Kawasaki Steel Corporation

Kawatetsu Mining Co., Ltd.

Other

Kabushiki Kaisha Toshiba

Yasutaka Fukuda

Michio Shimotomai

Yoshihito Tachi

Akira Fujita

Tetsuo Inoue

Tetsuhiko Mizoguchi

Yukiko Ozaki

Shigeru Yatabe

Junichi Shimomura

Yoko Kitano

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 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.

Magnetic ferrite film for magnetic devices

This invention provides permanent magnets that are excellent not only in magnetic properties but also corrosion resistance by using two magnetically useful phases, i.e., RE.sub.2 TM.sub.14 B phase having a high residual magnetic flux density and a low melting point RE-TM' phase or RE-TM'-B phase which enhances the sinterability and possesses a cleaning action against grain boundaries of the RE.sub.2 TM.sub.14 B main phase. Further the invention provides a method for forming an electrochemically noble composition as a starting material to prepare a two phase magnet.

Corrosion-resistant rare earth metal-transition metal series magnets and

A corrosion-resistant rare earth metal-transition metal-boron permanent magnet having improved corrosion resistance and excellent magnetic properties, including RE: 10-25 at % (where RE is at least one of Y, Sc and lanthanides), B: 2-20 at % and the remainder being substantially Fe, Co and Ni. In this case, the magnet has an average crystal grain size of 0.1-50 .mu.m and includes a crystal grain boundary phase of RE(Ni.sub.1-x-y Co.sub.x Fe.sub.y) compound having a thickness of not more than 10 .mu.m.

Corrosion-resistant rare earth metal-transition metal-boron permanent

A corrosion-resistant rare earth metal-transition metal magnet alloy having excellent coercive force, squareness, corrosion resistance and temperature characteristics is disclosed, which alloy consists of at least one of rare earth element inclusive of Y; B; occasionally at least one of Mg, Al, Si, Ca, Ti, V, Cr, Mn, Cu, Zn, Ga, Ge, Zr, Nb, Mo, In, Sn, Ta and W; and the remainder being transition metals of Fe, Co and Ni.

Growing community of inventors

Chiba, Japan

Yasutaka Fukuda