A voltage-controlled oscillator includes a piezoelectric element, a first package, an electronic element, and a second package. The first package contains the piezoelectric element. The second package contains the electronic element and the first package. The second package includes a base, and a lid. The electronic element and the first package are mounted in the base. The lid hermetically seals the electronic element and the first package together with the base. The base includes a substrate part, a first frame part, and a second frame part. The substrate part includes a first major face and a second major face opposite to the first face. The electronic element is mounted on the first major face. The first frame part includes a first frame face on which the first package is mounted. The first frame part is located on a peripheral edge of the first major face.

A method is provided for manufacturing a resonance device, the method includes forming a recessed portion that forms a vibration space for a resonator in an object that is at least one of an upper lid and a lower lid and includes etching on the object by isotropic etching while the object is covered with a mask having a peripheral portion having a frame shape and a stopper formation that extends from the peripheral portion toward an inside of the peripheral portion. The method further includes etching the object while the object is covered with the mask to form a stopper at a position overlapping with the stopper formation on a bottom surface of the recessed portion in a plan view of the object. In this aspect, the stopper restricts collision of the resonator with the bottom surface of the recessed portion.

A wafer-level chip-scale package includes a polymeric body having a conductive via passing through the polymeric body and a piezoelectric substrate directly bonded to an upper end of the conductive via. The wafer-level chip-scale package further includes a cavity defined between a portion of the polymeric body and the piezoelectric substrate and a metal seal ring disposed in the body and having an upper end bonded to the piezoelectric substrate, the metal seal ring passing only partially through the body.

A MEMS device including an active layer having a first surface and a second surface is provided. A first electrode and a second electrode, and at least one reconfigurable electrode segment are arranged over the first surface of the active layer. At least one reconfiguration layer is arranged over the second surface of the active layer. The at least one reconfigurable electrode segment and the at least one reconfiguration layer overlaps. One or more via contacts are disposed through the active layer configured to couple the at least one reconfigurable electrode segment and the at least one reconfiguration layer. The at least one reconfiguration layer is coupled to a reconfiguration switch for reconfiguring electrical connections to the at least one reconfigurable electrode segment. The MEMS device is configured to generate different resonant frequencies by reconfiguring the electrical connections to the at least one reconfigurable electrode segment using the reconfiguration switch.

An SAW device includes a piezoelectric substrate, an IDT electrode on a first major surface of the piezoelectric substrate, a capacitance element which is located on the first major surface and is connected to the IDT electrode, and a cover which is superimposed only on the capacitance element between the IDT electrode and the capacitance element.

An acoustic wave device includes a support including a support substrate with a thickness in a first direction, a piezoelectric layer on the support in the first direction on the support, and resonators each including a functional electrode on the piezoelectric layer in the first direction on the piezoelectric layer. The support includes space portions therein at positions where the functional electrodes at least partially overlap in a planar view in the first direction. The support includes a lead portion communicating with at least one of the space portions in a planar view in the first direction, at a position that does not overlap the space portion. At least one lead portion communicates with at least two of the space portions. The piezoelectric layer includes a through-hole penetrating the piezoelectric layer at a position overlapping the lead portion in a planar view in the first direction.

A vibration device including a vibrator, a circuit component, a relay substrate disposed between the vibrator and the circuit component, a package that accommodates the vibrator, the circuit component, and the relay substrate, a first metal bump that joins the circuit component to the package, a second metal bump that joins the relay substrate to the circuit component, and a third metal bump that joins the vibrator to the relay substrate.

Provided is a multiplexer that includes a first filter (first transmission filter), a second filter (second reception filter), a third filter (third reception filter), a first inductor, and a second inductor. The first inductor is connected in series with one parallel arm resonator (second parallel arm resonator) of the first filter between the one parallel arm resonator and ground. The second inductor is connected in series with another parallel arm resonator (third parallel arm resonator) of the first filter between the other parallel arm resonator and ground. The first inductor and the second inductor have the same winding direction as each other from the first filter side toward the ground side thereof.

A resonator element includes a quartz crystal substrate including a supporting section, a resonating section, and a coupling section coupling the supporting section and the resonating section and having thickness smaller than the thickness of the supporting section, the supporting section including a first principal plane and a first side surface coupling the first principal plane and the coupling section, a first excitation electrode disposed in the resonating section, a second excitation electrode disposed in the resonating section and overlapping the first excitation electrode via the resonating section, and first and second pad electrodes including portions disposed on the first principal plane, the first and second pad electrodes being electrically coupled to the first and second excitation electrodes.

A vibrator device includes a circuit element, which has a first terminal and is a quadrangle in plan view, a vibrator, which is disposed on an active surface and is a quadrangle in plan view, a base, on which the circuit element is disposed and which has a second terminal, and a wire which connects the first terminal and the second terminal together. In plan view of the circuit element, at least one side of the vibrator is disposed along a direction where the one side intersects each of two adjacent sides of the circuit element, and the vibrator does not overlap the first terminal.