公开(公告)号：US11609284B2

公开(公告)日：2023-03-21

申请号：US15069084

申请日：2016-03-14

Applicant: TDK CORPORATION

Inventor： Kei Tanabe

IPC: G01R33/00 ,  G01R33/09

Abstract: The present invention relates to a magnetic sensor which can improve the detection precision of a weak magnetic field and can be downsized. A magnetic sensor is provided with a magnetic body changing the direction of a magnetic field input to a magnetoresistance effect element in the vicinity of the magnetoresistance effect element in which the resistance value changes according to the direction of the input magnetic field, the magnetic body has a mean for changing the direction of a magnetic field on the surface at a side where the magnetoresistance effect element is formed. The chamfer part of the magnetic body may be chamfered with a shape having at least one flat surface.

公开(公告)号：US11269024B2

公开(公告)日：2022-03-08

申请号：US16613671

申请日：2018-05-14

Applicant: TDK Corporation

Inventor： Kei Tanabe

IPC: G01R33/09 ,  H05K1/18 ,  H01F7/20

Abstract: To provide a magnetic sensor capable of supporting a magnetic block stably and allowing a further size reduction of the sensor chip. A magnetic sensor includes a sensor chip and a magnetic block which are mounted on a circuit board. The sensor chip is mounted on the circuit board such that a mounted surface thereof faces a mounting surface, and the magnetic block is mounted on the circuit board such that first and second surfaces and face an element formation surface and the mounting surface, respectively. The magnetic block has a cutout portion, and some of terminal electrodes E11 to E16 are disposed within a space formed by the cutout portion. According to the present invention, the magnetic block can be supported stably. In addition, the presence of the cutout portion in the magnetic block allows a further size reduction of the sensor chip.

公开(公告)号：US11073576B2

公开(公告)日：2021-07-27

申请号：US15770195

申请日：2016-10-20

Applicant: TDK CORPORATION

Inventor： Kei Tanabe

IPC: G01R33/09 ,  G01R33/025 ,  G01R33/00 ,  A61B5/05

Abstract: An object of the present invention is to selectively detect a detection magnetic field without separately providing a sensor for detecting an environmental magnetic field. A magnetic field detection device includes a magnetic field detection unit 10 that generates an output signal S1 according to a magnetic field, a first signal generation unit 20 that extracts a predetermined frequency component from the output signal S1 and generates a cancel signal S2 based on the predetermined frequency component, a first magnetic field generation unit 40 that applies a first cancel magnetic field to the magnetic field detection unit 10 based on the cancel signal S2, and a second signal generation unit 30 that generates a detection signal S3 based on the output signal S1 of the magnetic field detection unit 10 to which the first cancel magnetic field is applied. According to the present invention, a cancel signal is generated based on a frequency component of an output signal, and a first cancel magnetic field is applied to a magnetic field detection unit using the cancel signal. Therefore, it is not necessary to separately provide a sensor for detecting an environmental magnetic field. Because this configuration reduces the number of parts, downsizing and cost reduction can be realized.

公开(公告)号：US11022660B2

公开(公告)日：2021-06-01

申请号：US16085706

申请日：2016-10-20

Applicant: TDK CORPORATION

Inventor： Kei Tanabe

IPC: G01R33/09 ,  H01L43/08 ,  G01R33/12 ,  H01L43/10 ,  G11B5/39

Abstract: The size and cost of a magnetic sensor suitable for closed loop control is reduced. A magnetic sensor includes a magnetoresistive effect element that is electrically connected between terminals and extends in the x-direction and a magnetic member that is electrically connected between the terminals and extends in the x-direction along the magnetoresistive effect element. The magnetoresistive effect element is disposed offset with respect to the center position of the magnetic member in the y-direction. Magnetic flux to be detected is collected by a magnetic member and current is made to flow in the magnetic member in accordance with the resistance value of the magnetoresistive effect element, achieving closed loop control. The magnetic member functions both as a magnetism collection function and as a cancel coil, which reduces the number of elements required, and which also achieves a reduction in size and cost.

公开(公告)号：US11022659B2

公开(公告)日：2021-06-01

申请号：US15776234

申请日：2016-10-20

Applicant: TDK CORPORATION

Inventor： Yuki Asazuma ,  Kei Tanabe ,  Akihiro Unno ,  Atsushi Matsuda ,  Masashi Takahashi

IPC: G01R33/09 ,  H01L43/08 ,  G01R33/00 ,  G01R33/025

Abstract: An object of the present invention is to provide a magnetic sensor that can reduce influences of a disturbance magnetic field while ensuring high detection sensitivity. The magnetic sensor includes a sensor chip 20 having an element formation surface 20S on which magnetic detection elements MR3, MR4 are formed, a first magnetic member 31 placed on the element formation surface 20S and having a first height H1 as a height from the element formation surface 20S, and a second magnetic member 32 located on an opposite side of the magnetic detection elements MR3, MR4 to the first magnetic member 31 and having a second height H2 lower than the first height H1. According to the present invention, because the height H2 of the second magnetic member 32 is lower than that of the first magnetic member 31, a detection magnetic field attracted to the second magnetic member 32 can be reduced while a disturbance magnetic field is shielded by the second magnetic member 32. Accordingly, influences of the disturbance magnetic field can be reduced while high detection sensitivity is ensured.

公开(公告)号：US10859642B2

公开(公告)日：2020-12-08

申请号：US16078565

申请日：2016-10-20

Applicant: TDK CORPORATION

Inventor： Kei Tanabe

IPC: G01R33/09 ,  G01R33/02 ,  H01L43/08

Abstract: An object of the present invention is to provide a magnetic sensor having enhanced magnetic detection sensitivity by bending magnetic flux more largely. A magnetic sensor includes magnetic detection elements MR1 and MR2 positioned on a plane P separating a first space S1 and a second space S2, a first magnetic member 31 disposed in the first space S1 so as to be between the magnetic detection elements MR1 and MR2 when viewed in the z-direction, and a second magnetic member 32 disposed in the second space S2. The magnetic detection element MR1 is positioned between the first magnetic member 31 and a first part 32a of the second magnetic member 32 when viewed in the z-direction. The magnetic detection element MR2 is positioned between the first magnetic member 31 and a second part 32b of the second magnetic member 32 when viewed in the z-direction. According to the present invention, magnetic flux collected by the first magnetic member is attracted to the first and second parts of the second magnetic member, allowing the magnetic flux to be bent more largely. Thus, the magnetic detection sensitivity of the magnetic sensor can be enhanced.