The resonator includes a vibrating portion that has three or more vibrating arms each having a fixed end and an open end and at least two vibrating arms undergoing out-of-plane bending in different phases. Moreover, the resonator includes a first base portion having a first front end connected to the fixed ends and a first rear end facing the first front end, a second base portion having a second front end facing the first rear end and a second rear end facing the second front end, and a connecting portion connected between a vicinity of a center of the first rear end and a vicinity of a center of the second front end, a holding portion that is provided in at least a part of a periphery of the vibrating portion, and a holding arm that is provided between the vibrating portion and the holding portion.

A piezoelectric resonator unit includes a piezoelectric substrate, first and second excitation electrodes, first and second connecting electrodes, and first and second exterior members. The first excitation electrode and first connecting electrode are disposed on a first main surface of the piezoelectric substrate and are electrically connected to each other. Similarly, the second excitation electrode and the second connecting electrode are disposed on a second main surface of the piezoelectric substrate and are electrically connected to each other. First and second exterior members bonded to the substrate with sealing members interposed. The first exterior member includes a first terminal portion formed in a shape that externally exposes at least part of the first connecting electrode. A first outer electrode covers the first terminal portion and the exposed portion of the first connecting electrode protruding from the first exterior member.

A film bulk acoustic resonator (FBAR) structure includes a bottom cap wafer, a piezoelectric layer disposed on the bottom cap wafer, a bottom electrode disposed below the piezoelectric layer, and a top electrode disposed above the piezoelectric layer. Portions of the bottom electrode, the piezoelectric layer, and the top electrode that overlap with each other constitute a piezoelectric stack. The FBAR structure further includes a lower cavity disposed below the piezoelectric stack. A projection of the piezoelectric stack is located within the lower cavity.

In a piezoelectric resonator device according to one or more embodiments, an internal space for hermetically sealing a vibrating part including a first excitation electrode and a second excitation electrode of a crystal resonator plate is formed by bonding a first sealing member and a second sealing member respectively to the crystal resonator plate. A through hole is formed in the second sealing member. A through electrode is formed along an inner wall surface of the through hole to establish conduction between an electrode formed on a first main surface and an external electrode terminal formed on a second main surface. A corrosion resistance structure to solder is formed on the through electrode that establishes conduction between the electrode and the external electrode terminal with a conductive metal other than Au.

Acoustic resonator devices and filters are disclosed. An acoustic resonator chip includes a piezoelectric plate attached to a substrate, a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A first conductor pattern formed on a surface of the piezoelectric plate includes an interdigital transducer with interleaved fingers on the diaphragm, and a first plurality of contact pads. A second conductor pattern is formed on a surface of an interposer, the second conductor pattern including a second plurality of contact pads. Each pad of the first plurality of contact pads is directly bonded to a respective pad of the second plurality of contact pads. A seal is formed between a perimeter of the acoustic resonator chip and a perimeter of the interposer.

Acoustic resonator devices and filters are disclosed. An acoustic resonator chip includes a piezoelectric plate attached to a substrate. Portions of the piezoelectric plate form at least first and second diaphragms spanning respective cavities in the substrate. A first conductor pattern on the surface of the piezoelectric plate includes a first plurality of contact pads and at least first and second IDTs with interleaved fingers of each IDT on respective diaphragms. An interposer includes a second plurality of contacts pads. A plurality of conductive balls bond each of the contact pads of the first plurality of contact pads to respective contact pads of the second plurality of contact pads.

A crystal oscillator includes: a crystal resonator plate having a first excitation electrode and a second excitation electrode. A first sealing member covers the first excitation electrode of the crystal resonator plate. A second sealing member covers the second excitation electrode of the crystal resonator plate. An internal space is formed by bonding the first sealing member to the crystal resonator plate and the second sealing member to the crystal resonator plate, and seals a vibrating part of the crystal resonator plate. First and second shield electrodes are connected to a fixed potential (e.g. GND potential) in the internal space.

A crystal resonator (101) includes: a piezoelectric resonator plate (2) on which a first excitation electrode and a second excitation electrode are formed; a first sealing member (3) that covers the first excitation electrode of the piezoelectric resonator plate (2); and a second sealing member (4) that covers the second excitation electrode of the piezoelectric resonator plate (2). The first sealing member (3) is bonded to the piezoelectric resonator plate (2) while the second sealing member (4) is bonded to the piezoelectric resonator plate (2) so that an internal space (13), which hermetically seals a vibrating part including the first excitation electrode and the second excitation electrode of the piezoelectric resonator plate (2), is formed. Plating films (51, 52) are formed respectively on both the first sealing member (3) and the second sealing member (4), on respective surfaces opposite to surfaces to be bonded to the piezoelectric resonator plate (2).

A crystal vibration element that includes a crystal piece that has a prescribed crystal orientation, and a first direction and a second direction in a plan view thereof; and excitation electrodes that are respectively provided on front and rear surfaces of the crystal piece in order to excite a thickness shear vibration in the crystal piece upon application of an alternating electric field. A vibration distribution of the crystal piece has a vibration region that extends in a band-like shape in the second direction of the crystal piece and non-vibration regions that are adjacent to opposed sides of the vibration region in the first direction of the crystal piece.

A quartz crystal resonator is provided that includes a body portion with first and second main surfaces facing each other and, in plan view has a pair of long sides extending in a first direction and a pair of short sides extending in a second intersecting direction. Moreover, first and second excitation electrodes are disposed on the first and second main surfaces respectively; a frame surrounds the body portion at both ends and is separated from the both ends; and first and second coupling portions extend from the short sides in the first direction with widths of the short sides. At least one of the first and second coupling portions has a portion whose thickness in a third direction is smaller than a thickness in the third direction of a region of the body portion where the first excitation electrode and the second excitation electrode face each other.