. Phys. Lett. 75 (1999) 58CrossRefGoogle Scholar
  7. 7.
    S.W. Chen, C.M. Chen, W.C. Liu, J. Electron. Mater. 27 (1998) 1193CrossRefGoogle Scholar
  8. 8.
    C.M. Chen, S.W. Chen, Acta Mater. 50 (2002) 2461CrossRefGoogle Scholar
  9. 9.
    Q.L. Yang, J.K. Shang, J. Electron. Mater. 34 (2005) 1363CrossRefGoogle Scholar
  10. 10.
    L.T. Chen, C.M. Chen, J. Mater. Res. 21 (2006) 962CrossRefGoogle Scholar
  11. 11.
    C.M. Chen, L.T. Chen, Y.S. Lin, J. Electron. Mater. 36 (2007) 168CrossRefGoogle Scholar
  12. 12.
    C.M. Chen, C.C. Huang, C.N. Liao, K.M. Liou, J. Electron. Mater. 36 (2007) 760CrossRefGoogle Scholar
  13. 13.
    H. Ye, C. Basaran, D.C. Hopkins, Int. J. Solids Struct. 41 (2004) 2743CrossRefGoogle Scholar
  14. 14.
    Y.C. Hsu, C.K. Chou, P.C. Liu, C. Chen, D.J. Yao, T. Chou, K.N. Tu, J. Appl. Phys. 033523 (2005) 98Google Scholar
  15. 15.
    C.C. Lu, S.J. Wang, C.Y. Liu, J. Electron. Mater. 32 (2003) 1515CrossRefGoogle Scholar
  16. 16.
    X.F. Zhang, J.D. Guo, J.K. Shang, Scripta Mater. 57 (2007) 513CrossRefGoogle Scholar
  17. 17.
    S.M. Kuo, K.L. Lin, J. Mater. Res. 22 (2007) 1240CrossRefGoogle Scholar
  18. 18.
    T.B. Massalski, ed., Binary Alloy Phase Diagrams (Materials Park, OH: ASM International, 1990)Google Scholar

Copyright information

© TMS 2008

Authors and Affiliations

  1. 1.Department of Chemical EngineeringNational Chung-Hsing UniversityTaichungTaiwan

Personalised recommendations