Quartz Vibrating Beam Accelerometer System Based On DETF

Quartz vibrating beam accelerometer (QVBA) has been attracting continued attention for its high sensitivity, digital output, and simple structure and so on. QVBA has very outstanding advantages on costs, volume and power dissipation. The finite element method is used to simulate the vibration mode and optimize the sensing element structure improving sensitivity. Exciting electrode patterns are optimized to reduce impedance near resonance frequency. Both the main two parts of the accelerometer, a double-ended tuning fork and a base-proof mass structure, are fabricated using a quartz wet etching process on Z cut quartz wafers. Taking advantage of self-alignment function of the flip chip bonding process, the two parts were precisely bonded at the desired joint position via AuSn solder. Under the action of a self-excitation circuit, static performance is obtained. The accelerometer is tested in standard atmosphere and high sensitivity up to 82.356 Hz/g and bias stability of 1.19 mg was achieved. The results indicate that the proposed sensor has favorable features, which provides a cost-effective and high-performance approach for low accuracy measurement.