A New Method of Excluding The External Acceleration's Effect in A Micromachined Magnetometer for Navigation Systems

摘要

This paper presents the fabrication and test of a new type of magnetometer-accelerometer. The resonant magnetometers that use the Lorentz force have been reported but they have the critical problem of failing to exclude the effect of acceleration when a magnetic field and acceleration are applied simultaneously. Therefore, we have conceived a new resonant micro sensor detecting both acceleration and the geomagnetic field simultaneously and minimizing the interference with each other. To realize this concept, a conducting line is formed on a spring part of a silicon accelerometer having two mass plates. The process uses a silicon-on-glass (SOG) wafer, an inverted SOG wafer, and a gold-silicon eutectic bonding for the wafer-level hermetic packaging. This newly developed sensor is enough for the 10 degree electronic display of the orientation angle and can be used in a portable navigator such as SmartPhones and PDAs that need a small, low cost and low power electronic compass.