Functional element units and a connection line electrically connecting the functional element units are formed on one principal surface of a piezoelectric motherboard. A resin support layer enclosing the functional element units is formed on the one principal surface of the motherboard. An elastic wave device with the functional units is obtained by dividing a multilayer body including the motherboard, the functional element units, and the support layer into a plurality of sections along a dicing line. The connection line includes a line main body positioned on the dicing line, and a connection unit in which the line main body and the functional element units are electrically connected. Prior to dividing the multilayer body, a retaining member made of resin which straddles the line main body in the width direction of the line main body is formed separate from the support layer on the motherboard.

A crystal vibrator includes an AT-cut crystal substrate with a vibration portion having a principal surface and a peripheral portion surrounding and thinner than the vibration portion. An excitation electrode is formed on the principal surface and an extension electrode is electrically connected to the excitation electrode. The vibration portion has a first short-edge side lateral surface that abuts the peripheral portion at an acute angle and a tapered lateral surface adjacent to the first short-edge side lateral surface and inclined with respect to the X axis in the XZ plane. The tapered lateral surface abuts the peripheral portion at an angle that is greater than the angle defined by the first short-edge side lateral surface. The extension electrode extends from the excitation electrode through the tapered lateral surface to a first short-edge side in a longitudinal direction parallel to the Z axis.

Filter devices and methods of fabrication are disclosed. A filter device includes a piezoelectric plate attached to a substrate, portions of the piezoelectric plate forming diaphragms spanning respective cavities in the substrate. A conductor pattern formed on a surface of the piezoelectric plate includes a plurality of interdigital transducers (IDTs) of a respective plurality of acoustic resonators including a shunt resonator and a series resonator, interleaved fingers of each of the plurality of IDTs disposed on one of the diaphragms. Radio frequency signals applied to the IDTs excite respective primary shear acoustic modes in the respective diaphragms. A thickness of a first dielectric layer disposed on the front surface between the fingers of the IDT of the shunt resonator is greater than a thickness of a second dielectric layer disposed on the front surface between the fingers of the IDT of the series resonator.

Acoustic resonator devices and filters are disclosed. An acoustic resonator includes a substrate and a piezoelectric plate having parallel front and back surfaces, the back surface attached to 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 a portion of the piezoelectric plate suspended over a cavity formed in the substrate.

There is disclosed acoustic resonators and filter devices. An acoustic resonator device includes a piezoelectric plate, and an interdigital transducer (IDT) formed on a front surface of the piezoelectric plate. The IDT includes interleaved fingers. At least one of the interleaved fingers includes a first layer adjacent the piezoelectric plate and a second layer over the first layer, wherein a width of the first layer is constant, and wherein a width of the second layer varies along a length of the at least one interleaved finger.

Acoustic resonator devices and filters are disclosed. An acoustic resonator includes a substrate and a piezoelectric plate having parallel front and back surfaces, the back surface attached to 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 a portion of the piezoelectric plate suspended over a cavity formed in the substrate.

In one embodiment, a bonded quartz wafer package includes a first quartz wafer including at least one quartz-based device, a second quartz wafer disposed above the first quartz wafer, and a liquid crystal polymer (LCP) bonding layer disposed in between the first and second quartz wafers that bonds the first and second quartz wafers together.

Functional element units and a connection line electrically connecting the functional element units are formed on one principal surface of a piezoelectric motherboard. A resin support layer enclosing the functional element units is formed on the one principal surface of the motherboard. An elastic wave device with the functional units is obtained by dividing a multilayer body including the motherboard, the functional element units, and the support layer into a plurality of sections along a dicing line. The connection line includes a line main body positioned on the dicing line, and a connection unit in which the line main body and the functional element units are electrically connected. Prior to dividing the multilayer body, a retaining member made of resin which straddles the line main body in the width direction of the line main body is formed separate from the support layer on the motherboard.

An object is to provide a frequency adjustment method for a piezoelectric resonator device that is applicable to a microminiaturized device and that can adjust the frequency without deteriorating the accuracy of frequency adjustment. A frequency adjustment method for a tuning-fork quartz resonator is applicable to a tuning-fork quartz resonator that includes a tuning-fork quartz resonator piece having a pair of resonator arms 31, 32 and metallic adjustment films W formed on the resonator arms. The frequency adjustment method adjusts the frequency by reduction of a mass of the metallic adjustment films W. The frequency adjustment method includes: a rough adjustment step for roughly adjusting the frequency by partially thinning or removing the metallic adjustment films W; and a fine adjustment step for finely adjusting the frequency by at least partially thinning or removing products W1, W2 derived from the metallic adjustment film W during the rough adjustment step.

A manufacturing a process is provided for the bulk manufacture of transducer arrays, including arrays having at least one 3D printed (or otherwise additive manufactured) acoustic matching layers. In certain implementations, the manufactured transducers include a composite-piezoelectric transducer on a de-matching layer. In one implementation, by producing multiple arrays at once on a common carrier, and by using direct-deposit additive processes for the matching layers, the described processes greatly reduce the number of parts and the number of manual operations.