Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Michio Hasegawa

Masashi Sahashi

Koichiro Inomata

Tetsuhiko Mizoguchi

Toshiro Sato

Hiroshi Tomita

Atsuhito Sawabe

Toshihiro Onodera

Senji Shimanuki

Yuji Iseki

Yuji Ide

Masakatsu Haga

Kunio Matsukura

Isamu Yanase

Yasunori Iwamoto

Yoshihiko Yamaguchi

Tadahiko Kobayashi

Takao Sawa

Yoshio Takamura

Shoichi Higo

Seiji Kajiwara

Disclosed herein is a planar magnetic element comprising a substrate, a first magnetic layer arranged over the substrate, a first insulation layer arranged over the first magnetic layer, a planer coil formed of a conductor, having a plurality of turns, arranged over the first insulation layer and having a gap aspect ratio of at least 1, the gap aspect ratio being the ratio of the thickness of the conductor to the gap between any adjacent two of the turns, a second insulation layer arranged over the planar coil, and a second magnetic layer arranged over the second insulation layer. When used as an inductor, the planar magnetic element has a great quality coefficient Q. When used as a transformer, it has a large gain and a high voltage ratio. Since the element is small and thin, it is suitable for use in an integrated circuit, and can greatly contribute to miniaturization of electronic devices.

Planar magnetic element

A planar inductor has a spiral coil, insulating layers stacked on both surfaces of the spiral coil, and ferromagnetic layers stacked on the insulating layers, wherein each ferromagnetic layer has a saturation magnetization 4&pgr;M of 10 kG or more, and a thickness of 100 &mgr;m or less.

Planar inductor

A planar inductor has a spiral coil, insulating layers stacked on both surfaces of the spiral coil, and ferromagnetic layers stacked on the insulating layers, wherein each ferromagnetic layer has a saturation magnetization 4&pgr;M,of 10 kG or more, and a thickness of 100 &mgr;m or less.

Disclosed is a dc-to-dc converter comprising a switching transistor, a pulse-width modulation controller, a sandwich-type planar inductor, which accumulates an electromagnetic energy at ON state and releases the accumulated electromagnetic energy at OFF state of the switching transistor, a smoothing capacitor, a rectifying element, and a planar search coil for detecting an overcurrent flowing the planar coil, disposed on one of the outer surfaces of the soft magnetic layers constituting the planar inductor.

Magnetic element for power supply and DC-to-DC converter

Magnetic element for power supply and dc-to-dc converter

Disclosed is a planar inductor which has spiral conductor coil means sandwiched between ferromagnetic layers with insulating layers interposed therebetween. The spiral conductor coil means is formed of two spiral conductor coils of the same shape arranged flush with and close to each other. Moreover, the two spiral conductor coils are connected electrically to each other so that currents of different directions flow individually through the conductor coils. Furthermore, the spiral conductor coil means is sandwiched between the two ferromagnetic layers with the insulating layers therebetween, each of the ferromagnetic layers having an area greater than the combined area of the two conductor coils. In the planar inductor according to the present invention, inductance is prevented from lowering while its components are being bonded together, so that the inductance value per unit volume is increased.

There is disclosed an amorphous alloy for a magnetic core material represented by the formula

Amorphous alloy for magnetic core material

There is disclosed a low-loss amorphous alloy represented by the following formula:

Low-loss amorphous alloy

A high frequency switching circuit comprised of a single-ended switching circuit, rectifying-smoothing circuit and magnetic amplifier which is connected between said single-ended switching circuit and rectifying-smoothing circuit. The magnetic amplifier includes a saturable reactor which has a coercive force Hc of 0.6 Oe or above and a rectangular ratio Br/Bs of 80% or below at an operating frequency of 20 kHz. The saturable reactor is prepared from an amorphous magnetic alloy having a composition of

High frequency switching circuit

A switching element, a transformer having a primary winding connected through said switching element to a DC power supply and a resonance capacitor connected in parallel with the primary winding of said transformer constitute a single-ended switching circuit. A magnetic amplifier is connected between the secondary side circuit of the transformer of the single-ended switching circuit and a rectifying/smoothing circuit, thus forming a high frequency switching circuit.

An amorphous magnetic alloy has a general formula:

Amorphous magnetic alloy

A rolled core is formed by winding a thin body of an amorphous magnetic alloy having positive magnetostriction characteristics so that, of the two surfaces the surface of smaller surface coarseness faces inward. This rolled core is improved in iron loss over a rolled core obtained by winding the thin body so that the surface of greater surface coarseness faces inward. Breakage of the thin body tends to occur less frequently when it is wound so that the surface faces inward.

Growing community of inventors

Yokohama, Japan

Michio Hasegawa