An elastic wave device includes a piezoelectric film and a high acoustic velocity member in which an acoustic velocity of a bulk wave propagating in the high acoustic velocity member is larger than an acoustic velocity of a main mode elastic wave propagating in the piezoelectric film, the piezoelectric film that is directly or indirectly laminated on the high acoustic velocity member, a first conductive film provided on the piezoelectric film, and a second conductive film that is provided on the piezoelectric film and on at least a portion of the first conductive film. A plurality of IDT electrodes including electrode fingers and busbars are provided on the piezoelectric film, at least electrode fingers of a plurality of IDT electrodes are defined by the first conductive film, and at least a portion of connection wiring with which the plurality of IDT electrodes are connected to each other is defined the second conductive film.

The integrated circuit device includes: a pad that has a shape having a longitudinal direction and a lateral direction; a circuit that overlaps the pad in a plan view, and that is electrically coupled to the pad; a lead-out wiring that is led out from an outer edge on a longitudinal side of the pad along the lateral direction of the pad; and a via group that electrically couples the lead-out wiring and a wiring of the circuit and that does not overlap the pad in the plan view.

Aspects of this disclosure relate to an acoustic wave device with a plurality of piezoelectric layers positioned laterally relative to each other between two electrodes. One of the piezoelectric layers has a different property than another of the piezoelectric layers. Examples of the different property include c-axis orientation, doping concentration, dopant material, and piezoelectric material. At least part of each of the piezoelectric layers can be in a main acoustically active region of the acoustic wave device.

A composite substrate 10 includes a first substrate 10 comprised of a piezoelectric single crystal and a second substrate 20 comprised of a silicon single crystal bonded to the first substrate 10. In the second substrate, a planar orientation is (111), and ψ of Euler angles (φ, θ, ψ) is offset from 0°. Due to this, a bulk wave spurious is reduced in a specific frequency band.

An acoustic wave device includes a high-acoustic-velocity layer, a piezoelectric layer made of lithium tantalate, and an interdigital transducer electrode that are successively laminated. An acoustic velocity of a bulk wave propagating in the high-acoustic-velocity layer is higher than an acoustic velocity of an acoustic wave propagating in the piezoelectric layer, and an acoustic velocity Vsub of a fast transversal bulk wave propagating in the high-acoustic-velocity layer satisfies Vsh0≤Vsub≤Vsp with respect to an acoustic velocity Vsh0 of an SH0 mode and an acoustic velocity Vsp of a mode becoming a spurious of which acoustic velocity is not lower than the acoustic velocity of the SH0 mode, wherein the acoustic velocity Vsh0 and the acoustic velocity Vsp is obtained from Eq. (1).

A piezoelectric resonator device having a sandwich structure is provided. A crystal oscillator includes: a crystal resonator plate; a first sealing member covering a first excitation electrode of the crystal resonator plate; and a second sealing member covering a second excitation electrode of the crystal resonator plate. A parallelepiped shaped package is formed by bonding: the first sealing member to the crystal resonator plate; and the second sealing member to the crystal resonator plate. The package includes an internal space in which is hermetically sealed a vibrating part of the crystal resonator plate including the first excitation electrode and the second excitation electrode. A bonding material hermetically sealing the vibrating part of the crystal resonator plate is formed to have an annular shape in plan view, and is disposed along an outer peripheral edge of the package.

Aspects of this disclosure relate to acoustic wave devices that include a plurality of stacked piezoelectric layers positioned between electrodes. Such acoustic wave devices can excite an overtone mode as a main mode. Related acoustic wave filters, radio frequency modules, wireless communication devices, and methods are also disclosed.

A vibrator, a vibrating element and a method for producing the vibrating element may include vibrating piece having a central portion and a peripheral portion. The vibrator, the vibrating element and the method may further include a pair of excitation electrodes provided on a first side and a second side of a main surface of the central portion. The vibrator, the vibrating element and the method may further include a pair of connection electrodes provided on the peripheral portion and electrically connected to the pair of excitation electrodes. The vibrator, the vibrating element and the method may further include a substrate configured to be connected to the pair of connection electrodes via an electrically-conductive holding member interposed therebetween and configured to support the vibration element in an excitable manner.

A piezoelectric structure is disclosed which includes a single crystal having piezoelectric coefficients d.sub.31 and d.sub.32 of opposite magnitude, such that when an alternating electric field is applied in the Z direction, the piezoelectric structure expands in one of the X and Y directions and contracts in the other of the X and Y direction, a first electrode coupled to the single crystal, and a second electrode coupled to the single crystal, wherein the alternating electric field is input to the single crystal through the first and second electrodes.

The integrated circuit device includes: a pad that has a shape having a longitudinal direction and a lateral direction; a circuit that overlaps the pad in a plan view, and that is electrically coupled to the pad; a lead-out wiring that is led out from an outer edge on a longitudinal side of the pad along the lateral direction of the pad; and a via group that electrically couples the lead-out wiring and a wiring of the circuit and that does not overlap the pad in the plan view.