Murata Manufacturing Co., Ltd.

Ryuhei Yoshida

Masaya Wajima

Kenichi Sakai

Hideaki Kuroda

Daisaku Kugo

Tsuneo Amano

Jiro Inoue

Takashi Yamamoto

Hiroyuki Takahashi

Shungo Morinaga

Ryoji Takagi

Nobuhiro Kitajima

Kazuhiro Sawai

Satoshi Miura

Makoto Miyadera

In a piezoelectric resonator, first and second resonance electrodes are provided on the upper surface and the lower surface of a piezoelectric member, inner electrode layers for leading the first and second resonance electrodes to the upper and lower surfaces are provided and extend to the upper and lower surfaces of the piezoelectric member, and connecting electrodes are provided on the upper and lower surfaces of the piezoelectric member, and are electrically connected to the corresponding resonance electrodes via the inner electrode layers.

Electronic component

A method for producing an energy trap piezoelectric resonator which operates in a thickness longitudinal vibration mode and which includes a piezoelectric member and first and second vibrating electrodes disposed on respective major surfaces of the piezoelectric member, involves the use of a piezoelectric material having an R value and an A value which are selected such that Qe&equals;C/(R&times;A), where R and A are the average pore size in micrometers and the porosity in percent of the piezoelectric member, respectively. Here, Qe is a value at a frequency to be used and C is a constant that is determined by the piezoelectric material of the piezoelectric member. An energy trap, thickness longitudinal piezoelectric resonator produced by this method has a sufficiently high response to a vibration mode to be used, without any limitation on the type of piezoelectric material and size of the piezoelectric member and the frequency to be used.

Piezoelectric resonator and manufacturing method thereof

A piezoelectric oscillator is constructed to prevent deterioration of frequency accuracy caused by external-capacitance variations to maintain a high degree of frequency accuracy. Additionally, an undesired short-circuit is prevented from occurring even when the height of the oscillator is reduced. In this oscillator, on an upper surface of a capacitor substrate only first and second external electrodes connected to a piezoelectric resonator are provided. The piezoelectric resonator connects to the external electrodes. A parallel capacitance section for loading capacitance in parallel to the piezoelectric resonator is connected between the first and second external electrodes. Additionally, load capacitance sections for interposing load capacitances are connected between the first external electrode and a third external electrode and between the second and third external electrodes. The parallel capacitance section and the pair of load capacitance sections are contained in the capacitor substrate.

Piezoelectric oscillator

An energy-trap type piezoelectric resonator utilizes a fundamental wave of a thickness shear vibration mode and includes resonance electrodes provided on both main surfaces of a substantially rectangular piezoelectric plate so as to face each other with the piezoelectric plate disposed therebetween. An energy trap vibration portion including a portion of the piezoelectric plate where the resonance electrodes overlap each other is asymmetrical with respect to the center in the longitudinal direction of the piezoelectric plate.

Piezoelectric resonator

An energy-trapping piezoelectric vibration device generates a thickness shear mode and includes an elongated piezoelectric element having first and second longitudinally opposed ends, top and bottom surfaces provided between the first and second ends such that the top and bottom surfaces oppose each other, and beveled surfaces disposed at a vicinity of the first and second ends such that the thickness of the piezoelectric element gradually decreases towards the first and second ends, respectively. First and second vibration electrodes are disposed on the top surface and the bottom surface of the piezoelectric element, respectively. The first and second vibration electrodes are located at an approximate middle portion of the piezoelectric element so as to oppose each other with the piezoelectric element disposed therebetween, to define opposing portions which constitute a vibrator. A roughness of the beveled surfaces is greater than a roughness of a flat portion of the top and bottom surfaces of the piezoelectric substrate disposed beneath the vibration electrodes.

Piezoelectric vibration device and piezoelectric resonance component

An electronic component includes an electronic component element having a substantially rectangular plate disposed between upper and lower case substrates in the form of substantially rectangular plates such that the upper and lower case substrates and the electronic component element are stacked and define an integral unit. Assuming that the length of the shorter sides and the length of the longer sides of the electronic component element are a,and b,, respectively, and that the length of the shorter sides and the length of the longer sides of the lower case substrate,are a,and b,, respectively, the relationships a,<a,and b,<b,are satisfied.

A piezoelectric resonator adapted to generate a third harmonic wave of a thickness extensional vibration mode in which the fundamental wave is lead out of the vibrating portion and suppressed effectively. The piezoelectric resonator includes a vibrating portion with vibration electrodes opposing each other in the middle of a piezoelectric plate, lead-out electrodes electrically connected to the vibration electrodes, and a floating electrode disposed along the short side edge on at least one major surface of the piezoelectric plate or in the vicinity of the edge.

A surface mounting structure is arranged to minimize a height dimension of an electronic component. A surface mount type electronic component is provided on the surface mounting structure. The surface mount type electronic component includes a piezoelectric component element including an insulating substrate, and a piezo-resonator mounted on a mounting surface of the insulating substrate. The piezoelectric component element is mounted on a printed circuit board, with the mounting surface being arranged to face a surface of the printed circuit board. A recess is formed in the printed circuit board and a portion of the piezoelectric component element is accommodated in the recess. A conductive adhesive is located on external connection electrodes provided on the mounting surface and is firmly attached to circuit patterns on the printed circuit board so that the piezoelectric component element is fixed to the printed circuit board. Further, the external connection electrodes are electrically connected to the circuit patterns.

Surface mounting structure and surface mount type electronic component included therein

A capacitor-included, chip-type piezoelectric resonator allows minute and highly precise adjustment of electrostatic capacitance and the resonance frequency after production of the piezoelectric resonator by laminating a piezoelectric element and dielectric substrates. The resonator includes a piezoelectric substrate laminated with dielectric substrates and external electrodes disposed on the laminate body. A plurality of external electrodes are arranged to extend from the outer major surface of the first dielectric substrate to the outer major surface of the second dielectric substrate along first and second side surfaces disposed opposite to each other. On the outer major surface of the second dielectric substrate, at least one external electrode is divided into first and second electrode portions.

Chip-type piezoelectric resonator and method for adjusting resonance frequency thereof

A piezoelectric resonator includes two sealing substrates, a seal portion, and an energy-trap type piezoelectric resonance element which is adapted to vibrate in a third harmonic of thickness extensional vibration. The piezoelectric resonance element includes a piezoelectric substrate and a pair of excitation electrodes, which are disposed on opposite major surfaces of the piezoelectric substrate. A portion of the piezoelectric substrate sandwiched by the excitation electrodes defines a vibrating portion. The sealing substrates each have a cavity formed therein and are attached onto the corresponding major surfaces of the piezoelectric substrate such that the cavities define a space for vibration. The seal portion is formed around the vibration space so as to damp leaking vibration. The vibrating portion is arranged such that the approximate center thereof is spaced from the approximate center of the vibration space as viewed along the major surfaces of the piezoelectric resonance element.

An electronic component is constructed to prevent damage and stripping off or separation at adhered portions thereof even if the component is exposed to abrupt temperature changes to thereby provide a highly reliable component. A piezoelectric vibrating element defining a first substrate and an electronic component case including a pair of substrates which are second substrates are adhered together through an adhesive layer so as to define a closed space. The adhesive layer includes a fillet portion which is arranged to extend along lateral walls of the recess to edges of the closed space to prevent separation at adhesion interface surfaces of the substrates.

Electronic component having structure for preventing separation at

An energy-trapping thickness-shear resonator includes a piezoelectric substrate, a first electrode extending from a first end to a central portion of a first surface of the piezoelectric substrate and a second electrode extending from a second end to the central portion of a second surface of the substrate. Thus, the resonator utilizes thickness shear vibrations generated in a portion of the piezoelectric substrate located between the first and second electrodes at the central portion of the substrate. The width W of the la substrate is set to be equal to or less than about 0.7 mm and also to satisfy both of the following expressions (1) and (3) or to satisfy both of the expressions (2) and (3):

Energy-trapping thickness-shear resonator and electronic components

Disclosed herein is an energy-trapped type piezoelectric resonator, which comprises a piezoelectric resonance element having a piezoelectric plate and a pair of resonance electrodes formed on opposite major surfaces of the piezoelectric plate to have portions opposed to each other through the piezoelectric plate for defining a resonance part through the opposed portions of the resonance electrodes, a pair of reinforcing members holding both major surfaces of the piezoelectric resonance element to be integrated with the same so as to define a space in a region around the resonance part of the piezoelectric resonance element and not to inhibit the resonance part from vibration, and a pair of terminals, holding the piezoelectric resonance element and the pair of reinforcing members as integrated, electrically connected with the pair of resonance electrodes of the piezoelectric resonance element respectively.

Method of making a energy-trapped type piezoelectric resonator

An energy-trap chip-type piezoelectric resonance component has a resonance part defined by first and second resonance electrodes which are formed on a pair of opposite surfaces of a piezoelectric plate so that vibrational energy of the resonance part is partially trapped, and first and second holding plates which are bonded to both sides of the pair of opposite surfaces through adhesive layers, and the adhesive layers are applied onto regions other than that provided with the resonance part for allowing vibration of the resonance part, while the same contain granular solids.

Energy-trap chip-type piezoelectric resonance component

A piezoelectric-resonance device comprising a piezoelectric ceramic body, a pair of excitation electrodes provided so as to be opposed to each other with the piezoelectric ceramic body interposed therebetween, and connecting conductive portions connecting the excitation electrodes and side edges of the piezoelectric ceramic material, a portion, which is interposed between the excitation electrodes, of the piezoelectric ceramic body being polarized in the opposite direction to the direction of polarization of the other portion thereof.

Growing community of inventors

Toyama, Japan

Ryuhei Yoshida