A piezoelectric device includes a piezoelectric vibrating piece and a container. The piezoelectric vibrating piece has a rectangular planar shape and has a portion of a first side secured to the container. The piezoelectric vibrating piece has a second side opposing the first side and includes a projecting portion that projects outward from the second side in at least one of proximity of both ends of the second side along the second side.

A piezoelectric resonator unit includes a piezoelectric substrate, first and second excitation electrodes, first and second connecting electrodes, and first and second exterior members. The first excitation electrode and first connecting electrode are disposed on a first main surface of the piezoelectric substrate and are electrically connected to each other. Similarly, the second excitation electrode and the second connecting electrode are disposed on a second main surface of the piezoelectric substrate and are electrically connected to each other. First and second exterior members bonded to the substrate with sealing members interposed. The first exterior member includes a first terminal portion formed in a shape that externally exposes at least part of the first connecting electrode. A first outer electrode covers the first terminal portion and the exposed portion of the first connecting electrode protruding from the first exterior member.

A bulk acoustic resonator includes: a substrate; a first electrode disposed on the substrate; a piezoelectric layer disposed to cover at least a portion of the first electrode; a second electrode disposed to cover at least a portion of the piezoelectric layer; a metal pad connected to the first electrode and the second electrode; and a protective layer disposed to cover at least the metal pad.

A package for an electronic component, the package comprising a front end, a back end, and an active membrane layer sandwiched between front and back electrodes of conducting material; wherein front electrode has a surface that extends beyond an adjacent surface of the active membrane layer, the active membrane mechanically supported by the front end and covered by a back end comprising at least one back cavity having organic walls and lid of organic material, with filled through vias traversing the organic walls and lid for coupling to the electrodes by an internal routing layer; the vias being coupleable by external solderable bumps to a circuit board for coupling the package in a flip chip configuration.

There is disclosed acoustic resonators and filter devices. An acoustic resonator includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces, the back surface attached to the 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 single-crystal piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm. The interleaved fingers include a first layer having a rectangular shape adjacent the diaphragm and a second layer over the first layer opposite the diaphragm, and wherein a width of the second layer varies along a length of each finger.

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.

There is provided a piezoelectric stack, including: a substrate; an electrode film; and a piezoelectric film which is comprised of alkali niobium oxide of a perovskite structure represented by a composition formula of (K.sub.1-xNa.sub.x)NbO.sub.3 (0<x<1), wherein the piezoelectric film comprises crystals having a grain size with a standard deviation of 0.42 m or less.

A package for an electronic component wherein the package comprises a front end, a back end, and an active membrane layer sandwiched between front and back electrodes of conducting material; the active membrane being mechanically supported by the front end and covered by a back end comprising at least one back cavity having organic walls and lid, with filled through vias traversing the organic lid and walls for coupling to the electrodes by an internal routing layer; the vias being coupleable by external solderable bumps to a circuit board for coupling the package in a flip chip configuration.

An electronic component housing package includes: a base section having a mounting section for an electronic component; a projecting part that is positioned on the base section and projects from the base section; a frame part that is positioned on the base section and surrounds the mounting section; a frame-shaped metalized layer that is positioned on the frame part; a plurality of external connection conductors that is positioned opposite the mounting section in the thickness direction; a connection conductor which is positioned on the projecting part and for connecting to the electronic component; and a wiring conductor that is connected to the connection conductor and that is led out to the base section. The thickness of the connection conductor gradually increases toward the wiring conductor.

A package for an electronic component wherein the package comprises a front end, a back end, and an active membrane layer sandwiched between front and back electrodes of conducting material; the active membrane being mechanically supported by the front end and covered by a back end comprising at least one back cavity having organic walls and lid, with filled through vias traversing the organic lid and walls for coupling to the electrodes by an internal routing layer; the vias being coupleable by external solderable bumps to a circuit board for coupling the package in a flip chip configuration.