Package Induced Stress Simulation and Experimental Verification

During and after packaging mechanical stresses and deformations can be imposed on the active MEMS structures, which can have a large impact on the device performance, operating range and reliability [1]. This effect can for example be assessed by coupled package and device modelling [2,3]. To be able to assess this impact for molded sensors, parametric package models have been set-up, which can describe and quantify the mechanical stresses occurring during molding, temperature change and long term operation. Stresses, which build up after molding of a device (i.e. after post-mold cure), are sensitive with regard to the properties of the packaging materials (i.e. CTE, Young's Modulus, glass transition temperature). For a reliable design, the question arises, which property has the largest impact and how the mechanical stresses can be reduced