Murata Manufacturing Co., Ltd.

Takaomi Toi

Koki Sasaki

Tetsuya Morinaga

Shinya Hirai

Masahiro Bando

Tetsuo Hatakenaka

Takayuki Hirotsuji

Kazuo Kasahara

Kosuke Ishida

Hiroyuki Yasuzawa

Katsuhiko Tsubana

Hiroshi Marusawa

Mizuho Katsuta

Tatsuyuki Yamada

Kazuhide Kudo

Yoshio Hanato

Daisuke Ishide

A common mode choke coil as an electronic component includes a laminate. The laminate includes insulating layers stacked in a thickness direction and has a recess sinking in a stacking direction of the insulating layers. The laminate includes at least one coil conductor therein. The recess is filled with a magnetic resin material. The magnetic resin material is formed of a magnetic powder-containing resin that is a mixture of a soft magnetic metal powder and a thermosetting resin. The soft magnetic metal powder has an average particle size of 12 &#x3bc;m or less. The magnetic powder-containing resin contains 65 vol % or more and 85 vol % or less of the soft magnetic metal powder.

Electronic component

A multilayer transformer component includes a chip body including a primary-side coil and a secondary-side coil, and first to fourth external electrodes. The primary-side coil includes a body portion, a first lead, and a second lead, and the secondary-side coil includes a body portion, a third lead, and a fourth lead. A first projection and a second projection of each body portion are arranged to lie substantially on a linear line. The first lead and the fourth lead are arranged to be line-symmetrical with respect to a center line which is arranged at an approximate center between respective distal ends of the first projection and the second projection, and which is perpendicular or substantially perpendicular to an overlying direction of the primary-side and secondary-side coils. The second lead and the third lead are also arranged to be line-symmetrical with respect to the center line.

Multilayer transformer component

A wire-wound coil includes a ferrite core having a winding core portion and flange portions, a wire wound around the winding core portion, electrodes connected to the wire on lower surfaces of the flange portions, and a ferrite plate attached to upper surfaces of both of the end flange portions so as to extend over the winding core portion. The flange portions and the ferrite plate are provided with corresponding recessed and projecting portions and, and the flange portions and the ferrite plate are integrated through the recessed and projecting portions. Joint sections between the flange portions and the ferrite plate include contact sections that are in direct contact with each other, and adhesion sections arranged to receive an adhesive.

Wire-wound coil

A wire-wound type chip coil can take various inductance values while maintaining its outer dimension at a specified fixed value. A chip coil is formed by winding at least two conductive wires regularly in a single layer around a core made of a magnetic material and firmly connecting both ends of each conductive wire to terminal electrodes disposed on respective flanges of the core. This makes it possible to obtain a great current capacity. Furthermore, the inductance decreases because of an increase in the magnetic path length. A great number of different inductance values can be easily obtained by properly selecting parameters including the number of substantially parallel conductive wires, the diameter of each conductive wire, and the number of turns.

Method of adjusting a characteristic of wire-wound type chip coil by adjusting the space between conductive wires

A wire-wound type chip coil can take various inductance values while maintaining its outer dimension at a specific fixed value. A chip coil is formed by winding at least two conductive wires regularly in a single layer around a core made of a magnetic material and firmly connecting both ends of each conductive wire to terminal electrodes disposed on respective flanges of the core. This makes it possible to obtain a great current capacity. Furthermore, the inductance decreases because of an increase in the magnetic path length. A great number of different inductance values can be easily obtained by properly selecting parameters including the number of substantially parallel conductive wires, the diameter of each conductive wire, and the number of turns.

Wire-wound type chip coil and method of adjusting a characteristic thereof

A coil-winding method for forming a coil unit includes the steps of winding first and second wires substantially parallel to each other simultaneously around a first layer position of a core to form a first turn, winding the first and second wires simultaneously to form a second turn while the second wire is disposed directly around the core, the first wire of the second turn adjacent to the first turn being disposed between the first and second wires of the first turn in the first layer so as to form a second layer, and winding the first and second wires simultaneously to form a third turn while the second wire is disposed directly around the core, the first wire of the third turn being disposed in the second layer and wound between the second wire of the first turn and the second wire of the second turn in the first layer.

Coil-winding method and coil unit formed by the method

A common-mode choke coil includes a core having flanges disposed at both ends and a winding section arranged between the flanges. Electrodes are disposed in the flanges, while two pieces of wire are wound around the winding section and ends of the pieces of wire are connected to the electrodes. A ferrite plate with a relative magnetic permeability that is smaller than that of the core is attached on the upper surface of the flanges with an adhesive so as to cover the wire.

Common-mode choke coil

A coil device includes terminal electrodes each including a bottom-surface electrode provided on a bottom surface of a flange, side-surface electrodes provided on side surfaces of the flange, and an end-surface electrode provided on an end surface of the flange at the lower part of the end surface. The end-surface electrode is arranged on the end surface of the flange so that the upper edge of the end-surface electrode is disposed at a first level that is substantially the same as that of the upper edges of the side-surface electrodes in the vicinity of boundaries between the end surface and each side surface of the flange and is disposed at a second level lower than the first level at an approximate central portion of the end surface of the flange.

Method for manufacturing a coil device

An electronic device such as a chip coil including an electric wire firmly connected to electrodes in a highly reliable fashion is constructed to be mounted on a printed circuit board or substrate in a stable and reliable manner. At both ends of a core of the chip coil, there are provided electrodes having a multilayer structure including a high-conductivity layer made of Ag, Ag&mdash;Pd, or a similar material; a solder barrier layer made of Ni; and an easy-soldering layer made of Sn or solder. End portions of the electric wire are embedded in the easy-soldering layer so that the resultant electrode structure has a substantially flat surface. A thermo-compression process is performed so that the end portions of the electric wire are connected to the solder barrier layer via solid welding and to the easy-soldering layer via brazing.

Electronic device having electric wires and method of producing same

An electronic component is constructed to prevent Cu elution to a solder from a wire, and also prevents the wire from becoming thin and being broken. A chip coil includes electrodes provided at both ends of a core. The electrodes include an underlying metal layer (Ag), a Ni plated layer, and a Sn&mdash;Cu plated layer arranged in this sequence from the bottom thereof. Ends of a wire are embedded in the Sn&mdash;Cu plated layer of the electrodes by thermal compression bonding. When the chip coil is mounted on a land of a substrate by a reflow soldering, the Cu of the Sn&mdash;Cu plated layer is eluted into the reflow solder, and Cu elution from the wire is prevented

Electronic component having wire

Coil device and method for manufacturing the same

An electronic device such as a chip coil including an electric wire firmly connected to electrodes in a highly reliable fashion is constructed to be mounted on a printed circuit board or substrate in a stable and reliable manner. At both ends of a core of the chip coil, there are provided electrodes having a multilayer structure including a high-conductivity layer made of Ag, Ag--Pd, or a similar material; a solder barrier layer made of Ni; and an easy-soldering layer made of Sn or solder. End portions of the electric wire are embedded in the easy-soldering layer so that the resultant electrode structure has a substantially flat surface. A thermo-compression process is performed so that the end portions of the electric wire are connected to the solder barrier layer via solid welding and to the easy-soldering layer via brazing.

Growing community of inventors

Machida, Japan

Takaomi Toi