An overview of quartz MEMS devices

The most outstanding feature of quartz crystal device is its frequency stability in wide range of temperature. In the last ten years, miniaturization of quartz devices has been accelerated. The newest resonators are 1/500 in size compared to those in ten years ago. Miniaturization of devices in general sacrifices its quality factor (Q value), S/N ratio, frequency-temperature stability, and product uniformity. QMEMS is a promising mass-production process to solve problems mentioned above. The flexibility of design makes possible quartz devices with 3 dimensional configurations. As a result, mechanical energy dispersion was prevented efficiently by the isolation design of miniature tuning fork and gyro sensor. Using the QMEMS process, the frequency stability in range of less than 2×10−7 can be guaranteed in TCXO. These advances in leaps of properties were supported by QMEMS technology. At the same time QMEMS technology is an efficient mass production system to make uniform resonators with small tolerance.