An acoustic resonator includes: a substrate; a resonance part including a lower electrode, a piezoelectric layer, and an upper electrode sequentially stacked on the substrate, and a frame formed on the upper electrode along an edge of the upper electrode; and a trench part formed in at least one side of the resonance part and making a thickness of the resonance part asymmetrical.

A piezoelectric multilayer component having a stack of sintered piezoelectric layers and inner electrodes arranged between the piezoelectric layers. A region which has poling cracks is present on the surface of at least one electrode, and the poling cracks are separated from a surface of at least one of the inner electrodes by the region having the poling cracks.

A method for manufacturing a plurality of fingerprint identification modules simultaneously is provided. A first thin film and a second thin film are formed on a first transfer base and a second transfer base respectively. The first thin film and the second thin film are cut respectively to form a plurality of first thin film units and a plurality of second thin film units. The first transfer base and the second transfer base are adhered on opposite surfaces of a substrate. The first thin film units and the second thin film units are cut respectively to form a plurality of the first piezoelectric layers and a plurality of the second piezoelectric layers. A plurality of first slits and a plurality of second slits are formed on opposite surfaces of the substrate for breaking the mother base into the fingerprint identification modules.

A lead-out wiring, which is connected to a comb-shaped electrode formed on a principal surface of a piezoelectric substrate and is disposed to extend to an outer edge of the piezoelectric substrate an outer surrounding wall layer, which is arranged surrounding an outer periphery of the piezoelectric substrate including the lead-out wiring and forms a hollow portion that serves as an operation space for the comb-shaped electrode, and a top board, which bridges the outer surrounding wall layer to seal the hollow portion, are included.

A piezoelectric ceramic sputtering target containing a perovskite type oxide represented by chemical formula (I) of ABO.sub.3 as a main component, wherein the component A of the chemical formula (I) contains at least K (potassium) and/or Na (sodium), the component B of the chemical formula (I) contains at least one selected from the group consisting of Nb (niobium), Ta (tantalum) and Zr (zirconium) with Nb (niobium) as a necessity, the piezoelectric ceramic sputtering target is composed of a plurality of crystal grains and grain boundaries existing among the crystal grains, and in the grain boundary, the molar ratio of at least one of Nb (niobium), Ta (tantalum), and Zr (zirconium) in the B components is higher than the molar ratio in the interior of the crystal grains by 30% or more.

An ultrasonic transducer includes a stack of flat electrodes between which are interposed ceramic wafers of substantially same surface area as the electrodes, stacked contours of the ceramic wafers and electrode wafers defining substantially flat or cylindrical side faces of the stack. A method of manufacturing the transducer includes: alternatively stacking a ceramic wafer and an electrode wafer, placing between each ceramic wafer and its two neighboring electrodes a composition of which at least 75% by weight, or at least 80% by weight, that includes silver nanoparticles having a grain size of smaller than or equal to 80 nanometers, or smaller than or equal to 60 nanometers; and compressing the stack by heating to a temperature of less than or equal to 280° C., or between 200° C. and 250° C.

The present invention provides a piezoelectric material not containing lead and potassium, having a high relative density, a high Curie temperature, and a high mechanical quality factor, and exhibiting good piezoelectricity. The piezoelectric material contains 0.04 percent by mole or more and 2.00 percent by mole or less of Cu relative to 1 mol of metal oxide represented by General formula (1) below.
((Na.sub.1-zLi.sub.z).sub.xBa.sub.1-y)(Nb.sub.yTi.sub.1-y)O.sub.3 (in Formula, 0.70≦x≦0.99, 0.75≦y≦0.99, and 0<z<0.15, and x<y)  General formula (1)

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.

An electroacoustic transducer includes: a polygonal-shaped laminated piezoelectric element including alternately stacked piezoelectric layers and electrode layers, with the piezoelectric layers placed between at least one pair of electrode layers having different polarities; and a circular vibration plate on which the laminated piezoelectric element is placed. Of the piezoelectric layers sandwiched between the at least one pair of electrode layers, the total volume (V) of those effective layers that overlap the at least one pair of electrode layers as viewed from the stacking direction satisfies the condition below:

0.2πR.sup.2×ts≦V≦2.0πR.sup.2×ts

wherein π represents the ratio of the circumference of a circle to its diameter, R represents the radius of the vibration plate, and ts represents the thickness of the vibration plate.

A micro-vibration sensor and preparation method thereof. The method includes a metal sheet is coated with first curing material, and first curing material is cured into first cured layer; piezoelectric thin film element is attached to edge of first cured layer; one side, attached with piezoelectric thin film element, of first cured layer is vertically placed into second curing material, and second curing material is cured into second cured layer; and metal sheet is removed to obtain micro-vibration sensor. Due to fact that piezoelectric thin film element is arranged at a crack tip, during micro-vibration, stress in stress field of crack tip is rapidly increased due to crack stress deformation, and stress signal is efficiently converted into electric signal; and micro-vibration sensor has characteristics of being low in detection limit and high in accuracy.