Aspects of this disclosure relate to acoustic wave devices on stacked die. A first die can include first acoustic wave device configured to generate a boundary acoustic wave. A second die can include a second acoustic wave device configured to generate a second boundary acoustic wave, in which the second die is stacked with the first die. The first acoustic wave resonator can include a piezoelectric layer, an interdigital transducer electrode on the piezoelectric layer, and high acoustic velocity layers on opposing sides of the piezoelectric layer. The high acoustic velocity layers can each have an acoustic velocity that is greater than a velocity of the boundary acoustic wave.

A resonator device includes: a resonator element; a heat generating unit; a first package including a first base at which the resonator element and the heat generating unit are disposed, and a first lid bonded to the first base so as to accommodate the resonator element between the first lid and the first base; and a low emissivity layer that is disposed at an inner surface of the first lid and that has an emissivity lower than an emissivity of the first lid. In addition, a constituent material of the first lid is silicon, and the emissivity of the low emissivity layer at room temperature is less than 0.5.

An electronic device and associated methods are disclosed. In one example, the electronic device includes a MEMS die located within a substrate, and below a processor die. In selected examples, the MEMS die includes a resonator. Example methods of forming MEMS resonator devices are also shown.

A multi-level stacked AW filter package including a first acoustic wave (AW) filter stacked on a second AW filter employs semiconductor fabrication methods and structures, including a metallization layer comprising interconnects to couple a contact surface to the second AW filter. Each AW filter includes an AW filter circuit on a semiconductor substrate. A second substrate disposed on a frame on the substrate protects the AW filter circuit. In a multi-level AW filter package, the second substrate of the first AW filter comprises a glass substrate with a similar expansion rate as the semiconductor substrate. The interconnects coupling the second AW filter to the contact surface are disposed on insulators on the side wall surfaces of the semiconductor substrates of the first AW filter for isolation. In a stacked AW filter package comprising a single AW filter, the interconnects couple the contact surface to the AW filter.

Electroacoustic devices with a capacitive element and methods for fabricating such electroacoustic devices. An example method includes forming an acoustic device above a first region of a substrate, and forming a capacitive element above a second region of the substrate and adjacent to the acoustic device. The forming of the capacitive element may include forming a protective layer above the substrate where a first portion of the protective layer is above the second region of the substrate and a second portion of the protective layer is above the first region of the substrate, forming a dielectric region above the protective layer, and forming an electrode above the dielectric region. The dielectric region may include a different material than the protective layer.

A resonator device includes a substrate, a heater provided to the substrate, a temperature sensor provided to the substrate, a resonator element having a bond part bonded to the substrate, and a lid bonded to the substrate so as to house the resonator element in cooperation with the substrate, and the bond part is arranged to overlap the heater in a plan view.

The present invention is able to reduce a CI value without requiring precise processing of a crystal blank.

An electrode structure of a crystal unit (1) according to the present invention includes driven electrodes (21, 22) arranged at least at a center on main surfaces (11, 12) of a crystal blank (10). The driven electrodes (21, 22) have a structure in which vibration energy of thickness shear vibration of the crystal blank (10) is concentrated in a central region of the crystal blank (10).

A thin-film bulk acoustic resonator (FBAR) apparatus includes a lower dielectric layer including a first cavity; an upper dielectric layer including a second cavity, wherein the upper dielectric layer is on the lower dielectric layer; and an acoustic resonance film that is positioned between and separating the first and the second cavities. The acoustic resonance film includes a lower electrode layer, an upper electrode layer, and a piezoelectric film that is sandwiched between the lower and upper electrode layers. A plan view of the first and the second cavities overlap to form an overlapped region having a polygonal shape without parallel sides.

A crystal oscillator (101) includes: a piezoelectric resonator plate (2) on which a first excitation electrode and a second excitation electrode are formed; a first sealing member (3) covering the first excitation electrode of the piezoelectric resonator plate (2); a second sealing member (4) covering the second excitation electrode of the piezoelectric resonator plate (2); and an internal space (13) formed by bonding the first sealing member (3) to the piezoelectric resonator plate (2) and by bonding the second sealing member (4) to the piezoelectric resonator plate (2), so as to hermetically seal a vibrating part including the first excitation electrode and the second excitation electrode of the piezoelectric resonator plate (2). An electrode pattern (371) including a mounting pad for wire bonding is formed on an outer surface (first main surface (311)) of the first sealing member (3).

An acoustic wave device includes a substrate, a functional element provided on the substrate, a cover layer provided on or above the substrate to cover the functional element, and a protection layer that covers the cover layer. The cover layer includes a curved portion that is curved to protrude outward. A hollow space is defined between the curved portion and the substrate, and the functional element is provided in the hollow space. The acoustic wave device also includes a conductive portion that is provided between the curved portion and the protection layer and extends along a surface of the curved portion.