Patent ID: 6898832

Claim:
A method for manufacturing a quartz crystal unit, comprising the steps of: forming at least one quartz crystal tuning fork resonator by etching a quartz crystal wafer to form a quartz crystal tuning fork base, a plurality of quartz crystal tuning fork tines connected to the quartz crystal tuning fork base, and at least one groove having a plurality of stepped portions in at least one of opposite main surfaces of each of the quartz crystal tuning fork tines, and disposing a first electrode on at least one of the stepped portions of at least one of the grooves and a second electrode on at least one side surface of each of the quartz crystal tuning fork tines; adjusting at least twice and in different steps a frequency of oscillation of the quartz crystal tuning fork resonator; providing a case having an interior space and an open end communicating with the interior space; providing a lid for covering the open end of the case; mounting the quartz crystal tuning fork resonator in the interior space of the case; and connecting the lid to the case to cover the open end thereof.