A method of manufacture for an acoustic resonator or filter device. In an example, the present method can include forming metal electrodes with different geometric areas and profile shapes coupled to a piezoelectric layer overlying a substrate. These metal electrodes can also be formed within cavities of the piezoelectric layer or the substrate with varying geometric areas. Combined with specific dimensional ratios and ion implantations, such techniques can increase device performance metrics. In an example, the present method can include forming various types of perimeter structures surrounding the metal electrodes, which can be on top or bottom of the piezoelectric layer. These perimeter structures can use various combinations of modifications to shape, material, and continuity. These perimeter structures can also be combined with sandbar structures, piezoelectric layer cavities, the geometric variations previously discussed to improve device performance metrics.

In a piezoelectric resonator device according to an embodiment, an internal space is formed by bonding a first sealing member to a crystal resonator plate and bonding a second sealing member to the crystal resonator plate. The internal space hermetically seals a vibrating part including a first excitation electrode and a second excitation electrode of the crystal resonator plate. Seal paths that hermetically seal the vibrating part of the crystal resonator plate are formed to have an annular shape in plan view. A plurality of external electrode terminals is formed on a second main surface of the second sealing member to be electrically connected to an external circuit board. The external electrode terminals are respectively disposed on and along an external frame part surrounding the internal space in plan view.

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.

A method of manufacture for an acoustic resonator or filter device. In an example, the present method can include forming metal electrodes with different geometric areas and profile shapes coupled to a piezoelectric layer overlying a substrate. These metal electrodes can also be formed within cavities of the piezoelectric layer or the substrate with varying geometric areas. Combined with specific dimensional ratios and ion implantations, such techniques can increase device performance metrics. In an example, the present method can include forming various types of perimeter structures surrounding the metal electrodes, which can be on top or bottom of the piezoelectric layer. These perimeter structures can use various combinations of modifications to shape, material, and continuity. These perimeter structures can also be combined with sandbar structures, piezoelectric layer cavities, the geometric variations previously discussed to improve device performance metrics.

A vibrator device includes: an element substrate including a frame portion having a first surface and a second surface, and a vibrator element disposed inside the frame portion; a first substrate having a third surface and a fourth surface, the first substrate being bonded to the first surface of the frame portion at the third surface; a second substrate having a fifth surface and a sixth surface, the second substrate being bonded to the second surface of the frame portion at the fifth surface; and a cavity surrounded by the frame portion, the first substrate, and the second substrate. The second substrate includes a through electrode at a position overlapping the frame portion in the plan view. An outer shape of the through electrode in the sixth surface in the plan view includes a first portion and a second portion. The first portion is located at a position closer to the cavity than is the second portion. A curvature of the first portion is smaller than a curvature of the second portion.

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.

A method of manufacture for an acoustic resonator or filter device. In an example, the present method can include forming metal electrodes with different geometric areas and profile shapes coupled to a piezoelectric layer overlying a substrate. These metal electrodes can also be formed within cavities of the piezoelectric layer or the substrate with varying geometric areas. Combined with specific dimensional ratios and ion implantations, such techniques can increase device performance metrics. In an example, the present method can include forming various types of perimeter structures surrounding the metal electrodes, which can be on top or bottom of the piezoelectric layer. These perimeter structures can use various combinations of modifications to shape, material, and continuity. These perimeter structures can also be combined with sandbar structures, piezoelectric layer cavities, the geometric variations previously discussed to improve device performance metrics.

A method of manufacture for an acoustic resonator or filter device. In an example, the present method can include forming metal electrodes with different geometric areas and profile shapes coupled to a piezoelectric layer overlying a substrate. These metal electrodes can also be formed within cavities of the piezoelectric layer or the substrate with varying geometric areas. Combined with specific dimensional ratios and ion implantations, such techniques can increase device performance metrics. In an example, the present method can include forming various types of perimeter structures surrounding the metal electrodes, which can be on top or bottom of the piezoelectric layer. These perimeter structures can use various combinations of modifications to shape, material, and continuity. These perimeter structures can also be combined with sandbar structures, piezoelectric layer cavities, the geometric variations previously discussed to improve device performance metrics.

A through hole formed in an AT-cut crystal plate includes an inclined surface (72) that extends from a peripheral area toward a penetrating part (71) in a center part of the through hole. The inclined surface (72) includes: a first crystal surface S1 that extends from the penetrating part (71) toward the peripheral area of the through hole in a −Z′ and a +X directions; a second crystal surface S2 that extends from the penetrating part (71) toward the peripheral area of the through hole in the −Z′ and the +X directions and that contacts with the first crystal surface S1 in the +Z′ and the +X directions of the first crystal surface S1; and a third crystal surface S3 that contacts with the second crystal surface S2 in the +X direction of the second crystal surface S2 and that contacts with the main surface of the AT-cut crystal plate. A compensation surface Sc is formed between the main surface of the AT-cut crystal plate and the three crystal surfaces Si to S3 to prevent first and second ridge lines L1 and L2 from reaching the main surface of the AT-cut crystal plate.

An RF triplexer circuit device using modified lattice, lattice, and ladder circuit topologies. The devices can include four resonator devices and four shunt resonator devices. In the ladder topology, the resonator devices are connected in series from an input port to an output port while shunt resonator devices are coupled the nodes between the resonator devices. In the lattice topology, a top and a bottom serial configurations each includes a pair of resonator devices that are coupled to differential input and output ports. A pair of shunt resonators is cross-coupled between each pair of a top serial configuration resonator and a bottom serial configuration resonator. The modified lattice topology adds baluns or inductor devices between top and bottom nodes of the top and bottom serial configurations of the lattice configuration. These topologies may be applied using single crystal or polycrystalline bulk acoustic wave (BAW) resonators.