Murata Manufacturing Co., Ltd.

Murata Manufacturingco., Ltd.

Masakazu Yoshio

Kenichi Kotani

Mitsuhiro Yamada

Koichi Yamasaki

TO reduce frequency variations caused by a change in frequency constant and suppress unnecessary vibrations in the case where the frequency constant of apiezoelectric substrate has a gradient. A piezoelectric resonator has vibrating electrodesandfacing each other, which are formed on two major surfaces of apiezoelectric substrate Ia, and trapped vibrations are generated between the two vibrating electrodes. The piezoelectric substrate Ia has a constant thickness. The frequency constant of the piezoelectric substrate Ia has a gradient in a surface direction. The vibrating electrodesandare formed to have a gradient thickness so that the thickness gradually increases as the frequency constant of the piezoelectric substrate increases. By forming the vibrating electrodes to have a gradient thickness, unnecessary in-band vibrations are suppressed, and frequency variations are reduced.

Piezoelectric resonator and method for producing the same

An energy trap type piezoelectric resonator component includes a piezoelectric resonator using a third overtone of a thickness longitudinal vibration. The piezoelectric resonator includes a piezoelectric substrate, and first and second vibrating electrodes, having an elliptical shape, and respectively arranged on portions of first and second major surfaces of the piezoelectric substrate such that the first and second vibrating electrodes face each other with the piezoelectric substrate interposed therebetween. A flattening ratio 'a/b' of a minor axis diameter 'b' to a major axis diameter &#x201c;a&#x201d; of the elliptical shape is within a range of from about 1.2 to about 1.45. The resonator is thus compact, effectively controls the fundamental wave of the thickness longitudinal vibration as a spurious wave, is relatively free from area restraints of the electrode and dimensional constraints, and meets a variety of frequency requirements in a wide range.

Energy trap type piezoelectric resonator component

A piezoelectric resonator component includes an energy-trapped piezoelectric resonator utilizing a third order harmonic wave of thickness longitudinal vibration and including a piezoelectric substrate having first and second major surfaces and polarized in a direction of thickness between the first and second major surfaces, and first and second vibrating electrodes opposed to each other with the piezoelectric substrate interposed therebetween, and first and second casing substrates respectively laminated on the first and second major surfaces of the piezoelectric resonator so that cavities are arranged so as not to interfere with vibration of a vibration section where the first and second vibrating electrodes face each other through the piezoelectric substrate. The first and second vibrating electrodes are dimensioned so that the difference between the peak values of the phases of S0 and S1 modes of the fundamental wave of the thickness longitudinal vibration falls within a range of about &#xb1;5 degrees.

Piezoelectric resonator component

A small and easily produced piezoelectric resonator, which effectively damps unwanted vibration and utilizes intended vibration includes excitation electrodes provided on both main surfaces of a piezoelectric substrate, and first and second lead-out electrodes and first and second terminal electrodes electrically connected to the excitation electrodes, respectively. At least one of the terminal electrodes includes an electrode extension portion arranged to extend into the imaginary region where the first and second excitation electrodes are extended to at least one of the side edges of the piezoelectric substrate.

Piezoelectric resonator

A piezoelectric resonator has a structure that enables easy manufacturing thereof and that damps the fundamental wave of a thickness vertical vibration mode with high accuracy, while effectively utilizing the resonance characteristics based on the third harmonic. In the piezoelectric resonator, first and second excitation electrodes are located on two main surfaces of a piezoelectric substrate, lead-out electrodes and terminal electrodes are provided for each of the first and second excitation electrodes, and each of the terminal electrodes is arranged to occupy an area that is not less than about 10% of the area of an annular region which ranges over a normal-line distance of about 1.2 d to about 2 d from the outer peripheral edge of each of the excitation electrodes, where d is the diameter of each of the excitation electrodes.

A piezoelectric component includes leads and being arranged to suppress the adhesion of solder or a conductive adhesive agent to lead-out electrodes or vibration electrodes thereof, which is therefore resistant to the deterioration of electrical characteristics such as resonance characteristics, and which minimizes fluctuation of the electrical characteristics. In this piezoelectric component having the leads, the vibration electrodes are provided on each of the first and second main surfaces of a piezoelectric plate, and each of the vibrating electrodes is connected to a terminal electrode via a lead-out electrode. Each of the holding portions of a lead terminal is bonded to the terminal electrode, and is arranged so as not to extend onto the lead-out electrode.

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Toyama-ken, Japan

Masakazu Yoshio