Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-10T23:56:32.386Z Has data issue: false hasContentIssue false
  • English
  • Français

Microstructural evolution in lead-free solder alloys: Part I. Cast Sn–Ag–Cu eutectic

Published online by Cambridge University Press:  03 March 2011

Sarah L. Allen ,
Michael R. Notis ,
Richard R. Chromik  and
Richard P. Vinci
Sarah L. Allen
Affiliation:
Department of Materials Science and Engineering, Lehigh University, Whitaker Laboratory,5 East Packer Avenue, Bethlehem, Pennsylvania 18015
Michael R. Notis
Affiliation:
Department of Materials Science and Engineering, Lehigh University, Whitaker Laboratory,5 East Packer Avenue, Bethlehem, Pennsylvania 18015
Richard R. Chromik
Affiliation:
Department of Materials Science and Engineering, Lehigh University, Whitaker Laboratory,5 East Packer Avenue, Bethlehem, Pennsylvania 18015
Richard P. Vinci
Affiliation:
Department of Materials Science and Engineering, Lehigh University, Whitaker Laboratory,5 East Packer Avenue, Bethlehem, Pennsylvania 18015
Get access

Abstract

Coarsening of the ternary eutectic in cast Sn–Ag–Cu lead-free solder alloys was investigated. The process was found to follow r3 ∝ t kinetics where r is the rod radius of the dispersed phase and t is time. The effective activation energy for the process is 69 ± 5 kJmol-1. The two types of intermetallic rods, Cu6Sn5 and Ag3Sn, in the eutectic structure coarsen at different rates, with each having a different rate-controlling mechanism. The overall coarsening kinetics for the Sn–Ag–Cu ternary eutectic is significantly slower than that found for the Pb-Sn eutectic, which has implications for long-term reliability of Sn–Ag–Cu solder joints.

Keywords

AgingKineticsJoining
Type
Articles
Information
Journal of Materials Research , Volume 19 , Issue 5 , May 2004 , pp. 1417 - 1424
Copyright
Copyright © Materials Research Society 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Jung, K. and Conrad, H., Microstructure coarsening during static annealing of 60Sn40Pb solder joints II: Eutectic coarsening kinetics. J. Electron Mater. 30, 1303 (2001).Google Scholar
2Allen, S.L., Notis, M.R., Chromik, R.R., Vinci, R.P., Lewis, D.J. and Schaefer, R., Microstructural evolution in lead-free solder alloys: Part II. Directionally solidified Sn-Ag-Cu, Sn-Cu and Sn-Ag. J. Mater. Res. 19, 1425 (2004).Google Scholar
3Gibson, A.W., Choi, S.L., Subramanian, K.N. and Bieler, T.R. in Design and Reliability of Solders and Solder Interconnections, edited by Mahidhara, R.K., Frear, D.R., Sastry, S.M.L., Murty, K.L., Liaw, P.K., and Winterbottom, W. (The Minerals, Metals and Materials Society, Warrendale, PA, 1997), p. 97.Google Scholar
4Dyson, B.F., Diffusion of gold and silver in tin single crystals. J. App. Phys. 37, 2375 (1966).CrossRefGoogle Scholar
5Greenwood, G.W., The growth of dispersed precipitates in solutions. Acta Metall. 4, 243 (1956).CrossRefGoogle Scholar
6Lifshitz, I.M. and Slyozov, V.V., The kinetics of precipitation from supersaturated solid solutions. J. Phys. Chem. Solids 19, 35 (1961).CrossRefGoogle Scholar
7Wagner, C., Theorie der altering von niederschlägen durch umlösen (Ostwald-reifung). Z. Elektrochem. 65, 581 (1961).Google Scholar
8Ardell, A., Isotropic fiber coarsening in unidirectionally solidified eutectic alloys,. Metall. Trans. 3, 1395 (1971).Google Scholar
9Cline, H.E., Shape instabilities of eutectic composites at elevated temperatures. Acta Metall. 19, 481 (1971).CrossRefGoogle Scholar
10Rayleigh, Lord, On the instability of jets. Lond. Math. Soc. Proc. 10 4. (1879).Google Scholar
11Smartt, H.B. and Courtney, T.H., The kinetics of coarsening in the Al-Al3Ni system. Metall. Trans. A 7A, 123 (1976).CrossRefGoogle Scholar
12Lin, L.Y., Courtney, T.H., Stark, J.P. and Ralls, K.M., The thermal stability of the fibrous copper-chromium eutectic. Metall. Trans. A 7A, 1435 (1976).Google Scholar
13Dyson, B.F., Thomas, A.R. and Turnbull, D., Interstitial diffusion of copper in tin. J. Appl. Phys. 38, 3408 (1967).CrossRefGoogle Scholar
14Meakin, J.D. and Klokholm, E., Self-diffusion in tin single crystals. Trans. AIME 280, 463 (1960).Google Scholar
15 U.R. Kattner: Data from thermodynamically evaluated Sn–Ag and Sn-Cu binary phase diagrams (personal communication, 2002).Google Scholar
16Holmes, W.C. and Hoyt, J.J. in Nucleation and Growth Processes in Materials, edited by Gonis, A., Turchi, P.E.A., and Ardell, A.J. (Mater. Res. Symp. Soc. Proc. 580, Warrendale, PA, 2000), p. 315.Google Scholar
17Moon, K.W., Boettinger, W.J., Kattner, U.R., Biancaniello, F.S. and Handwerker, C.A., Experimental and thermodynamic assessment of Sn-Ag-Cu solder alloys. J. Electron. Mater. 29, 1122 (2000).CrossRefGoogle Scholar