An array of piezoelectric micromachined ultrasonic transducers (PMUTs) includes a first piezoelectric layer and a second piezoelectric layer, a dielectric layer positioned between the first piezoelectric layer and the second piezoelectric layer, and a plurality of conductive layers positioned on opposing surfaces of the first piezoelectric layer and opposing surfaces of the second piezoelectric layer. A plurality of isolation trenches extend through the dielectric layer and at least a portion of conductive layers of the plurality of conductive layers, where the plurality of isolation trenches are positioned between neighboring PMUTs of the array of PMUTs such that the neighboring PMUTs are electrically isolated, and wherein the plurality of isolation trenches relieve stress in the dielectric layer.

A surface acoustic wave device includes a piezoelectric substrate and an IDT electrode on the piezoelectric substrate. The IDT electrode includes a main electrode layer and a barrier layer between the piezoelectric substrate and the main electrode layer. The main electrode layer is inside a region in which the barrier layer is provided in plan view to suppress diffusion between the piezoelectric substrate and the main electrode layer when a voltage is applied to the IDT electrode.

An elastic wave device includes a piezoelectric substrate, an IDT electrode, and a cover member. The IDT electrode is provided on the piezoelectric substrate. The cover member is provided above the piezoelectric substrate and separate from the IDT electrode. The cover member includes a first cover member and a second cover member. The second cover member is laminated on a side of the first cover member opposite to the piezoelectric substrate. The glass transition point of the first cover member is higher than that of the second cover member.

An elastic wave device includes IDT electrodes on a first main surface of a piezoelectric substrate and a heat dissipating film on a second main surface and including a pair of opposing main surfaces and side surfaces connecting the pair of main surfaces. At least a portion of the side surfaces of the heat dissipating film is located in an inner side portion relative to the outer circumference of the second main surface of the piezoelectric substrate on an arbitrary cross section along a direction connecting the pair of main surfaces of the heat dissipating film.

A force sensor includes a pressure-receiving member; a sensor substrate including a displaceable portion to be displaced under a load received by the pressure-receiving member, and piezoelectric resistors configured to electrically detect an amount of displacement of the displaceable portion; a base substrate having a sensor-mounting surface, and including electrical wiring portions electrically connected to the piezoelectric resistors; and a package substrate having a substrate-mounting surface and a pad surface provided with pad electrodes. The pressure-receiving member, the sensor substrate, and the base substrate are stacked in a normal direction to the substrate-mounting surface. When seen in the normal direction, an entirety of the displaceable portion is located within the pressure-receiving member. The pad surface is provided with, when seen in the normal direction, a fixing terminal at least a part of which overlaps at least a part of a first area that coincides with the pressure-receiving member.

An electronic component has a main body. The main body includes a porous material having surface pores at a surface of the main body. A passivation liquid is arranged in the surface pores. A method of forming an electronic component is also disclosed as is a method of passivating a body.

A bulk acoustic wave resonator structure that isolates the core resonator from both environmental effects and aging effects. The structure has a piezoelectric layer at least partially disposed between two electrodes. The structure is protected against contamination, package leaks, and changes to the piezoelectric material due to external effects while still providing inertial resistance. The structure has one or more protective elements that limit aging effects to at or below a specified threshold. The resonator behavior is stabilized across the entire bandwidth of the resonance, not just at the series resonance. Examples of protective elements include a collar of material around the core resonator so that perimeter and edge-related environmental and aging phenomena are kept away from the core resonator, a Bragg reflector formed above or below the piezoelectric layer and a cap formed over the piezoelectric layer. The resonator structure is suspended in a cavity in a cap structure.

A piezoelectric fiber composite and a magnetoelectric laminate composite including the same are disclosed. The piezoelectric fiber composite includes a first protective layer having a first electrode, a second protective layer having a second electrode, and a piezoelectric fiber layer formed between the first and the second electrode and having piezoelectric fibers arranged in the longitudinal direction of the composite, wherein the piezoelectric fibers include a single-crystal piezoelectric material and are configured such that a <011> direction of the single crystal is identical to a thickness direction of the composite and a <001> direction of the single crystal is identical to a longitudinal direction of the composite, thus exhibiting superior piezoelectric strain properties and sensing properties. Also, the magnetoelectric laminate composite includes the piezoelectric fiber composite and a magnetostrictive layer including a magnetostrictive material such as nickel (Ni) or Metglas (FeBSi alloy), thus ensuring significantly improved magnetoelectric properties.

Provided is a piezoelectric device capable of improving measurement precision of a temperature of a piezoelectric element. A piezoelectric device (1) includes a package (2) including a housing member (4) having a thermistor substrate (3) and a frame (7) provided to project from a first main surface (3a) of the thermistor substrate (3) and in which a housing part (6) is formed by the first main surface (3a) and the frame (7) and a lid (9) provided on the frame (7) to cover a space (5) of the housing part (6), and a piezoelectric vibration element (5) provided on the first main surface (3a) of the thermistor substrate (3) in the housing part (6), wherein the thermistor substrate (3) is a multilayer negative temperature coefficient (NTC) thermistor.

Provided is a piezoelectric element capable of preventing the occurrence of poor connection to an electrode layer.

A piezoelectric element includes a piezoelectric layer, electrode layers formed on both sides of the piezoelectric layer, and a protective layer laminated on a surface of the electrode layer opposite to a surface on a piezoelectric layer side, in which the piezoelectric element includes a conductive foil laminated on a surface of the protective layer opposite to the electrode layer, the protective layer has a hole that penetrates from a surface to the electrode layer, the conductive foil includes an opening portion at a position that overlaps with the hole of the protective layer in a surface direction, the piezoelectric element includes a filling member consisting of a conductive material, which is formed on at least a part of a surface of the conductive foil from insides of the hole of the protective layer and an opening portion of the conductive foil and is electrically connected to the electrode layer and the conductive foil, and a covering member that covers the filling member and the conductive foil, the covering member has a through-hole at a position that does not overlap with the filling member in the surface direction, and the piezoelectric element includes a conductive member, which is inserted into the through-hole of the covering member and electrically connected to the conductive foil.