An elastic boundary wave device includes a first medium with piezoelectricity, an electrode exciting an elastic wave and provided on the first medium, a second medium made of a different material from the first medium and provided on the first medium to cover the electrode, and a sound absorbing portion provided on the second medium.

Elastic boundary wave device

Provided are a power generating device that can make for reductions in size and increases in output and a power generating module using the same. In a power generating device (1), a power generating part (20) has a plurality of power generating elements (200) comprising one group of two electrodes (22, 23) formed on facing each other on two surfaces in the direction of thickness of a piezoelectric body (21) and a functional part (21a) sandwiched by the one group of two electrodes (22, 23) in the piezoelectric body (21). In addition, in the power generating device (1), the plurality of power generating elements (200) are formed from one or a plurality of first power generating elements (201) and one or a plurality of second power generating elements (202). The orientations of the polarization of first power generating element (201) and second power generating element (202) along the direction of thickness of the piezoelectric body (21) are opposite to each other. In the power generating part (20), the first generating element (201) and the second power generating element (202), which form a pair, are connected by wiring part (24) which connects electrodes (22, 22), formed on the same surface side in the direction of thickness of the piezoelectric body (21), to each other, and all of the plurality of power generating elements (200) are connected in series.

Power generating device and power generating module using same

PROBLEM TO BE SOLVED: To provide a method of manufacturing a piezoelectric device with which a structure preventing chipping or cracking can be easily obtained. SOLUTION: The present invention relates to the method of manufacturing a piezoelectric device, including: a piezoelectric element mounting step of mounting piezoelectric elements on a mount substrate; a substrate bonding step of bonding a cover substrate to the mount substrate so as to house and seal respective piezoelectric elements in individual spaces; a dividing groove forming step of forming a dividing groove for fragmentation for each piezoelectric element on the surface of the mount substrate and the cover substrate; a step of coating the surface including the inside of the dividing groove of the mount substrate and the cover substrate with a protective material; and a division and fragmentation step of dividing and fragmenting the dividing groove as cutting lines, wherein a piezoelectric device in a structure where the coating with the protective material is performed beforehand and chipping or cracking is prevented by division into pieces, is obtained. COPYRIGHT: (C)2009,JPO&INPIT

Method of manufacturing piezoelectric device

A method of manufacturing an edge reflection type surface acoustic wave device includes the step of preparing a surface acoustic wave mother substrate having a plurality of interdigital transducers formed on one main surface thereof. A cut groove is formed in the substrate by cutting the surface acoustic wave mother substrate beginning from the one main surface side thereof. This step of forming a cut groove is repeated so as to produce a plurality of cut grooves so that the first reflection edge of the respective surface acoustic wave devices are sequentially formed. Next, similarly, cut grooves are sequentially formed on the surface acoustic wave mother substrate from the one main-face side thereof so as not to reach the other main surface thereof, whereby the second reflection edges of the respective surface acoustic wave devices are sequentially formed.

Method of producing edge reflection type surface acoustic wave device

PURPOSE:To obtain the surface wave device using an SH-type surface wave where the spurious due to a bulk wave is reduced and a package structure is simplified. CONSTITUTION:By providing a resin layer 13 formed on an upper surface 16a of a piezo-electric substrate 16 so as to cover an interdigital transducer, the package structure is simplified by emitting the formation of voids. Level differences 17a and 17b are provided on the end face of a piezo-electric substrate 16, end face parts 18a and 18b lower than the end faces 17a and 17b are made rough surfaces. By forming the resin layer 13 so as to cover the upper end face parts 19a and 19b, the spurious due to the reflection in the end face of the bulk wave is reduced in the surface wave device.

Surface wave device and its production

PURPOSE:To provide a production method of the end face reflection surface wave resonator in which a position of an end face being a reflecting face, that is, a width of an electrode finger of an IDT electrode is formed with high accuracy resulting in obtaining high performance and having a low occurrence rate of defective products. CONSTITUTION:In the manufacture of the end face reflection type surface wave resonator in which plural numbers of IDT electrodes being components of the end face reflection surface wave resonator are formed on a piezoelectric mother substrate 1, the piezoelectric mother substrate is cut by a cutter to cut out individual resonators, each IDT electrode is formed on the piezoelectric mother substrate 1 in the relation of L>T (W is a width of an electrode finger 13 of the IDT electrode, T is a thickness of a blade of a cutter, and L is an interval of adjacent cut lines when the width of the electrode finger at both ends of the IDT electrode is W/2), and the piezoelectric mother substrate 1 is cut along one cut line of adjacent cut lines and then the piezoelectric mother substrate is cut along the other cut line of the adjacent cut lines to cut out each resonator.

Manufacture of end face reflection surface wave resonator

PURPOSE:To obtain a method of polarization which can polarize a piezoelectric plate at a relatively low voltage regardless of dimension of its planar shape and by making it difficult to develop warps and cracks of a piezoelectric plate. CONSTITUTION:A plurality of pairs of electrodes 22, 22b-29a, 29b overlapping one another via a piezoelectric plate 21 are formed on the piezoelectric plate, and voltage is impressed between a common electrode 31 and a common electrode formed in a position of overlapping with the common electrode 31 via the piezoelectric plate and between a common electrode 32 and a common electrode formed under the piezoelectric plate 21 so as to overlap with the common electrode 32 via the piezoelectric plate 21, whereby electrodes overlapping via the piezoelectric plate 21 are connected at the same potential. Direct voltage is impressed between each pair of electrodes and adjacent pairs of electrodes, resulting in polarization treatment.

Method of polarizing piezoelectric plate

PURPOSE:To polarize a piezoelectric substrate simply and well without damaging it by a method wherein one pair of faced polarization electrodes are formed on both main faces of the piezoelectric substrate and a required DC voltage is applied between the polarization electrodes. CONSTITUTION:Three pairs of polarization electrodes 12a 13a to 12c and 13c are formed so as to be faced with both main faces 11a, 11b of a piezoelectric substrate 11; a + DC voltage is applied to the electrodes 12a, 13a, 12c, 13c; a-DC voltage is applied to the electrodes 12b, 13b. Then, electric-field components (C) become parallel with the respective main faces 11a, 11b; the substrate 11 is not damaged by a warp; the substrate 11 can be polarized simply and well by using a small voltage. After this treatment, the polarization electrodes are removed and a resonance circuit or the like can be formed on the substrate.

Kadota Michio

Papers

Surface wave device and its production

Manufacture of end face reflection surface wave resonator

Method of polarizing piezoelectric plate

Method for polarization of piezoelectric substrate