A bulk-acoustic wave resonator includes a substrate, a resonance portion including a first electrode, a piezoelectric layer, and a second electrode, stacked in this order on the substrate, and a seed layer disposed below the first electrode, wherein the resonance portion includes an active portion disposed in a central portion of the resonance portion, and a lateral resonance suppressing portion disposed to surround the active portion, wherein a thickness distribution of the seed layer, the first electrode, the piezoelectric layer, and the second electrode in the lateral resonance suppressing portion is different from a thickness distribution in the active portion.

There is provided an acoustic resonator including: a resonance part including a first electrode, a second electrode, and a piezoelectric layer interposed between the first and second electrodes; and a substrate provided below the resonance part, wherein the substrate includes at least one via hole penetrating through the substrate and a connective conductor formed in the via hole and connected to at least one of the first and second electrodes. Therefore, reliability of the connective conductor formed in the substrate may be secured.

A filter device having a pass band and a stop band on a lower frequency side than the pass band includes a filter having a pass band including the pass band, a series arm resonator connected in series to the filter, a first inductor directly connected in series to the series arm resonator, and a parallel arm resonator connected between a node on a path connecting the filter and the series arm resonator and the ground. The parallel arm resonator constitutes a resonance circuit having a resonant frequency at which an attenuation pole corresponding to a high frequency end of the first stop band, and the series arm resonator and the inductor constitute a resonance circuit having an anti-resonant frequency on a lower frequency side than the pass band and having a sub-resonant frequency higher than a resonant frequency of the resonance circuit.

The disclosure is directed to an electronic device with a solder interconnect and multiple material encapsulant. The electronic device includes a die last assembly with the die assembled to an electronic packaging substrate by a solder interconnect. At least a portion of a first dielectric material and the die are milled or ground, with a second dielectric material applied over an exposed portion of the die. A shield is then positioned over and electrically insulated from the die. Accordingly, such a configuration reduces a thickness or height of an electronic device with shielding and a die last assembly.

A bulk acoustic wave resonator structure that isolates the core resonator from both environmental effects and aging effects. The structure has a piezoelectric layer at least partially disposed between two electrodes. The structure is protected against contamination, package leaks, and changes to the piezoelectric material due to external effects while still providing inertial resistance. The structure has one or more protective elements that limit aging effects to at or below a specified threshold. The resonator behavior is stabilized across the entire bandwidth of the resonance, not just at the series resonance. Examples of protective elements include a collar of material around the core resonator so that perimeter and edge-related environmental and aging phenomena are kept away from the core resonator, a Bragg reflector formed above or below the piezoelectric layer and a cap formed over the piezoelectric layer. The resonator structure is suspended in a cavity in a cap structure.

A vibrator includes a vibration element having an excitation section which is provided with excitation electrodes, and which excites a thickness shear vibration, and a fixation section electrically coupled to at least one of the excitation electrodes, a vibration attenuator disposed on at least one of principal surfaces of the vibration element, and a support substrate having a coupling electrode which is electrically coupled to the fixation section, and which supports the vibration element, wherein the vibration attenuator is disposed at the fixation section side of the excitation electrodes, and at an outer circumferential edge side of the vibration element from the fixation section in a direction perpendicular to a direction in which the excitation electrodes and the fixation section are arranged side by side.

An acoustic wave device includes a high-acoustic-velocity support substrate, a low-acoustic-velocity film provided on the high-acoustic-velocity support substrate, a piezoelectric layer provided on the low-acoustic-velocity film, and an IDT electrode provided on the piezoelectric layer. An acoustic velocity of a bulk wave propagating through the high-acoustic-velocity support substrate is higher than an acoustic velocity of an acoustic wave propagating through the piezoelectric layer. An acoustic velocity of a bulk wave propagating through the low-acoustic-velocity film is lower than an acoustic velocity of a bulk wave propagating through the piezoelectric layer. The low-acoustic-velocity film has a first portion and a second portion that is located closer to the high-acoustic-velocity support substrate than the first portion. The first and second portions include the same or similar materials. A density in the first portion of the low-acoustic-velocity film and a density in the second portion of that are different.

An acoustic resonator package includes a substrate, an acoustic resonator disposed on the substrate, the acoustic resonator including a first hydrophobic layer, a cap configured to accommodate the acoustic resonator, a bonding portion configured to bond the substrate to the cap, and a second hydrophobic layer disposed on the substrate at a position between the acoustic resonator and the bonding portion.

A Bulk Acoustic Wave (BAW) resonator with an electrically isolated Border (BO) ring is provided. One BAW resonator includes a bottom electrode and a piezoelectric layer over the bottom electrode and having a top surface with a first portion and second portion about the first portion. The BAW resonator also includes a top electrode over the first portion of the piezoelectric layer and a BO ring including a non-conductive portion that is over the second portion of the piezoelectric layer and adjacent to the piezoelectric layer. The BAW resonator may be a Solidly Mounted BAW (SMR-BAW) resonator or a Film BAW Resonator (FBAR). A radio frequency filter including a ladder configuration with the above BAW resonator as a series BAW resonator and methods for fabricating the above BAW resonator are also provided.

A vibrator includes a vibration element having an excitation section which is provided with excitation electrodes, and which excites a thickness shear vibration, and a fixation section electrically coupled to at least one of the excitation electrodes, a vibration attenuator disposed on at least one of principal surfaces of the vibration element, and a support substrate having a coupling electrode which is electrically coupled to the fixation section, and which supports the vibration element, wherein the vibration attenuator is disposed at the fixation section side of the excitation electrodes, and at an outer circumferential edge side of the vibration element from the fixation section in a direction perpendicular to a direction in which the excitation electrodes and the fixation section are arranged side by side.