Temperature Robust Silicon Resonant Accelerometer with Stress Isolation Frame Mounted on Axis-Symmetrical Anchors

Abstract

This paper presents a novel silicon resonant accelerometer (SRA) with a stress isolation frame mounted on axis-symmetrical anchors to improve the temperature performance. The stress-insensitive design prevents the thermal stress produced by the mismatch of the thermal expansion coefficients (CTE) of the heterogeneous materials in the device from transmitting to double-ended tuning forks (DETF), resulting in reducing the thermal sensitivity of SRA. The results show the scale factor is 516 Hz/g and the average nominal frequency of the two DETFs is ∼138.4 kHz with the closely matched temperature coefficients of frequency (TCF) 5.72 Hz/°C and 5.92 Hz/ °C, respectively. The bias thermal sensitivity and compensated stability are 0.42 mg/°C and 0.6 mg over the temperature range from −40 °C to 40 °C, which is competitive compared with previously reported results in literatures.