The present disclosure relates to a wafer-level packaged (WLP) bulk acoustic wave (BAW) device, which includes a BAW resonator and a WLP enclosure. The BAW resonator includes a piezoelectric layer with an interface opening, a bottom electrode lead underneath the interface opening, an interface structure extending over the interface opening and connected with the bottom electrode lead, a passivation layer with a passivation opening over the interface structure, and an oxide adhesion layer with an adhesion opening over the passivation layer. The WLP enclosure includes an outer wall directly residing over the oxide adhesion layer, and a through-WLP via encompassed by the outer wall and vertically aligned with the adhesion opening and the passivation opening. A portion of the interface structure is exposed to the through-WLP via through the adhesion opening and the passivation opening.

A bulk acoustic wave (BAW) resonator includes a solidly mounted reflector, for example, a Bragg-type reflector, a piezoelectric layer, and first and second electrodes on first and second surfaces, respectively, of the piezoelectric layer. A filter device or filter system includes at least one BAW resonator. Related methods of fabrication include forming the BAW resonator.

Bulk acoustic wave resonators of two or more different filters can be on a common die. The two filters can be included in a multiplexer, such as a duplexer, or implemented as standalone filters. With bulk acoustic wave resonators of two or more filters on the same die, the filters can be implemented in less physical space compared to implementing the same filters of different die. Related methods, radio frequency systems, radio frequency modules, and wireless communication devices are also disclosed.

A bulk-acoustic wave resonator includes: a resonator comprising a central portion in which a first electrode, a piezoelectric layer, and a second electrode are sequentially stacked on a substrate, and an extension portion disposed along a periphery of the central portion; and an insertion layer disposed below the piezoelectric layer in the extension portion to raise the piezoelectric layer. The insertion layer may have a first inclined surface formed along a side surface facing the central portion, and the first electrode may have a second inclined surface extending from a lower end of the first inclined surface of the insertion layer.

A stacked AW filter package includes a first substrate stacked on a second substrate. The first substrate has a first AW filter circuit on first surface and a metal layer on a second surface. The second substrate has a second AW filter circuit disposed in a cavity between the metal layer of the first substrate and a third surface of the second substrate. The metal layer is coupled to the second AW filter circuit by a metal interconnect formed in a metallization layer on a side surface of the first substrate. The metal layer provides isolation to reduce cross-talk (e.g., electromagnetic interference) within the stacked AW filter package between the first AW filter circuit and the second AW filter circuit. Including the metal layer in the stacked AW filter package improves signal quality of transmitted and received signals filtered in the first and second AW filter circuits.

A method and structure for a single crystal acoustic electronic device. The device includes a substrate having an enhancement layer formed overlying its surface region, a support layer formed overlying the enhancement layer, and an air cavity formed through a portion of the support layer. A single crystal piezoelectric material is formed overlying the air cavity and a portion of the enhancement layer. Also, a first electrode material coupled to the backside surface region of the crystal piezoelectric material and spatially configured within the cavity. A second electrode material is formed overlying the topside of the piezoelectric material, and a dielectric layer formed overlying the second electrode material. Further, one or more shunt layers can be formed around the perimeter of a resonator region of the device to connect the piezoelectric material to the enhancement layer.

The disclosure provides a packaging structure and method of an acoustic device, relating the technical field of semiconductors, including: a substrate and a piezoelectric stack structure located on the substrate, a first organic material layer is disposed on the piezoelectric stack structure, a second organic material layer is disposed on the first organic material layer, the first organic material layer includes a first supporting part and a second supporting part, the second supporting part forms a first acoustic reflection structure, when being transmitted to the first acoustic reflection structure, acoustic waves can be reflected back to the effective area, so that the loss of the acoustic waves is reduced, and the performance of the acoustic device is improved. The first supporting part is matched with the second organic material layer to form a second acoustic reflection structure, so that when part of acoustic waves are not reflected back by the first acoustic reflection structure and are transmitted to the second acoustic reflection structure, the acoustic waves can be reflected back to the effective area, so that the loss of the acoustic waves is further reduced, and the performance of the acoustic device is improved.

Acoustic resonator devices and filters are disclosed. An acoustic resonator chip includes a piezoelectric plate attached to a substrate, a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A first conductor pattern formed on a surface of the piezoelectric plate includes interleaved fingers of an interdigital transducer on the diaphragm and a first plurality of contact pads. A second conductor pattern is formed on a surface of an interposer, the second conductor pattern including a second plurality of contact pads. Each pad of the first plurality of contact pads is directly connected to a respective pad of the second plurality of contact pads. A seal is formed between a perimeter of the piezoelectric plate and a perimeter of the interposer.

Methods of making acoustic resonator devices and filters are disclosed. A method of fabricating an acoustic resonator device includes fabricating an acoustic resonator chip including: attaching a back surface of a piezoelectric plate to a front surface of a substrate, such that portions of the piezoelectric plate form at least first and second diaphragms spanning at least first and second cavities, and forming a first conductor pattern as one or more conductor layers on the piezoelectric plate. The first conductor pattern includes at least first and second interdigitated transducers (IDTs) and a first plurality of contact pads. The method further includes fabricating an interposer having front and back surface and a second plurality of contact pads on the interposer back surface, forming conductive balls, and bonding each of the first plurality of contact pads to a respective pad of the second plurality of contact pads using the respective conductive ball.

The invention relates to a covering (1) for an electronic component (e.g. of the MEMS, BAW, or SAW type). The covering comprises at least one layer (5, 6, 7) having a structure (19, 20, 21) with a number of prominences (8, 9, 15) and/or depressions (10, 11, 16). The invention furthermore relates to a method for producing a covering (1) of this type.