Patent ID: 8806738
Filing Date: 2014-08-19
Classification: H01L,H03B,H03H,H04R,Y10T

Abstract:
1. A method for manufacturing a quartz crystal unit, comprising the steps of: providing a case having an open end; providing a lid for covering the open end of the case; forming a quartz crystal tuning fork resonator having a quartz crystal tuning fork shape including a quartz crystal tuning fork base, and first and second quartz crystal tuning fork tines connected to the quartz crystal tuning fork base, each of the first and second quartz crystal tuning fork tines having opposite main surfaces and opposite side surfaces; forming at least one groove in at least one of the opposite main surfaces of each of the first and second quartz crystal tuning fork tines so that a width of the at least one groove formed in the at least one of the opposite main surfaces of each of the first and second quartz crystal tuning fork tines is greater than a distance in the width direction of the at least one groove measured from an outer edge of the at least one groove to an outer edge of the corresponding one of the first and second quartz crystal tuning fork tines and less than a spaced-apart distance between the first and second quartz crystal tuning fork tines, the quartz crystal tuning fork resonator having a series resistance R determining each of a length of the at least one groove formed in the at least one of the opposite main surfaces of each of the first and second quartz crystal tuning fork tines and an overall length of the quartz crystal tuning fork resonator so that the series resistance R housing the quartz crystal tuning fork resonator in the case; and connecting the lid to the case to cover the open end of the case.