Journal of Electronic Materials

, Volume 31, Issue 2, pp 161–167 | Cite as

Determination of the eutectic structure in the Ag-Cu-Sn system

  • Daniel Lewis
  • Sarah Allen
  • Michael Notis
  • Adam Scotch
Regular Issue Paper

Abstract

A search for lead-free solder alloys has produced an alloy in the Ag-Cu-Sn system. This alloy is of great importance to the soldering community, and proper determination of structure, processing, and properties will be significant. In the present study, tin-rich alloys were fabricated to better determine the much-debated morphology of secondary and tertiary phases in the eutectic structure. A deep etching procedure was used to reveal the growth structure of monovariant “eutectic-like” reactions as well as the ternary eutectic reaction. Scanning electron microscopy (SEM) and electron-probe microanalysis (EPMA) verified the three-phase nature of the eutectic. The rodlike eutectic structure in this system is consistent with the more simplified volume fraction and surface energy models that have been presented in the literature.

Key words

Lead-free solder alloy silver-copper-tin eutectic microstructure 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    C.M. Miller, I.E. Anderson, and J.F. Smith, J. Electron. Mater. 23, 595 (1994).Google Scholar
  2. 2.
    I.E. Anderson, F.G. Yost, J.F. Smith, C.M. Miller, and R.L. Terpstra, inventors; Pb-Free Sn-Ag-Cu Ternary Eutectic Solder, Patent number 5,527,628 (June 18, 1996).Google Scholar
  3. 3.
    K.W. Moon, W.J. Boettinger, U.R. Kattner, F.S. Biancaniello, C.A. Handwerker, J. Electron. Mater. 29, 1122 (2000).CrossRefGoogle Scholar
  4. 4.
    M.E. Loomans and M.E. Fine, Metall. Mater. Trans. A 31A, 1155 (2000).Google Scholar
  5. 5.
    F.C. Frank and K.E. Puttick, Acta Metall. 4, 206 (1956).CrossRefGoogle Scholar
  6. 6.
    D. Cooksey, D. Munson, M. Wilkinson, and A. Hellawell, Phil. Mag. 10, 745 (1964).Google Scholar
  7. 7.
    W. Minford, R. Bradt, and V. Stubican, J. Am. Ceram. Soc. 62, 154 (1979).CrossRefGoogle Scholar
  8. 8.
    K. Jackson and J. Hunt, Trans. TMS-AIME 236, 1129 (1966).Google Scholar
  9. 9.
    T. Himemiya and T. Umeda, Mater. Trans. JIM 40, 665 (1999).Google Scholar
  10. 10.
    M. Taylor, R. Fidler, and R. Smith, Metall. Trans. 2, 1793 (1971).Google Scholar
  11. 11.
    M. Croker, R. Fidler, and R. Smith, Proc. R. Soc. London A 335, 15 (1973).CrossRefGoogle Scholar
  12. 12.
    M.A. Ruggiero and J. Rutter, Mater. Sci. Technol. 13, 5 (1997).Google Scholar
  13. 13.
    I.E. Jackson, Metallography 14, 107 (1981).CrossRefGoogle Scholar

Copyright information

© TMS-The Minerals, Metals and Materials Society 2002

Authors and Affiliations

  • Daniel Lewis
    • 1
  • Sarah Allen
    • 2
  • Michael Notis
    • 1
  • Adam Scotch
    • 1
  1. 1.Department of Materials Science and EngineeringLehigh UniversityBethlehem
  2. 2.Manchester Materials Science CentreUniversity of Manchester and University of Manchester Institute of Science and TechnologyManchesterUnited Kingdom

Personalised recommendations