Finite Element Method Design and Fabrication of Thermo-sensitive Quartz Tuning Fork Resonators as Temperature Sensor

Piezoelectric resonators have widely been utilized not only for time keeping devices but also for temperature measurement sensors. In order to obtain a temperature sensor having low power consumption, low cost, fast response, high sensitivity and high precision, resonance frequency of quartz tuning fork crystal for use in temperature sensor was analyzed by the finite element method (FEM). FEM was used to model optimum tuning fork geometry, tine tip and tine surface electrode shape and thickness with a resonance frequency close to 40 kHz as design targets. This type of sensor was designed with a new ZYtw-cut was proved that working at flexural vibration mode was better than at the others. The fabrication of resonators was realized by employing photolithography and chemical etching. Moreover tuning fork resonators were further processed for packaged in holders and filled with helium 90 Pa and thus fabricated were evaluated by measuring resonance frequency. The results of the experiment show that it is possible to construct a miniature and an excellent quartz tuning-fork temperature sensor