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Journal of Materials Science

, Volume 44, Issue 2, pp 545–555 | Cite as

Very long-term aging of 52In–48Sn (at.%) solder joints on Cu-plated stainless steel substrates

  • D. F. SusanEmail author
  • J. A. Rejent
  • P. F. Hlava
  • P. T. Vianco
Article

Abstract

Long-term metallurgical aging was studied in thermal switches comprised of 52In–48Sn (at.%) alloy solder plugs contained in Cu-plated stainless steel cylinders. These switches are locking devices designed so that, if overheated, a “fusible” alloy melts and allows the activation of a spring-loaded mechanism. The soldered assemblies studied ranged in age from about 24 to 28 years old at the time of this analysis. A concern has been the buildup of intermetallic compound (IMC) within the solder or at the solder/substrate interface, which could raise the switch operating temperature. In this work, the melting temperature of the aged solder alloy was slightly lower (116.3 ± 0.3 °C) than the expected value, 118.4 °C (245 °F), based on differential scanning calorimetry (DSC). The slight decrease in melting temperature range was caused by the diffusion of a small amount of Cu into the solder during processing and possibly during long-term service. The interfacial IMC layer was primarily Cu2In3Sn. The IMC thickness agreed with that predicted by growth kinetics determined in a previous study, assuming aging temperatures in the vicinity of room temperature. Differences in the IMC phase chemistries were found between earlier research, which employed bulk Cu substrates, and the present analyses with thin electroplated Cu substrates. Evidence was found for depletion of the thin Cu plating layer over time, as well as incorporation of Fe and Ni from the stainless steel into the IMC layer.

Keywords

Differential Scanning Calorimetry Solder Alloy Bulk Solder Differential Scanning Calorimetry Experiment Plating Layer 

Notes

Acknowledgements

The authors would like to thank Dr. Mike Dugger for careful review of the manuscript. Sincere thanks also to Alice Kilgo for metallography and to Bonnie McKenzie for SEM analysis. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the US Department of Energy’s National Nuclear Security Administration under Contract DE-AC04-94AL85000.

References

  1. 1.
    Yost FG, Romig AD (1984) Storage life of thermal detents, SAND84-0678. Sandia National Laboratories, Albuquerque, NM, USAGoogle Scholar
  2. 2.
    Romig AD, Yost FG, Hlava PF (1984) In: Romig AD, Glodstein JI (eds) Microbeam analysis—1984. San Francisco Press Inc., San Francisco, CA, USAGoogle Scholar
  3. 3.
    Vianco PT, Hlava PF, Kilgo AC (1994) J Electron Mater 23(7):583CrossRefGoogle Scholar
  4. 4.
    Sommadossi S, Gust W, Mittemeijer EJ (2002) Mat Chem Phys 77:924CrossRefGoogle Scholar
  5. 5.
    Chuang TH, Yu CL, Chang SY, Wang SS (2002) J Electron Mater 31(6):640CrossRefGoogle Scholar
  6. 6.
    Kim D-G, Jung S-B (2005) J Alloy Compd 386:151CrossRefGoogle Scholar
  7. 7.
    Okamoto H (1992) In: White CET, Okamoto H (eds) Phase diagrams of indium alloys and their engineering application. ASM International, Materials Park, OH, pp 255–257Google Scholar
  8. 8.
    Liu XJ, Liu HS, Ohnuma I, Kainuma R, Ishida K, Itabashi S, Kameda K, Yamaguchi K (2001) J Electron Mater 30:1093CrossRefGoogle Scholar
  9. 9.
    Lee B-J, Oh C-S, Shim J-H (1996) J Electron Mater 25(6):983CrossRefGoogle Scholar
  10. 10.
    Chen S-W, Wang C-H, Lin S-K, Chiu C-N (2007) J Mater Sci Mater Electron 18:19CrossRefGoogle Scholar
  11. 11.
    Vianco PT (1999) Soldering handbook, 3rd edn. American Welding Society, Miami, FL, pp 147–151Google Scholar
  12. 12.
    Velikanova T, Turchanin M, Fabrichnaya O (2007) In: Effenberg G, Ilyenko S (eds) Non-ferrous metal systems, part 3. Springer-Verlag, Berlin, pp 249–273Google Scholar
  13. 13.
    Lin S-K, Yang C-F, Wu S-H, Chen S-W (2008) J Electron Mater 37(4):498CrossRefGoogle Scholar

Copyright information

© U.S. Government 2008

Authors and Affiliations

  • D. F. Susan
    • 1
    Email author
  • J. A. Rejent
    • 1
  • P. F. Hlava
    • 1
  • P. T. Vianco
    • 1
  1. 1.Sandia National LaboratoriesAlbuquerqueUSA

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