Magnetic sensor and magnetic balance type current sensor including the same
View Patent ↗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.
1. A magnetic sensor, comprising:
a magnetoresistance effect element formed in a striped form and having a sensitivity axis in a predetermined direction, the magnetoresistance effect element having a laminated structure including:
a free magnetic layer whose magnetization varies with respect to an external magnetic field applied thereto;
a non-magnetic layer; and
a fixed magnetic layer whose magnetization is fixed; and
a hard bias layer disposed outside of the magnetoresistance effect element in a longitudinal direction of the striped form,
wherein the hard bias layer is separated from the magnetoresistance effect element by a distance in the longitudinal direction without overlapping therewith.
2. The magnetic sensor according to claim 1 ,
wherein a length of the longitudinal direction of the magnetoresistance effect element is in a range of 60 μm to 380 μm.
3. The magnetic sensor according to claim 1 ,
wherein a length of a width direction of the magnetoresistance effect element is in a range of 2 μm to 9 μm.
4. The magnetic sensor according to claim 1 ,
wherein the distance between the hard bias layer and the magnetoresistance effect element is equal to or less than 3 μm.
5. The magnetic sensor according to claim 1 ,
wherein a thickness of the hard bias layer is equal to or larger than 40 nm.
6. The magnetic sensor according to claim 1 ,
wherein the magnetoresistance effect element is a spin valve type Giant Magneto Resistance (GMR) element or a spin valve type Tunnel Magneto Resistance (TMR) element.
7. A magnetic balance type current sensor comprising:
a magnetic sensor according to claim 1 of which characteristics vary due to an induction magnetic field from measured current; and
a feedback coil which is disposed adjacent to the magnetic sensor, and configured to generate a canceling magnetic field which offsets the induction magnetic field.