A resonator device includes: a resonator element; a first package that accommodates the resonator element; and a second package in which the first package is accommodated and fixed. The first package includes a base substrate that has a first surface on which the resonator element is disposed and a second surface which is in a front-back relationship with the first surface, and that contains single crystal silicon, an integrated circuit that is provided on the first surface or the second surface and that includes a temperature sensor circuit and a heater circuit, and a lid that is bonded to the base substrate such that the resonator element is accommodated between the lid and the base substrate.

A resonator device includes: a resonator element; a first package that accommodates the resonator element; and a second package in which the first package is accommodated and fixed. The first package includes a base substrate that has a first surface on which the resonator element is disposed and a second surface which is in a front-back relationship with the first surface, and that contains single crystal silicon, an integrated circuit that is provided on the first surface or the second surface and that includes a temperature sensor circuit and a heater circuit, and a lid that is bonded to the base substrate such that the resonator element is accommodated between the lid and the base substrate.

A resonator device includes: a base having a first surface and a second surface that are in front-back relation; a resonator element that is located at a first surface with respect to the base and that includes a resonation substrate and an electrode disposed at a surface of the resonation substrate on a base side; a conductive layer that is disposed at the first surface and that includes a joint portion joined to the electrode; and a stress relaxation layer that is interposed between the base and the conductive layer and that at least partially overlaps with the joint portion in a plan view of the base. The stress relaxation layer includes an exposed portion exposed from the conductive layer.

A method for manufacturing a resonator element includes: a substrate preparation step of preparing a substrate; an etching step of performing an etching process on the substrate to form a resonator element, a frame portion, and a holding portion that couples the resonator element and the frame portion; and a break-off step of breaking off the resonator element from the frame portion. The holding portion includes a narrow portion in which a part of a width is narrow. The width of the narrow portion is minimum at a position closer to a resonator element side than at a center of the holding portion. In a cross-sectional view, an angle formed by a side surface of the narrow portion with respect to a flat surface of the holding portion is in a range of 85° or more and 95° or less. The etching process is dry etching.

A method for manufacturing a resonator element includes: a substrate preparation step of preparing a substrate; an etching step of performing an etching process on the substrate to form a resonator element, a frame portion, and a holding portion that couples the resonator element and the frame portion; and a break-off step of breaking off the resonator element from the frame portion. The holding portion includes a narrow portion in which a part of a width is narrow. The width of the narrow portion is minimum at a position closer to a resonator element side than at a center of the holding portion. In a cross-sectional view, an angle formed by a side surface of the narrow portion with respect to a flat surface of the holding portion is in a range of 85° or more and 95° or less. The etching process is dry etching.

A crystal oscillator device is disclosed. The crystal oscillator device includes a crystal piece provided in a casing; a pair of excitation electrodes provided for the crystal piece; a coil provided on the crystal piece; a magnetic flux generating member configured to generate magnetic flux passing through the coil; and an alarm generator configured to generate an alarm based on a signal whose amplitude is equal to or less than a reference value, the signal being generated in the coil.

A surface-guided bulk wave transducer includes a stack of an acoustic substrate, an electric ground plane, and a network of synchronous acoustic excitation sources with two combs of elementary piezoelectric transducers alternately interlaced two-by-two according to a periodic network step corresponding to a propagation mode of a surface-guided bulk wave of the acoustic substrate. Each elementary piezoelectric transducer includes a single and different rod with a parallelepipedal shape for which the nature, the cut of the piezoelectric material, the height h, and the width are selected for increasing the electromechanical coupling coefficient of the transducer assembly to a high level.

A surface-guided bulk wave transducer includes a stack of an acoustic substrate, an electric ground plane, and a network of synchronous acoustic excitation sources with two combs of elementary piezoelectric transducers alternately interlaced two-by-two according to a periodic network step corresponding to a propagation mode of a surface-guided bulk wave of the acoustic substrate. Each elementary piezoelectric transducer includes a single and different rod with a parallelepipedal shape for which the nature, the cut of the piezoelectric material, the height h, and the width are selected for increasing the electromechanical coupling coefficient of the transducer assembly to a high level.

A vibrating element includes a piezoelectric substrate having an excitation section adapted to excite a thickness-shear vibration, and provided with a step section in each of side surfaces on both ends, and a peripheral section having a thickness smaller than a thickness of the excitation section, and the peripheral section has at least one projection section disposed on both principal surfaces in an area where a vibratory displacement when the excitation section excites a vibration is sufficiently attenuated.

A vibrating element includes a piezoelectric substrate having an excitation section adapted to excite a thickness-shear vibration, and provided with a step section in each of side surfaces on both ends, and a peripheral section having a thickness smaller than a thickness of the excitation section, and the peripheral section has at least one projection section disposed on both principal surfaces in an area where a vibratory displacement when the excitation section excites a vibration is sufficiently attenuated.