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Talks and Poster Presentations (without Proceedings-Entry):

P. Hoffmann, M. Springer, M. Todt, B. Karunamurthy, M. Nelhiebel, H. E. Pettermann:
"Simulation of fatigue damage in power semiconductors subjected to transient thermo-mechanical loading";
Talk: 90th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM 2019), Vienna; 2019-02-18 - 2019-02-22.



English abstract:
Power semiconductors are often subjected to short electric overload pulses which induce very high temperature gradients in the metallization stack. Consequently, high mechanical stresses and strains occur, which in turn can lead to material failure. In preceding works [1,2] a continuum damage mechanics approach has been formulated and implemented into the finite element method which allows the prediction of damage onset and evolution of the material level as well as spatial damage evolution under cyclic thermo-mechanical loading conditions. Such a framework provides a step towards physical lifetime assessment of power semiconductor devices but, so far has only been used for quasi-static loading conditions.
As semiconductors are often subjected to transient thermal loads, the simulation framework is extended accordingly. The transient thermal and the mechanical fields are treated in a sequentially coupled manner. The time-dependent temperature field obtained from an initially conducted thermal analysis is used as input for the fatigue damage simulations. To account for the influence of the damage evolution on the local thermal conductivity, the transient temperature field is recomputed after a specific number of load cycles and the fatigue damage computations are resumed with the updated time-dependent temperature field. The extended simulation methodology is applied to predict fatigue damage in the powermetallization layer of semiconductor devices. Realistic transient thermal boundary conditions are considered in the model. The simulation framework is formulated in a way that it can easily be adapted to different geometries and boundary conditions. One possible application for this framework would be the extraction of fatigue material parameters from experiments.

[1] M. Springer, H. E. Pettermann: "Fatigue life predictions of metal structures based on a lowcycle, multiaxial fatigue damage model "; International Journal of Fatigue, 116 (2018), S. 355 - 365.
[2] G. Kravchenko, B. Karunamurthy, M. Nelhiebel, H. E. Pettermann: "Finite Element Analysis of Fatigue cracks Formation in Power Metallization of a Semiconductor Device Subjected to Active Cycling"; in: "Proceedings of the 14th Conference on Thermal, Mechanical and MultiPhysics Simulation and Experiments in Microelectronics and Microsystems", IEEE, Piscataway, NJ, (2013), Paper-Nr. 91, 6 S.

Created from the Publication Database of the Vienna University of Technology.