A microstructurally based model of solder joints under conditions of thermomechanical fatigue
- Sandia National Labs., Albuquerque, NM (United States)
- California Univ., Davis, CA (United States)
The thermomechanical fatigue failure of solder joints in increasingly becoming an important reliability issue. In this paper we present two computational methodologies that have been developed to predict the behavior of near eutectic Sn-Pb solder joints under fatigue conditions that are based on metallurgical tests as fundamental input for constitutive relations. The two-phase model mathematically predicts the heterogeneous coarsening behavior of near eutectic Sn-Pb solder. The finite element simulations from this model agree well with experimental thermomechanical fatigue tests. The simulations show that the presence of an initial heterogeneity in the solder microstructure could significantly degrade the fatigue lifetime. The single phase model is a computational technique that was developed to predict solder joint behavior using materials data for constitutive relation constants that could be determined through straightforward metallurgical experiments. A shear/torsion test sample was developed to impose strain in two different orientations. Materials constants were derived from these tests and the results showed an adequate fit to experimental results. The single-phase model could be very useful for conditions where microstructural evolution is not a dominant factor in fatigue.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 10115612
- Report Number(s):
- SAND-94-0951C; CONF-950344-5; ON: DE95006226; BR: GB0103012
- Resource Relation:
- Conference: InterPack `95: international electronic packaging conference,Maui, HI (United States),26-30 Mar 1995; Other Information: PBD: [1994]
- Country of Publication:
- United States
- Language:
- English
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