UNIT, OSCILLATOR AND ELECTRONIC APPARATUS

A unit comprising a quartz crystal resonator having an overall length less than 2.1 mm and a base portion including a length less than 0.5 mm and a width less than 0.55 mm, and vibrational arms, mounting arms being connected to the base portion through connecting portions, each vibrational arm having a first vibrational portion including a first width and a first length within a range of 0.32 mm to 0.72 mm and a second vibrational portion including a second width greater than the first width and a second length less than the first length, a groove being formed in at least one of opposite main surfaces of the first vibrational portions of the vibrational arms, a width of the groove being less than 0.07 mm and a distance in the width direction of the groove measured from an outer edge of the groove to an outer edge of the corresponding arm being less than 0.015 mm, a width of the mounting arms being less than 0.45 mm and a width of the connecting portions being less than 0.41 mm, the second width being greater than a spaced-apart distance between the second vibrational portions.