Alps Electric Co., Ltd.

Tdk Corporation

Alps Green Devices Co., Ltd.

Alps Alpine Co., Ltd.

Alps Electronics Co., Ltd.

Alps Green Devices., Ltd.

Yosuke Ide

Masamichi Saito

Naoya Hasegawa

Yoshihiro Nishiyama

Masahiko Ishizone

Kenichi Tanaka

Akira Takahashi

Kazumasa Nishimura

Ryo Nakabayashi

Hidekazu Kobayashi

Eiji Umetsu

Kenji Ichinohe

Masahiro Iizuka

Naoki Sakatsume

Tsuyoshi Nojima

Shigenobu Miyajima

Yasuo Hayakawa

Akio Hanada

Tatsuya Kogure

Fumihito Koike

Kazuaki Ikarashi

Takuya Seino

Mitsuo Aratono

Hideaki Kawasaki

Kenji Honda

Toshihiro Kuriyama

Yoshihiko Kakihara

Shinji Mitsuya

Masahiro Oshima

Masahiro Ooshima

Kota Asatsuma

Naoki Sakazume

Hidenori Hataya

Naoya Hasegawn

Hideharu Matsuo

Hasahiko Ishizone

Yoshihiro Nishiyana

Mitsuhiro Goto

Hidekezu Kobayashi

Norimasa Okanishi

A magnetic sensor includes a magnetic-field detector including magneto-resistance elements, and a shield. Since the feedback coil is disposed so as to overlap with the magnetic-field detector, and the shield is disposed so as to overlap with the feedback coil, the cancellation field of the feedback coil makes it difficult to cause magnetization saturation. The shield is annular in shape as viewed from a direction normal to the shield. This allows maintaining the magnetic-field shielding action of the shield to enhance the effect of shielding the magnetic field in a direction perpendicular to the sensitivity.

Magnetic sensor and current sensor including magneto-resistance element

A magnetic sensor includes a magnetoresistive element having a sensitivity axis in a Y direction, a magnetic shield disposed apart in a Z direction from the magnetoresistive element and configured to attenuate the intensity of a magnetic field to be measured, and a magnetic balance coil. The magnetic shield includes a first shield part longitudinally extending in the X direction and second shield parts provided on either side of the first shield part. The first shield part has a portion that overlaps the magnetoresistive element when viewed in the Z direction. Each second shield part has a portion that overlaps the magnetoresistive element when viewed in the X direction. A magnetic path for a magnetic field in the X direction can be formed from one of the second shield parts to the other one of the second shield parts via the first shield part.

Magnetic sensor and current sensor

Magnetic detectors and a lower insulating layer covering the magnetic detectors are disposed on a substrate. On the lower insulating layer, a coil layer including a plurality of segments forming a counter detector of a feedback coil is disposed. Height adjustment layers are disposed on both sides of the coil layer. The coil layer and the height adjustment layers are covered with an upper insulating layer, and a shield layer is disposed thereon. Accordingly, the shield layer can be made substantially flat.

Current detection device

A magnetometric sensor comprises a magnetoresistance effect element having a sensitivity axis in a specific direction; including a fixed magnetic layer, a nonmagnetic material layer, and a free magnetic layer stacked in this order on a substrate; and including a first antiferromagnetic layer on the free magnetic layer on the opposite side to the side facing the nonmagnetic material layer to cause an exchange coupling bias between the first antiferromagnetic layer and the free magnetic layer and align the magnetization direction of the free magnetic layer in a prescribed direction in a state of permitting variation in magnetization. The free magnetic layer includes a first free magnetic sub-layer, a misfit-reducing sub-layer for decreasing the lattice mismatch of the free magnetic layer with the first antiferromagnetic layer, and a second free magnetic sub-layer ferromagnetically coupled to the first free magnetic sub-layer in this order from the first antiferromagnetic layer side.

Magnetometric sensor and current sensor

A magnetic sensor includes: a magnetoresistive effect element having a sensitivity axis in a specific direction in which a fixed magnetic layer, a nonmagnetic material layer, and a free magnetic layer are laminated in this order; an antiferromagnetic layer which generates an exchange coupling bias with the free magnetic layer and which aligns the magnetization direction thereof in a predetermined direction provided on the free magnetic layer; and a ferromagnetic layer which generates an exchange coupling bias with the antiferromagnetic layer and which aligns the magnetization direction thereof in a predetermined direction provided on the antiferromagnetic layer. The magnetization direction on the exchange coupling bias in the free magnetic layer is the same direction as that on the exchange coupling bias in the ferromagnetic layer, and the ferromagnetic layer is able to impart a reflux magnetic field having a component along a sensitivity axis to the free magnetic layer.

Magnetic sensor, method for manufacturing magnetic sensor, and current sensor

A GMR element includes a fixed magnetic layer in which magnetization is fixed; a free magnetic layer in which magnetization is changed by an external magnetic field; and a spacer layer which is positioned between the fixed magnetic layer and the free magnetic layer, in which the free magnetic layer is formed by laminating a CoFe alloy and a CoFeB alloy. A current sensor uses the GMR element.

Giant magnetoresistance element and current sensor using the same

A current sensor includes a magnetic sensor module including a plurality of magnetic sensor units connected in series. The magnetic sensor units each include a first magnetic sensor element and a second magnetic sensor element which have sensitivity axes oriented in opposite directions. A first terminal of the first magnetic sensor unit is connected to a first potential source. A third terminal of the first magnetic sensor unit is connected to a second potential source. A second terminal and a fourth terminal of the last magnetic sensor unit are connected to constitute a sensor output terminal. The first terminal of each of the magnetic sensor units excluding the first magnetic sensor unit is connected to the second terminal of the next magnetic sensor unit and the third terminal thereof is connected to the fourth terminal of the next magnetic sensor unit.

Current sensor

A current sensor includes a magnetoresistive element that has a stripe shape and that has a sensing axis in a certain direction. The magnetoresistive element includes element portions that are disposed so as to be spaced apart from each other in a longitudinal direction of the stripe shape, and permanent magnet portions, each of which is disposed between adjacent ones of the element portions. Each element portion has a layered structure including a free magnetic layer whose magnetization direction is changed with respect to an external magnetic field, a non-magnetic intermediate layer, and a ferromagnetic pinned layer whose magnetization direction is pinned. The permanent magnet portion includes a hard bias layer, and an electrode layer that is disposed so as to cover the hard bias layer.

A current sensor includes a substrate, a conductive body being provided above the substrate and extending in one direction, and magnetoresistance effect elements being provided between the substrate and the conductive body and outputting output signals owing to an induction magnetic field from a current to be measured being conducted through the conductive body, wherein each of the magnetoresistance effect elements has a laminated structure including a ferromagnetic fixed layer whose magnetization direction is fixed, a non-magnetic intermediate layer, and a free magnetic layer whose magnetization direction fluctuates with respect to an external magnetic field, the ferromagnetic fixed layer is a self-pinned type formed by antiferromagnetically coupling a first ferromagnetic film and a second ferromagnetic film through an antiparallel coupling film, the Curie temperatures of the first ferromagnetic film and the second ferromagnetic film are approximately equal, and a difference between the magnetization amounts thereof is substantially zero.

A magnetism sensor comprises a magnetoresistive element, the resistance of which changes due to the application of an induced magnetic field from the current being measured, and a fixed-resistance element. The fixed-resistance element has a self-pinned ferromagnetic fixed layer comprising a first ferromagnetic film and a second ferromagnetic film coupled antiferromagnetically with an antiparallel coupling film interposed therebetween. The antiparallel coupling film is a ruthenium film that exhibits an antiferromagnetic coupling effect with a first peak thickness. The difference between the degrees of magnetization of the first ferromagnetic film and the second ferromagnetic film is effectively zero.

Magnetic sensor and magnetic balance type current sensor utilizing same

A current sensor including a magnetic detecting bridge circuit which is constituted of four magneto-resistance effect elements with a resistance value varied by application of an induced magnetic field from a current to be measured, and which has an output between two magneto-resistance effect elements. The four magneto-resistance effect elements have the same resistance change rate, and include a self-pinned type ferromagnetic fixed layer which is formed by anti-ferromagnetically coupling a first ferromagnetic film and a second ferromagnetic film via an antiparallel coupling film therebetween, a nonmagnetic intermediate layer, and a soft magnetic free layer. Magnetization directions of the ferromagnetic fixed layers of the two magneto-resistance effect elements providing the output are different from each other by 180&#xb0;. The magnetic detecting bridge circuit has wiring symmetrical to a power supply point.

A magnetic balance type current sensor includes a magnetoresistance effect element whose resistance value changes owing to the application of an induction magnetic field from a current to be measured; a feedback coil disposed in the vicinity of the magnetoresistance effect element and generating a cancelling magnetic field cancelling out the induction magnetic field; a magnetic field detection bridge circuit including two outputs causing a voltage difference corresponding to the induction magnetic field to occur; and a magnetic shield attenuating the induction magnetic field and enhancing the cancelling magnetic field, wherein, on the basis of the current flowing through the feedback coil at the time of an equilibrium state in which the induction magnetic field and the cancelling magnetic field are cancelled out, the current to be measured is measured, wherein the feedback coil, the magnetic shield, and the magnetic field detection bridge circuit are formed on a same substrate.

Magnetic balance type current sensor

A magnetic-balance-system current sensor includes: a magnetoresistive element, a resistance value of the magnetoresistive element being changed by applying an induction magnetic field generated by a measurement target current; magnetic cores disposed near the magnetoresistive element; a feedback coil disposed near the magnetoresistive element and configured to generate a cancelling magnetic field that cancels out the induction magnetic field; and a magnetic-field detecting bridge circuit having two outputs. The measurement target current is measured on the basis of a current flowing through the feedback coil when the induction magnetic field and the induction magnetic field and the cancelling magnetic field cancel each other out. The feedback coil, the magnetic cores, and the magnetic-field detecting bridge circuit are formed on a same substrate. The feedback coil is of a spiral type, and the magnetic cores are provided above and below the feedback coil.

Magnetic-balance-system current sensor

A magnetic sensor includes a magnetoresistance effect element and a hard bias layer. The magnetoresistance effect element is configured to have a striped form which has a sensitivity axis in a predetermined direction, and configured to have a structure in which a free magnetic layer, in which magnetization varies with respect to an external magnetic field, a non-magnetic layer, and a fixed magnetic layer, in which the magnetization is fixed, are laminated. The hard bias layer is disposed in a longitudinal direction of the striped form, disposed outside of the magnetoresistance effect element to be separated from the magnetoresistance effect element.

Magnetic sensor and magnetic balance type current sensor including the same

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Niigata-ken, Japan

Yosuke Ide