Skip to main content
Log in

Interfacial morphology and concentration profile in the unleaded solder/Cu joint assembly

  • Published:
Journal of Materials Science: Materials in Electronics Aims and scope Submit manuscript

Abstract

A joint assembly of lead-free solder/intermetallic layers/copper was prepared by hot-dipped solder coated on a copper substrate and then by thermal ageing at 100, 125, 150, and 170°C for 50, 100, 200, and 600 h, respectively. Results of interfacial morphologies and concentration profiles on the solder/copper joint were presented. Optical and scanning electron microscope (OM and SEM) were used to measure the thickness of intermetallic layers and then to illucidate the development of microstructure at the joint assembly. The phases of intermetallic compound were identified to be Cu3Sn and Cu6Sn5 by both X-ray mapping in electron probe micro-analysis (EPMA), and X-ray diffraction. The intermetallic layers, subtracted from the initial thickness formed by hot dipping, showed a linear dependence on the square root of ageing time at various ageing temperatures. The diffusion coefficients of intermetallic compounds are estimated by an Arrhenius equation, and the pre-exponential terms of Cu3Sn layer and Cu6Sn5 layer are 7.10×10-7cm2s-1 and 6.1×10-3cm2s-1, respectively. The associated activation energies of Cu3Sn layer and Cu6Sn5 layer are 57.03kJmol-1 and 83.76kJmol-1, respectively. A model of a diffusion-controlled mechanism is used to fit the concentration profiles of the joint assembly, and exhibits a fairly good quantitative agreement with the measured data. The initial thickness formed as soldering proceeds is also taken into account to evaluate the apparent thickness by introducing a term of corrected ageing time. ©1999 Kluwer Academic Publishers

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

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Z. Mei and J. W. Morris, Jr, J.Electron.Mater. 21 (1992) 599.

    Google Scholar 

  2. C. H. Reader, L. E. Felton, V. A. Tanzi and D. B. Knorr, J. Electron. Mater. 23 (1994) 611.

    Google Scholar 

  3. M. Mccormack and S. JIN, ibid. 23 (1994) 635.

    Google Scholar 

  4. M. Mccormack and S. Jin, ibid. 23 (1994) 687.

    Google Scholar 

  5. J. Glazer, ibid. 23 (1994) 693.

    Google Scholar 

  6. E. P. Wood and K. L. Nimmo, ibid. 23 (1994) 709.

    Google Scholar 

  7. S. K. Kang, ibid. 23 (1994) 701.

    Google Scholar 

  8. M. Mccormack and S. Jin, ibid. 23 (1994) 715.

    Google Scholar 

  9. F. Bartels and J. W. Morris, Jr, ibid. 23 (1994) 787.

    Google Scholar 

  10. D. Yao and J. K. Shang, IEEE Trans.Compon Hybrids Manuf.Technol.B. 19 (1996) 154.

    Google Scholar 

  11. L. E. Felton, C. H. Raeder and D. B. Knorr, J.Met. 45 (1993) 28.

    Google Scholar 

  12. M. Mccormack and S. Jin, ibid. 45 (1993) 36.

    Google Scholar 

  13. J. Glazer, Int.Mater.Rev. 40 (1995) 65.

    Google Scholar 

  14. H. K. Kim and K. N. Tu, Phys.Rev. B 53 (1996) 16027.

    Google Scholar 

  15. J. G. Duh, C. C. Young and Y. G. Lee, in Proceedings of the Second International Symposium on Electronic Packaging Technology, 1996, edited by K. Bi, X. Zong, S. Liu and F. Liu (Commercial Press Shanghai Plant, Shanghai, China) p. 330.

    Google Scholar 

  16. Y. G. Lee and J. G. Duh, in 1998 Proceedings Pan Pacific Microelectronics Symposium, Kona, Hawaii (Surface Mount Technology Association, Edina, Minnesota, USA) p. 501.

  17. J. S. Huang, J. Zhang, A. Cuevas and K. N. Tu, Mater.Chem.Phys. 49 (1997) 33.

    Google Scholar 

  18. Y. Wu, J. A. Sees et. al., J.Electron.Mater. 23 (1993) 759.

    Google Scholar 

  19. P. Vianco, P. F. Hlava and A. C. Kilgo, ibid. 23 (1994) 583.

    Google Scholar 

  20. P. T. Vianco, A. C. Kilgo and R. Grant, ibid. 24 (1995) 1493.

    Google Scholar 

  21. H. K. Kim, H. K. Liou and K. N. Tu, Appl.Phys.Lett. 66 (1995) 1237.

    Google Scholar 

  22. Z. Mei, A. J. Sunwoo and J. W. Morris, JR, Metall Trans.A 23 (1992) 857.

    Google Scholar 

  23. K. Hoshino, Y. Iijima and K. I. Hirtano, Trans.Jpn.Inst.Met. 21 (1980) 674.

    Google Scholar 

  24. K. N. Tu and R. D. Thompson, Appl.Phys.Lett. 67 (1995) 2795.

    Google Scholar 

  25. K. F. Dreyer, W. K. Neils, R. R. Chromik, D. Grosman and E. J. Cotts, ibid. 67 (1995) 2795.

    Google Scholar 

  26. W. Jost, in “Diffusion in Solids, Liquids, Gases” 3rd Edn (Academic Press, New York, 1960) p. 71.

    Google Scholar 

  27. G. V. Kidson, J.Nucl.Mater. 3 (1961) 21.

    Google Scholar 

  28. P. G. Shewmon, in “Diffusion in Solids” (McGraw-Hill, 1963) p. 30.

  29. M. G. Pecht, in “Soldering Process and Equipment” (John Wiley & Sons. New York, 1993) Ch. 2.

    Google Scholar 

  30. J. R. Manning, Phys.Rev. 16 (1960) 819.

    Google Scholar 

  31. M. Hansen, in “Constitution of Binary Alloys” (McGraw-Hill, New York, 1958) p. 633.

    Google Scholar 

  32. In “Binary Alloys Phase Diagrams” Vol. 2, 2nd Edn (ASM 1990) p. 1481.

  33. B. D. Bastow and D. H. Kirkwood, J.Inst.Met. 100 (1972) 24.

    Google Scholar 

  34. Fon Kon et al., in “Method of Numerical Calculation” (Country Guardagainst Industrial Publish, Bejing, China, 1978) p. 154.

    Google Scholar 

  35. F. Abautret and P. Eveno, Rev.Phys.Appl. 25 (1990) 1113.

    Google Scholar 

  36. J. I. Goldstein, D. E. Newbury, P. Echlin, D. C. Joy, C. Fiori and E. Lifshin, in “Scanning Electron Microscopy and X-ray Microanalysis” (Plenum Press, New York and London, 1992) p. 109.

    Google Scholar 

  37. E. L. Erickson, P. L. Hopkins and P. T. Vianco, J.Electron.Mater. 23 (1994) p. 583.

    Google Scholar 

  38. S. Bader, W. Gust and H. Heiber, Acta.Metall.Mater. 43 (1995) 329.

    Google Scholar 

  39. J. G. Duh, PhD Thesis, Purdue University, USA (1983).

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to J. G. Duh*.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Lee, Y.G., Duh*, J.G. Interfacial morphology and concentration profile in the unleaded solder/Cu joint assembly. Journal of Materials Science: Materials in Electronics 10, 33–43 (1999). https://doi.org/10.1023/A:1008975006706

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/A:1008975006706

Keywords

Navigation