Patent ID: 6987347

Claim:
A piezoelectric resonator component comprising: an energy-trapped piezoelectric resonator utilizing a third order harmonic wave of thickness longitudinal vibration and including a piezoelectric substrate having first and second major surfaces and being polarized in a direction of thickness between the first and second major surfaces, and first and second vibrating electrodes opposed to each other with the piezoelectric substrate interposed therebetween; and first and second casing substrates respectively laminated on the first and second major surfaces of the piezoelectric resonator such that cavities are provided and arranged such that the first and second casing substrates do not interfere with vibration of a vibration section where the first and second vibrating electrodes face each other through the piezoelectric substrate; wherein the first and second vibrating electrodes are dimensioned such that the difference between the peak values of the phases of S 0 and S 1 modes of the fundamental wave of the thickness longitudinal vibration falls within a range of about ±5 degrees, wherein the S 0 mode is the symmetrical mode of the fundamental wave and the S 1 mode is the symmetrical mode of the first harmonic wave of the fundamental wave; each of the first and second vibrating electrodes has a substantially circular planar shape; each of the cavities has a substantially square planar shape; and a relationship R/t=0.40A/t+1.40 to 0.33A/t+1.95 is maintained where R represents a diameter of the substantially circular planar shape of the first and second vibrating electrodes, A represents a length of each side of the substantially square planar shape of the cavity, and t represents a thickness of the piezoelectric substrate.