Abstract: A piezoelectric resonator is provided that includes a piezoelectric element having first and second main surfaces; a first electrode including a first excitation electrode on the first main surface and a first extended electrode coupled to a first outer peripheral portion of the first excitation electrode; and a second excitation electrode provided on the second main surface. At least one cavity is in at least one of the first electrode and the second excitation electrode in the region where the first electrode overlaps the second excitation electrode and is within a range of a distance of four times or less a thickness of the piezoelectric element from a boundary between the first excitation electrode and the first extended electrode.

Abstract: A piezoelectric vibration element that includes: a piezoelectric substrate; a first excitation electrode on a first main surface of the piezoelectric substrate; a second excitation electrode on a second main surface of the piezoelectric substrate; and a mass-adding film at least a part of which overlaps with the first excitation electrode, the mass-adding film including a first part and a second part which do not overlap a central portion of the first excitation electrode, the first part extends along a first outer edge portion of the first excitation electrode and the second part extends along a second outer edge portion of the first excitation electrode so as to define a high acoustic velocity region, a first low acoustic velocity region, and a second low acoustic velocity region in a plan view.

Abstract: A piezoelectric vibration element according to an exemplary aspect of the present disclosure includes a piezoelectric piece having a first main surface and a second main surface. The first main surface and the second main surface face each other in a facing direction. The piezoelectric vibration element also includes a first excitation electrode on the first main surface and a second excitation electrode on the second main surface. In a plan view in the facing direction, a first area of the first excitation electrode is smaller than a second area of the second excitation electrode, and a part of the second excitation electrode overlaps an entirety of the first excitation electrode, and a first thickness of the first excitation electrode along the facing direction is smaller than a second thickness of the second excitation electrode along the facing direction.

Abstract: A piezoelectric resonator that includes: a piezoelectric member and an excitation electrode that overlap with each other in a thickness direction, the piezoelectric resonator has a high acoustic velocity region and a low acoustic velocity region, in a plan view in the thickness direction, the high acoustic velocity region overlaps a center portion of the excitation electrode, and the low acoustic velocity region overlaps an end portion of the excitation electrode, the high acoustic velocity region includes a plurality of holes, in a first direction intersecting the thickness direction, a dimension of a portion of the low acoustic velocity region adjacent to the high acoustic velocity region in the first direction is smaller than a dimension of the high acoustic velocity region in the first direction, and in the plan view, an area of the low acoustic velocity region is smaller than an area of the high acoustic velocity region.

Abstract: A piezoelectric resonator unit that includes a base, a cover, and a laminated structure disposed between the base and the cover. The laminated structure includes a piezoelectric resonator having a piezoelectric layer with a pair of principal surfaces facing each other, and a pair of excitation electrodes disposed on respective surfaces of the pair of principal surfaces so as to face each other with the piezoelectric layer therebetween, a semiconductor layer laminated on a side of one of the pair of principal surfaces of the piezoelectric layer, and a pair of measurement electrodes provided on the semiconductor layer. The pair of measurement electrodes measure signals based on temperature of the piezoelectric resonator through the semiconductor layer.

Abstract: A resonator is provided that includes a vibration member that includes a substrate, a metal layer formed along one of main surfaces of the substrate, and a piezoelectric thin film disposed between the substrate and the metal layer. The vibration member vibrates such that a main vibration is a contour vibration. Moreover, a frame surrounds at least a portion of the vibration member, and a support unit connects the vibration member to the frame. The vibration member includes depressed portions on or above the one of main surfaces where the piezoelectric thin film is removed.

Abstract: A crystal resonator is provided that includes a crystal substrate having first and second main surfaces; a first and second comb electrodes on the first main surface and that each include electrode fingers that are alternately arranged. The first comb electrode includes a first electrode finger and the second comb electrode includes a second electrode finger adjacent to the first electrode finger. Thickness shear vibration is excited at a portion overlapping with a gap between the first and second electrode fingers, depending on a potential difference between the first and second electrode fingers. A duty ratio (L1+L2 (/(2×P1) on a first main surface side is from 0.15 to 0.33 inclusive or from 0.62 to 0.82 inclusive where a width of the first electrode finger is denoted as L1, a width of the second electrode finger is and a distance between the first and second electrode fingers is P1.

Abstract: A resonator is provided that includes a vibrator with two portions that vibrate in phases opposite to each other; a frame that is disposed to surround at least part of the vibrator; and a holding unit that supports a boundary between the two portions and connects the vibrator to the frame. Moreover, a frequency adjustment film is disposed on a surface of the vibrator in an area between a connection portion of the holding unit connected to the vibrator and an end of the vibrator that faces the connection portion in a direction along the boundary between the two portions.

Abstract: A resonator is provided that includes a piezoelectric layer having a first and second surfaces that oppose each other, an IDT electrode on the first surface of the piezoelectric layer, and a high acoustic velocity substrate on the second surface of the piezoelectric layer. The piezoelectric layer is made from a quartz crystal having cut-angles obtained by rotating a plane orthogonal to a crystal Y-axis about a crystal X-axis, in a propagation direction at 90°±10° to the crystal X-axis of the piezoelectric layer, an acoustic velocity in the high acoustic velocity substrate is higher than an acoustic velocity in the piezoelectric layer, and the IDT electrode includes a comb-shaped electrode including multiple electrode fingers aligned in the propagation direction.

Abstract: A resonator includes a vibration portion that has a substrate having a main surface, a lower electrode on the main surface of the substrate, a piezoelectric film on the lower electrode, and an upper electrode on the piezoelectric film. A frame surrounds at least part of the vibration portion. Opening grooves having different widths in a first direction in a plan view of the main surface are provided in a periphery of the vibration portion. In a plan view of the main surface, the upper electrode is provided so as to be spaced from an outer edge of the substrate by a gap which is along the first direction, such that a length of the gap in a region where a width of the opening groove is large is larger than a length of the gap in a region where a width of the opening groove is small.

Abstract: A piezoelectric vibration element that includes a piezoelectric piece having a first principal surface and a second principal surface; a via electrode penetrating the piezoelectric piece from the first principal surface to the second principal surface thereof; a conductive etch stop film covering the via electrode on the second principal surface; and a wiring electrode covering at least part of an outer edge of the conductive etch stop film on the second principal surface.

Abstract: A crystal oscillation element includes a crystal piece having principal planes defined by a first base axis and a second base axis that intersects the first base axis, and an excitation electrode unit at the principal planes of the crystal piece. The excitation electrode unit has flat plate portions and thick film portions located at electrode ends on the principal planes and that have a thickness larger than that of the flat plate portions. The thick film portion has first protruding portions at the ends in the axis direction of the first base axis, extend in the axis direction of the second base axis and protrude from the flat plate portion, and second protruding portions at the ends in the axis direction of the second base axis, extend in the axis direction of the first base axis and protrude from the flat plate portion.

Abstract: A quartz crystal resonator unit that includes: a piezoelectric blank; a first excitation electrode on a first principal surface and within at least a part of a vibration portion of the piezoelectric blank; a second excitation electrode on a second principal surface and within at least a part of the vibration portion of the piezoelectric blank; a first extended electrode on the first principal surface and electrically connected to the first excitation electrode; and a second extended electrode on the second principal surface and electrically connected to the second excitation electrode; and an insulation layer including a hollow portion which defines a space with the second excitation electrode. A thickness of the first extended electrode is larger than a thickness of the second extended electrode. An end portion of the first extended electrode extends over the hollow portion in a plan view of the piezoelectric vibrator.

Abstract: A quartz crystal resonator that includes a quartz crystal element having main surfaces extending in a plane ? degrees around a Z axis of the quartz crystal element and ? degrees around an X? axis of the quartz crystal element; and an electrode in contact with the quartz crystal element, where x=t/T?0.01, |??(?98.6x3+114.0x2?22.3x+1.3)|?5 and |??(?9.5x3?10.9x2+1.4x+35.3)|?0.5, wherein T is a thickness of the quartz crystal element and t is a thickness of the electrode.

Abstract: A resonance device with improved precision of temperature control. The resonance device includes a platform; a resonator including a vibrator and one or more holding arms that connect the vibrator and the platform to each other such that a first groove is provided around the vibrator. Moreover, the resonance device includes a sensor with a measurement portion that measures temperature and a heater formed on the platform. A second groove is provided between the measurement portion and the heater.

Abstract: A vibrator is provided that includes a substrate having a major surface defined in width and length directions and one or more electrodes formed at least in a substantial entire region of the major surface of the substrate in the length direction, and that performs, as main vibration, expansion-contraction vibration along the width direction in accordance with a voltage applied to the electrodes. Moreover, a holder surrounds at least a portion of the vibrator; and a holding arm connects the vibrator to the holder. Moreover, the vibrator has a width Wo in the width direction positioned at an end in the length direction and includes, to have a width Wm differing from the width Wo and positioned between a pair of ends opposing in the length direction, a variant portion at least one or more locations that is in a shape recessed or projecting in the width direction.

Abstract: A resonator is provided that includes a vibrator with two portions that vibrate in phases opposite to each other; a frame that is disposed to surround at least part of the vibrator; and a holding unit that supports a boundary between the two portions and connects the vibrator to the frame. Moreover, a frequency adjustment film is disposed on a surface of the vibrator in an area between a connection portion of the holding unit connected to the vibrator and an end of the vibrator that faces the connection portion in a direction along the boundary between the two portions.

Abstract: A resonator that includes a piezoelectric vibrating portion; a retainer provided in at least part of an area surrounding the piezoelectric vibrating portion; a first node generating portion disposed between the piezoelectric vibrating portion and the retainer; a first connecting arm that connects the first node generating portion to a region in the piezoelectric vibrating portion that faces the first node generating portion; and a first retaining arm that connects the first node generating portion to a region in the retainer that faces the first node generating portion. The first node generating portion is substantially symmetrical with respect to each of two lines passing through a center of the first node generating portion along a first direction and a second direction orthogonal to the first direction, with the first direction being a direction that the first connecting arm connects the first node generating portion to the piezoelectric vibrating portion.

Abstract: A piezoelectric resonator unit that includes a base, a cover, and a laminated structure disposed between the base and the cover. The laminated structure includes a piezoelectric resonator having a piezoelectric layer with a pair of principal surfaces facing each other, and a pair of excitation electrodes disposed on respective surfaces of the pair of principal surfaces so as to face each other with the piezoelectric layer therebetween, a semiconductor layer laminated on a side of one of the pair of principal surfaces of the piezoelectric layer, and a pair of measurement electrodes provided on the semiconductor layer. The pair of measurement electrodes measure signals based on temperature of the piezoelectric resonator through the semiconductor layer.

Abstract: A resonator is provided that includes a vibration part, a frame, and a support arm. The vibration part includes an Si substrate that has a principal surface with a width W in an X-axis direction and a length L in a Y-axis direction. The vibration part is configured to vibrate mainly in a contour vibration mode. The support arm extends in the Y-axis direction and connects the frame to one of two ends in the Y-axis direction of the vibration part. When the principal surface of the Si substrate is viewed in a plan view, the width W is at its maximum Wmax at a point in the Y-axis direction and decreases with increasing proximity to the one of the two end portions in the Y-axis direction of the vibration part and with increasing proximity to the other end portion in the Y-axis direction of the vibration part.