Murata Manufacturing Co., Ltd.

Mitsunori Ishimasa

Keiichi Kami

Tetsuo Takeshima

Manabu Sumita

Kazuyuki Noto

Motoyoshi Sakai

Kazuaki Hamada

Yuk Yokoi

Manabu Sunita

A piezoelectric vibrator includes a piezoelectric vibrating element, and a base member having a mounting surface to which the piezoelectric vibrating element is mounted, and a mount surface positioned on the opposite side to the mounting surface. The base member includes an electrode pattern formed at the mount surface that includes a ground electrode and a signal electrode that is electrically connected to the piezoelectric vibrating element. Moreover, the mount surface is a rectangular shape, the signal and ground electrodes are arranged in a region of the mount surface closer to any one side thereof, with the one side defining part of outer edges of the mount surface, and a distance from an outer edge of the signal electrode to the one side of the mount surface is longer than a distance from an outer edge of the ground electrode to the one side of the mount surface.

Piezoelectric vibrator

A piezoelectric electroacoustic transducer includes a substantially rectangular piezoelectric diaphragm, a case having supports to support the four corners of the bottom surface of the piezoelectric diaphragm, terminals fixed to the case, each including an inner connection portion exposed near the supports, a first elastic adhesive disposed between the periphery of the piezoelectric diaphragm and the terminals, a conductive adhesive disposed between electrodes of the piezoelectric diaphragm and the terminals across the top surface of the first elastic adhesive, a second elastic adhesive filling and sealing a gap between the periphery of the piezoelectric diaphragm and an inner portion of the case, and an overamplitude-preventing receiver provided on a bottom wall of the case to limit the amplitude of vibration of the piezoelectric diaphragm to a predetermined range. The overamplitude-preventing receiver is disposed closer to the center of the piezoelectric diaphragm than the supports.

Piezoelectric electroacoustic transducer

A package of a surface-mountable electronic component to be reflow-soldered to a circuit board at about 250&#xb0; C. or more includes a case and a cover. The cover has a softening temperature lower than the reflow temperature, and the case has a softening temperature higher than the reflow temperature. In the package, softening the cover compensates for the stress on the bonded surfaces resulting from a difference in thermal expansion between the case and the cover caused during reflow.

Package of surface-mountable electronic component

An insert terminal containing case includes a bottom wall, four side walls, and an opening at the upper portion, wherein a terminal made of a metal plate is vertically fixed to at least one of the four side walls by insert molding. A groove is vertically arranged at the outer side surface of the side wall fixing the terminal, the groove extending downward, the outer side surface of the terminal is partially exposed at the groove, and the inner side surface opposite the outer side surface of the terminal exposed at the groove is partially exposed at the inner side surface of the side wall. Therefore, when the terminal is provided in the case by insert molding, molding can be performed only using upper and lower dies. Furthermore, the terminal can be reliably exposed at the inner surface of the side wall. The insert terminal containing case has the minimum difference between the opening dimension of the case and the dimension of a piezoelectric diaphragm and is molded without using a sliding die.

Insert terminal-containing case, piezoelectric electroacoustic transducer using the same, and process for producing insert terminal-containing case

A piezoelectric electroacoustic transducer includes a piezoelectric sounding body in which bending vibration is generated by applying an alternating signal between two electrodes, a case housing the piezoelectric sounding body, and a pair of terminals insert-molded in the case. In the piezoelectric electroacoustic transducer, internal connection portions of the pair of terminals are exposed on the inside surface of the side wall portion of the case so as to extend in a direction that is substantially perpendicular relative to the piezoelectric sounding body, and the internal connection portions of the terminals are electrically connected to the electrodes of the piezoelectric sounding body by using conductive adhesive. The internal connection portions of the terminals do not largely extend inside the case and accordingly, the dimensional difference between the case and the piezoelectric sounding body is minimized.

A piezoelectric electro-acoustic transducer includes a substantially rectangular piezoelectric diaphragm, a casing having a support unit for supporting four corners of the piezoelectric diaphragm, terminals fixed to the casing such that an internal connection portion of the terminal is exposed in the vicinity of the support unit, a first elastic adhesive for coating between the external periphery of the piezoelectric diaphragm and the internal connection portion of the terminal therewith, a conductive adhesive for coating between electrodes of the piezoelectric diaphragm and the internal connection portion of the terminal via the upper surface of the first elastic adhesive therewith, and a second elastic adhesive for sealing the external periphery of the piezoelectric diaphragm and the internal periphery of the casing, and a cradle provided in the internal periphery of the casing as well as below the piezoelectric diaphragm in the vicinity that is coated with the first elastic adhesive for forming a gap for stopping flow of the first elastic adhesive at a position lower than the support unit as well as between the upper surface of the cradle and the bottom surface of the piezoelectric diaphragm.

Growing community of inventors

Toyama, Japan

Mitsunori Ishimasa