Tin pest in Sn-0.5 wt.% Cu lead-free solder


Tin pest (the product of the allotropic transformation of β-tin into α-tin at temperatures below 286 K) has been observed in a Sn-0.5 wt.% Cu solder alloy. Some 40 percent of the specimen surface was transformed into gray tin after aging at 255K for 1.5 years, and after 1.8 years, the proportion increased to about 70 percent. The degree of transformation in work-hardened areas is much higher than in other areas, suggesting residual stress might provide an additional driving force for the transformation into α-tin. The allotropic change results in a 26 percent increase in volume, and cracks are initiated to accommodate the changes in volume. Results indicate that tin pest could lead to total disintegration of micro-electronic solder joints. The tin-copper eutectic system may become a prominent lead-free solder, and tin pest could have major ramifications on service lifetime of electronic assemblies.

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


  1. 1.

    D. Napp, SAMPE Journal, 32 (1996), p. 59.

    CAS  Google Scholar 

  2. 2.

    B. Trumble, IEEE Spectrum, 35 (1998), p. 55.

    Article  Google Scholar 

  3. 3.

    For example, Lead Free Solder Project, Final Report, NCMS Report 0401RE96 (Ann Arbor, MI: National Center for Manufacturing Sciences, August 1997).

  4. 4.

    The Properties of Ti, Publ. 218 (Uxbtridge, U.K.: Tin Research Institute, 1954).

  5. 5.

    Y. Kariya, C.R. Gagg, and W.J. Plumbridge, Soldering and Surface Mount Technology, in print.

  6. 6.

    W.G. Burgers and L.J. Groen, Faraday Soc. Discussions, 23 (1957), p. 183.

    Article  Google Scholar 

  7. 7.

    H.E. Hedges, Tin and its Alloys (London: Edward Arnold Ltd., 1960), p. 51.

    Google Scholar 

  8. 8.

    G.V. Ratnor and R.W. Smith, Proc. Roy. Soc., 224 (1958), p. 101.

    Google Scholar 

Download references

Author information



Additional information

For more information, contact Y. Kariya, The Open University, Materials Engineering Department, Walton Hall, Milton Keynes, MK7 6AA, United Kingdom; 011-44-1908-652-630; fax 011-44-1908-655-120; e-mail y.kariya@open.ac.uk.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Kariya, Y., Williams, N., Gagg, C. et al. Tin pest in Sn-0.5 wt.% Cu lead-free solder. JOM 53, 39–41 (2001). https://doi.org/10.1007/s11837-001-0101-0

Download citation


  • Residual Stress
  • Solder Joint
  • Solder Alloy
  • Allotropic Transformation
  • Service Lifetime