Murata Manufacturing Co., Ltd.

Murata Mfg. Co., Ltd.

Tomoaki Ushiro

Kazutaka Nakamura

Toshio Kawabata

Yasunobu Yoneda

Akinori Nakayama

Hiroyuki Takeuchi

Hiroshi Komatsu

Hisashi Katsurada

Hiroyuki Kubota

Yukio Sakabe

Masaaki Taniguchi

Atsuo Senda

Takuji Nakagawa

Hisato Oshima

Toshi Numata

Hiroshi Morii

Yasushi Ueno

Daiji Kono

Tomio Yamasaki

Tohru Tominaga

Masahiro Yuruki

Tooru Tominaga

In a chip type common mode choke coil, a plurality of non-magnetic sheets on which conductor lines are formed are laminated one on another to form a non-magnetic member, and the conductor lines are connected to form primary and secondary coils inside the non-magnetic member, and a pair of magnetic layers are formed on the upper and lower surface of the non-magnetic member, and magnetic cores are arranged substantially at the centers of the loops of the coils in such a manner that they penetrate the non-magnetic member and are connected to the pair of magnetic layers, whereby a closed magnetic path crossing the primary and secondary coils is formed.

Method of manufacturing chip-type common mode choke coil

A process for producing a voltage-dependent nonlinear resistor that contains zinc oxide as a major component and that also contains a minor oxide component, is improved by the steps of adding an organometallic compound as the minor oxide component to the powder of zinc oxide, mixing the two components, forming the mixture into a shape and sintering the shape. The organometallic compound as the minor oxide component is either a compound in which a hydrocarbon group is bound to a metal atom or a compound in which the hydrogen atom in a carboxyl, hydroxyl, imino group, etc., is replaced by a metal. The method is capable of reducing the scattering of the electrical characteristics of the voltage-dependent nonlinear resistor, which contributes to an improvement of the change of varistor voltage by surge current.

Process for producing a voltage-dependent nonlinear resistor

Two parts of magnetic layers are placed so as to clamp a coil forming unit consisting of an alternated laminate of non-magnetic layers and electrode layers. The coil forming unit is surrounded by the magnetic body to form a closed magnetic circuit. When manufacturing the laminated transformer, a plurality of sets of U-shaped electrodes are deposited on non-magnetic green sheets. Then, the non-magnetic green sheets are laminated to form the coil forming unit consisting of the alternated laminate of the non-magnetic layers and the electrode layers. Magnetic green sheets are laminated thereto and clamp the non-magnetic green sheets therebetween to form a laminate. The laminate is pressed and additional magnetic body portions are formed in the center and on the side faces of the coil forming units. The laminate is pressed and cut into green elements. The green elements are sintered into monolithic bodies of the laminated transformer.

Laminated transformer

Chip-type common mode choke coil

In A method of manufacturing a solid inductor having an inner conductor formed by passing through a magnetic, material. A vitreous diffused material is applied to the surface of the magnetic material, and the diffused material is diffused into the magnetic material by heat treatment, to form a diffusion layer exhibiting low permeability. The thickness of this diffusion layer is adjusted, thereby to make it possible to adjust the inductance value of the solid inductor as well as to improve resistance to humidity of the solid inductor.

Method of manufacturing a solid inductor

A composite electronic part includes a dielectric ceramic portion consisting of a Pb group dielectric material. Inside the dielectric ceramic portion, an internal electrode constituting a portion of a capacitor is formed. The dielectric ceramic portion is bonded to a magnetic ceramic portion consisting of a Ni--Zn group ferrite material by an intermediate layer consisting of a ceramic material containing Pb, Ni, Fe and Nb as main components. Inside the magnetic ceramic portion, an internal electrode constituting a portion of an inductor is formed. Furthermore, at end portions of the dielectric ceramic portion, intermediate layer and magnetic ceramic portion, a plurality of external electrodes consisting of, for example, Ag are formed, and connected to the predetermined internal electrodes.

Composite electronic part

A resistor 1 in which at least one resistance film 4 is embedded in a ceramic sintered body 3, glass is diffused into the sintered body 3 to form a glass diffusion layer 6, and both end faces 4a and 4b of the resistance film 4 are respectively exposed to both end faces 3a and 3b of the ceramic sintered body 3.

Ceramic resistor wherein a resistance film is embedded

In a solid inductor having an inner conductor formed by passing through a magnetic material, a vitreous diffused material is applied to the surface of the magnetic material, and the diffused material is diffused into the magnetic material by heat treatment, to form a diffusion layer exhibiting low permeability. The thickness of this diffusion layer is adjusted, thereby to make it possible to adjust the inductance value of the solid inductor as well as to improve resistance to humidity of the solid inductor.

Solid inductor with vitreous diffused outer layer

A chip type varistor in which first and second inner electrodes are embedded in a sintered body obtained by laminating a plurality of semiconductor ceramics layers so as not to be overlapped with each other in the direction of thickness of the ceramics layers, respective one edges of the first and second inner electrodes are led out to one and the other of a pair of side surfaces opposed to each other of the sintered body and are electrically connected to outer electrodes formed on the pair of side surfaces of the sintered body, respectively, a non-connected type inner electrode which is not electrically connected to the above described outer electrodes is embedded in the sintered body, and the non-connected type inner electrode is arranged so as to be overlapped with the first and second inner electrodes while being separated by the semiconductor ceramics layer.

Chip type varistor

A conductor pattern for forming coils and lead-out electrodes which are led out from the coils are formed on a magnetic substance sheet. Furthermore, said magnetic substance sheet is provided with through-holes for connecting the conductor patterns. The magnetic substance sheets disposed respectively just over and just under the conductor pattern that becomes the lead-out electrodes are coated with non-magnetic material paste. A laminated chip common mode choke coil is produced by laminating these magnetic substance sheets and baking them integrally and thereafter forming external electrodes. The non-magnetic material diffuses into the magnetic substance sheet by baking the lamination of the magnetic substance sheets, and the permeability of that portion becomes low. Therefore, the magnetic reluctance around the lead-out electrode becomes high, thus reducing leakage flux around that portion. Thereby, coupling between two coils formed in the choke coil becomes good.

Laminated chip common mode choke coil

A work holder (12) for holding a workpiece (2) while partially masking the same by use of a mask (18). The workpiece and the mask are elastically pressed against each other by an aggregate (15) of heat-resistant fiber such as metal fiber or ceramic fiber, so that the workpiece and the mask are brought into close contact with each other. This work holder is adapted to form a resistor film (9) on a part of the surface of a chip (2) to form a chip-type resistor (1), for example, by a thin film forming method such as sputtering.

Growing community of inventors

Nagaokakyo, Japan

Tomoaki Ushiro