Influence of materials data on the performance modelling in the design of MEMS packages

To predict the performance and the reliability of microsystems in the development process, simulation is a powerful tool which is still gaining greater importance. The accuracy of the simulation results depends substantially on the quality of the available materials data. Realistic results can only be achieved in thermo-mechanical computations when the temperature dependency as well as the nonlinearities and the time-dependence of the materials properties are taken into account. The first part of the work reported here is dedicated to the data and materials models for the simulation of MEMS assemblies. As part of this work measured materials data as well as suitable models for their numerical representation are demonstrated. In the presentation, the results of the measurements of most of the relevant properties of package and assembly materials are presented. These comprise bonding wires, moulding compounds and conductive adhesives under typical service conditions. The corresponding materials modelling for finite element simulations will be shown.