Patent ID: 8405474

Claim:
A piezoelectric vibration piece comprising: a base made of a piezoelectric material; a first and second vibration arms integrally formed with the base; elongate grooves formed along longitudinal directions of the first and second vibration arms in principal surfaces of the first and second vibration arms; inner electrodes disposed in the elongate grooves; side electrodes disposed on side surfaces of the first and second vibration arms; wherein widening portions being formed at a junction of the first and second vibration arms and the base; wherein each of the widening portions includes an inner widening portion located adjacent to a crotch portion between the first vibration arm and the second vibration arm; wherein a width of an at least one of the inner widening portions being widened toward the base while a widening degree is changed at a change point; wherein the side electrode formed on a tip side of at least one of the first and second vibration arms from the at least one of the inner widening portions being not led to the principal surface located between at least one of the elongate groove and at least one of the side surface; and wherein the side electrode formed on the at least one of the inner widening portions being led to the principal surface and the side surface of at least one of the first and second vibration arms at the inner widening portion and covers the change point.