Frequency adjustment method of vibrator element

A frequency adjustment method of a vibrator element, the method comprising:

• preparing the vibrator element, the vibrator element having:
• a vibrating arm, the vibrating arm having a first surface and a second surface outwardly opposite to each other along a first direction, a thickness along the first direction of the vibrating arm being defined as T;
• a first weight placed on the first surface of the vibrating arm;
• and
• a second weight placed on the second surface of the vibrating arm, wherein the first weight has a non-overlapping region which does not overlap the second weight when viewed along the first direction;
• preparing a substrate, the substrate including a wiring portion;
• fixing the vibrator element to the substrate by causing the second surface of the vibrator element to face the substrate;
• and
• irradiating the non-overlapping region of the first weight with an energy ray to remove a portion of the non-overlapping region of the first weight so as to adjust a resonance frequency of the vibrating arm,
• wherein a separation distance in the first direction of the vibrating arm between a centroid of a weight including the first weight and the second weight and a centroid of the vibrating arm in a cross-sectional view of the vibrating arm is defined as D, and
• after the portion of the non-overlapping region of the first weight is removed, 0<D≤0.2T.