Monitoring the Growth of the α Phase in Tin Alloys by Electrical Resistance Measurements

The β phase of tin is stable only down to 13°C. Below that temperature the thermodynamically stable phase is α tin, more commonly known as tin pest. This phase has gained notoriety because of the catastrophic consequences of the transforming metal. Interest in this subject increased after the transition from tin–lead to lead-free solder, driven by European restriction of the use of hazardous substances (RoHS) legislation. Lead-free alloys contain from 95% to 99% tin and could potentially be susceptible to the β/α transformation mentioned above. The nucleation of the α phase takes a long time to occur, months or even years, especially in alloys of tin. For this reason this phenomenon is particularly difficult to study. The growth, however, occurs faster, and this paper describes a procedure for observing and measuring growth based on electrical measurements. Furthermore, a sample preparation technique that considerably accelerates the nucleation in alloys is described. Seven binary alloys were tested with this procedure and ranked in terms of their propensity to transform. Experimental results demonstrated that the α crystal growth is not stopped by alloying, but just decelerated, and that lead and bismuth are the most effective at this. The same procedure was then demonstrated successfully on printed circuit boards and hence is shown to be a general method for monitoring α tin growth in critical field applications.

This is a preview of subscription content, log in to check access.

References

  1. 1.

    L.D. Brownlee, Nature 166, 482 (1950). doi: 10.1038/166482a0.

    Article  ADS  CAS  Google Scholar 

  2. 2.

    W.L. Williams, ASTM Spec. Tech. Publ. 189, 149 (1956). doi: 10.1520/STP44117S

  3. 3.

    A. Bornemann, ASTM Spec. Tech. Publ. 189, 129 (1956). doi: 10.1520/STP44116S

  4. 4.

    E.O. Hall, The Mechanism of Phase Transformations in Metals (London, UK: Institute of Metals, 1955), pp. 87–92.

  5. 5.

    W.J. Plumbridge, J. Mater. Sci: Mater. Electron. 18, 307 (2007). doi:10.1007/s10854-006-9025-3

    Article  CAS  Google Scholar 

  6. 6.

    W.J. Plumbridge, Circuit Word 33, 1 (2007). doi:10.1108/03056120710723661.

    Google Scholar 

  7. 7.

    W.J. Plumbridge, J. Electron. Mater. 37, 2 (2008). doi:10.1007/s11664-007-0165-x.

    Article  Google Scholar 

  8. 8.

    K. Sweatman, S. Suenaga, and T. Nishimura, Proceedings of JEDEX (San Jose, 2005).

  9. 9.

    G.V. Raynor and R.W. Smith, Proc. Roy. Soc. 244A, 101 (1958).

    ADS  Google Scholar 

  10. 10.

    J.H. Becker, J. Appl. Phys. 29, 1110 (1958). doi: 10.1063/1.1723369.

    Article  ADS  CAS  Google Scholar 

  11. 11.

    N.A. Gorynuova, Dokl. Akad. Nauk SSSR 75, 51 (1950).

    Google Scholar 

  12. 12.

    R.R. Rogers and J.F. Fydell, J. Electrochem. Soc. 100, 383 (1953).

    Article  CAS  Google Scholar 

  13. 13.

    R.G. Wolfson, M.E. Fine and A.W. Ewald, J. Appl. Phys. 31, 1973 (1960).

    Article  ADS  CAS  Google Scholar 

  14. 14.

    D. Di Maio and C. Hunt, J. Mater. Sci: Mater. Electron. 20, 386 (2009). doi: 10.1007/s10854-008-9739-5

  15. 15.

    A. D. Styrkas, Inor. Mat. 39, 8 (2003).

    Google Scholar 

  16. 16.

    J. Murray, D.A. Knopf and A.K. Bertram, Nature, 434, 10 (2005). doi:10.1038/434010a.

    Article  ADS  Google Scholar 

Download references

Acknowledgements

The work was carried out as part of a project in the Materials Characterisation Programme of the UK Department for Innovation, Universities, and Skills. The authors are grateful to Milos Dusek for␣useful discussions around the experimental technique.

Author information

Affiliations

Authors

Corresponding author

Correspondence to D. Di Maio.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Di Maio, D., Hunt, C.P. Monitoring the Growth of the α Phase in Tin Alloys by Electrical Resistance Measurements. Journal of Elec Materi 38, 1874–1880 (2009). https://doi.org/10.1007/s11664-009-0822-3

Download citation

Keywords

  • Solder alloys
  • electronic packaging
  • allotropic transformations