Design of A New Groove Structure of Quartz Tuning Fork with High Performance

This paper presents a novel tuning fork with variable beam profile. Variable cross-section “H” shaped grooves were set on the upper and lower surfaces of the tuning fork due to the anisotropy of quartz crystal. This design improves the steepness of the groove's sidewalls, effectively improves the excitation electric field strength and the voltage excitation efficiency along the tuning fork, and reduces the value of the impedance of the resonator. By simulating and analyzing the tuning fork with three different cross-sections, the voltage excitation efficiency of variable cross-section “H” shaped grooves was much larger than that of two others by about 64%, and the stress utilization efficiency along the length of the tuning fork was also larger than that of two others. The resonant elements of the two cross-section shapes were fabricated on a standard three-inch wafer, and the test results showed that the quality factor of the variable cross-section “H” shaped groove was similar to that of the “H” shaped cross-section. However, the dynamic resistance decreases from 602.992 kΩ to 464.013 kΩ.