Investigation of MEMS resonator characteristics during long-term and wide temperature variation operation

Two types of single-crystal silicon micromechanical resonators having resonant frequencies at 150 kHz and 130 kHz were tested under harsh environment to investigate stability. To observe long-term stability, the main characteristics, such as resonant frequency and quality factor were measured over 2,500 hrs continuously while maintaining constant environmental temperature at 25°C±0.1°C. A separate experiment was also initiated to show stability during temperature cycling from -50 °C to 80 °C. In both experiments, the total change in resonant frequency were less than 10 ppm and quality factor less than 10%, which demonstrates the stability of encapsulated micromechanical resonators upon exposure to harsh environments.