A method for manufacturing a piezoelectric vibration element that includes preparing a piezoelectric substrate; providing a first electrode layer on a first main surface of the piezoelectric substrate; arranging a mask on a side of the first main surface of the piezoelectric substrate, the mask including a center region and a peripheral region located along a periphery of the center region; and irradiating a radiation beam through the mask toward the first main surface of the piezoelectric substrate such that a larger amount of the radiation beam passes through the peripheral region than the center region of the mask so as to remove a part of the first electrode layer to form a first excitation electrode that decreases in thickness from the center region to the peripheral region of the mask on the first main surface of the piezoelectric substrate.

A piezoelectric resonator unit comprises a first enclosure portion that includes a first principal surface portion and a substantially curtain-shaped portion which cooperate to define a first recessed portion. The first principal surface portion has a first flat principal surface and the substantially curtain-shaped portion surrounds the first principal surface when viewed from a normal direction to the first principal surface. A second enclosure portion has a flat second principal surface and cooperates with the first recessed portion to define an enclosure which houses a piezoelectric resonator. A brazing material joins a distal end of the first enclosure portion to the second enclosure portion to hermetically seal the enclosure. An inner peripheral surface of the substantially curtain-shaped portion includes a stepped portion that is defined by adjacent thicker and a thinner portions of the substantially curtain-shaped portion. A surface of the stepped portion is formed of a single material.

A method of manufacturing a piezoelectric resonator unit that includes mounting a piezoelectric resonator on a base member, the piezoelectric resonator including a piezoelectric element and a pair of excitation electrodes facing each other with the piezoelectric element interposed therebetween, each of the pair of excitation electrodes including an underlying layer containing chromium and a surface layer on the underlying layer; forming chromium oxide on the surface layer of each of the pair of excitation electrodes by oxidizing chromium diffused from the underlying layer such that an amount of the chromium oxide is larger on the surface layer of the excitation electrode on a base member side than on the surface layer of the excitation electrode on a lid member side among the pair of excitation electrodes; and joining a lid member to the base member such that the piezoelectric resonator is between the base member and the lid member.

A MEMS resonator comprising a baseplate wafer; a piezoelectric HF-VHF resonator that comprises a monolithic piezoelectric member having at least two separate spring piezoelectric support members integrally extending therefrom, each spring piezoelectric support member having at least a rounded corner; said piezoelectric resonator being attached to the baseplate wafer by said support members; wherein said monolithic piezoelectric member comprises first and second main surfaces joined by side edges; at least one of said side edges forming an angle of between 90 and 105 degrees with one of the first and second main surfaces.

The vibrator element includes a base part, a vibrating arm extending from the base part, and a weight provided to the vibrating arm, wherein the weight includes a thick film part, a thin film part thinner in film thickness than the thick film part, and a connection part which is located between the thick film part and the thin film part to connect the thick film part and the thin film part to each other, and which forms a taper shape gradually decreasing in film thickness in a direction from the thick film part side toward the thin film part.

The vibrator element includes at least one vibrating arm, and a weight provided to the vibrating arm, the weight is provided with at least one processing scar, when an axis which overlaps a center in a width direction of the vibrating arm, and which extends along an extending direction of the vibrating arm is a central axis, and an axis which overlaps a centroid of the vibrating arm, and which extends along the extending direction of the vibrating arm is a centroid axis, the processing scar is formed in at least an area at the centroid axis side with respect to the central axis, and S1>S2 an area of the processing scar located at the centroid axis side with respect to the central axis is S1, and an area of the processing scar located at an opposite side to the centroid axis with respect to the central axis is S2.

A microelectromechanical resonator device has: a main body, with a first surface and a second surface, opposite to one another along a vertical axis, and made of a first layer and a second layer, arranged on the first layer; a cap, having a respective first surface and a respective second surface, opposite to one another along the vertical axis, and coupled to the main body by bonding elements; and a piezoelectric resonator structure formed by: a mobile element, constituted by a resonator portion of the first layer, suspended in cantilever fashion with respect to an internal cavity provided in the second layer and moreover, on the opposite side, with respect to a housing cavity provided in the cap; a region of piezoelectric material, arranged on the mobile element on the first surface of the main body; and a top electrode, arranged on the region of piezoelectric material, the mobile element constituting a bottom electrode of the piezoelectric resonator structure.

A piezoelectric device includes a container and an AT-cut crystal element. The AT-cut crystal element has at least one side surface intersecting with a Z-axis of the crystallographic axis of the crystal constituted of three surfaces. The first surface is a surface equivalent to a surface formed by rotating the principal surface by 43.5 with an X-axis of the crystal as a rotation axis. The second surface is a surface equivalent to a surface formed by rotating the principal surface by 575 with the X-axis. The third surface is a surface equivalent to a surface formed by rotating the principal surface by 425 with the X-axis. When two corner portions on a side of a second side opposed to the first side of the AT-cut crystal element are viewed in plan view, each of the two corner portions have an approximately right angle.

A microelectromechanical resonator device has: a main body, with a first surface and a second surface, opposite to one another along a vertical axis, and made of a first layer and a second layer, arranged on the first layer; a cap, having a respective first surface and a respective second surface, opposite to one another along the vertical axis, and coupled to the main body by bonding elements; and a piezoelectric resonator structure formed by: a mobile element, constituted by a resonator portion of the first layer, suspended in cantilever fashion with respect to an internal cavity provided in the second layer and moreover, on the opposite side, with respect to a housing cavity provided in the cap; a region of piezoelectric material, arranged on the mobile element on the first surface of the main body; and a top electrode, arranged on the region of piezoelectric material, the mobile element constituting a bottom electrode of the piezoelectric resonator structure.

A vibrator device includes a silicon substrate having a through hole, a first terminal placed on a first surface of the silicon substrate, a second terminal placed on a second surface opposite to the first surface of the silicon substrate, a wire passing the through hole and electrically coupling the first terminal and the second terminal, a resin layer placed between the wire and an inner wall defining the through hole, a silicon oxide layer placed between the resin layer and the inner wall, and a vibrator element bonded to the first terminal.