Murata Manufacturing Co., Ltd.

Kazuo Kasahara

Tetsuya Morinaga

Masahiro Bando

Takaomi Toi

Koki Sasaki

Tetsuo Hatakenaka

Takayuki Hirotsuji

Yoshio Hanato

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

A chip-type common mode choke coil having protrusions extending in an axial direction of a winding core portion and being formed in areas between a plurality of electrodes (four electrodes), at the inside surfaces of two flanges, that is, at opposing surfaces of the two flanges, one being disposed on each end of the winding core portion, in order to increase the stroke distances between the corresponding electrodes. In the choke coil, the protrusions separate the corresponding electrodes in order to prevent the occurrence of a short circuit caused by two wires also coming into contact with the electrodes adjacent to the electrodes to which they are primarily to be connected. For the protrusions, protrusions having at least one of a triangular shape, a square shape, a rectangular shape, a trapezoidal shape, and a substantially semicircular shape in plan view are disposed. Accordingly, the chip-type common mode choke coil makes it possible to prevent the occurrence of a short circuit caused by the wires coming into contact with the corresponding adjacent electrodes, the occurrence of reduced withstand pressure, and the occurrence of insufficient insulation. In addition, it can have high mechanical strength as a result of increased cross-sectional areas of the legs, and be highly reliable.

Chip-type common mode choke coil

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

Sabae, Japan

Kazuo Kasahara