WO2014148437A1 - 磁気センサ - Google Patents
磁気センサ Download PDFInfo
- Publication number
- WO2014148437A1 WO2014148437A1 PCT/JP2014/057152 JP2014057152W WO2014148437A1 WO 2014148437 A1 WO2014148437 A1 WO 2014148437A1 JP 2014057152 W JP2014057152 W JP 2014057152W WO 2014148437 A1 WO2014148437 A1 WO 2014148437A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- current line
- current
- magnetic sensor
- magnetoresistive effect
- effect element
- Prior art date
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/0023—Electronic aspects, e.g. circuits for stimulation, evaluation, control; Treating the measured signals; calibration
- G01R33/0041—Electronic aspects, e.g. circuits for stimulation, evaluation, control; Treating the measured signals; calibration using feed-back or modulation techniques
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
- G01R33/06—Measuring direction or magnitude of magnetic fields or magnetic flux using galvano-magnetic devices
- G01R33/09—Magnetoresistive devices
- G01R33/093—Magnetoresistive devices using multilayer structures, e.g. giant magnetoresistance sensors
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10B—ELECTRONIC MEMORY DEVICES
- H10B61/00—Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N50/00—Galvanomagnetic devices
- H10N50/10—Magnetoresistive devices
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N59/00—Integrated devices, or assemblies of multiple devices, comprising at least one galvanomagnetic or Hall-effect element covered by groups H10N50/00 - H10N52/00
Definitions
- the present invention relates to a magnetic sensor and a magnetic sensor using a magnetoresistive effect element.
- a magnetic core C-shaped magnetic core having a ring shape so as to surround a conductor such as a current line and having a gap in a part of the ring shape is disposed in the gap portion.
- a magnetic sensor having a magnetic detection element such as a Hall element and a winding (coil) wound around a magnetic core is known.
- a magnetic detection element arranged in a gap detects a magnetic field induced in a magnetic core by a current flowing through a conductor, and a feedback current is supplied to the winding so that the magnetic field in the magnetic core becomes zero.
- the value is converted into a voltage by a detection resistor, and the magnitude of the current flowing through the conductor is obtained from this voltage value.
- the magnetic sensor having the above-described magnetic core is formed so that the magnetic core surrounds the conductor, an induced magnetic field generated in the magnetic core becomes large. Therefore, there is a problem that the amount of current flowing as the feedback current increases, and as a result, power consumption increases. For this reason, for example, in a device in which current is supplied by a battery, various problems such as shortening of a usable time by one charge have occurred.
- a planar coil including a linear portion in which a plurality of linearly extending current lines are arranged in parallel and a direction extending in the same direction as a direction in which the current lines of the linear portion extend.
- a feedback current is passed through the current line (planar coil), and the magnitude of the detection target current is obtained from the magnitude of the feedback current.
- the magnetic sensor having such a configuration has an advantage that power consumption can be reduced as compared with the above-described magnetic sensor in which a magnetic core is formed so as to surround a conductor to be measured.
- the present invention aims to provide a magnetic sensor that operates with less power consumption, especially with less feedback current. To do.
- the present inventors do not use a method of driving one magnetoresistive effect element by an induced magnetic field generated by one current line closest to the magnetoresistive effect element, but in series with respect to one magnetoresistive effect element.
- the present inventors have found a system that can be practically driven by an induced magnetic field generated by a plurality of current lines connected to the, and arrived at the present invention.
- Aspect 1 of the present invention includes a first current line, a second current line, and a third current line that are arranged in parallel to each other in the width direction and are electrically connected in series, and the second current Induction caused by currents disposed in the lower part of the line, extending along the direction in which the second current line extends, and flowing through the first current line, the second current line and the third current line
- a magnetoresistive effect element whose electrical resistance changes according to a magnetic field, and a length L s from the outside of the first current line to the outside of the third current line in the width direction and the magnetoresistive effect element the width direction length W g of a magnetic sensor, characterized by the following formula (1) is satisfied.
- L s / W g ⁇ 5 (1)
- Embodiment 2 of the present invention is characterized in that the second and the length W g of the width direction of the current line length W p the width direction of the magnetoresistive element satisfies the following expression (2)
- the magnetic sensor according to aspect 1. W p ⁇ W g (2)
- Aspect 3 of the present invention is the magnetic sensor according to aspect 1 or 2, wherein a plurality of the magnetoresistive effect elements are arranged.
- Aspect 4 of the present invention is characterized in that the first current line, the second current line, and the third current line are part of a planar coil. It is a sensor.
- a yoke layer covering the first current line, the second current line, and the third current line is formed of the first current line, the second current line, and the third current line. 5.
- Aspect 6 of the present invention is characterized in that the first current line, the second current line, and the third current line are each formed in two or more layers in the vertical direction.
- the magnetic sensor according to any one of the above.
- Aspect 7 of the present invention is a plurality of bias magnetic field applying current lines extending in a direction perpendicular to a direction in which the second current line extends, wherein the magnetoresistance is generated by an induced magnetic field generated by a flowing current. 7.
- Aspect 8 of the present invention is characterized in that the plurality of bias magnetic field applying current lines are arranged above the first current line, the second current line, and the third current line. It is a magnetic sensor as described in above.
- a ninth aspect of the present invention is the magnetic sensor according to the seventh aspect, wherein the plurality of bias magnetic field applying current lines are arranged between the second current line and the magnetoresistive element. is there.
- Aspect 10 of the present invention is characterized in that the plurality of bias magnetic field applying current lines are arranged below the first current line, the second current line, and the third current line. It is a magnetic sensor as described in above.
- Aspect 11 of the present invention is the magnetic sensor according to any one of aspects 1 to 10, wherein the magnetoresistive element is a spin valve giant magnetoresistive element.
- a fourth current line extending in parallel with the first current line and disposed outside the first current line, and in parallel with the third current line
- a fifth current line extending outside the third current line and a lower part of the fourth current line, comprising a soft magnetic material; 5, a first yoke layer not electrically connected to the magnetoresistive effect element, and a lower portion of the fifth current line, comprising a soft magnetic material, the first to second
- the magnetic sensor according to any one of aspects 1 to 11, further comprising: 5 current lines; and a second yoke layer not electrically connected to the magnetoresistive effect element.
- Aspect 13 of the present invention is characterized in that two or more magnetoresistive elements are arranged, and the two or more magnetoresistive elements are electrically connected to form a bridge circuit.
- the magnetic sensor according to any one of 1 to 12.
- Aspect 14 of the present invention is the magnetic sensor according to aspect 13, wherein the bridge circuit is a half-bridge circuit.
- Aspect 15 of the present invention is characterized in that four or more magnetoresistive elements are arranged, and the bridge circuit is a full bridge circuit using the four or more magnetoresistive elements.
- the magnetic sensor according to the present invention has an appropriate arrangement of a current line through which a feedback current flows and a magnetoresistive element whose electrical resistance changes due to an induced magnetic field (feedback magnetic field) generated by the current flowing through the current line. .
- a magnetic sensor that operates with low power consumption can be provided.
- FIG. 1 is a diagram showing one current line 20 and a magnetoresistive effect element 10 for flowing a feedback current.
- 1A is a perspective view
- FIG. 1B is a cross-sectional view
- FIG. 1C is a plan view.
- FIG. 2 is a plan view showing a planar coil 70 including the current line 20 shown in FIG.
- FIG. 3A is a top view of the magnetic sensor 100 according to Embodiment 1 of the present invention
- FIG. 3B is a cross-sectional view showing a 1b-1b cross section of FIG. 3A.
- FIG. 4 is a cross-sectional view illustrating the relationship between the length L s and the length W g of the magnetoresistive effect element 10.
- FIG. 5 is a top view illustrating a form in which a plurality of magnetoresistive elements 10 are arranged.
- FIG. 6 is a diagram showing a model used for examining the influence of the number of current lines.
- FIG. 7 is a graph showing simulation results.
- FIG. 8 is a diagram showing a model used for examining the influence of the number of magnetoresistive elements.
- FIG. 9 is a graph showing simulation results.
- FIG. 10 is a graph showing a simulation result.
- FIG. 11 is a graph showing a simulation result different from FIG. 12 shows a magnetic sensor 120 which is a modification of the first embodiment described above,
- FIG. 12A is a top view of the magnetic sensor 120, and
- FIG. 12B is a plan view shown in FIG. FIG.
- FIG. 12C is an enlarged top view of the straight portion B of the coil 70
- FIG. 12C is a cross-sectional view showing a 2c-2c cross section of FIG. 13 shows a magnetic sensor 130 according to Embodiment 2 of the present invention
- FIG. 13 (a) is a top view of the magnetic sensor 130
- FIG. 13 (b) is a planar coil 70 shown in FIG. 13 (a).
- FIG. 13C is a cross-sectional view showing a 3c-3c cross section of FIG. 13B.
- FIG. 14 is a graph showing a simulation result.
- 15 shows a magnetic sensor 140 according to Embodiment 3 of the present invention
- FIG. 15 (a) is a top view of the magnetic sensor 140
- FIG. 15 (a) is a top view of the magnetic sensor 140
- FIG. 15 (b) is a planar coil 70 shown in FIG. 15 (a).
- FIG. 15C is a cross-sectional view showing a 4c-4c cross section of FIG. 15B.
- FIG. 16 is a graph showing a simulation result.
- 17 shows a magnetic sensor 150 according to Embodiment 4 of the present invention
- FIG. 17 (a) is a top view of the magnetic sensor 150
- FIG. 17 (b) is a planar coil 70 shown in FIG. 17 (a).
- FIG. 17C is a cross-sectional view showing a 5c-5c cross section of FIG. 17B.
- 18 shows a magnetic sensor 160 according to a modification of the fourth embodiment
- FIG. 18 (a) is a top view of the magnetic sensor 160
- FIG. 18 (b) is a planar coil 70 shown in FIG. 18 (a).
- FIG. 18C is a cross-sectional view showing a 6c-6c cross section of FIG. 18B.
- 19 shows a magnetic sensor 170 according to Embodiment 5 of the present invention, FIG. 19 (a) is a top view of the magnetic sensor 170, and FIG. 19 (b) is a planar coil 70 shown in FIG. 19 (a).
- FIG. 19 (c) is a cross-sectional view showing a 7c-7c cross section of FIG. 19 (b).
- 20 shows a magnetic sensor 180 according to Embodiment 6 of the present invention, FIG. 20 (a) is a top view of the magnetic sensor 180, and FIG. 20 (b) is a planar coil 70 shown in FIG.
- FIG. 20C is a cross-sectional view showing an 8c-8c cross section of FIG. 20B.
- FIG. 21 shows a magnetic sensor 190 according to a modification of the sixth embodiment, FIG. 21 (a) is a top view of the magnetic sensor 190, and FIG. 21 (b) is a planar coil 70 shown in FIG. 21 (a).
- FIG. 21 (c) is a cross-sectional view showing a 9c-9c cross section of FIG. 21 (b).
- 22 shows a magnetic sensor 200 according to Embodiment 7 of the present invention, FIG. 22 (a) is a top view of the magnetic sensor 200, and FIG. 22 (b) is a planar coil 70 shown in FIG. 22 (a).
- FIG. 22 shows a magnetic sensor 200 according to Embodiment 7 of the present invention, FIG. 22 (a) is a top view of the magnetic sensor 200, and FIG. 22 (b) is a planar coil 70 shown in FIG. 22 (a).
- FIG. 22 shows a magnetic sensor 200 according
- FIG. 22 (c) is a cross-sectional view showing a 10c-10c cross section of FIG. 22 (b).
- FIG. 23 shows a magnetic sensor 210 according to a modification of the seventh embodiment, FIG. 23 (a) is a top view of the magnetic sensor 210, and FIG. 23 (b) is a planar coil 70 shown in FIG. 23 (a).
- FIG. 23C is a cross-sectional view showing a cross section 11c-11c of FIG. 23B.
- 24 shows a magnetic sensor 220 according to Embodiment 8 of the present invention, FIG. 24 (a) is a top view of the magnetic sensor 220, and FIG. 24 (b) is a planar coil 70 shown in FIG. 24 (a).
- FIG. 24 shows a magnetic sensor 220 according to Embodiment 8 of the present invention, FIG. 24 (a) is a top view of the magnetic sensor 220, and FIG. 24 (b) is a planar coil 70 shown in FIG. 24 (a).
- FIG. 24 shows
- FIG. 24C is a cross-sectional view showing a cross section 12c-12c of FIG. 24B.
- 25 shows a magnetic sensor 230 according to a modification of the eighth embodiment
- FIG. 25 (a) is a top view of the magnetic sensor 230
- FIG. 25 (b) is a planar coil 70 shown in FIG. 25 (a).
- FIG. 25C is a cross-sectional view showing a 13c-13c cross-section of FIG. 25B.
- FIG. 26 is a plan view showing a magnetic sensor 240 according to Embodiment 9 of the present invention.
- FIG. 27 is a schematic circuit diagram showing an example of a magnetic sensor circuit (feedback circuit).
- FIG. 28 is a schematic circuit diagram showing an example in which a full bridge circuit is configured using four magnetoresistive elements 10.
- FIG. 29 is a cross-sectional view showing a cross section of Example Sample 1.
- FIG. 28 is a schematic circuit diagram showing an example in which a full bridge circuit is configured using four magnetoresistive
- FIG. 1 is a diagram showing one current line 20 and a magnetoresistive effect element 10 for flowing a feedback current.
- 1A is a perspective view
- FIG. 1B is a cross-sectional view
- FIG. 1C is a plan view.
- FIG. 2 is a plan view showing a planar coil 70 including the current line 20 shown in FIG.
- FIG. 1 (hereinafter referred to as “FIG. 1”) collectively refers to a plurality of figures having the same number as shown in FIG. 1A to FIG.
- the magnetoresistive effect element 10 is disposed below the current line 20 via the insulating layer 12 disposed as necessary.
- the magnetoresistive element 10 extends in parallel to the direction in which the current line 20 extends (that is, the magnetoresistive element 10 extends in the direction in which the current line 20 extends).
- the magnetoresistive effect element 10 is an element whose electric resistance changes according to the direction and strength of a magnetic field (external magnetic field) applied from the outside, preferably a GMR element (giant magnetoresistive effect element), more preferably.
- the current line 20 is a linearly extending conductor, and is, for example, the long side direction (Y direction) in the rectangular appearance of the planar coil 70 shown in FIG. 2 (viewed from the ⁇ Z direction in FIG. 2). ) And extending in parallel with each other, and one of the conductors of the portion where the plurality of conductors are arranged (straight line portion B shown in FIG. 2).
- the magnetoresistive effect element 10 and the current line 20 are connected to a feedback circuit (magnetic sensor circuit) not shown in FIGS.
- a feedback circuit magnetic sensor circuit
- FIG. 1A when an external magnetic field 32 that is a part of an induced magnetic field generated by a conductor to be measured is applied to the magnetoresistive effect element 10, the electrical resistance of the magnetoresistive effect element 10 changes.
- the feedback current is fed from the feedback circuit to the current line 20 so as to form a feedback magnetic field 30 that cancels the external magnetic field 32 (ie, has the same magnitude as the external magnetic field 32 and in the opposite direction). 34 is supplied.
- the magnitude of the feedback current 34 (or the magnitude of the voltage for flowing the current 34)
- the magnitude of the external magnetic field 32 can be obtained.
- the magnitude of the current flowing through the detection target conductor can be obtained from the magnitude of the external magnetic field 32.
- the term “external magnetic field” means an induced magnetic field caused by a current flowing through a detection target (current to be measured).
- the feedback current 34 occupies a considerable portion of the power consumption of the entire sensor. Reducing the feedback current leads to a reduction in power consumption of the entire sensor.
- the inventors of the present application have arranged three current lines arranged in parallel with each other in the width direction and electrically connected in series (in order, the first current line and the second current).
- the length L s (that is, L s in the width direction is the first length from the outside of the first current line to the outside of the third current line in the width direction).
- the length of the current line, the distance (gap) between the first current line and the second current line, the length of the second current line, and the distance between the second current line and the third current line And the length W g of the magnetoresistive element in the width direction satisfy the following expression (1).
- the feed formed by the first current line is arranged by arranging the first to third current lines and the magnetoresistive effect element.
- the present inventors have found that a magnetic field and a feedback magnetic field formed by a third current line can be effectively applied to the magnetoresistive element, and that a desired feedback magnetic field can be applied to the magnetoresistive element with a small current. is there. L s / W g ⁇ 5 (1) Details of the present invention will be described below.
- FIG. 3A is a top view of the magnetic sensor 100 according to Embodiment 1 of the present invention
- FIG. 3B is a cross-sectional view showing a 1b-1b cross section of FIG. It is.
- the magnetic sensor 100 has a plurality of current lines 20 extending in the same direction and electrically connected in series.
- the current line 20 is a current line that constitutes the straight portion B of the planar coil 70 shown in FIG. This is because a feedback current can be passed through all the current lines 20 by applying a voltage to both ends of the planar coil.
- the magnetic sensor 100 has one or a plurality of magnetoresistive elements 10.
- the number of magnetoresistive elements 10 should be larger.
- a differential output can be obtained only with a sensor chip including a magnetoresistive effect element without an external resistor or the like, and therefore at least two magnetoresistive effect elements 10 are arranged. It is preferable. If there are the magnetoresistive effect element 10 on both sides parallel to the extending direction of the two magnetoresistive effect elements, the magnetic flux density of the magnetoresistive effect element is amplified. Therefore, four or more magnetoresistive effect elements 10 are arranged. More preferably. In the embodiment shown in FIG.
- the magnetic sensor 100 has five magnetoresistive elements 10. The positional relationship between the magnetoresistive effect element 10 and the current line 20 will be described below with reference to FIG. In FIG. 3, in order to individually identify the magnetoresistive effect elements, any one of the reference numerals “10a” to “10e” is assigned to each of the magnetoresistive effect elements 10.
- a current line (first current line) 20a, a current line (second current line) 20b, and a current line (third current) are sequentially arranged along the width direction (X direction).
- Line) 20c,... are arranged in parallel to the current line 20k.
- each of the current lines 20a to 20k has a width direction (X direction) length Wp , and the adjacent current lines 20 are distances (current lines).
- the gap between the two members 20) is separated by d2.
- the magnetoresistive effect element 10a extends below the current line (second current line) 20b (below (or directly below) in the height direction of the current line (Z direction in FIG. 3)).
- the current line 20 (20b) and the magnetoresistive effect element 10 (10a) are arranged so as to be parallel to the current direction.
- the current line 20 (20b) and the magnetoresistive effect element 10 (10a) may be disposed between the two.
- the magnetoresistive element 10a has a length in the width direction (X direction) of W g (in the embodiment of FIG. 3, the other magnetoresistive elements 10b to 10e have a length in the width direction of W g ).
- the length L s shown in FIG. 3B is the third current from the outside of the first current line 20a in the width direction (the left end of the first current line 20a in FIG. 3B). This is the length to the outside of the line (in FIG. 3B, the right end of the third current line 20c).
- the length L s is the length of the first current line 20a in the width direction, the distance (gap) between the first current line 20a and the second current line 20b, and the second The total of the length of the current line 20b, the distance (gap) between the second current line 20b and the third current line 20c, and the length of the third current line 20c.
- L s is 3W p + 2d 2 .
- the magnetic sensor 100 is configured such that the length L s and the length W g satisfy the expression (1).
- L s / W g ⁇ 5 (1) Satisfying the expression (1) is that the magnetoresistive effect element 10a has a sufficient length in the width direction with respect to the length in the width direction of the current line 20 (current lines 20a to 20c). It means that in addition to the feedback magnetic field by the current line 20b positioned immediately above the element 10a, the feedback magnetic field by the current line 20a and the current line 20c located on both sides of the current line 20b is also efficiently applied.
- the magnetic sensor 100 allows a current to flow through one current line. This means that a stronger feedback magnetic field can be applied to the magnetoresistive effect element 10 with a smaller amount of current.
- the length L s and the length W g satisfy the formula (1A). This is because a strong feedback magnetic field can be more reliably applied to the magnetoresistive effect element 10 with a small current.
- L s / W g ⁇ 3 (1A) The effect obtained by satisfying the expressions (1) and (1A) is also clarified in the simulation results described later.
- the center of the length L s coincides with the center of the length W g of the magnetoresistive effect element 10 (the center in the width direction of the magnetoresistive effect element 10). This is because the magnetoresistive effect element 10 can efficiently receive the feedback magnetic field from the first current line 20a and the third current line 20c located on both sides of the second current line 20b.
- the length W g in the width direction of the magnetoresistive element 10 and the length W p in the width direction of the current line 20 satisfy the following expression (2).
- the expression (2) means that the length in the width direction of the magnetoresistive effect element 10 is longer than the length in the width direction of the current line 20 (in particular, the current line 20b).
- satisfying the expression (2) means that the end portion in the width direction of the magnetoresistive effect element 10 is close to the first current line 20a or the third current line 20c. Thereby, the feedback magnetic field by the current line 20a and the current line 20c can be reliably applied to the magnetoresistive effect element 10.
- FIG. 4 is a cross-sectional view illustrating the relationship between the length L s and the length W g of the magnetoresistive effect element 10.
- 4A shows the case of W g ⁇ W p + 2d 2
- FIG. 4B shows the case of W g ⁇ W p + 2d 2
- FIG. 4D shows a case where W g > L s .
- FIG. 4A is the same as the embodiment of FIG.
- the end of the magnetoresistive effect element 10a (both ends) is the outer end of the first current line 20a (the left end in FIG. 4C).
- the outer end of the third current line 20c (the right end in FIG. 4C).
- the end (both ends) of the magnetoresistive effect element 10a is the outer end of the first current line 20a (the left end in FIG. 4D).
- the outer end portion of the third current line 20c (the right end portion in FIG. 4D).
- the extending direction of the magnetoresistive effect element (second magnetoresistive effect element) 10b extends below the current line 20d via the insulating layer 12b, and the extending direction is parallel to the extending direction of the current line 20d. It is arranged to be.
- the first current line is the current line 20c
- the second current line is the current line 20d
- the third current line is the current line 20e, which satisfies the expression (1).
- a magnetoresistive effect element (third magnetoresistive effect element) 10c is arranged below the current line 20f via the insulating layer 12c so that its extending direction is parallel to the extending direction of the current line 20f. Yes.
- the first current line is the current line 20e
- the second current line is the current line 20f
- the third current line is the current line 20g, which satisfies the expression (1).
- the magnetoresistive effect element (fourth magnetoresistive effect element) 10d is arranged below the current line 20h via the insulating layer 12d so that its extending direction is parallel to the extending direction of the current line 20h. ing.
- the first current line is the current line 20g
- the second current line is the current line 20h
- the third current line is the current line 20i, which satisfies the expression (1).
- the magnetoresistive effect element (fifth magnetoresistive effect element) 10e is arranged below the current line 20j via the insulating layer 12e so that its extending direction is parallel to the extending direction of the current line 20j.
- the first current line is the current line 20i
- the second current line is the current line 20j
- the third current line is the current line 20k, which satisfies the expression (1).
- the current line 20c is a third current line in the case where the current line 20b in which the magnetoresistive effect element 10a is arranged is the second current line, and a magnetic line is formed below the current line 20c.
- This is also the first current line when the current line 20d on which the resistance effect element 10b is disposed is the second current line (the same applies to the current lines 20e, 20g, and 20i). In this way, one current line may serve as two of the first to third current lines.
- the current line may function as any one of the first to third current lines by arranging two or more current lines in which no magnetoresistive effect element is disposed.
- FIG. 5 is a top view illustrating a form in which a plurality of magnetoresistive elements 10 are arranged.
- FIG. 5A shows the same form as FIG. 3, and the magnetoresistive effect element 10 is arranged below every other current line 20a to 20d arranged in order.
- FIG. 5B the magnetoresistive effect element 10 is arranged on both the adjacent current line 20b and current line 20c.
- the current line 20b is the second current line for the magnetoresistive effect element 10a
- the current line 20c is the third current line
- the current line 20c is the second current line for the magnetoresistive effect element 10b.
- the current line 20b is the first current line.
- a plurality of magnetoresistive elements 10 are arranged below one current line. Any form shown in FIG. 5 can satisfy the expression (1).
- Current lines 20 shown in FIG. 3 (current lines 20a ⁇ 20k), as described above, have the same width W p, are arranged at equal intervals d 1. This form is preferable because the formed feedback magnetic field can be made uniform. However, it is not limited to this. As long as the expression (1) is satisfied, at least one of the lengths in the width direction of the first current line, the second current line, and the third current line may be different from the others. Further, the distance between the first current line and the second current line in the width direction may be different from the distance between the second current line and the third current line.
- the center in the width direction (X direction) of the current line 20b coincides with the center in the width direction (X direction) of the magnetoresistive effect terminal 10a (that is, the alternate long and short dash lines 36 and 38 passing through the current line 20b are also the center line in the width direction of the magnetoresistive effect element 10a). Is preferred. This is because the feedback magnetic field generated by the current line 20 is more uniformly applied to the magnetoresistive effect element 10a.
- the centers in the width direction of the current line 20d, current line 20f, current line 20h, and current line 20j are the magnetoresistive effect element 10b, magnetoresistive effect element 10c, magnetoresistive effect element 10d, and magnetoresistive effect element 10e, respectively. It coincides with the center in the width direction.
- FIG. 6 is a diagram showing a model used for examining the influence of the number of current lines.
- one current line 20 and an insulating layer 12 are provided below. 6B.
- the magnetoresistive element 10 is provided below the magnetoresistive effect element 10.
- One current line 20 not having a magnetoresistive effect element disposed under each of the arranged current lines 20 is disposed one by one.
- the model of FIG. 6C the model of FIG.
- two current lines 20 each having no magnetoresistive effect element are disposed below each of the current lines 20 in which the magnetoresistive effect element 10 is disposed below. . That is, in the model of FIG. 6A, a total of one current line 20 is arranged, in the model of FIG. 6B, a total of three current lines 20 are arranged, and in the model of FIG. 6C, a total of five current lines 20 are arranged. Has been.
- the current line 20 is a conductor made of copper having a width (X direction length) of 4 ⁇ m and a thickness (length in the Z direction) of 0.8 ⁇ m, and the current line 20 has a current of 10 mA. It was decided to shed.
- the distance (gap) between adjacent current lines 20 was 4 ⁇ m.
- the insulating layer 12 was 1 ⁇ m thick.
- the magnetoresistive effect element 10 is assumed to be an SVGMR element.
- the SVGMR element has a fixed layer composed of one or a plurality of layers including, for example, a CoFe layer in which the spin direction is fixed, and a free layer composed of, for example, a NiFe layer that easily changes the spin direction by an external magnetic field.
- the magnetoresistive effect element 10 was simulated as a single layer film of NiFe having a saturation magnetic flux density Bs of 1.4T, a length of 100 ⁇ m, a width of 10 ⁇ m, and a thickness of 20 nm. Using these models and parameters, simulation was performed using magnetic field analysis software J-MAG manufactured by JSOL Corporation.
- FIG. 7 is a graph showing simulation results. 7 indicates the position in the width direction of the magnetoresistive effect element 10, and 0 ⁇ m is the center in the width direction of the magnetoresistive effect element 10. The distance is shown as positive in the X direction and negative in the -X direction. As can be seen from FIG. 7, the magnetic flux density in the magnetoresistive effect element 10 is remarkably increased when the number of the current lines 20 is three compared to the case where the number of the current lines 20 is one. On the other hand, in the case where there are three and five current lines 20, the magnetic flux density in the magnetoresistive effect element 10 is larger in the case of five, but the difference is smaller.
- FIG. 8 is a diagram showing a model used for examining the influence of the number of magnetoresistive elements, and each model has the same 11 current lines 20 as FIG. 3, but FIG. In the model), only one magnetoresistive element 10 is arranged under the middle (sixth from the top in the figure) current line 20 via an insulating layer 12 (not shown). In the model of b), a total of three magnetoresistive effect elements 10 are arranged via the insulating layer 12 below the fourth, sixth and eighth current lines 20 from the top in FIG. 3) has the same configuration as the magnetic sensor 100 shown in FIG. 3, and therefore, a total of five magnetoresistive elements 10 are arranged. Using such a model, a simulation was performed under the same conditions as described above for [Influence of Number of Current Lines].
- FIG. 9 shows the simulation result.
- the horizontal axis “position in the X direction” of the graph of FIG. 9 indicates the magnetoresistive effect element 10 in the middle of the width direction in each model (the magnetoresistive effect element 10 shown only in FIG. 8A, FIG. 8B). ) Of the three magnetoresistive effect elements 10 shown in the drawing, the second magnetoresistive effect element 10 from the top of the drawing, and among the five magnetoresistive effect elements 10 shown in FIG.
- the position in the width direction in the third magnetoresistive effect element 10) from the top of the paper is shown, where 0 ⁇ m is the center in the width direction of the magnetoresistive effect element 10, and the distance from the center in the width direction is expressed as X The direction is positive and the -X direction is negative.
- the magnetic flux density in the magnetoresistive effect element 10 is remarkably increased by arranging a plurality of magnetoresistive effect elements 10.
- the number of the magnetoresistive effect elements 10 is 3 and 5 no significant difference is observed in the magnitude of the magnetic flux density in the magnetoresistive effect element 10.
- a simulation was performed using a configuration including the magnetoresistive effect element 10a disposed below the current line 20b via 12a.
- Current lines 20a, 20b, 20c have respective widths W p, the distance between the current line adjacent (clearance) has a d 2.
- Magneto-resistive element 10a has a width W g. Obtained by simulating a magnetic flux density of the magnetic resistance effect element in 10a, varying the ratio of the width W g of the length L s L s / W g.
- L s / W g was changed by changing W p from 2 ⁇ m to 10 ⁇ m, changing W g from 5 ⁇ m to 20 ⁇ m, and changing d 2 from 2 ⁇ m to 10 ⁇ m.
- the other conditions of the simulation are the same as those shown in the above [Influence of the number of current lines].
- FIG. 10 shows the simulation results. Each point on the graph is a calculated value, and the curve is a power approximation curve obtained from the points (calculated values) on these graphs. From FIG. 10, it can be seen that when L s / W g is 5 or less, the magnetic flux density in the magnetoresistive element can be set to a sufficiently large value of 0.15 (T) or more. In particular, it can be seen that when L s / W g is 3 or less, the magnetic flux density in the magnetoresistive effect element can provide a remarkably large feedback magnetic field of 0.26 or more.
- FIG. 11 is a graph showing a simulation result different from FIG. From FIG.
- FIG. 10 shows the result of the feedback current of 10 mA
- the magnetic flux density in the magnetoresistive effect element by applying the external magnetic field to be measured (for example, the external magnetic field induced by the current to be measured) is 0.15 (T).
- it can be canceled with a feedback current of 10 mA to achieve a magnetic equilibrium state.
- 11 (a) shows a magnetic flux density of the magnetic resistance effect element 10 when an external magnetic field parallel to the width direction to the magnetoresistive element 10 having a width W g is 5 ⁇ m is applied.
- the magnetic flux density is about 0.6 T with an external magnetic field of 50 Oe, and the magnetic flux density is about 0.2 T with a magnetic field to be measured of 20 Oe.
- FIG. 10 shows the result of the feedback current of 10 mA, it can be seen that the measurement target magnetic field of 20 Oe can be canceled with the feedback current of about 13 mA. It can also be seen that even if a disturbance magnetic field of 50 Oe is applied, if the reset current 39 mA is instantaneously applied, the magnetoresistive effect element 10 can be magnetically initialized. All of these current consumptions are clearly lower than those of conventional magnetic sensors.
- one of the conventional magnetic balance type current sensors is that the current wire to be measured generates an induced magnetic field in the C-type core, and a feedback current is applied to the winding so as to cancel the induced magnetic field.
- the current to be measured is measured by flowing a current value or a voltage value proportional to the current value.
- a value obtained by dividing the number of windings N1 of the measurement current line by the number of windings N2 of the feedback winding and multiplying by the measurement current value I, I ⁇ (N1 / N2) is a consumption current value necessary for feedback.
- the size of the sensor itself is required to be compact (for example, because it is mounted on a vehicle), and there is a limit to increasing N2 due to the limitation due to the allowable current value of the current line, resulting in an increase in current consumption.
- FIG. 11B shows the ratio of the magnetic flux density in the magnetoresistive element in the case of three current lines to the magnetic flux density in the magnetoresistive element in the case of one current line as an amplification factor.
- Widthwise length W g of the magnetoresistive element was 5 [mu] m. From FIG. 11 (b), it can be seen that when L s / W g is 5 or less, a significantly large feedback magnetic field can be applied. That is, when W g is 5 ⁇ m, L s is preferably 25 ⁇ m or less.
- the thickness of the current line 20 is preferably 0.4 .mu.m ⁇ 5 [mu] m, the width W p 2 [mu] m ⁇ 10 [mu] m, the distance between adjacent current lines 20 (gap) is 2 [mu] m ⁇ 10 [mu] m.
- the current line 20 is formed of a material having excellent electrical conductivity such as copper, silver, or aluminum.
- the width W g of the magnetoresistive effect element 10 is preferably 4 ⁇ m to 20 ⁇ m.
- the length of the magnetoresistive element 10 (the length in the direction along the current line 20) is preferably 500 ⁇ m or more in consideration of the withstand voltage.
- FIG. 12 shows a magnetic sensor 120 which is a modification of the first embodiment
- FIG. 12 (a) is a top view of the magnetic sensor 120
- FIG. 12 (b) is a planar coil 70 shown in FIG. 12 (a).
- FIG. 12C is a cross-sectional view showing a 2c-2c cross section of FIG. 12B.
- the magnetic sensor 120 is different from the magnetic sensor 100 in that the number of the current lines 20 arranged in the linear portion of the coil 70 is nine and the number of the magnetoresistive effect elements 10 is four. Other configurations are the same as those of the magnetic sensor 100.
- Embodiment 2 13 shows a magnetic sensor 130 according to Embodiment 2 of the present invention
- FIG. 13 (a) is a top view of the magnetic sensor 130
- FIG. 13 (b) is a planar coil 70 shown in FIG. 13 (a).
- FIG. 13C is a cross-sectional view showing a 3c-3c cross section of FIG. 13B.
- the magnetic sensor 130 is different from the magnetic sensor 120 according to the first embodiment in that the yoke layer 16 is provided above the current line 20.
- the yoke layer 16 includes three current lines (i.e., one current line 20 in which the magnetoresistive effect element 10 is disposed below and two current lines disposed on both sides of the current line 20 (that is, The combination of the first to third current lines) is arranged on the current line 20 so as to cover at least one set.
- two or more sets more preferably, as shown in FIG. 13, all sets of current lines 20 (in FIG. 13, four current lines have the magnetoresistive effect element 10 arranged below them, and the current lines
- the yoke layer 16 is provided on (upper part of) the current line 20 so as to cover a total of five current lines 20 arranged on both sides of each of the 20 current lines 20. Yes.
- the two outermost current lines 20 are Although only a part in the width direction (X direction) is covered by the yoke layer 16, the current line 20 in which the magnetoresistive effect element is not disposed in the lower portion may be covered only in the width direction. .
- an insulating layer 12 may be formed between the yoke layer 16 and the current line 20 as shown in FIG. .
- the yoke layer such as the yoke layer 16 may be made of any known soft magnetic material, and examples of suitable soft magnetic materials include permalloy (Ni—Fe alloy).
- the yoke layer can be formed, for example, by sputtering or plating a soft magnetic material.
- a magnetic field passing over the current line 20 that is, a magnetic field sandwiching the current line 20.
- Magnetic field passing through the opposite side to the side where the resistance effect element 10 is present passes through the yoke layer 16, so that the magnetic flux density of the portion increases, and the magnetic circuit is high together with the magnetoresistance effect element 10 located below the current line 20. It is considered that a larger amount of feedback magnetic field is applied to the magnetoresistive effect element 10 when current of the same magnitude is passed through the current line 20 because it is formed efficiently.
- the yoke layer 16 preferably has a thickness of 0.2 ⁇ m or more. Further, as shown in FIG. 13, the yoke layer preferably has a length (Y-direction length) that can cover the magnetoresistive effect element 10 in the length direction when viewed in plan. Further, as shown in FIG. 13C, when the insulating layer 12 is formed between the current line 20 and the yoke layer 16 and the yoke layer is conductive, the thickness of the insulating layer 12 is 1 ⁇ m or more. Is preferred.
- the current line 20 is a conductor made of copper and having a width (X direction length) of 4 ⁇ m and a thickness (Z direction length) of 1 ⁇ m.
- the distance (gap) between the adjacent current lines 20 was 4 ⁇ m.
- the insulating layer 12 disposed between the current line 20 and the magnetoresistive effect element 10 has a length (Y direction length) of 100 ⁇ m, a width of 4 ⁇ m, and a thickness of 1 ⁇ m.
- the magnetoresistive effect element 10 is assumed to be an SVGMR element.
- the SVGMR element has a fixed layer composed of one or a plurality of layers including, for example, a CoFe layer in which the spin direction is fixed, and a free layer composed of, for example, a NiFe layer that easily changes the spin direction by an external magnetic field.
- the magnetoresistive effect element 10 is a single layer film of NiFe having a saturation magnetic flux density Bs of 1.4T, a total magnetization of 28, a length of 100 ⁇ m, a width of 10 ⁇ m, and a thickness of 20 nm.
- a yoke layer 16 having a length (Y direction) of 100 ⁇ m, a width (X direction) of 10 ⁇ m, and a thickness of 0.2 ⁇ m was arranged as shown in FIG.
- the insulating layer 12 disposed between the current line 20 and the yoke layer 16 has a length of 100 ⁇ m, a width of 4 ⁇ m, and a thickness of 1 ⁇ m.
- FIG. 14 is a graph showing a simulation result.
- the horizontal axis of the graph in FIG. 14 indicates the magnitude of the current (feedback current) flowing through the current line, and the vertical axis indicates the magnitude of the magnetic field (magnetic flux density) applied to the magnetoresistive effect element 10.
- the magnitude of the magnetic field is indicated by a minus value, but a larger magnetic field indicates that a larger magnetic field is applied. From the result of FIG. 14, when the same current flows, the magnetic sensor 130 having the yoke layer 16 can apply a larger feedback magnetic field to the magnetoresistive effect element 10 as compared with the magnetic sensor 120 not having the soft magnetic material 16. I understand.
- Embodiment 3 15 shows a magnetic sensor 140 according to Embodiment 3 of the present invention
- FIG. 15 (a) is a top view of the magnetic sensor 140
- FIG. 15 (b) is a planar coil 70 shown in FIG. 15 (a).
- FIG. 15C is a cross-sectional view showing a 4c-4c cross section of FIG. 15B.
- the first current line 20A in the height direction (Z direction) and the insulating layer 12 thereon are interposed.
- the magnetic sensor 120 according to the first embodiment is different from the magnetic sensor 120 according to the first embodiment in that the second current line 20B is arranged in two layers. That is, in the present embodiment, the current line 20 includes the first current line 20A and the second current line 20B that are stacked with the insulating layer 12 interposed therebetween.
- the first current line 20 ⁇ / b> A and the magnetoresistive effect element 10 have the same configuration as the magnetic sensor 120.
- the 2nd current line 20B is arrange
- a magnetic field can be applied to the magnetoresistive element 10.
- the first current line 20 ⁇ / b> A and the second current line 20 ⁇ / b> B may have the same dimensions and materials as the current line 20.
- the first layer of the coil 70 constituted by the first current line 20A and the second layer of the coil 70B constituted by the second current line 20B; are the same when viewed from above.
- the first layer of the coil 70 and the second layer of the coil 70 are connected in series, and the same current flows through the first current line 20A and the second current line 20B.
- three or more layers of current lines through which feedback current flows may be formed.
- the first current line 20A was a conductor made of copper having a width (X direction length) of 4 ⁇ m and a thickness (Z direction length) of 1 ⁇ m and a rectangular cross section.
- the distance (gap) between the adjacent current lines 20A was 4 ⁇ m.
- the insulating layer 12 disposed between the first current line 20A and the magnetoresistive element 10 has a length (Y direction length) of 100 ⁇ m, a width of 4 ⁇ m, and a thickness of 1 ⁇ m.
- the second current line 20B is also a conductor made of copper having a width of 4 ⁇ m and a thickness of 1 ⁇ m and a rectangular cross section. The distance (gap) between the adjacent current lines 20B was 4 ⁇ m.
- the insulating layer 12 disposed between the first current line 20A and the second current line 20B has a length of 100 ⁇ m, a width of 4 ⁇ m, and a thickness of 1 ⁇ m. Other conditions were the same as the simulation conditions of the magnetic sensor 120 shown in the second embodiment.
- FIG. 16 is a graph showing a simulation result.
- the horizontal axis of the graph of FIG. 16 indicates the magnitude of the current (feedback current) that flows through the first current line 20A and the second current line 20B, and the vertical axis indicates the magnetic field (magnetic flux) applied to the magnetoresistive effect element 10. The density).
- the simulation result of the magnetic sensor 120 shown in Embodiment 2 is shown again.
- the magnitude of the magnetic field is shown as minus, but the larger the absolute value, the larger the magnetic field is applied. From the result of FIG. 16, when the same current is applied, the magnetic sensor 140 having the current line having the two-layer structure has a larger feedback than the magnetic sensor 120 having the current line having the one-layer structure. It can be seen that a magnetic field is applied.
- Embodiment 4 17 shows a magnetic sensor 150 according to Embodiment 4 of the present invention
- FIG. 17 (a) is a top view of the magnetic sensor 150
- FIG. 17 (b) is a planar coil 70 shown in FIG. 17 (a).
- FIG. 17C is a cross-sectional view showing a 5c-5c cross section of FIG. 17B.
- the magnetic sensor 150 is different from the magnetic sensor 120 according to the first embodiment in that a bias magnetic field applying current line 22 is provided on the current line 20 via the insulating layer 12.
- the magnetic sensor when an SVGMR element is used as the magnetoresistive effect element 10, it is preferable to apply a bias magnetic field and align the magnetic domains in the free layer whose spin direction is changed by external magnetization in order to obtain higher measurement accuracy.
- the magnetic sensor according to the present embodiment has a bias magnetic field application current line 22 for applying a bias magnetic field to the magnetoresistive effect element 10 in addition to the current line 20.
- the bias magnetic field applying current line 22 extends in a direction perpendicular to the extending direction (Y direction) of the magnetoresistive effect element 10 (that is, a direction perpendicular to the extending direction of the current line 20). As shown in FIG.
- a plurality of bias magnetic field applying current lines 22 are provided in parallel in the extending direction of the magnetoresistive effect element 10 so that a bias magnetic field can be applied over the entire length of the magnetoresistive effect element 10. It is preferable that they are arranged. In the embodiment of FIG. 17, 11 are arranged.
- the bias magnetic field applying current line 22 is preferably a part of the planar coil 72. This is because by applying a voltage to both ends of the planar coil 72, a current can be passed through the plurality of bias magnetic field applying current lines 22.
- the dimensions and constituent materials of the bias magnetic field application current line 22 may be the same as those of the current line 20.
- FIG. 18 shows a magnetic sensor 160 according to a modification of the fourth embodiment
- FIG. 18 (a) is a top view of the magnetic sensor 160
- FIG. 18 (b) is a planar coil 70 shown in FIG. 18 (a).
- FIG. 18C is a cross-sectional view showing a 6c-6c cross section of FIG. 18B.
- the insulating layer 12 may be disposed between the magnetoresistive effect element 10 and the current line 20 via the insulating layer 12 (both between the magnetoresistive effect element and between the current line 20.
- the magnetic sensor 120 according to the first embodiment is different from the magnetic sensor 120 according to the first embodiment in that a bias magnetic field applying current line 22 is provided.
- Other configurations of the magnetic sensor 160 may be the same as the configuration of the magnetic sensor 150. That is, in the magnetic sensor 150, the current line 20 is disposed closer to the magnetoresistive effect element 10 than the bias magnetic field applying current line 22, and in the magnetic sensor 160, the bias magnetic field applying current line 22 is positioned more than the current line 20. It is arranged at a position closer to the magnetoresistive element 10.
- the arrangement of the magnetic sensor 150 is preferable, and when more accurate measurement is required, the arrangement of the magnetic sensor 160 is preferable.
- Embodiment 5 19 shows a magnetic sensor 170 according to Embodiment 5 of the present invention
- FIG. 19 (a) is a top view of the magnetic sensor 170
- FIG. 19 (b) is a planar coil 70 shown in FIG. 19 (a).
- FIG. 19 (c) is a cross-sectional view showing a 7c-7c cross section of FIG. 19 (b).
- the magnetic sensor 170 has a configuration in which the current line 20 in the magnetic sensor 130 described above is changed to a two-layer structure including the first current line 20A and the second current line 20B shown in the magnetic sensor 140 described above. Have.
- Embodiment 6 20 shows a magnetic sensor 180 according to Embodiment 6 of the present invention
- FIG. 20 (a) is a top view of the magnetic sensor 180
- FIG. 20 (b) is a planar coil 70 shown in FIG. 20 (a).
- FIG. 20C is a cross-sectional view showing an 8c-8c cross section of FIG. 20B.
- the magnetic sensor 180 has a configuration in which the yoke layer 16 shown in the magnetic sensor 130 described above is provided on the bias magnetic field applying current line via the insulating layer 12 in the magnetic sensor 150 described above.
- FIG. 21 shows a magnetic sensor 190 according to a modification of the sixth embodiment
- FIG. 21 (a) is a top view of the magnetic sensor 190
- FIG. 21 (b) is a planar coil 70 shown in FIG. 21 (a).
- FIG. 21 (c) is a cross-sectional view showing a 9c-9c cross section of FIG. 21 (b).
- the magnetic sensor 190 has a configuration in which the yoke layer 16 shown in the magnetic sensor 130 described above is provided on the current line 20 via the insulating layer 12 in the magnetic sensor 160 described above.
- Embodiment 7 22 shows a magnetic sensor 200 according to Embodiment 7 of the present invention
- FIG. 22 (a) is a top view of the magnetic sensor 200
- FIG. 22 (b) is a planar coil 70 shown in FIG. 22 (a).
- FIG. 22 (c) is a cross-sectional view showing a 10c-10c cross section of FIG. 22 (b).
- the magnetic sensor 200 has a configuration in which the bias magnetic field applying current line 22 shown in the magnetic sensor 150 is provided on the second current line 20B via the insulating layer 12 in the magnetic sensor 140 described above. is doing.
- FIG. 23 shows a magnetic sensor 210 according to a modification of the seventh embodiment
- FIG. 23 (a) is a top view of the magnetic sensor 210
- FIG. 23 (b) is a planar coil 70 shown in FIG. 23 (a).
- FIG. 23C is a cross-sectional view showing a cross section 11c-11c of FIG. 23B.
- the magnetic sensor 210 is the same as the magnetic sensor 140 described above, with the insulating layer 12 interposed between the magnetoresistive effect element 10 and the first current line 20A (between the magnetoresistive effect element 10 and the current line 20). In this case, the insulating layer 12 may be disposed on both of them), and the bias magnetic field applying current line 22 shown in the magnetic sensor 160 is provided.
- Embodiment 8 24 shows a magnetic sensor 220 according to Embodiment 8 of the present invention
- FIG. 24 (a) is a top view of the magnetic sensor 220
- FIG. 24 (b) is a planar coil 70 shown in FIG. 24 (a).
- FIG. 24C is a cross-sectional view showing a cross section 12c-12c of FIG. 24B.
- the magnetic sensor 220 has a configuration in which the yoke layer 16 shown in the magnetic sensor 130 described above is provided on the bias magnetic field applying current line 22 via the insulating layer 12 in the magnetic sensor 200 described above. .
- FIG. 25 shows a magnetic sensor 230 according to a modification of the eighth embodiment
- FIG. 25 (a) is a top view of the magnetic sensor 230
- FIG. 25 (b) is a planar coil 70 shown in FIG. 25 (a).
- FIG. 25C is a cross-sectional view showing a 13c-13c cross-section of FIG. 25B.
- the magnetic sensor 230 has a configuration in which the yoke layer 16 shown in the magnetic sensor 130 is provided on the second current line 20B in the magnetic sensor 210 with the insulating layer 12 interposed therebetween.
- FIG. 26 is a plan view showing a magnetic sensor 240 according to Embodiment 9 of the present invention.
- a second current line 20 having the magnetoresistive effect element 10 disposed below it and a first current line disposed on both sides of the current line 20 (from the second current line in the X direction).
- Position) and the third current line (positioned in the ⁇ X direction from the second current line), and located on the outer side (X direction) of the first current line and provided with a yoke layer 14 below the first current line.
- a current line (fourth current line) 20 and a current line (fifth current line) 20 which is located outside ( ⁇ X direction) from the third current line and includes a yoke layer 14 below the current line.
- the fourth current line 20 and the fifth current line 20 extend in parallel with the first current line 20 (that is, extend in parallel with the second and third current lines).
- the magnetic field formed by the current line forms a magnetic circuit by the yoke layer and the magnetoresistive effect element, so that a higher magnetic field can be obtained with the same current. Can be applied to the magnetoresistive element 10.
- the fourth current line and the fifth current line are preferably electrically connected in series with the first to third current lines.
- the yoke layer 14 includes a soft magnetic material and is not electrically connected to the first to fifth current lines 20 and the magnetoresistive effect element 10.
- an alloy film such as permalloy may be formed. Further, it may be a multilayer film including a soft magnetic material layer.
- One form of such a multilayered yoke layer 14 is to form a magnetoresistive effect element (dummy magnetoresistive effect element) that is not electrically connected (for example, in FIG. 14 may be a dummy magnetoresistance effect element). Further, for example, in the magnetic sensor shown in FIG.
- the magnetoresistive effect elements 10a, 10b, 10d, and 10e are not electrically connected (not used as the magnetoresistive effect element) as the yoke layer 14 and are used as the magnetoresistive effect element. May use only the magnetoresistive effect element 10c.
- the configuration using the fourth current line, the fifth current line, and the yoke layer may be combined with one or more configurations of the first to eighth embodiments described above.
- the magnetic sensors 100, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, and 240 according to the present invention described above are, for example, sputtering, photolithography, etching, and plating. It can be formed by a known process such as
- the magnetic sensor of the present invention can be used as a magnetic sensor and / or a current sensor by connecting both ends of the coil 70 and the magnetoresistive element 10 to a magnetic sensor circuit (feedback circuit), for example.
- the magnetic sensor circuit may have any known configuration.
- FIG. 27 is a schematic circuit diagram showing an example of a magnetic sensor circuit (feedback circuit).
- the magnetic sensor circuit shown in FIG. 27 is a so-called magnetic balance type circuit, and can be used as, for example, a current sensor.
- one end side of the magnetoresistive effect element 10 (which may be two or more magnetoresistive effect elements 10) is connected so that current is supplied from the DC constant current source Icc or the constant voltage source Vcc.
- the other end side of the magnetoresistive effect element 10 is connected to a common terminal (GND) via a fixed resistor.
- GND common terminal
- the fixed resistance portion is one of the two types.
- the positive terminal (+) of the comparator 314 is connected to the common terminal (GND) via the reference power source 315.
- the output potential of the reference power source 315 is the potential of the magnetoresistive effect element 10 in a place where there is no magnetic field.
- the output of the comparator 314 is connected to one end of the coil 313 via a waveform shaping unit 341 and a low pass filter (LPF) 342, and is also connected to the output terminal OUT. Furthermore, the other end side of the coil 313 (which becomes the feedback coil 20) is connected to a common terminal (GND) via a fixed resistor 316.
- the magnetic sensor having the circuit shown in FIG. 27 obtains the voltage signal output from the magnetoresistive effect element 10 through the comparator 314, the waveform shaping unit 341, and the LPF 342. The output obtained through the LPF 342 becomes a voltage signal proportional to the difference between the potential of the reference power supply and the potential of the voltage signal output from the magnetoresistive effect element 10.
- this magnetic sensor when this magnetic sensor is arranged in the vicinity of a conductor (for example, a bus bar) through which the current to be measured flows, the resistance value of the magnetoresistive effect element 10 is changed by an induced magnetic field generated by the current to be measured. Then, since the output potential deviates from the potential when there is no magnetic field (as described above, the potential of the reference power supply is equal to this potential) (offset), it is obtained through the comparator 314, the waveform shaping unit 341, and the LPF 342. The output is a voltage signal having a magnitude corresponding to the amount of potential deviation. This voltage signal represents the strength of the induced magnetic field generated by the current to be measured (current flowing in the bus bar).
- This voltage signal is supplied to one end of the coil 313, and when a current flows through the coil 313, a feedback magnetic field (cancellation magnetic field) is generated.
- the magnetic flux generated by the cancel magnetic field is applied to the magnetoresistive effect element 10 together with the induced magnetic field generated from the current to be measured.
- a voltage signal V proportional to the amount of current supplied to the coil 313 when the magnetic flux passing through the magnetoresistive element 10 becomes zero (when the output voltage of the magnetoresistive element 10 is the same as the reference potential 315) is fixed resistance.
- the voltage is taken out as the voltage across the capacitor 316 (OUT). Then, this voltage signal V becomes an output signal proportional to the amount of current of the current under measurement (current flowing in the bus bar in the above example).
- FIG. 28 is a schematic circuit diagram showing an example in which a full bridge circuit is configured using four magnetoresistive elements 10. As shown in FIG.
- magnetoresistive effect elements 10 are arranged in one magnetic sensor to form a full bridge, so that the magnetoresistive effect element 10 cancels voltage changes such as common mode noise. Measurement accuracy is improved.
- one magnetoresistive element 10 is arranged on one current line by arranging two magnetoresistive elements 10 on one current line of the feedback coil along the direction in which the current of the current line flows. Compared to the case, the number of turns of the feedback coil can be reduced. As a result, the length of the feedback coil can be shortened and the resistance of the feedback coil is lowered, so that the feedback voltage can be lowered, and operation at a low voltage is possible.
- canceling magnetic noise can be expected by arranging the magnetoresistive effect element 10 in consideration of the direction of the magnetosensitive axis. For example, when a full bridge circuit is configured with two half bridges, noise due to a uniform external magnetic field can be reduced by placing the half bridges at positions where the directions of the induced magnetic fields generated from the same current line are opposite. Canceled. Note that, as described above, the full bridge circuit may be configured using, for example, three magnetoresistive elements 10 in addition to the four or four or more magnetoresistive elements 10.
- FB means a feedback coil
- Bias means a bias coil
- NiFe means a yoke layer
- Table 1 shows the corresponding embodiment for each sample. However, it should be noted that this indicates the closest embodiment and does not mean that the constituent requirements of the embodiments other than those described in Table 1 are not satisfied.
- a diagram showing the same configuration as each sample, and a more specific diagram showing a stacking order of the feedback coil, the bias coil, and the yoke layer (only when arranged) are shown in the “ Figure” column.
- the “ Figure” column among the feedback coil, bias coil, and yoke layer (only when arranged), the one located on the lowermost side (side closer to the magnetoresistive element 10) is shown on the left.
- the stacked feedback coil, bias coil, and yoke layer are shown from left to right in the stacking order.
- FIG. 29 is a cross-sectional view showing a cross section of Example Sample 1.
- FIG. The cross section of FIG. 29 is a cross section corresponding to FIG. 22c, that is, a cross section corresponding to the 10c-10c cross section of FIG. 22b.
- the details of the example sample will be described with reference to FIG.
- the dimensions described below are design values (target values), and due to manufacturing accuracy problems, the actual dimensions slightly deviate from these design values within the range where there is no problem in confirming the effect of the present invention. Note that it may be. All samples were formed on a substrate 40 made of non-magnetic silicon. Specifically, the two magnetoresistive elements 10 are arranged on the SiO 2 insulating layer 12 formed by oxidizing the surface of the substrate 40.
- the magnetoresistive effect element 10 used is a SVGMR element having a GMR magnetosensitive film (SVGMR magnetosensitive film).
- SVGMR magnetosensitive film GMR magnetosensitive film
- one of the two magnetoresistive effect elements 10 (the left side in FIG. 29) is further formed on the insulating layer 12 of the above-described SiO 2 with a thickness of 0.03 ⁇ m.
- the insulating layer 12 having a thickness of 0.03 ⁇ m.
- the width (length in the X direction) W g of the GMR magnetosensitive film of the magnetoresistive effect element 10 is appropriately selected so that L s / W g satisfies the conditions described in Table 1, and the magnetoresistive effect element 10
- the length of the GMR magnetosensitive film (the length in the Y direction) was selected according to the width so that the electric resistance was constant under all conditions.
- an insulating layer 12 having a thickness of 0.2 ⁇ m so as to cover the two magnetoresistive elements 10 an insulating layer 12 having a thickness of 1.3 ⁇ m was further formed.
- the feedback coil was a 7-turn planar coil, and seven current lines 20 were formed for one feedback coil on the cross section shown in FIG.
- the width W p of the current line 20 is 4 ⁇ m (the width can be measured, for example, by measuring the distance between the end portions in the top view), and the distance d 2 between the adjacent current lines 20 is 4 ⁇ m, and the thickness was 0.8 ⁇ m. Therefore, the length L s from the outside of the first current line to the outside of the third current line was 20 ⁇ m.
- the bias coil is a 16-turn planar coil
- the current line 22 has a width of 4 ⁇ m
- the distance between adjacent current lines 22 is 4 ⁇ m
- the thickness is 0.8 ⁇ m. there were.
- the feedback coil, bias coil, and wiring were formed by sputtering Al—Cu.
- a yoke layer having a width of 52 ⁇ m, a length of 138 ⁇ m, and a thickness of 1 ⁇ m was formed by plating Ni—Fe.
- any one of the feedback coil, bias coil, and yoke layer is laminated, and when another feedback coil, bias coil, or yoke layer is used, an insulating layer 12 having a thickness of 1.3 ⁇ m is provided therebetween.
- an insulating layer 12 having a thickness of 1.3 ⁇ m was provided on the uppermost one of the feedback coil, bias coil, and yoke layer. Therefore, in the case of Sample 1 shown in FIG. 29, the insulating layer 12 having a thickness of 1.3 ⁇ m is formed on the first current line 20A that is the current line of the first feedback coil.
- the second current line 20B which is the current line of the second feedback coil, is formed.
- An insulating film 12 is formed on the second current line 20 ⁇ / b> B, and a bias coil current line 22 is formed on the insulating layer 12. Further, the insulating layer 12 is also formed on the current line 22.
- the insulating layer 12 used in the example samples was formed by appropriately selecting from SiO 2 film, Al 2 O 3 film, and hard bake resist.
- Example Samples 1 to 18 produced in this manner while a bias current was applied.
- the operating range is the range that is output linearly with respect to the magnetic field.
- the maximum current required for feedback was measured.
- the obtained maximum feedback current (maximum FB current in Table 1) is shown in Table 1.
- Table 1 shows the maximum feedback current (maximum FB current in Table 1).
Landscapes
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Measuring Magnetic Variables (AREA)
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
- Hall/Mr Elements (AREA)
Abstract
Description
この磁気センサでは、導電体を流れる電流によって磁心内に誘導された磁界をギャップに配置した磁気検出素子が検出し、磁心内の磁界がゼロになるように巻線にフィードバック電流を流し、この電流値を検出抵抗により電圧換算し、この電圧値より導電体を流れる電流の大きさを求めている。
このため、例えば、バッテリーにより電流を供給している装置では、1回の充電で使用可能な時間が短くなる等の諸々の問題が生じていた。
この磁気抵抗効果素子を用いた磁気センサは、測定対象の導電体を流れる電流(検出対象電流)による誘導磁界のうち、一部分(測定対象の導電体を取り囲む円周方向の一部分)の磁界を磁気抵抗効果素子により検出し、検出した磁界をキャンセルするように(検出対象電流により磁気抵抗効果素子に印加された外部磁界と反対向きで同じ大きさの磁界を磁気抵抗効果素子に印加するように)電流線(平面コイル)にフィードバック電流を流し、このフィードバック電流の大きさから検出対象電流の大きさを求めている。
そして、これらの要望は全て、より少ない消費電力で機能する磁気センサを求めていることに他ならない
そこで本発明はより少ない消費電力、とりわけ少ないフィードバック電流により作動する磁気センサを提供することを目的とする。
本発明の態様1は、幅方向に順に互いに平行に配置され、電気的に直列に接続されている第1の電流線、第2の電流線および第3の電流線と、該第2の電流線の下部に配置され、該第2の電流線の延在する方向に沿って延在し、前記第1の電流線、第2の電流線および第3の電流線を流れる電流により生じた誘導磁界により電気抵抗が変化する磁気抵抗効果素子と、を有し、幅方向における、前記第1の電流線の外側から前記第3の電流線の外側までの長さLsと前記磁気抵抗効果素子の幅方向の長さWgとが下記(1)式を満足することを特徴とする磁気センサである。
Ls/Wg≦5 (1)
Wp≦Wg (2)
図1は、フィードバック電流を流すための1本の電流線20と磁気抵抗効果素子10とを示す図である。図1(a)は斜視図であり、図1(b)は断面図であり、図1(c)は平面図である。図2は、図1に示す電流線20を含む平面コイル70を示す平面図である。
図1(a)に示すように測定対象の導電体による誘導磁界の一部である外部磁界32が磁気抵抗効果素子10に印加されると磁気抵抗効果素子10の電気抵抗が変化する。磁気抵抗効果素子10の電気抵抗が変化すると、外部磁界32を打ち消す(すなわち外部磁界32と同じ大きさでかつ反対方向の)フィードバック磁界30を形成するように、フィードバック回路から電流線20にフィードバック電流34が供給される。
なお、本明細書において用語「外部磁界」とは検出対象を流れる電流(測定対象となる電流)による誘導磁界を意味する。
Ls/Wg≦5 (1)
以下に本発明の詳細を説明する。
1-1.磁気センサ100の構成
図3(a)は、本発明の実施形態1に係る磁気センサ100の上面図であり、図3(b)は、図3(a)の1b-1b断面を示す断面図である。
磁気センサ100は、同じ方向に延在し、かつ直列に電気的に接続されている複数の電流線20を有している。好ましい実施形態の1つでは電流線20は、図2に示す平面コイル70の直線部Bを構成する電流線である。平面コイルの両端部に電圧を印加することにより全ての電流線20にフィードバック電流を流すことができるからである。
図3(a)に示す実施形態では、11本の電流線20が配置されているが、3本以上であれば任意の本数の電流線20が配置されてよい。
同様に、図2に示す平面コイル70の直線部Bには7本の電流線20しか描かれていないが、コイル70の巻数を変えることにより直線部Bの電流線20の数を3本以上であれば任意の本数としてよい。
図3では、電流線20を個別に識別するために、電流線20のそれぞれに符号「20a」~「20k」のいずれかを付している。
ことが好ましい。
前記2個の磁気抵抗効果素子の延在方向と平行な両隣に磁気抵抗効果素子10があると磁気抵抗効果素子の磁束密度が増幅されるため、磁気抵抗効果素子10が4個以上配置されていることがより好ましい。図3に示す実施形態では、磁気センサ100は、5つの磁気抵抗効果素子10を有している。
図3を用いて磁気抵抗効果素子10と電流線20との位置関係を以下に説明する。図3では、磁気抵抗効果素子を個別に識別するために、個々の磁気抵抗効果素子10のそれぞれに符号「10a」~「10e」のいずれかを付している。
磁気抵抗効果素子10aは電流線(第2の電流線)20bの下部(電流線の高さ方向(図3のZ方向)における下部(または直下))にその延在方向が電流線20bの延在方向と平行になるように配置されている。
電流線20(20b)と磁気抵抗効果素子10(10a)との間の絶縁をより確実に行うために、図3に示すように電流線20(20b)と磁気抵抗効果素子10(10a)との間に絶縁層12(12a)を配置してよい。
図3(b)に示す長さLsは、幅方向における前記第1の電流線20aの外側(図3(b)では第1の電流線20aの左側の端部)から前記第3の電流線の外側(図3(b)では第3の電流線20cの右側の端部)までの長さである。
換言すれば、長さLsは、幅方向における、第1の電流線20aの長さと、第1の電流線20aと第2の電流線20bとの間の距離(隙間)と、第2の電流線20bの長さと、第2の電流線20bと第3の電流線20cとの間の距離(隙間)と、第3の電流線20cの長さの合計であり、図3の実施形態ではLsは3Wp+2d2となる。
Ls/Wg≦5 (1)
(1)式を満足することは、電流線20(電流線20a~20c)の幅方向の長さに対して磁気抵抗効果素子10aが十分な幅方向の長さを有することにより、磁気抵抗効果素子10aには、その直上に位置する電流線20bによるフィードバック磁界に加えて、電流線20bの両隣に位置する電流線20aと電流線20cによるフィードバック磁界も効率的に印加されることを意味する。
そして、このことは、電流線20a、電流線20bおよび電流線20cは同じ向きに、同じ電流が流れるように直列に接続されていることから、磁気センサ100では1本の電流線に電流を流した場合より少ない電流量で、より強いフィードバック磁界を磁気抵抗効果素子10に印加できることを意味する。
Ls/Wg≦3 (1A)
(1)式および(1A)式を満足することにより得られる効果については、後述するシミュレーションの結果でも明らかになっている。
また、好ましくは、磁気抵抗効果素子10の幅方向の長さWgと電流線20の幅方向の長さWpは以下に示す(2)式を満足する。(2)式は、磁気抵抗効果素子10の幅方向の長さが電流線20(とりわけ、電流線20b)の幅方向の長さより長いことを意味する。これにより、磁気抵抗効果素子10内の反磁界が小さくでき、感度が上がりやすくなる。そのため少ない消費電流でも高い出力が得られる。また、(2)式を満足していることは、磁気抵抗効果素子10の幅方向の端部が、第1の電流線20aまたは第3の電流線20cに接近していることを意味する。これにより、磁気抵抗効果素子10に電流線20aおよび電流線20cによるフィードバック磁界を確実に印可することができる。
Wp≦Wg (2)
図4は、長さLsと磁気抵抗効果素子10の長さWgの関係を例示する断面図である。図4(a)は、Wg≦Wp+2d2の場合を示し、図4(b)は、Wg≧Wp+2d2の場合を示し、図4(c)はWg=Lsの場合を示し、図4(d)はWg>Lsの場合を示す。
図4(a)は、図3(b)の実施形態と同じであり、幅方向の位置において、磁気抵抗効果素子10aの端部(両方の端部)は、第1の電流線20aと第2の電流線20bとの間および第2の電流線20bと第3の電流線20cとの間のどちらかに位置している。
図4(b)の場合、幅方向の位置において、磁気抵抗効果素子10aの端部(両方の端部)は、第1の電流線20aおよび第3の電流線20cのどちらかと重なる。
また、図4(b)の実施形態は、Wg=2Wpである場合を含み得る。
図4(c)の場合、幅方向の位置において、磁気抵抗効果素子10aの端部(両方の端部)は、第1の電流線20aの外側端部(図4(c)では左側端部)および第3の電流線20cの外側端部(図4(c)では右側端部)のどちらかと一致する。
図4(d)の場合、幅方向の位置において、磁気抵抗効果素子10aの端部(両方の端部)は、第1の電流線20aの外側端部(図4(d)では左側端部)および第3の電流線20cの外側端部(図4(d)では右側端部)のどちらかよりも外側となっている。
さらに磁気抵抗効果素子(第3の磁気抵抗効果素子)10cが絶縁層12cを介して電流線20fの下部に、その延在方向が電流線20fの延在方向と平行になるように配置されている。この場合、第1の電流線が電流線20eであり、第2の電流線が電流線20fであり、第3の電流線が電流線20gであり、(1)式を満足している。
また、磁気抵抗効果素子(第4の磁気抵抗効果素子)10dが絶縁層12dを介して電流線20hの下部に、その延在方向が電流線20hの延在方向と平行になるように配置されている。この場合、第1の電流線が電流線20gであり、第2の電流線が電流線20hであり、第3の電流線が電流線20iであり、(1)式を満足している。
さらにまた、磁気抵抗効果素子(第5の磁気抵抗効果素子)10eが絶縁層12eを介して電流線20jの下部に、その延在方向が電流線20jの延在方向と平行になるように配置されている。この場合、第1の電流線が電流線20iであり、第2の電流線が電流線20jであり、第3の電流線が電流線20kであり、(1)式を満足している。
また、例えば電流線20bと電流線20dの間、電流線20dと電流線20fとの間、電流線20fと電流線20hの間、および電流線20hと電流線20jの間に、それぞれ、その下部に磁気抵抗効果素子が配置されていない電流線を2本以上配置する等により、電流線が第1~第3の電流線のいずれか1つとしてのみ機能するようにしてもよい。
図5(a)は、図3と同じ形態であり、順に並ぶ電流線20a~20dの1つおきにその下部に磁気抵抗効果素子10を配置している。
図5(b)では、隣り合う電流線20bと電流線20cの両方に磁気抵抗効果素子10を配置している。この場合、磁気抵抗効果素子10aにとっては電流線20bが第2の電流線であり、電流線20cが第3の電流線であり、磁気抵抗効果素子10bにとっては電流線20cが第2の電流線であり、電流線20bが第1の電流線である。
図5(c)では、1本の電流線の下部に複数の磁気抵抗効果素子10(図5(c)では磁気抵抗効果素子10a、10bの2つ)が配置されている。
図5に示したいずれの形態も(1)式を満足させることが可能である。
同様に、電流線20d、電流線20f、電流線20hおよび電流線20jの幅方向の中心は、それぞれ、磁気抵抗効果素子10b、磁気抵抗効果素子10c、磁気抵抗効果素子10dおよび磁気抵抗効果素子10eの幅方向の中心と一致している。
次に、本発明の効果をより明確にするために行ったシミュレーションの結果を説明する。
[電流線の個数の影響]
図6は、電流線の個数の影響を調べるために用いたモデルを示す図であり、図6(a)のモデルでは1本の電流線20とその下に絶縁層12(不図示)を介して配置されている1つの磁気抵抗効果素子10とを有しており、図6(b)のモデルでは、図6(a)のモデルの構成に加えて、その下部に磁気抵抗効果素子10が配置されている電流線20の両隣に、その下に磁気抵抗効果素子が配置されていない電流線20をそれぞれ1本ずつ配置し、図6(c)のモデルでは、図6(a)のモデルの構成に加えて、その下部に磁気抵抗効果素子10が配置されている電流線20の両隣に、その下に磁気抵抗効果素子が配置されていない電流線20をそれぞれ2本ずつ配置している。
すなわち、図6(a)のモデルでは電流線20が合計1本、図6(b)のモデルでは電流線20が合計3本、図6(c)のモデルでは電流線20が合計5本配置されている。
絶縁層12は、厚さ1μmとした。
磁気抵抗効果素子10は、SVGMR素子を想定した。通常SVGMR素子は、スピンの方向を固定した、例えばCoFe層等を含む1または複数の層から成る固定層と、外部磁界により容易にスピンの向きが変わる、例えばNiFe層等から成るフリー層とを有するが、単純化のため、磁気抵抗効果素子10は、飽和磁束密度Bsが1.4T、長さ100μm、幅10μm、厚さ20nmのNiFeの単層膜としてシミュレーションを行った。
これらのモデルおよびパラメータを用い、シミュレーションは株式会社JSOL社製の磁界解析ソフトJ-MAGを用いて行った。
なお、図7のグラフの横軸「X方向位置」は、磁気抵抗効果素子10の幅方向の位置を示し、0μmが磁気抵抗効果素子10の幅方向の中心であり、幅方向の中心からの距離をX方向を正、-X方向を負で示している。
図7から判るように、電流線20が1本の場合と比べて、電流線20が3本となることで磁気抵抗効果素子10内の磁束密度が顕著に増加する。一方、電流線20が3本と5本の場合では、5本の場合の方が磁気抵抗効果素子10内の磁束密度は大きいが、その差は小さい。
図8は、磁気抵抗効果素子の個数の影響を調べるために用いたモデルを示す図であり、いずれのモデルも図3と同じ11本の電流線20を有しているが、図8(a)のモデルでは、磁気抵抗効果素子10は真ん中(図で上から6本目)の電流線20の下に絶縁層12(不図示)を介して1つ配置されているだけであり、図8(b)のモデルでは、磁気抵抗効果素子10は、図で上から4本目、6本目および8本目の電流線20の下に絶縁層12を介して合計3つ配置されており、図8(c)のモデルは図3に示した磁気センサ100と同じ構成を有しており、従って合計5つの磁気抵抗効果素子10が配置されている。
このようなモデルを用いて、上述の[電流線の個数の影響]で示したのと同じ条件でシミュレーションを行った。
図9から判るように、磁気抵抗効果素子10を複数配置することにより、磁気抵抗効果素子10内の磁束密度は顕著に増加する。一方、磁気抵抗効果素子10が3個と5個の場合では、磁気抵抗効果素子10内の磁束密度の大きさに大きな違いは認められない。
図3(b)に示す構成の一部である、電流線(第1の電流線)20a、電流線(第2の電流線)20bおよび電流線(第3の電流線)20cと、絶縁層12aを介して電流線20bの下部に配置されている磁気抵抗効果素子10aとから成る構成を用いてシミュレーションを行った。
電流線20a、20b、20cは、それぞれ幅Wpを有し、隣り合う電流線との距離(隙間)はd2となっている。従って、ここで、電流線20a~20cの幅(合計:3×Wp)と、電流線20aと電流線20bとの間の距離d2と、電流線20bと電流線20cとの間の距離d2との合計3Wp+2d2が長さLsである。
磁気抵抗効果素子10aは幅Wgを有している。
長さLsの幅Wgに対する比率であるLs/Wgを変化させた場合の磁気抵抗効果素子10a内の磁束密度をシミュレーションにより求めた。Wpを2μm~10μmまで変化させ、Wgを5μm~20μmまで変化させ、d2を2μm~10μmまで変化させることによりLs/Wgを変化させた。シミュレーションのその他の条件は上述の[電流線の個数の影響]で示したのと同じ条件である。
図10から、Ls/Wgが5以下であると磁気抵抗効果素子内の磁束密度を0.15(T)以上と十分に大きな値とできることが判る。特に、Ls/Wgが3以下であると、磁気抵抗効果素子内の磁束密度が0.26以上と顕著に大きなフィードバック磁界を与えることできることが判る。
図11は図10と別のシミュレーション結果を示すグラフである。
図10から、Ls/Wgが5以下であると、フィードバック電流による磁気抵抗効果素子内の磁束密度が0.15(T)以上になる。図10はフィードバック電流10mAの結果であるため、測定対象の外部磁界(例えば、測定対象の電流により誘起される外部磁界)印加による磁気抵抗効果素子内の磁束密度が0.15(T)であればフィードバック電流10mAでキャンセルでき磁気平衡状態にできる。
図11(a)は、幅Wgが5μmの磁気抵抗効果素子10に幅方向に平行な外部磁界が印加された場合の磁気抵抗効果素子10内の磁束密度を示す。50Oeの外部磁界で該磁束密度が約0.6T、同じく20Oeの測定対象磁界で該磁束密度が約0.2Tとなっていることがわかる。図10はフィードバック電流10mAの結果であるため、約13mAのフィードバック電流で20Oeの測定対象磁界をキャンセルできることがわかる。また、例え50Oeの外乱磁界が印加されてもリセット電流39mAを瞬間的に印加すれば磁気抵抗効果素子10を磁気的に初期状態にすることができることも判る。これらの消費電流はいずれも従来型の磁気センサよりも明らかに低い消費電流である。従来型の磁気平衡型電流センサの1つは、上述したように、測定対象の電流線がC型のコア内に誘導磁界を発生させ、その誘導磁界をキャンセルするようにフィードバック電流を巻線に流し、その電流値、またはそれに比例した電圧値を測定することにより測定対象電流を測定するものである。測定電流線の巻線数N1をフィードバック巻線の巻線数N2で割り、測定電流値Iをかけた数値、I×(N1/N2)がフィードバックに必要な消費電流値になる。センサ自体の大きさがコンパクトであることが要求され(たとえば車載のため)、電流線の許容電流値による制限などからN2を増やすことには限界があり、結果として消費電流は大きくなってしまう。
ここでLs/Wg=5の例として、Wp=5μm、Wg=5μm、d2=5μmなどWp=Wg=d2の条件を挙げることができる。
また、磁気抵抗効果素子10の幅Wgは好ましくは4μm~20μmである。磁気抵抗効果素子10の長さ(電流線20に沿った方向の長さ)は、絶縁耐圧を考慮すると500μm以上であることが好ましい。
それぞれの実施形態を説明する前にこれらの実施形態の説明に用いる図との比較を容易にする目的で磁気センサ120について説明しておく。
図12は、実施形態1の変形例である磁気センサ120を示し、図12(a)は磁気センサ120の上面図であり、図12(b)は図12(a)に示した平面コイル70の直線部Bを拡大した上面図であり、図12(c)は図12(b)の2c-2c断面を示す断面図である。
磁気センサ120では、コイル70の直線部に配置されている電流線20の数が9本であり、磁気抵抗効果素子10の数が4つである点が磁気センサ100と異なる。これ以外の構成は磁気センサ100と同じである。
図13は、本発明の実施形態2に係る磁気センサ130を示し、図13(a)は磁気センサ130の上面図であり、図13(b)は図13(a)に示した平面コイル70の直線部Bを拡大した上面図であり、図13(c)は図13(b)の3c-3c断面を示す断面図である。
磁気センサ130は、電流線20の上部にヨーク層16を有する点が実施形態1に係る磁気センサ120と異なる。
また、ヨーク層16と電流線20との間の絶縁を確実に行うために、図13(c)に示すように、ヨーク層16と電流線20との間に絶縁層12を形成してよい。
なお、ヨーク層16等のヨーク層は、既知の任意の軟磁性材料により構成してよく、好適な軟磁性材料の例としてパーマロイ(Ni-Fe合金)を挙げることができる。ヨーク層は、例えば、軟磁性材料をスパッタまたはめっきすることにより構成できる。
また、図13(c)に示すように電流線20とヨーク層16との間に絶縁層12を形成しヨーク層が導伝性である場合、絶縁層12の厚さは1μm以上であることが好ましい。
次に、本実施形態の効果をより明確にするために行ったシミュレーションの結果を説明する。
図12に示す構成を有する磁気センサ120と図13に示す構成を有する磁気センサ130をモデルとしてシミュレーションを行った。
電流線20と磁気抵抗効果素子10との間に配置した絶縁層12は、長さ(Y方向長さ)100μm、幅4μm、厚さ1μmとした。
磁気抵抗効果素子10は、SVGMR素子を想定した。通常SVGMR素子は、スピンの方向を固定した、例えばCoFe層等を含む1または複数の層から成る固定層と、外部磁界により容易にスピンの向きが変わる、例えばNiFe層等から成るフリー層とを有するが、単純化のため、磁気抵抗効果素子10は、飽和磁束密度Bsが1.4T、総磁化量28、長さ100μm、幅10μm、厚さ20nmのNiFeの単層膜とした。
さらに、磁気センサ130については長さ(Y方向)100μm、幅(X方向)10μm、厚さ0.2μmのヨーク層16を図13に示すように配置した。
電流線20とヨーク層16との間に配置した絶縁層12は、長さ100μm、幅4μm、厚さ1μmとした。
図14のグラフの横軸は電流線に流す電流(フィードバック電流)の大きさを示し、縦軸は磁気抵抗効果素子10に印加される磁界(磁束密度)の大きさを示す。図14では、磁界の大きさをマイナスで示しているが絶対値が大きいほどより大きな磁界が印加されることを示す。
図14の結果より、同じ電流を流した場合、ヨーク層16を有する磁気センサ130は、軟磁性材料16を有しない磁気センサ120と比べて、より大きなフィードバック磁界を磁気抵抗効果素子10に印加できることが判る。
図15は、本発明の実施形態3に係る磁気センサ140を示し、図15(a)は磁気センサ140の上面図であり、図15(b)は図15(a)に示した平面コイル70の直線部Bを拡大した上面図であり、図15(c)は図15(b)の4c-4c断面を示す断面図である。
磁気センサ140は、コイル70が2層構造を有することにより、図15(c)に示すように、高さ方向(Z方向)に第1の電流線20Aとその上に絶縁層12を介して配置されている第2の電流線20Bの2層になっている点が実施形態1に係る磁気センサ120と異なる。
すなわち、本実施形態においては電流線20は、絶縁層12を介して積層された第1の電流線20Aと第2の電流線20Bとから成る。
このように、電流線を2層にすることにより、電流線20Aと電流線20Bの両方で形成されたフィードバック磁界が磁気抵抗効果素子10に印加されることから、同じ電流値でより多くのフィードバック磁界を磁気抵抗効果素子10に印加できる。
第1の電流線20Aおよび第2の電流線20Bは、その寸法、構成する材料等は電流線20と同じであってよい。
またフィードバック電流を流す電流線を3層以上(高さ方向に3層以上)形成してもよい。
次に、本実施形態の効果をより明確にするために行ったシミュレーションの結果を説明する。
図15に示す構成を有する磁気センサ140をモデルとしてシミュレーションを行った。
第1の電流線20Aと磁気抵抗効果素子10との間に配置した絶縁層12は、長さ(Y方向長さ)100μm、幅4μm、厚さ1μmとした。
第2の電流線20Bも銅より成る幅4μm、厚さ1μmの断面が長方形形状の導体とした。また隣り合う電流線20Bの間の距離(隙間)は4μmとした。
第1の電流線20Aと第2の電流線20Bとの間に配置した絶縁層12は、長さ100μm、幅4μm、厚さ1μmとした。
これ以外の条件は、実施形態2に示した磁気センサ120のシミュレーション条件と同じにした。
図16のグラフの横軸は第1の電流線20Aと第2の電流線20Bとに流す電流(フィードバック電流)の大きさを示し、縦軸は磁気抵抗効果素子10に印加される磁界(磁束密度)の大きさを示す。
図16には、実施形態2で示した磁気センサ120のシミュレーション結果を再度示した。
図16では、磁界の大きさをマイナスで示しているが絶対値が大きいほどより大きな磁界が印加されることを示す。
図16の結果より、同じ電流を流した場合、電流線が2層構造となっている磁気センサ140は、電流線が1層構造である磁気センサ120と比べて磁気抵抗効果素子10により大きなフィードバック磁界が印加されることが判る。
図17は、本発明の実施形態4に係る磁気センサ150を示し、図17(a)は磁気センサ150の上面図であり、図17(b)は図17(a)に示した平面コイル70の直線部Bを拡大した上面図であり、図17(c)は図17(b)の5c-5c断面を示す断面図である。
磁気センサ150は、電流線20の上に絶縁層12を介してバイアス磁界印加用電流線22を有している点が実施形態1に係る磁気センサ120と異なる。
バイアス磁界印加用電流線22は、磁気抵抗効果素子10の延在方向(Y方向)に垂直な方向(すなわち電流線20の延在方向に垂直な方向)に延在している。
磁気抵抗効果素子10の全長に亘ってバイアス磁界を印加できるように、バイアス磁界印加用電流線22は、図17に示すように、磁気抵抗効果素子10の延在方向に亘って、平行に複数配置されていることが好ましい。図17の実施形態では11本配置されている。
なおバイアス磁界印加用電流線22の寸法および構成材料は電流線20と同じであってよい。
磁気センサ160は、磁気抵抗効果素子10と電流線20との間に絶縁層12を介して(磁気抵抗効果素子との間および電流線20との間の両方に絶縁層12が配置されてよい)バイアス磁界印加用電流線22を有している点が実施形態1に係る磁気センサ120と異なる。その他の磁気センサ160の構成は磁気センサ150の構成とおなじでよい。
すなわち、磁気センサ150ではバイアス磁界印加用電流線22よりも電流線20の方が磁気抵抗効果素子10に近い位置に配置され、磁気センサ160では電流線20よりもバイアス磁界印加用電流線22の方が磁気抵抗効果素子10に近い位置に配置されている。
被測定磁界範囲を大きくしたい場合つまりフィードバック磁界を大きくしたい場合は、磁気センサ150の配置の方が好ましく、より高精度な測定が必要な場合は、磁気センサ160の配置の方が好ましい。
図19は、本発明の実施形態5に係る磁気センサ170を示し、図19(a)は磁気センサ170の上面図であり、図19(b)は図19(a)に示した平面コイル70の直線部Bを拡大した上面図であり、図19(c)は図19(b)の7c-7c断面を示す断面図である。
磁気センサ170は、上述の磁気センサ130において、電流線20が、上述の磁気センサ140に示した第1の電流線20Aと第2の電流線20Bとから成る2層構造に変更された構成を有している。
図20は、本発明の実施形態6に係る磁気センサ180を示し、図20(a)は磁気センサ180の上面図であり、図20(b)は図20(a)に示した平面コイル70の直線部Bを拡大した上面図であり、図20(c)は図20(b)の8c-8c断面を示す断面図である。
磁気センサ180は、上述の磁気センサ150において、バイアス磁界印加用電流線の上に、絶縁層12を介して、上述の磁気センサ130に示したヨーク層16を設けた構成を有している。
磁気センサ190は、上述の磁気センサ160において、電流線20の上に、絶縁層12を介して、上述の磁気センサ130に示したヨーク層16を設けた構成を有している。
図22は、本発明の実施形態7に係る磁気センサ200を示し、図22(a)は磁気センサ200の上面図であり、図22(b)は図22(a)に示した平面コイル70の直線部Bを拡大した上面図であり、図22(c)は図22(b)の10c-10c断面を示す断面図である。
磁気センサ200は、上述の磁気センサ140において、第2の電流線20Bの上に、絶縁層12を介して、上述の磁気センサ150に示したバイアス磁界印加用電流線22を設けた構成を有している。
磁気センサ210は、上述の磁気センサ140において、磁気抵抗効果素子10と第1の電流線20Aとの間に絶縁層12を介して(磁気抵抗効果素子10との間および電流線20との間の両方に絶縁層12が配置されてよい)、上述の磁気センサ160に示したバイアス磁界印加用電流線22を設けた構成を有している。
図24は、本発明の実施形態8に係る磁気センサ220を示し、図24(a)は磁気センサ220の上面図であり、図24(b)は図24(a)に示した平面コイル70の直線部Bを拡大した上面図であり、図24(c)は図24(b)の12c-12c断面を示す断面図である。
磁気センサ220は、上述の磁気センサ200において、バイアス磁界印加用電流線22の上に、絶縁層12を介して、上述の磁気センサ130に示したヨーク層16を設けた構成を有している。
磁気センサ230は、上述の磁気センサ210において第2の電流線20Bの上に、絶縁層12を介して、上述の磁気センサ130に示したヨーク層16を設けた構成を有している。
図26は本発明の実施形態9に係る磁気センサ240を示す平面図である。
磁気センサ240では、その下部に磁気抵抗効果素子10が配置された第2の電流線20と、この電流線20の両隣に配置された第1の電流線(第2の電流線からX方向に位置)と第3の電流線(第2の電流線から-X方向に位置)に加えて、第1の電流線よりも外側(X方向)に位置し、その下部にヨーク層14を備えた電流線(第4の電流線)20と、第3の電流線よりも外側(-X方向)に位置し、その下部にヨーク層14を備えた電流線(第5の電流線)20とを有する。
第4の電流線20および第5の電流線20は、第1の電流線20と平行に延在している(すなわち第2および第3の電流線とも平行に延在している。)
ヨーク層14として、例えばパーマロイ等の合金膜を形成してよい。また、軟磁性材料層を含む多層膜であってもよい。このような多層膜のヨーク層14の1つの形態として、電気的に接続されていない磁気抵抗効果素子(ダミーの磁気抵抗効果素子)を形成することを例示できる(例えば、図26において、ヨーク層14をダミーの磁気抵抗効果素子としてよい)。
さらに、例えば、図3に示す磁気センサにおいて、磁気抵抗効果素子10a、10b、10d、10eを電気的に接続せず(磁気抵抗効果素子として用いず)ヨーク層14として用い、磁気抵抗効果素子としては磁気抵抗効果素子10cのみを用いてもよい。
磁気センサ回路は既知の任意の構成を有してよい。
図27は、磁気センサ回路(フィードバック回路)の例を示す概略回路図である。
図27に示す磁気センサ回路は、いわゆる磁気平衡型の回路であり、例えば電流センサとして利用できる。この磁気センサ回路は、磁気抵抗効果素子10(2つ以上の磁気抵抗効果素子10であってもよい)の一端側は直流の定電流源Iccまたは定電圧源Vccから電流の供給を受けるよう接続され、また、コンパレータ314の負極(-)端子に接続される。また、磁気抵抗効果素子10の他端側は固定抵抗を介して共通端子(GND)に接続される。磁気抵抗効果素子10が、固定層が反対向きの2種類の場合は、上記固定抵抗部分が2種類のうちのひとつとなる。なお、コンパレータ314の正極(+)端子は、基準電源315を介して共通端子(GND)に接続される。基準電源315の出力電位は、磁界のない場所における磁気抵抗効果素子10の電位とする。
図27に示す回路を備えた磁気センサは、磁気抵抗効果素子10が出力する電圧信号を、コンパレータ314、波形整形部341及びLPF342を通じて得る。このLPF342を介して得られた出力は、基準電源の電位と磁気抵抗効果素子10の出力する電圧信号の電位との差に比例する電圧信号となる。
ここで、この磁気センサを被測定電流の流れる導体(例えばバス・バー)の近傍に配すると、この被測定電流により生じる誘導磁界により磁気抵抗効果素子10の抵抗値が変化する。すると、その出力電位が磁界のないときの電位(既に述べたように基準電源の電位はこの電位に等しくしておく)からずれるので(オフセット)、コンパレータ314、波形整形部341及びLPF342を通じて得られる出力は、この電位のずれ量に応じた大きさの電圧信号となる。この電圧信号が被測定電流(バス・バー内を流れる電流)により生じる誘導磁界の強さを表す。
しかし、2つ以上の磁気抵抗効果素子10を電気的に接続して、ブリッジ回路を形成する構成はこれに限定されるものでなく、既知の任意の構成を用いてよい。
図28は、4つの磁気抵抗効果素子10を用いてフルブリッジ回路を構成した例を示す概略回路図である。
図28に示すように、1つの磁気センサに、4つの磁気抵抗効果素子10を配置して、フルブリッジの構成とすることで、磁気抵抗効果素子10がコモンモードノイズなどの電圧変化をキャンセルして、測定精度が向上する。
その場合に磁気抵抗効果素子10をフィードバックコイルの1つの電流線に、当該電流線の電流が流れる方向に沿って2つ配置することで、1つの電流線に1つの磁気抵抗効果素子10を配置した場合と比べ、フィードバックコイルの巻数を少なくできる。この結果、フィードバックコイルの長さを短くでき、フィードバックコイルの抵抗が下がるため、フィードバック電圧を下げる事ができ、低電圧で動作可能になる。
さらに、その感磁軸の向きを考慮して磁気抵抗効果素子10を配置することで磁気的なノイズのキャンセルも期待できる。例えば2つのハーフブリッジでフルブリッジ回路を構成した場合であれば、同じ電流線から発生する誘導磁界の向きが反対になる位置に、ハーフブリッジをそれぞれ配置することで、均一な外部磁界によるノイズはキャンセルされる。
なお、フルブリッジ回路は、上述のように、4つまたは4つ以上の磁気抵抗効果素子10を用いて構成する以外に、例えば3つの磁気抵抗効果素子10を用いて構成してもよい。
詳細を以下に示す。
表1は、作製したサンプルの詳細および得られた検出効率の結果を示す。
また、それぞれのサンプルと同じ構成を示す図、より具体的な、フィードバックコイルと、バイアスコイルと、ヨーク層(配置された場合のみ)の積層順を示す図を「図」欄に記載した。
なお、「図」欄では、フィードバックコイルと、バイアスコイルと、ヨーク層(配置された場合のみ)のうち、最も下側(磁気抵抗効果素子10に近い側)に位置するものを左に記載し、積層したフィードバックコイルと、バイアスコイルと、ヨーク層とを積層順左から右に記載している。
図29を用いて、実施例サンプルの詳細を説明する。以下に説明する寸法はいずれも設計値(狙い値)であり、製造上の精度の問題から、実際の寸法は、本発明の効果を確認するのに問題のない範囲でこの設計値から若干ずれている可能性があることに留意されたい。
いずれのサンプルも非磁性であるシリコンから成る基板40上に形成した。具体的には、基板40の表面を酸化して形成したSiO2の絶縁層12の上に2つの磁気抵抗効果素子10を配置した。用いた磁気抵抗効果素子10はGMR感磁膜(SVGMR感磁膜)を有する、SVGMR素子である。なお、図29から判るように、2つの磁気抵抗効果素子10のうちの1つ(図29の左側)は、上述のSiO2の絶縁層12の上に更に厚さ0.03μmの絶縁層12を形成した後、この厚さ0.03μmの絶縁層12上に形成した。磁気抵抗効果素子10のGMR感磁膜の幅(X方向の長さ)Wgは、それぞれLs/Wgが表1に記載した条件になるように適宜選択し、磁気抵抗効果素子10のGMR感磁膜の長さ(Y方向の長さ)は、全ての条件で電気抵抗が一定となるように幅に応じて長さを選択した。
2つの磁気抵抗効果素子10を覆うように、厚さ0.2μmの絶縁層12を形成した後、更に厚さ1.3μmの絶縁層12を形成した。
いずれの実施例サンプルでもフィードバックコイルは、7巻の平面コイルであり、図29に示す断面上に1つのフィードバックコイルについて7つの電流線20が形成された。
電流線20の幅Wpは4μm(幅は、例えば、上面視における端部間の距離を計測することにより測定可能)であり、隣り合う電流線20の距離d2は4μmであり、厚さは0.8μmであった。
従って、第1の電流線の外側から前記第3の電流線の外側までの長さLsは20μmであった。
フィードバックコイル、バイアスコイルおよび配線はAl-Cuをスパッタにより形成した。
また、ヨーク層を設ける場合は、幅52μm、長さ138μm、厚さ1μmのヨーク層をNi-Feをめっきにより形成した。
従って、図29に示すサンプル1の場合、1つ目のフィードバックコイルの電流線である第1の電流線20Aの上に厚さ1.3μmの絶縁層12が形成され、この絶縁層12の上に2つ目のフィードバックコイルの電流線である第2の電流線20Bが形成されている。そして、第2の電流線20Bの上に絶縁膜12が形成され、この絶縁層12の上にバイアスコイルの電流線22が形成されている。さらに、電流線22の上にも絶縁層12が形成されている。
なお、実施例サンプルで用いた絶縁層12は、SiO2膜、Al2O3膜、ハードベークレジストの中から適宜選択して形成した。
フィードバックに必要な最大電流の測定を行った。得られた最大フィードバック電流(表1の最大FB電流)を表1に示す。
検出効率=(動作範囲/2)/最大フィードバック電流
表1に示すように、比較例に対して、本発明の実施例ではフィードバック電流あたりの検出効率が大きくなっており、消費電流が小さくなっていることが確認できた。また、ヨーク層を設けることにより、さらに検出効率が高くなることもわかった。
12 絶縁層
14、16 ヨーク層
20 電流線
20A 第1の電流線
20B 第2の電流線
20C 第3の電流線
22 バイアス磁界印加用電流線
36、38 中心線
70、72 平面コイル
100、120、130、140、150、160、170、180、190、200、210、220、230、240 磁気センサ
Claims (15)
- 幅方向に順に互いに平行に配置され、電気的に直列に接続されている第1の電流線、第2の電流線および第3の電流線と、
該第2の電流線の下部に配置され、該第2の電流線の延在する方向に沿って延在し、前記第1の電流線、第2の電流線および第3の電流線を流れる電流により生じた誘導磁界により電気抵抗が変化する磁気抵抗効果素子と、
を有し、
幅方向における、前記第1の電流線の外側から前記第3の電流線の外側までの長さLsと前記磁気抵抗効果素子の幅方向の長さWgとが下記(1)式を満足することを特徴とする磁気センサ。
Ls/Wg≦5 (1)
- 前記第2の電流線の幅方向の長さWpと前記磁気抵抗効果素子の幅方向の長さWgとが下記(2)式を満足することを特徴とする請求項1に記載の磁気センサ。
Wp≦Wg (2)
- 前記磁気抵抗効果素子が複数配置されていることを特徴とする請求項1又は2に記載の磁気センサ。
- 前記第1の電流線、第2の電流線および第3の電流線が、平面コイルの一部であることを特徴とする請求項1~3のいずれか1項に記載の磁気センサ。
- 前記第1の電流線、第2の電流線および第3の電流線を覆うヨーク層が、該第1の電流線、第2の電流線および第3の電流線の上に配置されていることを特徴とする請求項1~4のいずれか1項に記載の磁気センサ。
- 前記前記第1の電流線、第2の電流線および第3の電流線が、それぞれ、上下方向に2層以上形成されていることを特徴とする請求項1~5のいずれか1項に記載の磁気センサ。
- 前記の第2の電流線の延在する方向に垂直な方向に延在する複数のバイアス磁界印加用電流線であって、流れる電流により生じた誘導磁界により前記磁気抵抗効果素子にバイアス磁界を印加するバイアス磁界印加用電流線をさらに有することを特徴とする請求項1~6のいずれか1項に記載の磁気センサ。
- 前記複数のバイアス磁界印加用電流線が、前記第1の電流線、第2の電流線および第3の電流線よりも上部に配置されることを特徴とする請求項7に記載の磁気センサ。
- 前記複数のバイアス磁界印加用電流線が、前記第2の電流線と前記磁気抵抗効果素子との間に配置されることを特徴とする請求項7に記載の磁気センサ。
- 前記複数のバイアス磁界印加用電流線が、前記第1の電流線、第2の電流線および第3
の電流線よりも下部に配置されることを特徴とする請求項7に記載の磁気センサ。 - 前記磁気抵抗効果素子が、スピンバルブ巨大磁気抵抗効果素子であることを特徴とする請求項1~10のいずれか1項に記載の磁気センサ。
- 前記第1の電流線と平行に延在し、かつ前記第1の電流線よりも外側に配置された第4の電流線と、
前記第3の電流線と平行に延在し、かつ前記第3の電流線よりも外側に配置された第5の電流線と、
前記第4の電流線の下部に配置され、軟磁性材料を含んで成り、前記第1~第5の電流線および前記磁気抵抗効果素子と電気的に接続されていない第1のヨーク層と、
前記第5の電流線の下部に配置され、軟磁性材料を含んで成り、前記第1~第5の電流線および前記磁気抵抗効果素子と電気的に接続されていない第2のヨーク層と、
を更に含むことを特徴とする請求項1~11のいずれか1項に記載の磁気センサ。 - 前記磁気抵抗効果素子が2つ以上配置され、該2つ以上の磁気抵抗効果素子が、ブリッジ回路を形成するように電気的に接続されていることを特徴とする請求項1~12のいずれか1項に記載の磁気センサ。
- 前記ブリッジ回路が、ハーフブリッジ回路であることを特徴とする請求項13に記載の磁気センサ。
- 前記ブリッジ回路が、フルブリッジ回路であることを特徴とする請求項13に記載の磁気センサ。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP14768164.7A EP2977777B1 (en) | 2013-03-18 | 2014-03-17 | Magnetic sensor |
JP2015506770A JP6406245B2 (ja) | 2013-03-18 | 2014-03-17 | 磁気センサ |
CN201480016300.7A CN105143902B (zh) | 2013-03-18 | 2014-03-17 | 磁传感器 |
US14/777,877 US9964602B2 (en) | 2013-03-18 | 2014-03-17 | Magnetic sensor |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2013-055449 | 2013-03-18 | ||
JP2013055449 | 2013-03-18 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2014148437A1 true WO2014148437A1 (ja) | 2014-09-25 |
Family
ID=51580116
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2014/057152 WO2014148437A1 (ja) | 2013-03-18 | 2014-03-17 | 磁気センサ |
Country Status (5)
Country | Link |
---|---|
US (1) | US9964602B2 (ja) |
EP (1) | EP2977777B1 (ja) |
JP (1) | JP6406245B2 (ja) |
CN (1) | CN105143902B (ja) |
WO (1) | WO2014148437A1 (ja) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2016080470A1 (ja) * | 2014-11-18 | 2016-05-26 | 日立金属株式会社 | 磁気センサ及びその製造方法並びにそれを用いた電流量検出器 |
WO2017169156A1 (ja) * | 2016-03-30 | 2017-10-05 | アルプス電気株式会社 | 平衡式磁界検知装置 |
JP2018505404A (ja) * | 2015-01-07 | 2018-02-22 | 江▲蘇▼多▲維▼科技有限公司Multidimension Technology Co., Ltd. | キャリブレーション/初期化コイルを有するシングルチップz軸線形磁気抵抗センサ |
JP2019518956A (ja) * | 2016-06-07 | 2019-07-04 | 江▲蘇▼多▲維▼科技有限公司Multidimension Technology Co., Ltd. | 補償コイルを有する磁気抵抗センサ |
JP2021028596A (ja) * | 2019-08-09 | 2021-02-25 | ビフレステック株式会社 | ゼロフラックス型磁気センサ |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP7049102B2 (ja) * | 2016-12-07 | 2022-04-06 | 旭化成エレクトロニクス株式会社 | 電流センサ |
WO2018143122A1 (ja) | 2017-02-02 | 2018-08-09 | アルプス電気株式会社 | 平衡式電流センサ |
US10739165B2 (en) * | 2017-07-05 | 2020-08-11 | Analog Devices Global | Magnetic field sensor |
CN110780243A (zh) * | 2019-11-19 | 2020-02-11 | 中国电子科技集团公司第四十九研究所 | 用于水下导航的高灵敏度微型磁传感单元、含有该传感单元的传感器及传感单元的制备方法 |
JP7106591B2 (ja) * | 2020-03-18 | 2022-07-26 | Tdk株式会社 | 磁場検出装置および電流検出装置 |
CN112014001B (zh) * | 2020-08-24 | 2022-06-10 | 歌尔微电子有限公司 | 微机电系统力学传感器、传感器单体及电子设备 |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003202365A (ja) * | 2001-10-29 | 2003-07-18 | Yamaha Corp | 磁気センサ |
WO2010143666A1 (ja) * | 2009-06-12 | 2010-12-16 | アルプス・グリーンデバイス株式会社 | 磁気平衡式電流センサ |
WO2011111493A1 (ja) * | 2010-03-12 | 2011-09-15 | アルプス・グリーンデバイス株式会社 | 電流センサ |
JP2011196798A (ja) | 2010-03-18 | 2011-10-06 | Tdk Corp | 電流センサ |
WO2013018665A1 (ja) * | 2011-08-01 | 2013-02-07 | アルプス・グリーンデバイス株式会社 | 電流センサ |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2052855B (en) * | 1979-03-30 | 1983-05-18 | Sony Corp | Magnetoresistive transducers |
US5390061A (en) * | 1990-06-08 | 1995-02-14 | Hitachi, Ltd. | Multilayer magnetoresistance effect-type magnetic head |
JP4105147B2 (ja) * | 2004-12-06 | 2008-06-25 | Tdk株式会社 | 電流センサ |
CN103069282B (zh) | 2010-08-23 | 2015-06-03 | 阿尔卑斯绿色器件株式会社 | 磁平衡式电流传感器 |
WO2013141124A1 (ja) * | 2012-03-23 | 2013-09-26 | 日立金属株式会社 | 磁気センサデバイス |
-
2014
- 2014-03-17 JP JP2015506770A patent/JP6406245B2/ja not_active Expired - Fee Related
- 2014-03-17 WO PCT/JP2014/057152 patent/WO2014148437A1/ja active Application Filing
- 2014-03-17 EP EP14768164.7A patent/EP2977777B1/en not_active Not-in-force
- 2014-03-17 CN CN201480016300.7A patent/CN105143902B/zh not_active Expired - Fee Related
- 2014-03-17 US US14/777,877 patent/US9964602B2/en not_active Expired - Fee Related
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003202365A (ja) * | 2001-10-29 | 2003-07-18 | Yamaha Corp | 磁気センサ |
WO2010143666A1 (ja) * | 2009-06-12 | 2010-12-16 | アルプス・グリーンデバイス株式会社 | 磁気平衡式電流センサ |
WO2011111493A1 (ja) * | 2010-03-12 | 2011-09-15 | アルプス・グリーンデバイス株式会社 | 電流センサ |
JP2011196798A (ja) | 2010-03-18 | 2011-10-06 | Tdk Corp | 電流センサ |
WO2013018665A1 (ja) * | 2011-08-01 | 2013-02-07 | アルプス・グリーンデバイス株式会社 | 電流センサ |
Non-Patent Citations (1)
Title |
---|
See also references of EP2977777A4 |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2016080470A1 (ja) * | 2014-11-18 | 2016-05-26 | 日立金属株式会社 | 磁気センサ及びその製造方法並びにそれを用いた電流量検出器 |
JPWO2016080470A1 (ja) * | 2014-11-18 | 2017-08-24 | 日立金属株式会社 | 磁気センサ及びその製造方法並びにそれを用いた電流量検出器 |
CN107110920A (zh) * | 2014-11-18 | 2017-08-29 | 日立金属株式会社 | 磁传感器及其制造方法以及使用该磁传感器的电流量检测器 |
US10545198B2 (en) | 2014-11-18 | 2020-01-28 | Hitachi Metals, Ltd. | Magnetic sensor, manufacturing method thereof, and current detector using the same |
JP2018505404A (ja) * | 2015-01-07 | 2018-02-22 | 江▲蘇▼多▲維▼科技有限公司Multidimension Technology Co., Ltd. | キャリブレーション/初期化コイルを有するシングルチップz軸線形磁気抵抗センサ |
WO2017169156A1 (ja) * | 2016-03-30 | 2017-10-05 | アルプス電気株式会社 | 平衡式磁界検知装置 |
JPWO2017169156A1 (ja) * | 2016-03-30 | 2018-07-05 | アルプス電気株式会社 | 平衡式磁界検知装置 |
JP2019518956A (ja) * | 2016-06-07 | 2019-07-04 | 江▲蘇▼多▲維▼科技有限公司Multidimension Technology Co., Ltd. | 補償コイルを有する磁気抵抗センサ |
JP2021028596A (ja) * | 2019-08-09 | 2021-02-25 | ビフレステック株式会社 | ゼロフラックス型磁気センサ |
Also Published As
Publication number | Publication date |
---|---|
US9964602B2 (en) | 2018-05-08 |
JPWO2014148437A1 (ja) | 2017-02-16 |
CN105143902B (zh) | 2018-01-23 |
EP2977777A4 (en) | 2017-02-22 |
EP2977777A1 (en) | 2016-01-27 |
JP6406245B2 (ja) | 2018-10-17 |
EP2977777B1 (en) | 2018-07-25 |
CN105143902A (zh) | 2015-12-09 |
US20160274196A1 (en) | 2016-09-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP6406245B2 (ja) | 磁気センサ | |
JP4458149B2 (ja) | 磁気カプラ | |
US8519704B2 (en) | Magnetic-balance-system current sensor | |
US8760158B2 (en) | Current sensor | |
JP5411285B2 (ja) | 磁気平衡式電流センサ | |
JP5888402B2 (ja) | 磁気センサ素子 | |
US20130057273A1 (en) | Current sensor | |
JP5487402B2 (ja) | 磁気平衡式電流センサ | |
JP6658676B2 (ja) | 電流センサ | |
JP5234459B2 (ja) | 電流センサ | |
WO2012053296A1 (ja) | 電流センサ | |
US20130057274A1 (en) | Current sensor | |
US9146260B2 (en) | Magnetic balance type current sensor | |
WO2015156260A1 (ja) | 電流検知装置 | |
WO2011111457A1 (ja) | 磁気センサ及びそれを備えた磁気平衡式電流センサ | |
WO2020054112A1 (ja) | 磁気センサおよび電流センサ | |
JP5509531B2 (ja) | 磁気カプラ | |
JP5422890B2 (ja) | 磁気カプラ | |
WO2015046206A1 (ja) | 電流センサ | |
JP2012198085A (ja) | 電流センサ |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 201480016300.7 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 14768164 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2015506770 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2014768164 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14777877 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |