A wafer level vacuum packaged silicon vibration beam accelerometer

This paper gives a detail description of a silicon vibration beam accelerometer which was fabricated by SOI technology and encapsulated in a wafer level vacuum package. The wafer level package gives advantage of small size and low cost, but also produce additional residual stresses that increased the temperature coefficient of the vibration beams. To solve this problem, the sensing structure was redesigned and reduce the temperature coefficient from 50Hz/°C to 10Hz/°C. Moreover, with carefully assembly, control and measure technology, the accelerometer system achieved reliable performance. Experiment result shows that the scale factor was 120Hz/g, measurement rang was ±50g with non-linearity coefficients of 19μg/g² and 0.06μg/g³, resolution was 10μg/sqrt(Hz), bias Allan variance was 10μg.