Journal of Electronic Materials

, Volume 38, Issue 2, pp 231–240

Anisotropic Crystal Plasticity Finite Element Modeling of the Effect of Crystal Orientation and Solder Joint Geometry on Deformation after Temperature Change

Authors

  • A. Zamiri
    • Mechanical EngineeringMichigan State University
    • Chemical Engineering and Materials ScienceMichigan State University
  • F. Pourboghrat
    • Mechanical EngineeringMichigan State University
Article

DOI: 10.1007/s11664-008-0595-0

Cite this article as:
Zamiri, A., Bieler, T. & Pourboghrat, F. Journal of Elec Materi (2009) 38: 231. doi:10.1007/s11664-008-0595-0

The crystal orientation of the tin phase in a Pb-free Sn solder joint has a significant effect on the stress state, and hence on the reliability of the solder joint. A set of crystal plasticity analyses was used to evaluate stress and strain resulting from a 165°C temperature change in a single-crystal joint using two simplified geometries used in practical solder joints. Phenomenological flow models for ten slip systems were estimated based upon semiquantitative information available in the literature, along with known anisotropic elastic property information. The results show that the internal energy of the system is a strong function of the tin crystal orientation and geometry of the solder joint. The internal energy (and presumably the likelihood of damage) is highest when the crystal c-axis lies in the plane of the substrate, leading to significant plastic deformation. When the a-axis is in the plane of the interface, deformation due to a 165°C temperature change is predominantly elastic. The texture of the copper substrate using isotropic Cu elastic properties, or anisotropic elastic properties with [001] \( \parallel \) substrate normal direction, does␣not have a significant effect on the stress or strain in the Sn phase of the joint.

Keywords

Finite elementsingle crystaltinthermal expansionanisotropy
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© TMS 2008