Void Formation by Kirkendall Effect in Solder Joints

  • M. J. M. Hermans
  • M. H. Biglari


From experiments by Smigelskas and Kirkendall [1], it was demonstrated that in a binary solution the rates at which the two types of atoms diffuse are not the same. Due to this phenomenon, it has frequently been observed that voids, or pores, form in the region of the diffusion zone from which there is a flow of mass. The formation of these voids strongly influences the mechanical properties. The Kirkendall experiment studied the diffusion of zinc and copper. Similar results have been found for a large range of binary alloys. In soldered joints, due to diffusion at the interfaces solder/substrate, void formation has been observed. For the new lead free solder alloys, the details of void formation by the Kirkendall effect have not been studied in great detail. Although a large amount of data are published, a comprehensive and detailed overview is lacking. Different researchers employ different process condition (reflow temperature and time, number of reflows, annealing temperature and time), which makes the comparison difficult. In general, only a reference is made to the occurrence of Kirkendall voids. In the first part of this paper, the principles of diffusion and the Kirkendall effect will be briefly described. This is followed by the mechanism of void formation. Finally, the effects in soldered joints will be discussed for a number of solder systems, which experience void formation by the Kirkendall effect.


Solder Joint Diffusion Couple Void Formation Interdiffusion Coefficient Kirkendall Void 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. 1.
    Smigelskas AD, Kirkendall EO (1947) Trans AIME 171:130Google Scholar
  2. 2.
    Reed-Hill RE (1973) Physical metallurgical principles, 2nd edn. D. Van Nostrand Company, ISBN 0-442-06864-6, pp 378–406Google Scholar
  3. 3.
    Porter DA, Easterling, KE (1981) Phase transformations in metals and Alloys, 1st edn. Van Nostrand Reinhold, ISBN 0-442-30439-0Google Scholar
  4. 4.
    van Dal MJH, Gusak AM, Cserhati C, Kodentsov AA, van Loo FJJ (2001) Microstructural stability of the Kirkendall plane in solid state diffusion. Phys Rev Lett 86(15):3352–3355CrossRefGoogle Scholar
  5. 5.
    Paul A, van Dal MJH, Kodentsov AA, van Loo FJJ (2004) The Kirkeldall effect in multiphase diffusion. Acta Mater 52:623–630CrossRefGoogle Scholar
  6. 6.
    Paul A (2004) The Kirkendall effect in solid state diffusion, PhD thesis, Eindhoven University of Technology, ISBN 90-386-2646-0Google Scholar
  7. 7.
    Roönkä K, van Loo FJJ, Kivilahti JK (1998) A diffusion-kinetic model for predicting solder/conductor interactions in high density interconnections. Metal Mater Trans 29A:2951CrossRefGoogle Scholar
  8. 8.
    Laurila T, Vuorinen V, Kivilahti JK (2005) Interfacial reactions between lead-free solders and common base materials. Mater Sci Eng R 49:1–60Google Scholar
  9. 9.
    Zeng K, Stierman R, Chiu T, Edwards D, Ano K, Tu KN (2005) Kirkendall void formation in eutectic SnPb solder joints on bare Cu and its effect on joint reliability. J Appl Phys 97:024508CrossRefGoogle Scholar
  10. 10.
    Liu CY, Tu KN, Sheng TT, Tung CH, Frear DR, Elenius P (2000) Electron microscopy study of interfacial reaction between eutectic SnPb and Cu/Ni(V)/Al thin film metallization. J Appl Phys 87(2):750–754CrossRefGoogle Scholar
  11. 11.
    Zeng K, Tu KN (2002) Six cases of reliability study of Pb-free solder joints in electronic packaging technology. Mater Sci Eng R38:55–105Google Scholar
  12. 12.
    Benneman S, Graff A, Schischka J, Petzold M, Theuss H, Dangelmaier J, Pressel K (2006) A SEM and TEM study of the interconnect microstructure and reliability for a new XFLGA package, 1st Electronics System integration Technology Conference, Dresden Germany, 5th–7th September 2006, 26–34Google Scholar
  13. 13.
    He M, Chen Z, Qi G (2004) Solid state interfacial reaction of Sn–37Pb and Sn–3.5Ag solders with Ni–P under bump metallization. Acta Mater 52:2047–2056CrossRefGoogle Scholar
  14. 14.
    He M, Chen Z, Qi GJ (2005) Mechanical strength of thermally aged Sn–3.5Ag/Ni-P Solder joints. Metal Mater Trans A 36A:65–75CrossRefGoogle Scholar
  15. 15.
    Jeon YD, Paik KW, Bok KS, Choi WS, Cho CL (2001) Studies on Ni–Sn intermetallic compound and P-rich Ni layer at the electroless nickel UBM solder interface and their effects on flip chip solder reliability. In: Electronic components and technology conference, IEEEGoogle Scholar
  16. 16.
    Li D, Liu C, Conway PP (2005) Characteristics of intermetallics and micromechanical properties during thermal ageing of Sn–Ag–Cu flip-chip solder interconnects. Mater Sci Eng A 391:95–103CrossRefGoogle Scholar
  17. 17.
    Jang JW, Kim PG, Tu KN, Frear DR, Thompson P (1999) Solder reaction-assisted crystallization of electroless Ni–P under bump metallization in low cost flip chip technology. J Appl Phys 85(12):8456–8463CrossRefGoogle Scholar
  18. 18.
    Islam MN, Chan YC, Rizvi MJ, Jillek W (2005) Investigations of interfacial reactions of Sn–Zn based and Sn–Ag–Cu lead-free solder alloys as replacement for Sn–Pb solder. J Alloy Compd 400:136–144CrossRefGoogle Scholar

Copyright information

© Springer-Verlag London Limited 2011

Authors and Affiliations

  1. 1.Delft University of Technology, Materials Science and Engineering Joining and Mechanical BehaviourDelftThe Netherlands
  2. 2.Mat-Tech BVEindhovenThe Netherlands

Personalised recommendations