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.

Acoustic resonators and filter devices. An acoustic resonator includes a piezoelectric plate having front and back surfaces, a portion of the piezoelectric plate forming a diaphragm, and a conductor pattern on the front surface, the conductor pattern including an interdigital transducer (IDT), fingers of the IDT on the diaphragm. A thickness of the interleaved fingers is greater than or equal to 0.85 times a thickness of the piezoelectric plate and less than or equal to 2.5 times the thickness of the piezoelectric plate. The IDT comprises a first portion having a first pitch and a first mark and a second portion having a second pitch and a second mark not equal to the first pitch and first mark.

Acoustic resonator devices, filters, and methods are disclosed. An acoustic resonator includes a substrate and a piezoelectric plate having front and back surfaces, the back surface attached to a surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm that spans a cavity in the substrate. An interdigital transducer (IDT) is formed on the front surface of the piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm. The IDT is configured to excite a primary acoustic mode in the diaphragm in response to a radio frequency signal applied to the IDT. At least one finger of the IDT is disposed in a groove in the diaphragm. A depth of the groove is less than a thickness of the at least one finger of the IDT.

A bulk acoustic resonator is provided that includes a substrate having a plurality of layers and having a cavity disposed in at least one of the plurality of layers of the substrate; a piezoelectric layer attached to the substrate and including a portion that is over the cavity in the substrate; and an interdigital transducer (IDT) on a surface of the piezoelectric layer and including interleaved fingers on the portion of the piezoelectric layer that is over the cavity. Moreover, at least one opening extends through the portion of the piezoelectric layer that is over the cavity. The at least one opening is an elongated slot.

A method of manufacturing a quartz crystal element includes preparing a quartz crystal wafer having a predetermined cutting angle with respect to a crystal axis of a quartz crystal, forming a first resist film having a first tilted part on a first surface of the quartz crystal wafer and dry-etching the first resist film with the quartz crystal, forming a first tilted surface by dry-etching the quartz crystal wafer from the first surface side, forming a second resist film having a second tilted part on a second surface of the quartz crystal wafer and dry-etching the second resist film with the quartz crystal, and forming a second tilted surface tilted by dry-etching the quartz crystal wafer from the second surface side. The quartz crystal element provided with the first tilted surface and the second tilted surface, and having a cutting angle different from the predetermined cutting angle is formed.

An acoustic resonator is fabricated with multiple piezoelectric plate thicknesses on a single chip. After conductor patterns are formed on a piezoelectric plate, the plate is bonded to a sacrificial substrate, with the conductor patterns facing the sacrificial substrate. The piezoelectric plate is then thinned to a desired thickness for shunt resonators. A mask is applied to the surface of the plate and selected areas of the piezoelectric plate are further thinned to a desired thickness for series resonators to form a thinned piezoelectric plate. A substrate with swimming pool cavities is bonded to the thinned piezoelectric plate, and the sacrificial substrate is removed.

Acoustic resonator devices and filters are disclosed. A piezoelectric plate is attached to a substrate, a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A first conductor pattern is formed on a surface of the piezoelectric plate. The first conductor pattern includes interleaved fingers of an interdigital transducer disposed on the diaphragm, and a first plurality of contact pads. A second conductor pattern is formed on a surface of a base, the second conductor pattern including a second plurality of contact pads. Each pad of the first plurality of contact pads is 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 base.

Switchable and/or tunable filters, methods of manufacture and design structures are disclosed herein. The method of forming the filters includes forming at least one piezoelectric filter structure comprising a plurality of electrodes formed to be in contact with at least one piezoelectric substrate. The method further includes forming a micro-electro-mechanical structure (MEMS) comprising a MEMS beam in which, upon actuation, the MEMS beam will turn on the at least one piezoelectric filter structure by interleaving electrodes in contact with the piezoelectric substrate or sandwiching the at least one piezoelectric substrate between the electrodes.

An acoustic resonator includes: a central portion; an extension portion extended outwardly of the central portion; a first electrode, a piezoelectric layer, and a second electrode sequentially stacked on a substrate, in the central portion; and an insertion layer disposed below the piezoelectric layer in the extension portion, wherein the piezoelectric layer includes a piezoelectric portion disposed in the central portion, and a bent portion disposed in the extension portion and extended from the piezoelectric portion at an incline depending on a shape of the insertion layer.