High-G Acceleration Sensors for the Automotive Industry

In this contribution two different technologies for robust high bandwidth accelerometers are presented. A comparison of BDRIE (Bonding and Deep RIE) and EPI-Poly (epitaxially grown Si on Poly-Si seed layer) with sacrificial layer is provided. These platforms are designed to sustain high-g loads of up to 4,000 g continuously, while enabling sub-g resolution by sufficient sensitivity at the same time at a bandwidth of up to 10 kHz. Both in-plane and out-of-plane sensor variant designs are investigated, enabling multi-axis sensing. Additionally, in-situ wafer-level characterization is evaluated as well as the performance of packaged samples in combination with capacitive readout ASIC with ΣΔ-ADC. Data of temperature response, shock impulse, centrifuge and tumble tests are included. A system with 0.2 g resolution, max range of ±1500 g and bandwidth of 6 kHz is demonstrated. Noise values of the Allan deviation reach values of about BI 340 µg and VRW 1.3 m/s/√h. Thereby, specifications are met for various potential applications in industrial and automotive sector, like intelligent tire monitoring.