<title>New sensor-on-chip technology for micromechanical acceleration-threshold switches</title>

Abstract

This paper describes the development of a sensor for measuring acceleration-thresholds in the low-g range. The processing of the device is based on a new integration concept for MEMS called Additive Electroplating Technology (AET). This technology allows the integration of fixed and moveable electroplated microstructures on top of a standard ASIC by a low temperature back-end process. This permits the fabrication of the sensor on top of a CMOS signal processing circuit, where the development and the fabrication of the ASIC is absolutely independent of the following back-end process. In this context, the additive electroplating technology combines the advantages of monolithic- and hybrid-integrated sensor with respect to the reduction of interconnections, short development cycles, low tooling costs, and high design flexibility. A detailed technical concept for the fabrication of electroplated micromechanical acceleration switches is presented in this paper. It comprises the aspects of the interface technology between the ASIC and the sensor structure, the sensor fabrication and the back-end processing to capsulate the dies. The paper concludes with a characterization of the devices. The measured results are compared with the expected results of the simulation.