To the production of a robust and highly accurate MEMS vibrating accelerometer

This paper presents Thales main results for the maturity development activities of TopAxyz MEMS Vibrating Beam Accelerometer (VBA) using a differential resonator architecture implemented on a planar SOI silicon layer. Proof of concept with Navigation grade performances level has already been presented at ISS2012. Development focused on two major challenges: to reach a high production yield and to demonstrate a high reliability level. It was mandatory to demonstrate these two topics to have a product with high maturity level at the product launch. In this paper we present the major design choices on MEMS, electronics architecture and packaging to reach yield and reliability. Product performances are detailed with highlights on navigation grade key characteristics which are bias and scale factor temperature stability, vibration susceptibility, warm-up response and random walk. Product reliability demonstration activities are also presented with examples on characterization of ESD and thermal cycles susceptibility. Evaluation of product long term bias and scale factor stability after 9 years storage associated to accelerated ageing are used to secure device lifetime. The VBA concept allows Thales to offer digital navigation grade MEMS accelerometer with demonstrated outstanding performances, cumulating very high input range (up to 100 g), below 50 Mg bias accuracy and less than 10 ppm scale factor accuracy. Thales MEMS accelerometer, compatible with the highest certified aerospace applications under DO-254 standards, now complements the current TopAxyz product line covering all applications in aerospace, land and naval domains.