Aging Response and Cryogenic Mechanical Properties of an In-Sn Eutectic Solder Alloy for Josephson Packaging

  • T. Caulfield
  • S. Purushothaman
  • D. P. Waldman
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 30)


Josephson computing technology entails the use of superconducting Josephson junction devices which combine high speeds and low power dissipation compared to conventional semiconductor devices.1–3 A low melting point (390K) In (52 weight %) Sn (48 weight %) eutectic alloy which is superconducting at 4.2K is used as an interconnection solder in Josephson packaging to enable chip and package part replacements to be done at reasonably low temperatures. For a typical contact application, about 25µm thick film of the alloy is usually evaporated onto 200 µm diameter contact pads of 100 nm each of Pd and Au and 230 nm of Nb situated on a Si substrate and subjected to reflow prior to use4,5. In the anticipated service cycle, the alloy undergoes rapid solidification after the reflow operation and could experience aging at room temperature (298K) during storage and/or at 348K where a reflow operation is carried out for interconnections using a second lower melting solder in the package. Subsequently, the whole package is cooled down to near 4.2K at which the superconducting junction devices operate. In such a service cycle, stresses can arise due to thermal contraction mismatch between the substrate and the solder and due to joining of parts made of dissimilar materials. Further, since 298K and 348K are significant fractions of the alloy melting point, one would expect significant changes in the as quenched microstructure and, as a result, in the mechanical properties of the alloy. Accordingly, it is necessary to study the low temperature mechanical behavior of the alloy and its dependence on aging at 298K and 348K and correlate them with the attendant changes in the microstructure. Recently, Yeh 6 reported on the shear and tensile properties of this alloy in the overaged condition, tested between room temperature and 77K. In this paper we extend this data base to 4.2K and document the microstructual and mechanical property changes caused by 298K and 348K aging treatments.


Ultimate Tensile Strength Void Nucleation Interconnection Solder 298K Aging Eutectic Solder Alloy 
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.
    W. Anacker, Computing at 4 degrees Kelvin, IEEE Spectrum, 16: 26 (1979).CrossRefGoogle Scholar
  2. 2.
    J. Matisoo, The superconducting computer, Scient. Amer. 242: 50 (1980).CrossRefGoogle Scholar
  3. 3.
    M. Ketchen et. al., A josephson technology system level experiment, IEEE EDL, EDL-2: 262 (1981).CrossRefGoogle Scholar
  4. 4.
    C. Y. Ting, K. R. Grebe, and D. P. Waldman, Controlled collapse reflow for josephson chip bonding, Proc. 157th ECS Meeting, 80–1: 210 (1980).Google Scholar
  5. 5.
    S. Lahiri et. al., Packaging technology for josephson integrated circuits, IEEE Trans. CHMT, DHMT-5271 (1982).Google Scholar
  6. 6.
    J. T. C. Yeh, Characterization of In-based eutectic alloys used in josephson packaging, Metall. Trans. 13A, 1547 (1982).CrossRefGoogle Scholar
  7. 7.
    S. Purushothaman and T. Caulfield, Cryogenic temperature mechanical properties of solid mercury, Unpublished Research, IBM-Watson Research Center, 1982.Google Scholar
  8. 8.
    J. S. Abell, A. G. Crocker and D. M. M. Guyoncourt, The orientation dependence of deformation modes of crystalline mercury at 77K, J. Mat. Sci 6: 361 (1971).CrossRefGoogle Scholar
  9. 9.
    J. S. Abell, Low temperature deformation properties of crystalline mercury, Acta. Met. 24K: 11 (1976).CrossRefGoogle Scholar
  10. 10.
    V. V. Pustovalov, V. V. Vershinina, S. V. Tsivinskiy, and S. N. Aleksandrov, Fiz. Metall. Metalloved. 30: 991 (1970).Google Scholar
  11. 11.
    A. S. Argon, and J. Im, Separation of second phase particles in spheroidized 1045 steel, Cu-0.6 Pct Cr alloy, and muraging steel in plastic straining, Metall. Trans. 6A: 839 (1975).CrossRefGoogle Scholar
  12. 12.
    M. A. Przystupa, M. G. Stout, and T. A. Courtney, The interaction between deformation, fracture initiation and fracture propagation in two phase CoCoAI alloys, Metall. Trans. 11A: 643 (1980).CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1984

Authors and Affiliations

  • T. Caulfield
    • 1
  • S. Purushothaman
    • 1
  • D. P. Waldman
    • 1
  1. 1.IBM Thomas J. Watson Research CenterYorktown HeightsUSA

Personalised recommendations