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.

An AT-cut crystal resonator plate (2) includes a first main surface (2a) on which a first excitation electrode (211) is formed and a second main surface (2b) on which a second excitation electrode (212) is formed. The AT-cut crystal resonator plate (2) further includes: a substantially rectangular-shaped vibrating part (21) that is piezoelectrically vibrated when a voltage is applied to the first excitation electrode (211) and the second excitation electrode (212); a holding part (22) protruding from a corner part (21a) of the vibrating part (21) in a Z′ axis direction of the AT-cut crystal; and an external frame part (23) configured to surround an external circumference of the vibrating part (21) and to hold the holding part (22).

The present disclosure provides a film bulk acoustic resonator and a method for fabricating the film bulk acoustic resonator. The resonator includes a carrier substrate; a support layer bonded on the carrier substrate, where the support layer encloses a first cavity exposing the carrier substrate; a piezoelectric stacked structure covering the first cavity, where the piezoelectric stacked structure includes a first electrode, a piezoelectric layer, and a second electrode which are stacked sequentially from a bottom to a top; and protrusions disposed at a boundary of an effective resonance region, where the protrusions are disposed on an upper surface or a lower surface of the piezoelectric stacked structure; or a part of the protrusions is disposed on the upper surface of the piezoelectric stacked structure, and another part of the protrusions is disposed on the lower surface of the piezoelectric stacked structure.

A laterally excited bulk wave resonator includes a supporting plate; a piezoelectric base having a back side attached to the supporting plate, in which a cavity is defined on a side of the supporting plate facing toward the piezoelectric base; a lower interdigital transducer provided at a back side of the piezoelectric base and located in the cavity; and an upper interdigital transducer provided at a front side of the piezoelectric base corresponding to the lower interdigital transducer. A first interdigital electrode of the lower interdigital transducer has a same polarity as a second interdigital electrode of the upper interdigital transducer at a position corresponding to the first interdigital electrode.

A vibration member is provided that includes a base with front and rear ends opposite to each other, and vibration arms fixed to the front end, extending away therefrom, and including at least one first vibration arm and a pair of second vibration arms positioned on both sides of a first vibration arm group including the at least one first vibration arm in a direction intersecting a longitudinal direction. A holding arm is provided that has one end connected to the base and the other end connected to a frame. A plurality of vibration portions include a piezoelectric film, and a lower electrode and an upper electrode that sandwich the piezoelectric film. A connection wiring line that connects the respective upper electrodes of the pair of second vibration arms to each other is provided in a region of at least either of the base or the holding arm.

A crystal oscillator includes an oscillating substrate, a hollow frame, a first electrode, and a second electrode. The oscillating substrate includes a main oscillating region and a thinned region that has a thickness smaller than that of the main oscillating region. The first and second electrodes are disposed on a first surface of the oscillating substrate and a second surface opposite to the first surface, respectively. The hollow frame is disposed on the second surface. The second electrode includes a second electrode portion that has at least one opening in positional correspondence with the thinned region. A method for making the crystal oscillator is also provided herein.

A resonance device is provided that includes a lower lid that has a recessed portion, and a resonator that is mounted on the lower lid and has a vibration arm that performs out-of-plane bending vibration in a space including the recessed portion and a frame provided around the vibration arm and having a facing portion facing a tip of the vibration arm. The facing portion of the frame is located in an outer-side portion of the resonator with respect to a straight line connecting an intersection point of a perpendicular extending from the tip of the vibration arm toward the recessed portion of the lower lid and the recessed portion of the lower lid, to a cavity edge of the recessed portion facing the tip of the vibration arm.

An oscillator wafer-level-package structure is provided, comprising a bottom layer, an oscillator crystal and a capping layer. The bottom layer includes an upper plane, the capping layer includes a lower plane, and the oscillator crystal is disposed between the bottom layer and the capping layer and includes at least one cavity. An upper seal ring and a lower seal ring are respectively surrounding the oscillator crystal such that the oscillator crystal is sealed in between the capping layer and the bottom layer by employing the upper and lower seal rings. In addition, a diffusion barrier is further disposed in the upper seal ring and in the lower seal ring for avoiding interface diffusion. Moreover, the present invention adopts the same material for fabricating the capping layer, the oscillator crystal and the bottom layer to achieve an optimal thermal stress result when realizing the packaging structure.

The piezoelectric vibration plate includes a piezoelectric substrate, a first driving electrode and a second driving electrode formed on main surfaces on both sides of the piezoelectric substrate, and a first mounting terminal and a second mounting terminal respectively connected to the first driving electrode and the second driving electrode. The first and second mounting terminals each have a metal film for mounting purpose formed on the piezoelectric substrate and a metal film for driving purpose formed on the metal film for mounting purpose. The metal films for mounting purpose each include a solder-resistant metal film. The metal films for driving purpose are formed in continuity with the first and second driving electrodes and constitute the first and second driving electrodes.

Metal films for first and second mounting terminals are formed at ends on both sides of a piezoelectric vibration plate across a vibrating portion, and first and second mounting terminals connected to these metal films are formed on outer surfaces of resin films adhered to the piezoelectric vibration plate. In case the metal films for first and second mounting terminals on both sides of the vibrating portion are desirably reduced in size in order to enlarge the vibrating portion, an adequate joining area for mounting purpose is still secured for the first and second mounting terminals formed on the outer surfaces of the resin films.