A crystal element includes a vibration part, a holding part, an electrode part, and a recess that corresponds to a recess and/or protrusion. The vibration part has a pair of vibration-part main surfaces. The holding part is formed integrally with the vibration part to be connected to an outer edge of vibration part and has a pair of holding-part main surfaces and holding-part side surfaces. The electrode part is provided at the vibration-part main surfaces. The recess is located at the holding-part side surfaces.

A quartz crystal resonator that includes a quartz crystal element having main surfaces extending in a plane φ degrees around a Z axis of the quartz crystal element and θ 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, |φ−(−98.6x.sup.3+114.0x.sup.2−22.3x+1.3)|≤5 and |θ−(−9.5x.sup.3−10.9x.sup.2+1.4x+35.3)|≤0.5, wherein T is a thickness of the quartz crystal element and t is a thickness of the electrode.

A resonator device includes a quartz crystal substrate, a resonator element including a first excitation electrode arranged on a first surface of the quartz crystal substrate, a second excitation electrode arranged on a second surface of the quartz crystal substrate in opposition to the first excitation electrode, and first and second pad electrodes that are arranged on the first surface and are coupled to the first and second excitation electrodes, a base including a substrate and first and second interconnects arranged on the substrate, a first bonding member bonding the first pad electrode to the first interconnect, and a second bonding member bonding the second pad electrode to the second interconnect. The first and second bonding members are arranged such that a first imaginary line that passes through a centroid of the resonator element and is parallel to an X axis is interposed between the first and second bonding members. An angle θ1 formed between the first imaginary line and a second imaginary line passing through the first bonding member and the second bonding member is 100°<θ1<140°.

A quartz crystal unit comprising a quartz crystal resonator having a base portion, and first and second tuning fork arms connected to the base portion, the base portion having a length less than 0.5 mm and greater than a spaced-apart distance between the first and second tuning fork arms, each of the first and second tuning fork arms having a width less than 0.1 mm and a length less than 1.56 mm, and a plurality of different widths including a first width and a second width greater than the first width, at least one groove being formed in at least one of opposite main surfaces of each of the first and second tuning fork arms so that a length of the at least one groove is within a range of 0.3 mm to 0.79 mm, the quartz crystal resonator being housed in a case, and a lid being connected to the case.

A circuit device includes a first terminal, a first oscillation circuit oscillating a resonator and generating a first voltage for automatic gain control for controlling amplitude of a signal output from the resonator, a digital signal generation circuit generating a digital signal corresponding to the first voltage, and a first interface circuit outputting the digital signal to the first terminal.

A vibrator device includes a base, a vibrator element attached to the base, and a lid housing the vibrator element between the base and itself and bonded to the base. The base has a semiconductor substrate including a first surface bonded to the lid and a second surface in a front-back relationship with the first surface, a first insulating layer placed on the first surface, first, second internal terminals placed on the first insulating layer and electrically coupled to the vibrator element, a second insulating layer placed on the second surface, and first, second external terminals placed on the second insulating layer and electrically coupled to the first, second internal terminals. The second insulating layer has a first external terminal region in which the first external terminal is placed and a second external terminal region separated from the first external terminal region, in which the second external terminal is placed.

An oscillator includes a package having a plurality of external terminals disposed on a mounting surface, a circuit element housed in the package, and a resonator which is housed in the package, and is electrically coupled to the circuit element, wherein the circuit element is electrically coupled to the package with a plurality of pads each of which is bonded to the package via a bump member, the circuit element overlaps at least one of the external terminals in a plan view, and each of the bump members is bonded to the package at a position where at least a part of the bump member does not overlap the plurality of external terminals in the plan view.

A vibrating arm of a vibrator element has a first surface, a second surface at an opposite side to the first surface in a Z direction, a first side surface and a second side surface as side surfaces, and a third side surface as a tip surface. At least one of the first side surface, the second side surface, and the third side surface includes a first side surface part tilted with respect to a Z direction, and a second side surface part tilted toward the first surface or the second surface with respect to the first side surface part. The first weight is arranged so that an outer edge of the first weight is located at inner side of innermost parts in the first side surface part and the second side surface part, or at the same position as the innermost parts when viewed from the Z direction.

Provided is a crystal element that includes: a crystal piece that is in a substantially rectangular shape on a plan view; an excitation electrode part located on both main surfaces of the crystal piece; a connection lead part extended to a first short-side of the crystal piece from the excitation electrode part; a convex part located on both ends of a second short-side of the crystal piece; and a projected part located on both ends of the first short-side of the crystal piece. Further, a concave part is located in the convex part, and a recessed part is located in the projected part.

A resonator device includes a base, a resonator element attached to the base, a cover accommodating the resonator element between the base and the cover, and a conductive bonding member positioned between the base and the cover and bonding the base to the cover. The base includes a resonator element mount surface on which the resonator element is attached, a first interconnect and a second interconnect that are arranged on the resonator element mount surface and that are electrically coupled to the resonator element, a bonding surface bonded to the cover through the bonding member, and a step between the resonator element mount surface and the bonding surface.