Characterizing the Anisotropic Hardening Behavior of Aluminum Bonding Wires

  • Holm Altenbach
  • Christian Dresbach
  • Matthias Petzold
Chapter
Part of the Advanced Structured Materials book series (STRUCTMAT, volume 16)

Abstract

In power electronic devices the electrical connections of different components are mainly realized by heavy aluminum wire bonding. When a device heats up or cools down during use, there is a relative displacement between the first and the second contact because of differences in thermal expansion coefficients of the components and the housing of the device. This cyclic thermo mechanical loading can lead to fatigue failure of the bonding wire. Especially when placed near mechanical working components (e.g. automotive engine) additional vibrations can increase damage evolution and heating can accelerate ageing effects of the bonding wire. In the last few years there have been multiple publications presenting experimental and numerical results for high and low cycle fatigue of wire bonded devices. But all of these publications did not consider the mechanical properties of the wire in an adequate way. We present results of a micro-compression test that allows the determination of the hardening behavior parallel and perpendicular to the wire axis at moderate and large strains of small wire cylinders. The hardening behavior in compression parallel to the wire axis correlates very well to the hardening behavior determined by tensile tests at moderate strains. The hardening behavior perpendicular to the wire axis shows an anisotropic behavior of the aluminum wires depending on the drawing texture which was also analyzed by electron backscatter diffraction methods. The results for different wire materials show a dependence of the yield stress on the grain size. With the determined hardening parameters it is possible to consider the hardening of the material during the bonding process.

keywords

Aluminum wire bonding Electron backscatter diffraction Micro compression test Hall-Petch relation 

References

  1. 1.
    Scheel, W.: Baugruppentechnologie der Elektronik. Verlag Technik GmbH, Berlin (1997)Google Scholar
  2. 2.
    Mehrotra, V., et al.: Wirebond reliability in IGBT-power modules: application of high resolution strain and temperature mapping. International Symposium on Power Semiconductor Devices and ICs ISPSD, Toronto, pp. 113–116 (1999)Google Scholar
  3. 3.
    Ramminger, S., et al.: Reliability model for Al wire bonds subjected to heel crack failures. J. Microrel. 40, 1521–1525 (2000)Google Scholar
  4. 4.
    Wilde, J.: Lebensdauerprognose von Drahtbond-Verbindungen für die Mechatronik mittels FEM. Elektronische Baugruppen, Aufbau und Verbindungstechnik, DVS/GMM-Fachtagung, Fellbach, 40 (2002)Google Scholar
  5. 5.
    Dresbach, C.: Ermittlung lokaler mechanischer Kennwerte mikroelektronischer Drahtkontaktierungen. Ph.D.-thesis Martin-Luther-University Halle-Wittenberg (2010)Google Scholar
  6. 6.
    Hall, E.O.: The deformation and ageing of mild steel: III discussion of results. Proc. Phys. Soc. 64, 747–753 (1951)CrossRefGoogle Scholar
  7. 7.
    Petch, N.J.: The cleavage strength of polycrystals. J. Iron Steel Inst. 25–28 (1953)Google Scholar
  8. 8.
    Hill, R.: The Mathematical Theory of Plasticity. Oxford University Press Inc., New York (1950)MATHGoogle Scholar
  9. 9.
    Charalambides, M.N. et al.: The analysis of the frictional effect on stress—strain data from uniaxial compression of cheese. J. Mater. Sci. 365, 2313–2321 (2001)CrossRefGoogle Scholar
  10. 10.
    Dresbach, C., et al.: Local hardening behavior of free air balls and heat affected zones of thermosonic wire bond interconnections. European Microelectronics and Packaging Conference EMPC, Rimini (2009)Google Scholar
  11. 11.
    Lemaitre, J., Chaboche, J.L: Mechanics of solid materials. Cambridge University Press, Cambridge (2002)Google Scholar
  12. 12.
    Dynardo: optiSLang the optimization structural language. Dynamic Software and Engineering GmbH (2008)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Holm Altenbach
    • 1
    • 2
  • Christian Dresbach
    • 3
    • 4
  • Matthias Petzold
    • 3
  1. 1.Martin-Luther-University Halle-WittenbergHalleGermany
  2. 2.Otto-von-Guericke-University MagdeburgMagdeburgGermany
  3. 3.Fraunhofer Institute for Mechanics of Materials IWMHalleGermany
  4. 4.German Aerospace CenterCologneGermany

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