3D stacked MEMS and ICs in a miniaturized sensor node

3D integration of micro electromechanical systems (MEMS) is expected to reduce the foot print of existing MEMS products and enable production of miniaturized sensor nodes on a large scale. However, 3D integration of MEMS is in general different from 3D integration of planar integrated circuits (ICs) due to additional mechanical requirements. Specifications regarding properties like stiffness, volume, and mass must be taken into consideration when selecting stacking technologies for MEMS. A demonstrator with a 3D integrated MEMS and the ideas behind the selection of stacking technologies are presented in this paper.