Simulation of thermomechanical stress of a MEMS microphone

With the aim to improve the accuracy of flip-chip MEMS microphones, the temperature hysteresis of sensitivity was investigated. Experiments with the solder alloys SAC357 and SAC105 showed that the alloy composition has an influence on the temperature hysteresis. A creep model for SAC387, based on Garofalo's creep model, has been developed, in order to simulate the sensitivity of MEMS microphones. This creep model uses joint data from different publications. A creep test based on the developed model was calculated. It could be shown, that the developed model is well suited for simulations of properties of flip-chip MEMS microphones with the solder alloy SAC387.