Murata Manufacturing Co., Ltd.

Manabu Sumita

Tetsuo Takeshima

Keiichi Kami

Mitsunori Ishimasa

Masakazu Yamauchi

Isao Ikeda

Kiyotaka Tajima

Sigemasa Kusabiraki

Shigemasa Kusabiraki

Muneyuki Daidai

Yuko Yokoi

Jun Harada

Takeshi Yamazaki

Shunjiro Imagawa

Hirohide Yoshino

Shigeo Ojima

Takashi Shimura

Toshiaki Yamashita

Takashi Mizuguchi

Kazuaki Hamada

Shushi Saoshita

Yuji Kosugi

Toshiaki Sugimura

Yuichi Sakai

Sadayuki Kato

Sigeo Ojima

Masaaki Tutiya

Takashi Hosoe

Masanari Nishikigawa

Kenichi Nishimoto

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.

Piezoelectric electroacoustic transducer

A piezoelectric type electroacoustic transducer includes a piezoelectric vibrating plate including a plurality of piezoelectric ceramic layers laminated to each other with an internal electrode being interposed between the piezoelectric ceramic layers, and main surface electrodes disposed on the main surfaces on the front and back sides of the piezoelectric vibrating plate, whereby the piezoelectric vibrating plate is surface-flexural-vibrated in the thickness direction thereof with an AC signal applied between the main surface electrodes and the internal electrode, and a box having supporting portions on which the outer peripheral portions on the back side of the piezoelectric vibrating plate is supported, the piezoelectric vibrating plate having a protecting film substantially on the entire surface on the back-side only or on the front and back sides of the piezoelectric vibrating plate, and the protecting film being formed by applying a resin in a film-shape and hardening the resin, or by bonding an adhesive sheet and hardening the sheet, and the piezoelectric vibrating plate being warped on the front-side thereof by utilization of the hardening shrink stresses of the protecting films.

Piezoelectric acoustic transducer

A piezoelectric electro-acoustic transducer includes a piezoelectric vibration plate having a plurality of piezoelectric ceramic layers laminated to each other with an internal electrode being interposed between the ceramic layers, and main surface electrodes provided on the front and back surfaces thereof, whereby area bending vibration is produced by applying an AC signal between the main surface electrodes and the internal electrode, respectively, a resin film having a size that is greater than the piezoelectric vibration plate and having the piezoelectric vibration plate bonded substantially to the central portion of the surface thereof, and a casing which accommodates the piezoelectric vibration plate and the resin film. The piezoelectric vibration plate has an area of about 40% to about 70% of that of the resin film. The inner peripheral surface of the case is provided with a supporting portion having a frame shape that is larger than that of the piezoelectric vibration plate, and the outer peripheral portion of the resin film having no piezoelectric vibration plate bonded thereto is supported by the supporting portion of the case.

Piezoelectric electro-acoustic transducer

A piezoelectric electroacoustic transducer includes a substantially rectangular piezoelectric diaphragm having an internal electrode, a plurality of laminated piezoelectric ceramic layers having the internal electrode interposed between two of the piezoelectric ceramic layers, principal-surface electrodes disposed on top and bottom principal surfaces of the piezoelectric diaphragm, the piezoelectric diaphragm generating surface bending-vibrations in response to application of an alternating signal between the principal-surface electrodes and the internal electrode, a resin film that is larger than the piezoelectric diaphragm and having the piezoelectric diaphragm affixed onto substantially a central portion of a front surface thereof, and a housing having a support for supporting the outer periphery of the resin film. The resin film has heat resistance at least a reflow-soldering temperature and at least one undulated portion bending in the front and rear directions thereof and formed in the outer periphery thereof, and the perimeter of the resin film including the four corners thereof is fixed to the support of the housing by adhesion.

A piezoelectric electroacoustic transducer includes a piezoelectric diaphragm having a substantially rectangular shape which vibrates in the thickness direction when an alternating current is applied between electrodes of the piezoelectric diaphragm, a housing which stores the piezoelectric diaphragm, and a pair of terminals formed in the housing by insert molding. One end of each terminal is inserted inside the housing and includes a body portion fixed to the housing and wing portions which extend from both sides of the body portion toward the corners of the housing. The wing portions are not fixed to the housing, and stress-relieving portions are disposed between the body portion and the wing portions so that the wing portions are able to move toward the inside of the housing. Each electrode of the piezoelectric diaphragm is connected to at least one of the wing portions of the terminals by a conductive adhesive.

A piezoelectric electroacoustic transducer includes a substantially square piezoelectric diaphragm flexually vibrating in a plate-thickness direction in response to application of an alternating signal between electrodes, a substantially rectangular insulating case having a supporting member disposed inside sidewalls of the case for supporting the diaphragm, terminals having internal connections exposed in a vicinity of the supporting member and external connections exposed outside the case and electrically connecting to the internal connections, a first adhesive applied to a shortest route located between the external periphery of the diaphragm and the internal connections and connecting the diaphragm to the internal connections so as to fix the diaphragm to the case, a conductive adhesive applied to electrodes of the diaphragm and the internal connections via the upper surface of the first adhesive by detouring from the shortest route to connect the diaphragm to the internal connections for electrically connecting the electrodes of the diaphragm to the internal connections of the terminals, and a second adhesive for sealing a clearance between the external periphery of the diaphragm and the internal periphery of the case. The first and second adhesives have a Young's modulus after curing smaller than that of the conductive adhesive.

Piezoelectric electroacoustic transducer and manufacturing method of the same

The invention provides a solder alloy of Sn, Sb, Ag and Cu, wherein the Sb is about 1.0-3.0 wt %; the Ag is about 1.0 wt % or more and about 2.0 wt % or less; the Cu is about 1.0 wt % or less; and the remainder is Sn. The solder alloy has a comparatively low Young's modulus and sufficient tensile characteristics. Therefore, it resists peeling from the bonded electrode, etc., even though a heat stress is added. Also, a solder which has an excellent solderbility to metal phases such as Cu and Ni can be provided. Therefore, a solder alloy excellent in thermal shock resistance can be provided. The solder alloy may be used for soldering the inside of an electronic component.

Solder alloy

A terminal for a piezoelectric device has a first contact portion and a second contact portion which are preferably formed as separate metallic elements. Each contact portion has a protrusion disposed thereon. A lubricant is located between the first contact portion and the second contact portion. The lubricant contains a hydrophilic group tending to form a hydrogen bond with a metal element and a lipophilic group extending in a straight chain from any such hydrogen bond and having a length at least several times that of the hydrophilic group. The lipophilic group has a molecular structure which urges away from the metallic surfaces of the contact portions.

Terminal for a piezoelectric device

An apparatus and process for forming at least one electrode of an electronic component includes the steps of preparing a work; placing a mask on a principal plane of the work; and applying an electrode material over the mask onto the principal plane of the work to form at least one electrode. The mask preferably comprises, for instance, a first masking portion having a substantially rectangular loop shape and a second masking portion having a substantially rectangular shape, and four pseudo masking portions shaped into substantially rectangular strips and which support the first masking portion. In this case, four through holes are formed in the masking member by the synergistic function of the first masking portion, the second masking portion, and the pseudo masking portions.

Apparatus and process for forming electrodes of electronic components

A terminal for a piezoelectric device has a base contact portion and a bent contact portion which are preferably formed by folding a metallic material. Each contact portion has a protrusion disposed thereon. A lubricant is located between the base contact portion and the bent contact portion. The lubricant contains a hydrophilic group tending to form a hydrogen bond with a metal element and a lipophilic group extending in a straight chain from any such hydrogen bond and having a length at least several times that of the hydrophilic group. The lipophilic group has a molecular structure which urges away from the metallic surfaces of the contact portions.

An electronic device which has piezoelectric resonators and terminals piled in a box-like case. The electronic device has a couple of terminals, each of which has a contact portion and a junction portion extending from the contact portion. In the case, the couple of terminals are integrated by electrically connecting the junction portions.

Piezoelectric device

A flux containing an activator of the nonionic halogen group is used in soldering one end of each of lead terminals 6a and 6b to each of drawing electrodes 5a and 5b of a ceramic element 2. After soldering them, a wax 9 is dripped on the periphery of vibrating electrodes 4a and 4b of the ceramic element 2. Then, an outer resin 10 is applied around the periphery of the ceramic element 2 and so on. By drying the outer resin 10, a solvent contained in the outer resin 10 is dispersed to the outside, and pores are formed in the outer resin 10 on paths through which the solvent has been dispersed. At the same time, a part of a residual flux 11 is absorbed into the pores formed in the outer resin 10. The whole is heated to 150.degree. C. to harden the outer resin 10. When the whole is heated, the wax 9 and the remaining part of the residual flux 11 are absorbed into the pores of the outer resin 10. As a result, a cavity 8 is formed around the periphery of the vibrating electrodes 4a and 4b. When the whole has been heated to 150.degree. C., the outer resin 10 is hardened, and an outer member 7 is formed.

Method for manufacturing an electronic component

An organic silicon compound 10 is applied around vibrating electrodes 3a and 3b of a piezoelectric resonant element 1. A compound such as silane, chlorosilane, silazane, silthiane, siloxane, cyclosilane, cyclosilazane, cyclosilthiane, cyclosiloxane, silanol, or metallosilicone is used as the organic silicon compound 10. Around the piezoelectric resonant element 1 and the organic silicon compound 10, for example, an ultraviolet ray curing resin is applied, and the ultraviolet ray curing resin is cured, thereby a permeable film 11 is formed. A cavity 12 is formed around the vibrating electrodes 3a and 3b by dispersing the organic silicon compound 10 to the outside through the film 11. Around the film 11, for example, an outer coating resin is applied, and the outer coating resin is cured, thereby an outer coating material 13 is formed.

Growing community of inventors

Toyama, Japan

Manabu Sumita