A crystal unit includes a crystal element, excitation electrodes, and a container. The crystal element vibrates in a thickness-shear mode. The excitation electrodes are disposed on front and back surfaces of the crystal element. The crystal element is mounted to the container. The excitation electrodes are disposed on the crystal element. When a thickness of the crystal element is expressed as T, and a total thickness of the excitation electrodes disposed on the front and back surfaces of the crystal element is expressed as t, a ratio t/T is from 0.026 to 0.030.

Provided are a solidly mounted resonator and a method for preparing a solidly mounted resonator. The solidly mounted resonator includes: a piezoelectric structure, wherein the piezoelectric structure includes: an upper electrode layer, a lower electrode layer and a piezoelectric layer. The lower electrode layer disposed corresponding to the piezoelectric structure, and the lower electrode layer includes: a protruding portion protruding downward corresponding to a lower surface of the lower electrode layer; the piezoelectric layer is disposed on an upper surface of the lower electrode layer; the upper electrode layer is disposed on an upper surface of the piezoelectric layer.

A film bulk acoustic wave resonator comprising a piezoelectric film having a central region defining a main active domain in which a main acoustic wave is generated during operation, an upper electrode disposed on a top surface of the piezoelectric film, a lower electrode disposed on a lower surface of the piezoelectric film, a dielectric material layer disposed on a lower surface of the lower electrode, and lower recessed frame regions disposed laterally on opposite sides of the central region, the lower recessed frame regions defined by regions of one of the dielectric material or of the lower electrode having a lesser thickness than the thickness of the one of the dielectric material layer or of the lower electrode in the central region.

An electronic device that includes a base substrate having a mounting surface; an electronic component having a mechanical vibration portion mounted on the mounting surface of the base substrate; an intermediate layer mounted on the base substrate and forming an internal space with the base substrate so as to accommodate the electronic component therein, the intermediate layer having at least one through-hole that opens the internal space to an outside; and a sealing layer on the intermediate layer and sealing the internal space by closing the at least one through-hole.

An electronic device that includes a base substrate having a mounting surface; an electronic component having a mechanical vibration portion mounted on the mounting surface of the base substrate; an intermediate layer mounted on the base substrate and forming an internal space with the base substrate so as to accommodate the electronic component therein, the intermediate layer having at least one through-hole that opens the internal space to an outside; and a sealing layer on the intermediate layer and sealing the internal space by closing the at least one through-hole.

A vibrator device includes abase, a circuit element that is attached to the base, and a vibrator element that is arranged at an active surface of the circuit element and is attached to the circuit element, and the circuit element includes a terminal for frequency adjustment that is used for frequency adjustment of the vibrator element and is disposed in a region that does not overlap the vibrator element when viewed in a plan view of the active surface.

A vibrator device includes: a base; a vibrator disposed in the base; and a lid including a substrate having a light transmitting property and a silicon substrate joined to the substrate and a part of the base surrounding the vibrator.

Lateral field excitation acoustic resonators and methods of manufacture are disclosed. In one aspect, an acoustically resonating material such as a piezoelectric film or membrane is spaced from a substrate by electrodes having an air gap therebetween. When current flows through the electrodes, lateral field acoustic waves are excited in the resonating material with relatively good coupling and adequate heat dissipation.

A method of manufacturing a piezoelectric resonator unit that includes mounting a piezoelectric resonator on a base member, the piezoelectric resonator including a piezoelectric element and a pair of excitation electrodes facing each other with the piezoelectric element interposed therebetween, each of the pair of excitation electrodes including an underlying layer containing chromium and a surface layer on the underlying layer; forming chromium oxide on the surface layer of each of the pair of excitation electrodes by oxidizing chromium diffused from the underlying layer such that an amount of the chromium oxide is larger on the surface layer of the excitation electrode on a base member side than on the surface layer of the excitation electrode on a lid member side among the pair of excitation electrodes; and joining a lid member to the base member such that the piezoelectric resonator is between the base member and the lid member.

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.