Murata Manufacturing Co., Ltd.

Hisato Oshima

Takashi Shikama

Masami Sugitani

Junichi Hamatani

Iwao Fukutani

Kenichi Saito

Takaaki Ooi

Toshinori Murakami

Yoshimi Tanaka

Junichi Inoue

Takahiro Yamamoto

Tomoaki Ushiro

Toshio Kawabata

Daiji Kono

Takeshi Shikama

Koji Yokoo

In a noise filter, an input side of a signal-line lead is inserted in a first substantially cylindrical ferrite bead, and an output side of the signal-line lead is inserted in a second substantially cylindrical ferrite bead. An input side of a ground lead is inserted in a third substantially cylindrical ferrite bead. The signal-line lead is inserted in a feedthrough capacitor such that the feedthrough capacitor is adjacent to an output side of the second substantially cylindrical ferrite bead. A multilayer capacitor is electrically coupled between the signal-line lead and the ground lead such that the multilayer capacitor is adjacent to an output side of the first substantially cylindrical ferrite bead and adjacent to an output side of the third substantially cylindrical ferrite bead. Each of an end of the signal-line lead and an end of the ground lead is flat, bent along an outer surface of a base member, and defines a surface-mount external terminal.

Noise filter having filter components fitted into depressions in a base member

A noise filter includes a capacitor having a hot side input terminal, a hot side output terminal, a ground side input terminal, and a ground side output terminal. A circuit board includes a hot side input electrode connected to the hot side input terminal, a hot side output electrode connected to the hot side output terminal, a ground side input electrode connected to the ground side input terminal, and a ground side output electrode connected to the ground side output terminal. The impedance of the ground side input terminal seen from the ground side output electrode is larger than both the impedance of the ground side output terminal seen from the ground side output electrode and the impedance of the hot side output terminal seen from the ground side output electrode. For this purpose, a stray capacitance formed between the ground side input electrode and the ground side output electrode is reduced by increasing a gap therebetween. Accordingly, excellent noise-reducing characteristics are provided.

Noise filter mounting structure

A composite inductor includes a block made of resin or rubber having a magnetic material dispersed therein. Spirally wound coils are buried in the block so that the coil axes of the coils are arranged in the same direction. The end portions of the coils are electrically connected to external electrodes provided on two surfaces of the block substantially at a right angle to the axes of the coils.

Composite inductor element

An inductor is constructed to achieve efficient formation of external electrodes, and exhibits high reliability of connection between the external electrodes and an internal conductor, and desired characteristics. In the method of manufacturing the inductor, a magnetic material formed by kneading a magnetic material and a resin is molded to form a magnetic material compact body in which the internal conductor is partially exposed from the external surface thereof, and then the surface of the magnetic material compact body is plated to form the external electrodes including a plated metal film and connected to the internal conductor. The surface of the magnetic material compact body is roughened, and then the external electrodes are formed via plating.

Inductor and method of producing the same

A method for manufacturing an inductor is performed in such a manner that the surface of a metal wire provided with an insulating film thereon is coated with a thermal melting resin. The thickness of the thermal melting resin is, for example, approximately 1 &#x3bc;m. As the thermal melting resin, a thermoplastic resin or a thermosetting resin, such as a polyimide resin or an epoxy resin, containing 85 wt % of a powdered ferrite is used. This coated metal wire is densely wound to form a solenoid-type coil conductor. Next, the thermal melting resin is softened by a heat treatment at, for example, 180&#xb0; C. and is then solidified by spontaneous cooling. Accordingly, the portions of the coil conductor adjacent to each other are bonded together by the thermal melting resin.

Method for manufacturing an inductor

A bead inductor has excellent productivity and increased reliability in the connection between an internal conductor and external terminals. A method for manufacturing such a bead inductor includes the steps of forming an internal conductor and the external terminals as an integral, unitary member such that the external terminals are disposed at both ends of the internal conductor and electrically connected thereto; positioning the integral, unitary member in a metallic mold; and molding a resin material or a rubber material including a powdered magnetic substance in the metallic mold so as to embed the internal conductor therein.

Bead inductor and method of manufacturing same

A method of manufacturing an inductor includes the step of molding a magnetic material formed by kneading a magnetic material and a resin to form a magnetic material compact body in which the internal conductor is partially exposed from the external surface thereof. Then the surface of the magnetic material compact body is plated to form the external electrodes including a plated metal film and connected to the internal conductor. The surface of the magnetic material compact body is roughened, and then the external electrodes are formed via plating.

Method of manufacturing an inductor

A method of producing a bead inductor includes the steps of forming an outer portion outside of a conductor coil, and forming a molded body with the conductor coil embedded therein. The outer portion is formed outside of the conductor coil by disposing the conductor coil in a cavity defined by first and second mold portions, with first and second gates formed in the first mold portion, inserting first and second spacer pin portions, which define a spacer pin which passes through the conductor coil and extends to and closes the second gate, and supplying material containing magnetic powder into the mold cavity from the first gate. The molded body is formed by closing the first gate after the formation of the outer portion, and supplying from the second gate material containing magnetic powder into a space formed by removing the spacer pin portions.

Apparatus for manufacturing bead inductor

A inductor is constructed such that at least about two-thirds of a final winding of wire at each end of an internal conductor-coil embedded in a molded magnetic body project from end surfaces of the molded magnetic body by at least about one-fifth of the diameter of the wire. External electrodes are connected with respective portions of the internal conductor-coil, which are exposed at the respective end surfaces of the molded magnetic body.

Inductor and method for manufacturing same

An electronic component includes an internal conductor (conductor coil) made of a metal that is embedded in a molded body. The molded body is formed by molding a ferrite resin into a fixed shape, such that at least a portion of the internal conductor is exposed on the surface of the molded body, and external electrodes, which are connected to the internal conductor, are provided in a fixed area, including the exposed portion of the internal conductor, on the surface of the molded body. The electronic component is manufactured by depositing palladium at a density of about 0.5 &mgr;g/cm to about 1.5 &mgr;g/cm in the area in which the internal conductor is not exposed on the molded body, and at a density of about 0.05 &mgr;g/cm to about 0.3 &mgr;g/cm on the internal conductor exposed on the surface of the molded body. The external electrodes are formed via a process of forming a metal film (electroless plating film) on the surface of the molded body by conducting electroless plating.

Electronic component and method of manufacturing same

A bead inductor includes a conductor coil defined by a wound, coated metallic wire, and an insulation coating which is removed on both end portions thereof. The conductor coil is embedded in a molded body with the end portions of the conductor coil being exposed at both end portions of the molded body. External terminals are attached to end portions of the conductor coil at both ends of the molded body so that the external terminals are electrically connected to the end portions of the conductor coil.

Bead inductor

A bead inductor with reliable electrical characteristics and which is constructed so as to be easily mass produced includes a substantially rectangular-parallelepiped core. The core includes an axial portion and an outer peripheral portion, and a coil is formed by winding a metal wire around the axial portion. The axial portion includes a central portion and a peripheral portion. A high strength material is used for the central portion. Metal caps are disposed on both ends of the core. The caps and the coil are connected electrically. In addition, the central portion of the axial portion may be a cavity.

Method of manufacturing bead inductor

A method for efficiently and economically manufacturing an inductor using a resin based magnetic material, and a highly reliable inductor that is manufactured by the method, produces a unique inductor including a molded magnetic material member. An inner conductor is disposed in the molded magnetic material member and is exposed at a surface of the molded magnetic material member. The molded magnetic material member is formed using the resin based magnetic material in which a component that functions as nuclei for applying electroless plating is blended, followed by forming a selectively coated molded body so that the area not provided with external electrodes on the surface of the molded magnetic material member is covered with an insulating resin and applying electroless plating on the molded magnetic material member (selectively coated molded body), thereby eliminating use of a resist agent that is required in the conventional manufacturing method, as well as a resist agent removing step with an alkali and solvent and a removing step of the electroless plating film with an acid, by forming the electroless plating film as the external electrodes on the desired area.

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Yokaichi, Japan

Hisato Oshima