Matsushita Electric Industrial Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Kazuhiro Okuda

Yasushi Goto

Seiichi Minami

Kenji Ueno

Yoshiko Higashi

Tomohiro Fujita

Hiroshi Fukushima

Ryohei Harada

Yuji Yasuoka

Kunitoshi Kawano

Satoshi Kawamura

Tsutomu Inuduka

Hiroki Moriwaki

Tomokazu Yamaguchi

An object of the present disclosure is to provide a common mode choke coil with high impedance and small variation. A common mode choke coil includes magnetic core having winding core part and a pair of flange parts provided on opposite ends of winding core part, external electrodes formed on each of flange parts, a pair of windings wound on winding core part, with each of the ends being drawn out and joined to one of external electrodes, and magnetic plate joined to the pair of flange parts with adhesive. Magnetic plate has joining parts joined to flange parts and opposing part opposing winding core part, and surface roughness of joining parts is smaller than surface roughness of opposing part.

Common mode choke coil and manufacturing method therefor

A piezoelectric ceramic composition including three components, Pb(ZnNb)O, PbTiO, and PbZrO, and having a basic composition formula of Pb(ZnNb)ZrTiO, where 0.90&#x3c;x+y+z&#x3c;1.0, exhibits excellent piezoelectric characteristics and heat resistance and has a low sintering temperature of about 900&#xb0; C., a coupling coefficient Kp not less than 0.50, and a Curie temperature not lower than 300&#xb0; C. A piezoelectric device using this composition may employ inexpensive silver and silver-palladium alloys containing a high percentage of silver as material of an internal electrode, thus being inexpensive and having excellent characteristics.

Piezoelectric porcelain composition, laminated piezoelectric device therefrom and process for producing the same

A piezoelectric ceramic compound expressed by a basic formula of Pb(ZnNb)ZrTiO(where 0.90&#x3c;a+x+y&#x3c;1.00) is provided. The starting materials for the piezoelectric ceramic compound are calcined. The calcined material is milled to provide powder. A formed body containing the powder is provided. The formed body is degreased at a temperature having the formed body not sintered. A sintered body is provided by sintering the degreased body. The sintered body is heated to subject the sintered body to predetermined heat treatment. The sintered body subjected to the predetermined heat treatment is polarized to provide the sintered body with a piezoelectric property, thus providing a piezoelectric ceramic device. This piezoelectric ceramic composition can be sintered together with an electrode consisting mainly of Ag at a low temperature. Even after the sintering, the composition has its insulation resistance not decrease and has its piezoelectric properties not decline. The piezoelectric ceramic composition has its insulation resistance not decrease even in high-temperature and high-humidity condition, thus having stable characteristics.

Method of producing piezoelectric ceramic device

A laminated piezoelectric transformer according to the present invention comprises (a) a laminated body formed by laminating a plurality of ceramic layers and a plurality of internal electrodes and (b) a plurality of external electrodes electrically connected with the internal electrodes and disposed on the surface of the laminated body. Further, the internal electrodes of the laminated piezoelectric transformer of the invention are characterized by having a plurality of primary internal electrodes positioned at the middle portion along the longitudinal direction of the laminated body and a plurality of secondary internal electrodes positioned at both end portions of the laminated body. By virtue of this configuration of the invention, the polarization volume on the secondary side can be enlarged and, therefore, the laminated piezoelectric transformer of the invention can step up voltages at high energy conversion efficiency.

Laminated piezoelectric transformer

Growing community of inventors

Osaka, Japan

Kazuhiro Okuda