Kawatetsu Mining Co., Ltd.

Other

Kabushiki Kaisha Toshiba

Yoshihito Tachi

Yasutaka Fukuda

Tetsuo Inoue

Tetsuhiko Mizoguchi

Shigeru Yatabe

Mitsuyoshi Matsushita

Toshio Ogawa

This invention provides a surface mounting type planar magnetic device comprised of upper ferrite magnetic film, lower ferrite magnetic film and a planar coil interposed therebetween. For applying surface mount technology, an opening is formed in the upper ferrite magnetic film above a coil terminal portion and then, an external electrode conductive with the coil terminal portion through the opening is formed on the upper ferrite magnetic film. Further, this surface mounting type planar magnetic device is of a thin structure and can be mounted on the surface of a printed board. Its power loss is small, its inductance is large, its frequency characteristic is excellent, the disparity of the characteristic is small and its reliability is excellent.

Surface mounting type planar magnetic device and production method thereof

A surface mounting type planar magnetic device comprised of upper ferrite magnetic film, lower ferrite magnetic film and a planar coil interposed therebetween. For applying surface mount technology, an opening is formed in the upper ferrite magnetic film above a coil terminal portion and then, an external electrode conductive with the coil terminal portion through the opening is formed on the upper ferrite magnetic film. Further, this surface mounting type planar magnetic device is of a thin structure and can be mounted on the surface of a printed board. Its power loss is small, its inductance is large, its frequency characteristic is excellent, the disparity of the characteristic is small and its reliability is excellent.

A domain controlled piezoelectnc single crystal is disclosed which uses a lateral vibration mode for an electromechanical coupling factor k not less than 70% and a piezoelectric constant &minus;d not less than 1200 pC/N, with an electromechanical coupling factor k in the longitudinal vibration mode not less than 80% and a piezoelectric constant d not less than 800 pC/N. Also, a piezoelectric single crystal is disclosed which uses a high-performance longitudinal vibration mode with k not more than 30%. A fabrication method applies a DC electric field of 400 V/mm to 1500 V/mm for a maximum of two hours in a temperature range of 20&deg; C. to 200&deg; C. as polarization conditions in the thickness direction of the piezoelectric single crystal. The method can include cooling, or heating and cooling between temperature boundaries of rhombohedral and tetragonal crystals or between tetragonal and cubic crystals or within a cubic crystal temperature range.

Domain controlled piezoelectric single crystal and fabrication method therefor

A magnetic ferrite paste is applied onto an Si substrate, and then sintered to form thereon a magnetic ferrite film having a mean composition that comprises from 40 to 50 mol % of Fe O , from 15 to 35 mol % of ZnO, from 0 to 20 mol % of CuO, and from 0 to 10 mol % of Bi O with NiO and inevitable impurities as the balance. The magnetic ferrite film thus formed on an Si substrate is for magnetic devices, and it forms a region not containing CuO or having a CuO content of at most 5 mol % around its interface directly adjacent to the surface of the Si substrate. The adhesiveness of the magnetic ferrite film to the underlying Si substrate is high, and the reliability of the magnetic device having the magnetic film is therefore high.

Growing community of inventors

Taito, Japan

Yoshihito Tachi