A Low Cost Angular Rate Sensor for Automotive Applications in Surface Micromachining Technology

A second generation angular rate sensor suitable for high volume production is presented. The sensor consists of an electrostatically driven oscillating disk, which reacts — due to the conservation law for angular momentums — with a tilt movement when an angular rate is applied. This tilt movement is detected capacitively by electrodes on the substrate underneath the oscillating disk. The sensor element is manufactured by using a standard surface micromachining process. The signal evaluation is realised in a switched capacitor technique. The PLCC44-packaged sensor provides a self test function and may be calibrated to a customer specific sensitivity (currently 7 mV/°/sec for a +/−250 °/sec Full Scale measurement range). The sensor is designed for automotive applications, especially for rollover sensing.