Reduced in size is a radio frequency component provided on a main surface of a mounting substrate on which an external connection electrode is disposed. A radio frequency module includes a mounting substrate, a first radio frequency component, and an external connection electrode. The mounting substrate has a first main surface and a second main surface opposed to each other. The first radio frequency component has a signal terminal and a ground terminal. The first radio frequency component is provided on the second main surface. The external connection electrode is provided on the second main surface. The first radio frequency component has a third main surface and a fourth main surface opposed to each other. The signal terminal is provided on the third main surface. The ground terminal is provided on the fourth main surface.

An acoustic wave device includes a first and second element substrates each having piezoelectricity, and bonding layers bonding the first and second element substrates to each other. First and second IDT electrodes and first and second wiring electrodes are respectively provided on the first and second element substrates. The first and second wiring electrodes are disposed one above the other with the bonding layer interposed therebetween to define a wiring electrode overlapped portion. In each of the wiring electrode overlapped portions, the first wiring electrode and the second wiring electrode are provided in one of combinations in which one wiring electrode is a signal wiring electrode and the other wiring electrode is a ground wiring electrode, both of the wiring electrodes are ground wiring electrodes, and both of the wiring electrodes are signal wiring electrodes at the same potential.

A multiplexer includes a transmit filter including first acoustic wave resonators connected to a first path between a common terminal and a transmit terminal, one or some first acoustic wave resonators of the first acoustic wave resonators being provided on a first substrate, and a remaining first acoustic wave resonator being provided on a second substrate, and a receive filter including second acoustic wave resonators connected to a second path between the common terminal and a receive terminal, one or some second acoustic wave resonators of the second acoustic wave resonators being provided on the first substrate and a remaining second acoustic wave resonator being provided on the second substrate, and a resonator closest to the receive terminal in a plan view among the one or some first and second acoustic wave resonators being a second acoustic wave resonator of the one or some second acoustic wave resonators.

A multiplexer includes: first and second substrates overlapping with each other with an air gap interposed therebetween; a first filter disposed on the first substrate and including first series resonators connected in series with a first path, and first parallel resonators; and a second filter disposed on the second substrate and including second series resonators connected in series with a second path, and second parallel resonators connected between the second path and a ground, each of the second series resonators and the second parallel resonators including a piezoelectric film, a first electrode interposed between the piezoelectric film and the second substrate, a second electrode interposed between the piezoelectric film and the air gap, and a resonance region, in at least one second parallel resonator, the first electrode being coupled to the second path, the second electrode being coupled to the ground, the resonance region overlapping with the first path.

An acoustic wave device includes a package substrate including first and second principal surfaces, an acoustic wave element at the first principal surface, a sealing resin layer covering at least a portion of the acoustic wave element, and a metal shield film covering the sealing resin layer. The package substrate includes a ground connection electrode in the package substrate, electrically connected to the acoustic wave element, and connected to a ground potential. The package substrate includes a side surface and a connection portion connected to at least a portion of an end edge on a side with the second principal surface in the side surface and at least a portion of an outer peripheral edge in the second principal surface. The shield film reaches the side surface of the package substrate and does not reach the connection portion, and the shield film is connected to the ground connection electrode.

Embodiments of this disclosure relate to reducing coupling between acoustic wave resonators. An isolation region of a substrate can be located between acoustic wave resonators. The isolation region can reduce capacitive coupling through the substrate between the acoustic wave resonators. In certain embodiments, the isolation region can be located between acoustic wave resonators of different filters to thereby increase isolation between the filters.

Embodiments of this disclosure relate to methods of manufacturing acoustic wave components that include acoustic wave resonators that share a substrate. Laser light can be applied to alter a region of the substrate that is located between two of the acoustic wave resonators. Altering the region with laser light can reduce coupling between the two acoustic resonators through the substrate. The substrate can be monolithic after laser the light is applied.

The radio frequency module includes a mounting board, a first metal member, and a second metal member. The first metal member and the second metal member are disposed on the mounting board. The first metal member has a longitudinal direction along a first direction in plan view from a thickness direction of the mounting board. The second metal member has a longitudinal direction along a second direction in plan view from the thickness direction of the mounting board. The first or second metal member is placed between a first electronic component and a second electronic component. The first metal member has a first recessed portion. The second metal member has a through hole and a second recessed portion. The through hole passes through the second metal member in the direction intersecting with the second direction. The second recessed portion faces and is in contact with the first recessed portion.

An acoustic wave device includes a piezoelectric substrate, an IDT electrode and an electrode pad provided on a front surface of the piezoelectric substrate, a support layer provided on the front surface so as to surround the IDT electrode, a first cover layer and a second cover layer provided on the support layer such that the first cover layer, the second cover layer, the support layer, and the piezoelectric substrate seal the IDT electrode in a hollow space, a UBM portion joined to the electrode pad, and a bump joined to the UBM portion. A joint surface of the UBM portion at which the UBM portion is joined to the bump has a spherical shape or substantially spherical shape that is convex towards the bump side.

An acoustic wave component is disclosed. The acoustic wave component can include a bulk acoustic wave resonator and a surface acoustic wave device. The bulk acoustic wave resonator can include a first portion of a ceramic substrate, a first piezoelectric layer positioned on the ceramic substrate, and electrodes positioned on opposing sides of the first piezoelectric layer. The surface acoustic wave device can include a second portion of the ceramic substrate, a second piezoelectric layer positioned on the ceramic substrate, and an interdigital transducer electrode on the second piezoelectric layer.