US 12,222,373 B2
Magnetic sensor and current sensor
Yosuke Ide, Niigata-ken (JP)
Assigned to Alps Alpine Co., Ltd., Tokyo (JP)
Filed by Alps Alpine Co., Ltd., Tokyo (JP)
Filed on Jan. 23, 2023, as Appl. No. 18/158,266.
Application 18/158,266 is a continuation of application No. PCT/JP2021/026150, filed on Jul. 12, 2021.
Claims priority of application No. 2020-136314 (JP), filed on Aug. 12, 2020.
Prior Publication US 2023/0160928 A1, May 25, 2023
Int. Cl. G01R 15/20 (2006.01); G01R 19/00 (2006.01); G01R 33/09 (2006.01)
CPC G01R 15/205 (2013.01) [G01R 19/0092 (2013.01); G01R 33/093 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A magnetic sensor for measuring a strength of a magnetic field to be measured, the magnetic sensor comprising:
at least one magnetoresistive element disposed on an element formation plane, such that a sensitivity axis of the magnetoresistive element extends in a first direction along the element formation plane;
a magnetic shield disposed over the magnetoresistive element so as to be apart from the magnetoresistive element in a normal direction perpendicular to the element formation plane; and
a magnetic balance coil disposed between the magnetoresistive element and the magnetic shield in the normal direction, the strength of the magnetic field being measured based on a current flowing through the magnetic balance coil,
wherein the magnetic shield includes:
a first shield part extending in a second direction along the element formation plane, the second direction being perpendicular to the first direction and a longitudinal direction of the first shield part; and
a pair of second shield parts provided on respective sides of the first shield part in the longitudinal direction,
wherein the first shield part overlaps to cover the magnetoresistive element when viewed from the normal direction, while each of the pair of second shield parts overlaps to cover the magnetoresistive element when viewed from the second direction, thereby providing a magnetic path for a magnetic field in the second direction from one of the second shield parts to the other of the second shield parts via the first shield part,
wherein the magnetic balance coil includes a first coil and a second coil, each of the first coil and the second coil including:
a parallel portion extending parallel to the second direction; and
a crossing portion extending from the parallel portion in a direction crossing the second direction, when viewed from the normal direction,
wherein the first coil and the second coil are disposed adjacent to each other, symmetrically with respect to a line extending in the second direction and passing through the magnetoresistive element, when viewed from the normal direction, thereby forming an adjacent portion including the parallel portion of the first coil and the parallel portion of the second coil adjacent to each other,
and wherein the first shield part overlaps the adjacent portion and covers the magnetoresistive element, but does not overlap the crossing portion, while each of the second shield parts is disposed between the crossing portion of the first coil and the crossing portion of the second coil, when viewed from the normal direction.