Nihon Dempa Kogyo Co. | Date: 2014-02-19
An oscillator circuit includes a crystal unit, a first variable capacitance element, a transistor, and a first capacitance element. The first variable capacitance element is disposed between a first terminal of the crystal unit and a ground. The transistor has a base connected to a second terminal of the crystal unit. The first capacitance element is disposed between an emitter and a collector of the transistor.
Nihon Dempa Kogyo Co. | Date: 2014-03-04
A sensing sensor includes a crystal element having a first excitation electrode, a second excitation electrode, and a common electrode, an adsorbing layer, a wiring board, and a channel forming member. The crystal element is secured to the wiring board so as to form a space at one surface side of the first vibrating region and the second vibrating region. The channel forming member is disposed to form a supply channel of sample solution upward of each of the first vibrating region and the second vibrating region. The channel forming member is disposed such that an inferior surface of a left edge and a right edge of the channel forming member is positioned on the common electrode. The channel forming member is formed such that an injection port of the sample solution and a discharge port of the sample solution are opposed to the crystal element.
Nihon Dempa Kogyo Co. | Date: 2014-02-25
A piezoelectric device includes a piezoelectric vibrating piece, a lid portion, and a base portion. The piezoelectric vibrating piece includes a vibrating portion, a framing portion surrounding the vibrating portion, an excitation electrode on the vibrating portion, and an extraction electrode on the framing portion. The extraction electrode is electrically connected to the excitation electrode. The lid portion is bonded to a front surface of the piezoelectric vibrating piece. The base portion is bonded to a back surface of the piezoelectric vibrating piece. The base portion includes an external electrode electrically connected to the extraction electrodes. The framing portion includes a metallic layer that allows a passivation. The metallic layer is disposed at an outer peripheral edge portion corresponding to the extraction electrode on at least one of a front surface and a back surface.
Nihon Dempa Kogyo Co. | Date: 2014-02-26
A method for fabricating a piezoelectric device that includes a piezoelectric resonator to be mounted on a solder applied over a surface of a substrate. The piezoelectric resonator includes a metal case and at least a pair of lead terminals extracted from the metal case. The lead terminal includes a first part, a second part, and a third part. The method includes: applying solder cream at a case region and a lead region of a surface of the substrate, the case region corresponding to the metal case, the lead region corresponding to the third part; placing a block solder with a smaller area than an area of the case region at the case region; arranging the metal case of the piezoelectric resonator to the case region, arranging the third part to the lead region; and heating the substrate and the piezoelectric resonator in a reflow furnace.
Nihon Dempa Kogyo Co. | Date: 2014-11-19
A surface acoustic wave device includes a quartz substrate and a periodic structure portion. The quartz substrate is constituted such that a surface acoustic wave is to propagate on a surface with an Euler angle of (0, 16<18.5, 0). The periodic structure portion is disposed on the quartz substrate and includes a plurality of electrodes extending in a direction intersecting with a direction of the propagation of the surface acoustic wave. The electrodes are disposed in parallel to one another along the propagation direction. The periodic structure portion is constituted to mainly contain aluminum. When a width dimension of the electrode in the propagation direction and a separation dimension between the electrodes adjacent to one another are respectively defined as L and S, a metallization ratio (=L(L+S)) is set to 0.4 or less.