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 quartz crystal resonator unit includes a quartz crystal substrate, first and second excitation electrodes, first and second conductive sealing members, and first and second exterior members. The first excitation electrode is disposed on a first main surface of the substrate with the first conductive sealing member surrounding the first excitation electrode. Similarly, the second excitation electrode is disposed on a second main surface of the substrate with the second conductive sealing surrounding the second excitation electrode. The first and second exterior members are bonded to the quartz crystal substrate with the first and second conductive sealing member respectively interposed therebetween and to cover the first and excitation electrodes, respectively. In a plan view of the first main surface of the substrate, at least part of the first conductive sealing member is located outward of the second conductive sealing member.

In a crystal resonator plate (2), a support part (24) extends from only one corner part positioned in the +X direction and in the Z direction of a vibrating part (22) to an external frame part (23) in the Z direction. The vibrating part (22) and at least part of the support part (24) form an etching region (Eg) having a thickness thinner than a thickness of the external frame part (23). A stepped part is formed at a boundary of the etching region (Eg), and a first lead-out wiring (223) is formed over the support part (24) to the external frame part (23) so as to overlap with the stepped part. At least part of the stepped part that is superimposed on the first lead-out wiring (223) is formed so as not to be parallel to the X axis in plan view.

An electronic component housing package includes: a base section having a mounting section for an electronic component; a projecting part that is positioned on the base section and projects from the base section; a frame part that is positioned on the base section and surrounds the mounting section; a frame-shaped metalized layer that is positioned on the frame part; a plurality of external connection conductors that is positioned opposite the mounting section in the thickness direction; a connection conductor which is positioned on the projecting part and for connecting to the electronic component; and a wiring conductor that is connected to the connection conductor and that is led out to the base section. The thickness of the connection conductor gradually increases toward the wiring conductor.

Filter devices and methods of fabrication are disclosed. A filter device includes a piezoelectric plate attached to a substrate, portions of the piezoelectric plate forming diaphragms spanning respective cavities in the substrate. A conductor pattern formed on a surface of the piezoelectric plate includes a plurality of interdigital transducers (IDTs) of a respective plurality of acoustic resonators including a shunt resonator and a series resonator, interleaved fingers of each of the plurality of IDTs disposed on one of the diaphragms. Radio frequency signals applied to the IDTs excite respective primary shear acoustic modes in the respective diaphragms. A thickness of a first dielectric layer disposed on the front surface between the fingers of the IDT of the shunt resonator is greater than a thickness of a second dielectric layer disposed on the front surface between the fingers of the IDT of the series resonator.

A bulk acoustic wave resonator includes a substrate including a cavity groove, a membrane layer disposed above the substrate and including a convex portion. And a lower electrode including a portion thereof disposed on the convex portion. The bulk acoustic wave resonator also includes a piezoelectric layer configured so that a portion of the piezoelectric layer is disposed above the convex portion, and an upper electrode disposed on the piezoelectric layer. A first space formed by the cavity groove and a second space formed by the convex portion form a cavity, the cavity groove is disposed below an active region, and the convex portion comprises an inclined surface disposed outside of the cavity groove.

Devices and processes for preparing devices are described for a bulk acoustic wave resonator. A stack includes a first electrode that is coupled to a first side of a piezoelectric layer and a second electrode that is coupled to a second side of the piezoelectric layer. The stack is configured to resonate in response to an electrical signal applied between the first electrode and the second electrode. A cavity frame is coupled to the first electrode and to the substrate. The cavity frame forms a perimeter around a cavity. Optionally, a heat dissipating frame is formed and coupled to the second electrode. The cavity frame and/or the heat dissipating frame improve the thermal stability of the bulk acoustic resonator.

Acoustic resonator devices and filters are disclosed. An acoustic resonator includes a substrate and a piezoelectric plate having parallel front and back surfaces, the back surface attached to the substrate. An interdigital transducer (IDT) is formed on the front surface of the piezoelectric plate such that interleaved fingers of the IDT are disposed on a portion of the piezoelectric plate suspended over a cavity formed in the substrate.

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 are disclosed. An acoustic resonator includes a substrate and a piezoelectric plate having parallel front and back surfaces, the back surface attached to the substrate. An interdigital transducer (IDT) is formed on the front surface of the piezoelectric plate such that interleaved fingers of the IDT are disposed on a portion of the piezoelectric plate suspended over a cavity formed in the substrate.