Investigation of the Influence of Voids n the Reliability of Solder Joints by Finite Element Method
Authors: Christian Schwarzer, Dennis Fuchs, Michael Kaloudis, Miriam Rauer, Ping Xu, Jörg Franke, Andreas Krügelstein Company: Fraunhofer ISC IWKS ARess, UAS Aschaffenburg, FAPS FAU Erlangen-Nürnberg Date Published: 9/17/2017
Abstract: This investigation focuses on the influence of voids on the reliability of solder joints for high-power LED applications. Concerning the long time scale for reliability tests such as the thermal shock test (TST), the finiteelement method (FEM) was employed to enable a simulation-aided analysis and to gain a better understanding of the fatigue behavior of the solder joints with different void distributions. Solder voids were analyzed by computed tomography (CT), and methods were developed to implement the voids from CT into FEM simulation models. For the material behaviors, the Garofalo equation was implemented for calculating the creep strain and to detect the crack initiation. Finally, the simulated results of crack initiation were compared with real experimental data. The comparison presented here shows good correlation between simulations and experimental tests with respect to failure modes such as the position of cracks. Potentials and challenges of using numerical methods with implemented CT data are addressed for further studies.