Method for manufacturing a quartz crystal unit

摘要

In a method for manufacturing a quartz crystal unit, a quartz crystal tuning fork resonator is formed by etching a quartz crystal wafer to form a quartz crystal tuning fork base, quartz crystal tuning fork tines connected to the quartz crystal tuning fork base, and a groove having stepped portions in at least one of opposite main surfaces of each of the quartz crystal tuning fork tines. A, and by disposing a first electrode is disposed on at least one of the stepped portions of each of the grooves and a second electrode is disposed on each of side surfacesat least one side surface of each of the quartz crystal tuning fork tines. A frequency of oscillation of the quartz crystal tuning fork resonator is adjusted at least twice and in different steps. The quartz crystal tuning fork resonator is then mounted in a case and an open end of the case is covered with a lid.An overall length of the resonator and a length of the groove are determined so that a series resistance R1 of a fundamental mode of vibration of the resonator is less than a series resistance R2 of a second overtone mode of vibration thereof or less than a series resistance R3 of a third overtone mode of vibration thereof.

主权项

id="REI-00234" date="20150623" 1. 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.