Fundamental Properties of Pb-Free Solder Alloys

  • Carol Handwerker
  • Ursula Kattner
  • Kil-Won Moon

The search for a global Pb-free replacement for Sn-Pb eutectic alloy has been an evolving process as the threat of a regional lead ban became a reality in July 2006. Over the twelve years from 1994 through 2006, the manufacturing, performance, and reliability criteria for Pb-free solder joints have become increasingly complex as relationships between the solder alloy, the circuit board materials and construction, and the component designs and materials have been revealed through widespread experimentation by companies, industrial consortia, and university researchers. The focus of this chapter is to examine the primary criteria used to develop the current generation of Pb-free solder alloys, the tradeoffs made between various properties once these primary criteria were satisfied, and the open questions regarding materials and processes that are as yet unanswered.


Solder Joint Solder Alloy Accelerate Thermal Cycling Pasty Range Fillet Lift 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    NCMS Lead-Free Solder Project Final Report, NCMS, National Center for Manufacturing Sciences, 3025 Boardwalk, Ann Arbor, Michigan 48108-3266, Report 0401RE96, August 1997, and CD-ROM database of complete dataset, including micrographs and raw data, August, 1999. Information on how to order these can be obtained from:
  2. 2.
    I. Artaki, D. Noctor, C. Desantis, W. Desaulnier, L. Felton, M. Palmer, J. Felty, J. Greaves, C.A. Handwerker, J. Mather, S. Schroeder, D. Napp, T.Y. Pan, J. Rosser, P. Vianco, G. Whitten, and Y. Zhu. Research trends in leadfree soldering in the US: NCMS lead-free solder project (Keynote). 602-605. 1999. IEEE Computer Society. Proceedings-EcoDesign ’99: First International Symposium on Environmentally Conscious Design and Inverse Manufacturing; February 1-3, 1999; Tokyo, Japan.Google Scholar
  3. 3.
    C.A. Handwerker, E.E. de Kluizenaar, K. Suganuma, F.W. Gayle, Major International Lead-Free Solder Studies, Eds., Puttlitz K.J., Stalter K.A. Handbook of Lead-Free Solder Technology and Microelectronic Assemblies. New York: Marcel Dekker. In press.Google Scholar
  4. 4.
    C.A. Handwerker, NCMS lead-free solder project: a summary of results, conclusions and recommendations. 1999. IPC. IPC Work ’99: An International Summit on Lead-Free Electronics Assemblies; Proceedings; October 23-28, 1999; Minneapolis, MN.Google Scholar
  5. 5.
    F. Gayle, G. Becka, A. Syed, J. Badgett, G. Whitten, T.-Y. Pan, A. Grusd, B. Bauer, R. Lathrop, J. Slattery, I. Anderson, J. Foley, A. Gickler, D. Napp, J. Mather, C. Olson, High temperature lead-free solder for microelectronics J. Minerals, Metals & Materials Soc. 53 (6): 17-21 June 2001.Google Scholar
  6. 6.
    F.W. Gayle, Fatigue-Resistant, High Temperature Solder, Advanced Materials & Processes 159 (4), April 2001, p. 43-44.Google Scholar
  7. 7.
    F.W. Gayle, G. Becka, A. Syed, J. Badgett, G. Whitten, T.-Y. Pan, A. Grusd, B. Bauer, R. Lathrop, J. Slattery, I. Anderson, J. Foley, A. Gickler, D. Napp, J. Mather, C. Olson, High temperature lead-free solder for microelectronics, NCMS, Ann Arbor, MI, 2001 (published on CD-ROM).Google Scholar
  8. 8.
    J.H. Vincent, B.P. Richards, D.R. Wallis, I. Gunter, M. Warwick, H.A.H. Steen, P.G. Harris, M.A. Whitmore, S. Billington, A.C. Harman, and E. Knight, “Alternative solders for electronics assemblies. Part 2: UK progress and preliminary trials,” Circuit World, 19: pp.32-34, 1993.CrossRefGoogle Scholar
  9. 9.
    Alternative Solders for Electronic Assemblies - Final Report of DTI Project 1991-1993, GEC Marconi, ITRI, BNR Europe, and Multicore Solders. DTI Report MS/20073, issued 10.26.93.Google Scholar
  10. 10.
    H. Vincent and G. Humpston, “Lead-free solders for electronic assembly,” GEC Journal of Research, 11: pp.76-89, 1994.Google Scholar
  11. 11.
    M. Harrison and J.H. Vincent, “Improved Design Life and Environmentally Aware Manufacturing of Electronic Assemblies by Lead-Free Soldering,”
  12. 12.
    M.R. Harrison and J. Vincent, “IDEALS: Improved design life and environmentally aware manufacturing of electronics assemblies by lead-free soldering”, Proc. IMAPS Europe ’99, (Harrogate, GB), June 1999.Google Scholar
  13. 13.
    C.A. Handwerker, F.W. Gayle, E. de Kluizenar, K. Suganama, Major International Lead (Pb)- Free Solder Studies, in Handbook of Lead-free Solder Technology for Microelectronics Assemblies, Eds. K.J. Puttlitz and K.A. Stalter, Marcel Dekker, 2004.Google Scholar
  14. 14.
    M.H. Biglari, M. Oddy, M.A. Oud, P. Davis, E.E. de Kluizenaar, P. Langeveld, and D. Schwarzbach, “Pb-free solders based on SnAgCu, SnAgBi, SnAg, and SnCu, for wave soldering of electronic assemblies,” Proc. Electronics Goes Green 2000+, (Berlin, Germany) September 2000.Google Scholar
  15. 15.
    J. Bath, C.A. Handwerker, E. Bradley, Research Update: Lead-Free Solder Alternatives, Circuits Assembly, May 2000, 31-40.Google Scholar
  16. 16.
    E. Bradley, NEMI Pb-free interconnect task group report. 1999. IPC Works ’99: An International Summit on Lead-Free Electronics Assemblies; Proceedings; October 23-28, 1999; Minneapolis, MN.Google Scholar
  17. 17.
    A. Rae and C.A. Handwerker, Circuits Assembly, April 2004, 20-25.Google Scholar
  18. 18.
    E. Bradley, J. Bath, C.A. Handwerker, R.D. Parker, Lead-Free Electronics: iNEMI Projects Lead to Successful Manufacturing, 2007, in press.Google Scholar
  19. 19.
    K. Suganuma, Research and development for lead-free soldering in Japan. 1999. IPC. IPC Work ’99: An International Summit on Lead-Free Electronics Assemblies; Proceedings; October 23-28, 1999; Minneapolis, MN.Google Scholar
  20. 20.
    JEITA Lead-free Roadmap 2002 for Commercialization of Lead-free Solder, September 2002, Lead-Free Soldering Roadmap Committee, Technical Standardization Committee on Electronics Assembly Technology, JEITA (Japan Electronics and Information Technology Industries Association).Google Scholar
  21. 21.
    NEDO Research and Development on Lead-Free Soldering, Report No.00-ki-17, JEIDA, Tokyo, Japan, 2000.Google Scholar
  22. 22.
    Lead-Free Soldering - An Analysis of the Current Status of Lead-Free Soldering, Report from the UK Department of Trade and Industry. Copies can be obtained from the ITRI website:
  23. 23.
    Second European Lead-Free Soldering Technology Roadmap, February 2003 and Framework for an International Lead-Free Soldering Roadmap, December 2002, Soldertec, available at
  24. 24.
    ASM Binary Alloy Phase Diagrams, Eds. T.B. Massalski, H. Okamoto, P.R. Subramanian, L. Kacprzak, ASM International, 1990.Google Scholar
  25. 25.
    U.R. Kattner, Phase diagrams for lead-free solder alloys, JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY, 54 (12): 45-51, 2002.Google Scholar
  26. 26.
    U.R. Kattner, C.A. Handwerker. Calculation of phase equilibria in candidate solder alloys. Zeitschrift fur Metallkunde 2001; 92(7): 740-746.Google Scholar
  27. 27.
    K.W. Moon, W.J. Boettinger, U.R. Kattner, F.S. Biancaniello, C.A. Hand-werker. Experimental and thermodynamic assessment of Sn-Ag-Cu solder alloys. Journal of Electronic Materials 2000; 29(10): 1122-1136.CrossRefGoogle Scholar
  28. 28.
    U.R. Kattner and W.J. Boettinger, “On the Sn-Bi-Ag ternary phase-diagram,” Journal of Electronic Materials 23 (1994) 603-10.CrossRefGoogle Scholar
  29. 29.
    K.W. Moon, W.J. Boettinger, U.R. Kattner, C.A. Handwerker, D.J. Lee, The effect of Pb contamination on the solidification behavior of Sn-Bi solders, J Elec. Mater. 30 (1): 45-52 (2001).CrossRefGoogle Scholar
  30. 30.
    S. Chada, W. Laub, R.A. Fournelle, and D. Shangguan, Copper substrate dissolution in eutectic Sn-Ag Solder and its Effect on Microstructure, J. Electronic Mater. 29, 1214-1221 (2000).CrossRefGoogle Scholar
  31. 31.
    T.M. Korhonen, P. Su, S.J. Hong, M.A. Korhonen, and C.-Y. Li, Reactions of Lead-Free Solders with CuNi Metallizations, J. Electronic Mater. 29 1194-1199 (2000).CrossRefGoogle Scholar
  32. 32.
    D. Swenson, The effects of suppressed beta tin nucleation on the microstructural evolution of lead-free solder joints, J. Mater. Sci. Mater. Electronics, 18 39-54 (2007).CrossRefGoogle Scholar
  33. 33.
    J.W. Jang and D. Frear, unpublished research.Google Scholar
  34. 34.
    JCAA/JG-PP No-Lead Solder Project: -55°C to +125°C Thermal Cycle Testing Final Project, Rockwell Collins, D. Hillman and R. Wilcoxon, May 28, 2006.Google Scholar
  35. 35.
    K.S. Kim, S.H. Huh, and K. Suganuma, Effects of cooling speed on microstructure and tensile properties of Sn-Ag-Cu alloys, Mater. Sci. Eng. A. 333 106-114 (2002).CrossRefGoogle Scholar
  36. 36.
    D.W. Henderson, T. Gosselin, A. Sarkhel, S.K. Kang, W.K. Choi, D.Y. Shih, C. Goldsmith, and K.J. Puttlitz, Ag3Sn plate formation in the solidification of near ternary eutectic Sn-Ag-Cu alloys, J. Mater. Res., 17 2775-2778 (2002).CrossRefGoogle Scholar
  37. 37.
    I.E. Anderson, J.C. Foley, B.A. Cook, J. Harringa, R.L. Terpstra, O. Unal, Alloying effects in near-eutectic Sn-Ag-Cu solder alloys for improved microstructural stability, J. Electron. Mater. 30 (9): 1050-1059 (2001).CrossRefGoogle Scholar
  38. 38.
    I.E. Anderson, B.A. Cook, J. Harringa, R.L. Terpstra, Microstructural modifications and properties of Sn-Ag-Cu solder joints induced by alloying, J. Electron.Mater. 31, 1166-1174 (2002).CrossRefGoogle Scholar
  39. 39.
    K.L. Buckmaster, J.J. Dziedzic, M.A. Masters, B.D. Poquette, G.W. Tormoen, D. Swenson, D.W. Henderson, T. Gosselin, S.K. Kang, D.Y. Shih and K.J. Put-tlitz, Presented at the TMS 2003 Fall Meeting, Chicago, IL, November, 2003.Google Scholar
  40. 40.
    M.A. Dudek, R.S. Sidhu, and N. Chawla, Novel rare-earth-containing lead-free solders with enhanced ductility, J. Metals 58 (6) 57-62 (2006).Google Scholar
  41. 41.
    K. Suganuma, Microstructural features of lift-off phenomenon in through hole circuit soldered by Sn-Bi. Scripta Materialia 1998; 38(9):1333-1340.CrossRefGoogle Scholar
  42. 42.
    W.J. Boettinger, C.A. Handwerker, B. Newbury, T.Y. Pan, J.M. Nicholson, Mechanism of fillet lifting in Sn-Bi alloys, J. Elec. Mater., 31 (5): 545-550 MAY 2002.CrossRefGoogle Scholar
  43. 43.
    H. Takao, H. Hasegawa, Influence of alloy composition on fillet-lifting phenomenon in Sn-Ag-Bi alloys, J. Elec. Mater., 30(2001), 513-520.CrossRefGoogle Scholar
  44. 44.
    P. Biocca, Solder Paste: What are the process requirements to achieve reliable lead-free wave soldering?,
  45. 45.
  46. 46.
    K.-W. Moon, U.R. Kattner, and C.A. Handwerker, The Effect of Bi Contamination on the Solidification Behavior of Sn-Pb Solder, J. Elec. Mater. Nov. 2006.Google Scholar
  47. 47.
    NIST Thermodynamic Database for Solder Alloys, http://www.metallurgy.nist. gov/phase/solder/
  48. 48.
    J.-O. Andersson, T. Helander, L. Höglund, P. Shi, and B. Sundman, Thermo-Calc and DICTRA, Computational Tool for Materials Science, Calphad 26 (2002) 273-312.Google Scholar
  49. 49.
    W.J. Boettinger, U.R. Kattner, S.R. Coriell, Y.A. Chang and B.A. Mueller, A Development of Multicomponent Solidification Micromodels Using a Thermodynamic Phase Diagram Data Base, in Modeling of Casting, Welding and Advanced Solidification Processes, VII, Eds. M. Cross and J. Campbell, TMS, Warrendale, PA, 1995, 649-656.Google Scholar
  50. 50.
    D.W.G. White, Surface tensions of Pb, Sn, and Pb-Sn alloys, Metallurgical Transactions, 2 (1971) 3067-3071.CrossRefGoogle Scholar
  51. 51.
    I. Ohnuma, X.J. Liu, H. Ohtani, K. Anzai, R. Kainuma, K. Ishida, Development of thermodynamic database for micro-soldering alloys, Electronics Packaging Technology Conference, 2000. (EPTC 2000). Proceedings of 3rd Conference, 2000, 91-96.Google Scholar
  52. 52.
    I. Ohnuma, M. Miyashita, K. Anzai, X.J. Liu, H. Ohtani, R. Kainuma, Phase equilibria and the related properties of Sn-Ag-Cu based Pb-free solder alloys. J. Elec. Mater. 2000; 29(10): 1137-1144.CrossRefGoogle Scholar
  53. 53.
    N.-C. Lee. Prospect of lead-free alternatives for reflow soldering. 1999. ICP. IPC Work ’99: An International Summit on Lead-Free Electronics Assemblies; Proceedings; October 23-28, 1999; Minneapolis, MN.Google Scholar
  54. 54.
    E. Bradley and J. Hranisavljevic, ECTC, 50th Electronic Components & Technology Conference, IEEE Transactions on Electronics Packaging Manufacturing 24:4 (10/2001) 255-260.CrossRefGoogle Scholar
  55. 55.
    J.P. Clech, Report to NIST on Review and Analysis of Lead-Free Solder Ma- terial Properties, 2002,
  56. 56.
    M. Kerr and N. Chawla, Creep deformation behavior of Sn-3.5Ag solder/Cu couple at small length scales, Acta Mater. 52 4527-4535 (2004).CrossRefGoogle Scholar
  57. 57.
    X. Deng, N. Chawla, K.K. Chawla, and M. Koopman, Deformation behavior of (Cu,Ag)-Sn intermetallics by nanoindentation, Acta. Mater. 52 4291-4303 (2004).CrossRefGoogle Scholar
  58. 58.
    F. Ochoa, X. Deng, and N. Chawla, Effects of cooling rate on creep behavior of a Sn-3.5Ag alloy, J. Electron. Mater. 33 1596-1607 (2004).CrossRefGoogle Scholar
  59. 59.
    Personal Communication D. Frear and E. Bradley (2000).Google Scholar
  60. 60.
    F. Guo, S. Choi, K.N. Subramanian, T.R. Bieler, J.P. Lucas, A. Achari, M. Paruchuri, Evaluation of creep behavior of near-eutectic Sn-Ag solders containing small amounts of alloy additions, Mater. Sci. Eng. A 35: 190-199 (2003).Google Scholar
  61. 61.
    R. Darveaux and K. Banerji, IEEE Trans. Components, Hybrid and Manufacturing Technology 15 1013-1024 (1992).CrossRefGoogle Scholar
  62. 62.
    J. Bartelo, S.R. Cain, D. Caletka, K. Darbha, T. Gosselin, D.W. Henderson, D. King, K. Knadle, A. Sarkhel, G. Thiel, C. Woychik, “Thermomechanical fatigue behavior of selected lead-free solders”, Proceedings, IPC SMEMA Council APEX 2001, Paper # LF2-2.Google Scholar
  63. 63.
    G. Swan, A. Woosley, K. Simmons, T. Koschmieder, T.T. Chong, and L. Matsushita. Development of lead-(Pb) and halogen free peripheral leaded and PBGA components to meet MSL3 at 260°C peak reflow profile. 1, 121-126. 9-11-2000. VDE Verlag. Proceedings, Electronics Goes Green 2000+, September 11-13, 2000, Berlin, Germany.Google Scholar

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Carol Handwerker
    • 1
  • Ursula Kattner
    • 2
  • Kil-Won Moon
    • 3
  1. 1.Materials and Electrical Engineering BuildingPurdue UniversityWest LafayetteUSA
  2. 2.National Institute of Standards and Technology (NIST)GaithersburgUSA
  3. 3.National Institute of Standards and Technology (NIST)GaithersburgUSA

Personalised recommendations