A crystal oscillator and a method for fabricating the same is provided. In the method, a crystal package is provided. The crystal package includes a crystal blank and at least one laser-penetrating area. The laser-penetrating area is exposed outside. The crystal package is provided with at least one airtight space therein. At least one getter is formed in the airtight space. The location of the laser-penetrating area corresponds to that of the getter. A laser beam penetrates through the laser-penetrating area to activate the getter, thereby increasing the degree of vacuum of the airtight space.

A resonance device is provided that includes a lower cover; an upper cover coupled to the lower cover; and a resonator that has vibration arms that generate bending vibration in an interior space provided between the lower cover and the upper cover. Moreover, the vibration arms have distal ends provided with metal films on a side that faces the upper cover, and a gap is provided between the distal ends of the vibration arms and the upper cover that is larger than a gap between the distal ends of the vibration arms and the lower cover.

A resonance device is provided that includes a lower cover; an upper cover coupled to the lower cover; and a resonator that has vibration arms that generate bending vibration in an interior space provided between the lower cover and the upper cover. Moreover, the vibration arms have distal ends provided with metal films on a side that faces the upper cover, and a gap is provided between the distal ends of the vibration arms and the upper cover that is larger than a gap between the distal ends of the vibration arms and the lower cover.

Acoustic resonator devices and filters are disclosed. An acoustic resonator includes a substrate and a piezoelectric plate supported by the substrate. A portion of the piezoelectric plate suspended across a cavity in the substrate forms a diaphragm. A decoupling dielectric layer is on a front surface of the diaphragm. An interdigital transducer (IDT) has interleaved fingers on the decoupling dielectric layer over the diaphragm. The IDT and piezoelectric plate are configured such that a radio frequency signal applied to the IDT excites shear acoustic waves in the diaphragm.

Acoustic resonator devices and filters are disclosed. An acoustic resonator includes a substrate and a piezoelectric plate supported by the substrate. A portion of the piezoelectric plate suspended across a cavity in the substrate forms a diaphragm. A decoupling dielectric layer is on a front surface of the diaphragm. An interdigital transducer (IDT) has interleaved fingers on the decoupling dielectric layer over the diaphragm. The IDT and piezoelectric plate are configured such that a radio frequency signal applied to the IDT excites shear acoustic waves in the diaphragm.

A vibrator includes: a base portion; a vibrating arm including an arm portion which extends from the base portion, and a weight portion which is located on a tip end side of the arm portion and which has a first main surface and a second main surface that are in a front-back relationship; and a weight film disposed at the first main surface of the weight portion. The first main surface includes a planar surface and an inclined surface inclined with respect to the planar surface. A method for manufacturing a vibrator includes: a preparation step of preparing the above-described vibrator; and a removing step of removing a part of the weight film by emitting an energy ray to the weight film. In the removing step, the weight film disposed at the planar surface is removed and the weight film disposed at the inclined surface is not removed by emitting the energy ray to the weight film from a normal direction of the planar surface.

A vibrator includes: a base portion; a vibrating arm including an arm portion which extends from the base portion, and a weight portion which is located on a tip end side of the arm portion and which has a first main surface and a second main surface that are in a front-back relationship; and a weight film disposed at the first main surface of the weight portion. The first main surface includes a first planar surface, a second planar surface which is located closer to the second main surface than is the first planar surface and which is parallel to the first planar surface, and an inclined surface which couples the first planar surface and the second planar surface and which forms an angle of 100° or less with the first planar surface. A method for manufacturing a vibrator includes: a preparation step of preparing the above-described vibrator; and a removing step of removing a part of the weight film by emitting an energy ray to the weight film from a normal direction of the first planar surface.

There is disclosed acoustic resonators and filter devices. An acoustic resonator device includes a piezoelectric plate, and an interdigital transducer (IDT) formed on a front surface of the piezoelectric plate. The IDT includes interleaved fingers. At least one of the interleaved fingers includes a first layer adjacent the piezoelectric plate and a second layer over the first layer, wherein a width of the first layer is constant, and wherein a width of the second layer varies along a length of the at least one interleaved finger.

Acoustic resonator devices and filters, and methods of making the same. An acoustic resonator includes a piezoelectric plate and an interdigital transducer (IDT) including interleaved fingers on the piezoelectric plate. The piezoelectric plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a shear primary acoustic mode within the piezoelectric plate. The acoustic resonator further includes a front-side dielectric layer on the piezoelectric plate between the fingers of the IDT, wherein a resonance frequency of the acoustic resonator device has an inverse dependence on a thickness of the front-side dielectric layer.

Acoustic resonator devices and filters, and methods of making the same. An acoustic resonator includes a piezoelectric plate and an interdigital transducer (IDT) including interleaved fingers on the piezoelectric plate. The piezoelectric plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a shear primary acoustic mode within the piezoelectric plate. The acoustic resonator further includes a front-side dielectric layer on the piezoelectric plate between the fingers of the IDT, wherein a resonance frequency of the acoustic resonator device has an inverse dependence on a thickness of the front-side dielectric layer.