The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 22, 2015
Filed:
Aug. 01, 2013
Piedek Technical Laboratory, Tokyo, JP;
Hirofumi Kawashima, Tokyo, JP;
PIEDEK TECHNICAL LABORATORY, , JP;
Abstract
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 aquartz crystaltuning fork base,quartz crystaltuning fork tines connected to thequartz crystaltuning fork base, and a groove having stepped portions in at least one of opposite main surfaces of each of thequartz crystaltuning fork tines. A, and by disposing afirst electrodeis disposedon at least one of the stepped portionsof each of the groovesand a second electrodeis disposedoneach of side surfacesat least one side surfaceof each of thequartz crystaltuning 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 Rof a fundamental mode of vibration of the resonator is less than a series resistance Rof a second overtone mode of vibration thereof or less than a series resistance Rof a third overtone mode of vibration thereof.