JP2001099654A - Flux gate sensor and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need of forming a solenoid-like coil to the periphery of a magnetic layer or applying an external magnetic field in a thickness direction to the thin film magnetic layer in a flux gate sensor. SOLUTION: Exciting coils 23 and detecting coils 24, and exciting coils 28 and detecting coils 29a, 29b are formed respectively on the same planes. Magnetic layers 26a and 26b are formed to an upper part of the exciting coils 23 and detecting coils 24, and to a lower part of the exciting coils 28 and detecting coils 29a, 29b. Manufacturing the flux gate sensor is facilitated and a sensitivity is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called fluxgate sensor in which an output voltage characteristic from a detection coil changes when an external magnetic field is applied to a magnetic core made of a soft magnetic material excited by an alternating current. The present invention relates to a fluxgate sensor capable of reducing the influence of a demagnetizing field sometimes generated in a magnetic core and improving the detection sensitivity of an external magnetic field, and a method of manufacturing the same.

[0002]

2. Description of the Related Art A flux gate sensor is a type of magnetic modulation type magnetic field sensor that can be used at room temperature, is easily miniaturized and has high sensitivity, and is excellent as a sensor for directly measuring a minute magnetic field. Having.

FIG. 12 is a conceptual diagram showing a basic structure of a flux gate sensor. The flux gate sensor basically includes a magnetic core made of a soft magnetic material, an excitation coil for AC-exciting the magnetic core, and a detection coil for extracting an output. An exciting magnetic field is generated by passing an alternating current of a fundamental frequency through the exciting coil, and the magnetic core is AC-excited in the element longitudinal direction (X direction). When the magnetic core is AC-excited, an induced current is generated in the detection coil,
A voltage is induced across the detection coil.

FIGS. 13 and 14 are diagrams for explaining the principle of magnetic field detection by the flux gate sensor of FIG.

When an alternating current having a fundamental frequency is applied to the exciting coil, an exciting magnetic field having a fundamental frequency is generated, and the magnetic core is excited. With the excitation of the magnetic core, the magnetic flux density linked to the detection coil changes, an induced current is generated in the detection coil, and a voltage is induced at both ends of the detection coil. FIG.
The excitation waveform of No. 3 is the waveform of the excitation magnetic field of the fundamental frequency, and the detection voltage waveform is the waveform of the voltage induced at both ends of the detection coil.

FIG. 13 shows a state where no external magnetic field is applied to the magnetic core. When no external magnetic field is applied to the magnetic core, the excitation waveform and the detected voltage waveform have the same shape.

FIG. 14 shows a state when an external magnetic field Hex is applied in the longitudinal direction of the magnetic core. When an external magnetic field Hex is applied in the longitudinal direction of the magnetic core, the BH curve (hysteresis curve) in FIG. 13 moves in the external magnetic field direction, the symmetry of the magnetic flux density of the magnetic core is broken, and the detected voltage waveform becomes Even harmonic components with respect to the included fundamental frequency increase.

The increase in the even-order harmonic components corresponds to the magnitude of the external magnetic field Hex. Even-order harmonic components of the detected voltage waveform are separated from the fundamental component by a signal processing circuit or synchronous rectification.

FIG. 15 shows a conventional example of a flux gate sensor formed using a thin film forming process, which operates based on the above-described principle.

In the flux gate sensor shown in FIG. 15, first, an inorganic insulating layer 2 made of SiO ₂ or the like is laminated on a substrate 1 made of Si or the like, and a lower layer portion 5b of an exciting coil 5 and a detecting coil are formed on the inorganic insulating layer 2. The lower layer portion 6b of the substrate 6 is patterned using a conductive material such as Al. A magnetic core 4 is formed in a rod shape from a soft magnetic material such as permalloy via the organic insulating layer 3 made of polyimide or the like on the lower layer portions 5b and 6b. The organic insulating layer 3 also covers the upper layer of the magnetic core 4, and the upper layer 5 a of the exciting coil 5 and the upper layer 6 a of the detection coil 6 are laminated on the organic insulating layer 3. The upper layer 5a and the lower layer 5b of the excitation coil 5 and the upper layer 6a and the lower layer 6b of the detection coil 6 are spirally connected to each other,
To form a solenoid-shaped coil wound around.

An exciting magnetic field is generated by applying an alternating current of a fundamental frequency to both ends of the exciting coil 5 to excite the magnetic core 4 in the element longitudinal direction (X direction). When the magnetic core 4 is AC-excited, an induced current is generated in the detection coil 6, and a voltage is induced at both ends of the detection coil 6. An external magnetic field Hex is applied in the longitudinal direction (X direction) of the magnetic core 4 and the detection coil 6
The external magnetic field Hex is measured by measuring the change of the even-order harmonic component with respect to the fundamental frequency included in the output.

[0012]

However, the flux gate sensor shown in FIG. 15 has the following disadvantages.

In the flux gate sensor shown in FIG. 15, the upper layer 5a and lower layer 5b of the exciting coil 5 and the upper layer 6a and lower layer 6b of the detection coil 6 are wound around the magnetic core 4. The coils are spirally connected to form a solenoid coil. However, as shown in FIG. 15, it is difficult to accurately pattern the upper layer portion 5a of the exciting coil 5 and the upper layer portion 6a of the detection coil 6 on the step formed by the magnetic core 4 and the organic insulating layer 3. There has been a problem that the error increases and the occurrence rate of defective products also increases.

Japanese Patent Application Laid-Open No. Hei 8-201061 discloses a fluxgate sensor in which an exciting coil and a detecting coil are patterned on a plane in order to avoid difficulties in manufacturing.

FIG. 16 is a plan view of the fluxgate sensor disclosed in Japanese Patent Application Laid-Open No. 8-201061.
The flux gate sensor of FIG. 16 has coils 12a and 12b formed by patterning a thin film of a low-resistance material.
(Excitation coil) inside the high magnetic permeability material thin film 11a, 11
b is formed. Furthermore, the high magnetic permeability material thin film 11
A coil (receiving coil 13, feedback coil 14) formed by patterning a thin film of a low-resistance material so as to surround a and 11b is formed.

However, in the flux gate sensor shown in FIG. 16, since the high permeability material thin films 11a and 11b are formed inside the coils 12a and 12b (excitation coils), the high permeability material thin films 11a and 11b are thin films. And the external magnetic field Hex to be detected is also applied in the thickness direction of the thin film (perpendicular to the paper). Therefore, when the external magnetic field Hex is applied, the external magnetic field Hex
In this case, the influence of the demagnetizing field generated in the opposite direction increases, and the detection sensitivity of the external magnetic field Hex decreases.

The present invention has been made to solve the above-mentioned conventional problems. In particular, an exciting coil and a detecting coil are formed on the same plane, and a magnetic layer is disposed above or below the exciting coil and the detecting coil. Accordingly, it is an object of the present invention to provide a fluxgate sensor which can be easily manufactured and can reduce the influence of a demagnetizing field, and a method of manufacturing the same.

[0018]

According to the present invention, there is provided an exciting coil in which an alternating current is applied to generate an induced magnetic field, a magnetic layer in which the induced magnetic field flows, and a voltage induced by the induced magnetic field flowing through the magnetic layer. The excitation coil is formed by being spirally wound on a substrate, and the detection coil is formed on the same plane on the inner peripheral side or outer peripheral side of the excitation coil. To form a coil layer together with the excitation coil, and the magnetic layer is formed above or below the excitation coil and the detection coil.

In the fluxgate sensor according to the present invention, since the detection coil is formed on the same plane as the excitation coil, it is not necessary to form the detection coil and the excitation coil with a stepped structure. Accordingly, the detection coil and the excitation coil can be easily formed, and the pattern can be accurately formed, so that a manufacturing error can be reduced and a defective product occurrence rate can be suppressed.

In the present invention, the exciting coil is formed in a spiral shape, and the magnetic layer is formed above or below the exciting coil.
The magnetic layer is excited in a plane direction by a magnetic field generated from the excitation coil. Therefore, when an external magnetic field to be detected is applied in the surface direction of the magnetic layer, the detection sensitivity of the external magnetic field is highest. Since the plane direction of the magnetic layer is the direction in which the demagnetizing coefficient is the lowest, the influence of the demagnetizing field when an external magnetic field is applied in the plane direction of the magnetic layer is small, and the detection sensitivity of the external magnetic field can be improved. .

It is preferable that the coil layer including the excitation coil and the detection coil is formed above and below the magnetic layer, since the detection sensitivity of the external magnetic field is improved.

When the coil layer including the excitation coil and the detection coil is formed above and below the magnetic layer, the excitation coil and the detection coil located above and below are respectively connected in series. Is preferred.

Further, a plurality of the magnetic layers may be provided, and each of the magnetic layers may be arranged at a position overlapping the exciting coil and the detecting coil.

Further, each of the plurality of magnetic layers is superimposed on an upper portion or a lower portion of a portion of the exciting coil formed in a plane and opposed on the plane, and the inner or outer periphery of the exciting coil is provided. When the plurality of detection coils formed on the side are formed in the same winding direction, and each of the detection coils faces a different one of the magnetic layers, a magnetic flux density crossing between the detection coils is reduced. The asymmetry can be increased, and the output voltage can be increased by differentially connecting the detection coils and extracting a detection output. That is, the detection sensitivity of the external magnetic field can be improved.

In order to differentially connect the plurality of detection coils, for example, the plurality of detection coils are connected to each other so as to form a figure eight coil shape.

Further, a pair of the detection coils is provided on the inner peripheral side or the outer peripheral side of a portion of the exciting coil which is wound in a plane and opposed on the plane, and another portion on which the exciting coil is opposed on the plane. If a pair of the detection coils is further provided on the inner peripheral side or outer peripheral side, not only the magnitude but also the direction of the external magnetic field can be detected.

The magnetic layer is preferably made of a magnetic material having a magnetic permeability at 1 MHz of 1,000 or more.

Further, it is preferable that the magnetic layer is formed of a soft magnetic thin film or ribbon having a large specific resistance and suitable for high-frequency excitation. For example, in the magnetic layer, the composition formula is represented by Fe _h M _i O _j , 50% or more of the entire structure is an amorphous phase, and the remainder is Fe crystal grains having a bcc structure with an average crystal grain size of 30 nm or less. It can be formed as a soft magnetic thin film.

Here, M is Ti, Zr, Hf, V, N
one or two selected from b, Ta, W and a rare earth element
H, i, j are at% and 45 ≦ h
≦ 70, 5 ≦ i ≦ 30, 10 ≦ j ≦ 40, h + i + j =
100 are satisfied.

Alternatively, the magnetic layer has a composition formula (Co)
_{1-c T c) x M} y X z O w is represented by, and an amorphous phase containing a large amount of oxide of the element M, bc composed mainly of Co and element T
It can be formed as a soft magnetic thin film in which a microcrystalline phase composed of one or more crystal grains of the c structure and the fcc structure is mixed.

Here, the element T is an element containing one or both of Fe and Ni, and the element M is
i, Zr, Hf, V, Nb, Ta, Cr, Mo, Si,
P, C, W, B, Al, Ga, Ge and one or more elements selected from rare earth elements, and X is Au,
Ag, Cu, Ru, Rh, Os, Ir, Pt, Pd, and at least one element selected from the group consisting of: 0 ≦ c ≦ 0.7, x, y, z, w is atomic%
Where 3 ≦ y ≦ 30, 0 ≦ z ≦ 20, 7 ≦ w ≦ 40, 20
<Y + z + w ≦ 60 is satisfied, and the balance is x.

[0032] Alternatively, the magnetic layer has a composition formula Co _l T
a _m is represented by Hf _n, amorphous phase can be formed as a soft magnetic thin film composed mainly.

Here, l, m and n are at% and 70 ≦ l
≦ 90, 5 ≦ m ≦ 21, 6.6 ≦ n ≦ 15, 1 ≦ m / n
<2.5 is satisfied.

In addition, a Co-Fe-Si-B-based Co-based amorphous soft magnetic ribbon is preferably used.

The method of manufacturing a flux gate sensor according to the present invention includes: (a) forming the exciting coil on a substrate by winding it in a spiral shape; and (b) inner or outer circumference of the exciting coil. Forming the detection coil on the same plane on the side, and (c) laminating a magnetic layer on a coil layer composed of the excitation coil and the detection coil. .

Further, after the step (c), (d) a step of forming another exciting coil on the magnetic layer by winding it in a spiral shape; and (e) an inner circumference of the other exciting coil. Forming another detection coil on the same plane on the side or the outer peripheral side so as to overlap with the magnetic layer, the coil layer composed of the excitation coil and the detection coil is formed above and below the magnetic layer. Flux gate sensor can be formed.

Alternatively, after the step (c), a coil layer comprising the excitation coil and the detection coil is formed to form a fluxgate sensor formed above and below the magnetic layer. (G) forming another exciting coil in a spiral shape, and (g) forming another detecting coil on the same plane on the inner or outer peripheral side of the other exciting coil. h) laminating an insulating layer on the other excitation coil and the other detection coil;
(I) combining the magnetic layer formed in the step (c) and the insulating layer formed in the step (h) with the other excitation coil and the other detection coil overlapping the magnetic layer; As described above.

Further, after the step (b), (j) a step of winding another excitation coil on another substrate in a spiral shape, and (k) an inner circumference of the other excitation coil. Forming another detection coil on the same plane on the side or the outer circumference; and (l) sandwiching a magnetic layer between the substrate and the other substrate, and forming the excitation coil formed in the step (a). A coil and the detection coil formed in the step (b), the other excitation coil formed in the step (j), and the other detection coil formed in the step (k). Bonding the substrate and the other substrate so as to overlap the magnetic layer.

In the present invention, the excitation coil in the step (a) and the detection coil in the step (b) can be formed simultaneously by plating or sputtering. Further, the other excitation coil and another detection coil can be formed simultaneously.

It is preferable that the method further includes a step of connecting the exciting coil and the other exciting coil in series, and a step of connecting the detecting coil and the other detecting coil in series.

In the step (c), a plurality of magnetic layers arranged on a plane may be provided, and each of the plurality of magnetic layers may be arranged at a position overlapping the exciting coil and the detecting coil. .

In the case where the magnetic layer is formed from a plurality of divided magnetic layers, in the step (c), a plurality of magnetic layers arranged on a plane are provided, and each of the plurality of magnetic layers is It is preferable that the excitation coil and the detection coil are arranged at positions overlapping with each other, and in the step (e), the other excitation coil and the other detection coil are arranged so as to overlap each of the plurality of magnetic layers. .

Alternatively, in the step (c), a plurality of magnetic layers arranged in a plane are provided, and each of the plurality of magnetic layers is arranged at a position overlapping the exciting coil and the detecting coil. In the step (i), it is preferable that the other excitation coil and the other detection coil are arranged so as to overlap each of the plurality of magnetic layers.

Alternatively, in the step (1), a plurality of the magnetic layers are arranged on a plane, and each of the plurality of magnetic layers is arranged at a position overlapping the exciting coil and the detecting coil. It is preferable that another excitation coil and the other detection coil are arranged so as to overlap each of the plurality of magnetic layers.

Preferably, the magnetic layer is formed of a magnetic material having a magnetic permeability at 1 MHz of 1,000 or more.

Specifically, the magnetic layer is formed by a composition formula of Fe
represented by _h M _i O _j, over 50% of the total tissue is amorphous phase, the balance being an average grain size below 30 nm bcc
It can be formed as a soft magnetic thin film having a structure of Fe crystal grains.

Where M is Ti, Zr, Hf, V, N
one or two selected from b, Ta, W and a rare earth element
H, i, j are at% and 45 ≦ h
≦ 70, 5 ≦ i ≦ 30, 10 ≦ j ≦ 40, h + i + j =
100 are satisfied.

The magnetic layer has a composition formula (Co _{1 -c}
Represented by _{T c) x M y X z} O w, and an amorphous phase containing a large amount of oxide of the element M, bcc mainly Co and element T
It can be formed as a soft magnetic thin film in which a microcrystalline phase composed of one or two or more crystal grains having a structure and an fcc structure is mixed.

Here, the element T is an element containing one or both of Fe and Ni, and the element M is
i, Zr, Hf, V, Nb, Ta, Cr, Mo, Si,
P, C, W, B, Al, Ga, Ge and one or more elements selected from rare earth elements, and X is Au,
Ag, Cu, Ru, Rh, Os, Ir, Pt, Pd, and at least one element selected from the group consisting of: 0 ≦ c ≦ 0.7, x, y, z, w is atomic%
Where 3 ≦ y ≦ 30, 0 ≦ z ≦ 20, 7 ≦ w ≦ 40, 20
<Y + z + w ≦ 60 is satisfied, and the balance is x.

[0050] Alternatively, the magnetic layer, composition formula Co _l
Ta _m is represented by Hf _n, amorphous phase can be formed as a soft magnetic thin film composed mainly.

Here, l, m and n are at% and 70 ≦ l
≦ 90, 5 ≦ m ≦ 21, 6.6 ≦ n ≦ 15, 1 ≦ m / n
<2.5 is satisfied.

In addition, a Co-based amorphous soft magnetic ribbon of the Co-Fe-Si-B type is preferably used.

[0053]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

In the flux gate sensor shown in FIG. 1, an exciting coil 23 and a detecting coil 24 are formed on the same plane on a substrate 21 with an insulating layer 22 interposed therebetween.
1 is formed. The detection coil 24 includes the exciting coil 2
3 is formed on the inner peripheral side. However, the detection coil 24
May be formed on the outer peripheral side of the exciting coil 23.

Further, magnetic layers 26a and 26b are formed on the coil layer C1 with an insulating layer 25 interposed therebetween.

In FIG. 1, an insulating layer 27 is laminated on the magnetic layers 26a and 26b. On this insulating layer 27, an exciting coil 28 and detection coils 29a and 29b are formed on the same plane, and a coil layer C2 is formed. Are formed. Detection coil 29
a and 29b are formed on the inner peripheral side of the exciting coil 28. However, the detection coils 29a and 29b may be formed on the outer peripheral side of the exciting coil 28. Coil layer C2
Is covered and protected by the insulating layer 30.

The exciting coils 23 and 28 are wound in a spiral shape. In the fluxgate sensor of FIG. 1, the exciting coil 23 and the exciting coil 28 are connected in series. The detection coil 29a, the detection coil 24, and the detection coil 29b are also connected in series.

The substrate 21 is made of glass, Si, SiO ₂ , Al ₂
O ₃ is formed in such insulating layers 22,25,27,30 organic material or SiO _2, such as a polyimide resin, Al ₂
It is formed of an inorganic material such as O ₃ .

The excitation coils 23, 28 and the detection coil 24,
Reference numerals 29a and 29b are made of a conductive material such as Cu or Al. The magnetic layers 26a and 26b are formed of a soft magnetic thin film or a ribbon described later.

In the present invention, since the detection coil 24 and the excitation coil 23 are formed on the same plane, it is not necessary to form the detection coil 24 and the excitation coil 23 with a structure having a step. Therefore, the formation of the detection coil 24 and the excitation coil 23 is facilitated, and the pattern can be accurately formed.
The occurrence rate of defective products can be suppressed. In FIG. 1, the detection coils 29a and 29b and the excitation coil 28 are also formed on the same plane, so that the pattern can be accurately formed.

In the present invention, since the upper surface of the coil layer is easily covered with the insulating layer to make the upper surface of the insulating layer flat, it is easy to form two or more coil layers. It becomes easier. To increase the number of turns of the excitation coil and the detection coil to reduce the AC current for excitation and to improve the detection sensitivity by connecting the excitation coil and the detection coil of the plurality of coil layers formed in a stack in series. Can be.

In the present invention, the magnetic layers 26a, 26b
Are formed above the exciting coil 23 and below the exciting coil 28. Since the exciting coils 23 and 28 are wound in a spiral shape, the magnetic layers 26a and 26b
Are excited in the plane direction by a magnetic field generated from the exciting coils 23 and 28. Therefore, when the external magnetic field to be detected is applied in the plane direction of the magnetic layers 26a and 26b (the X direction in the drawing), the detection sensitivity of the external magnetic field becomes highest. Magnetic layer 26
The direction of the demagnetizing field coefficient is the lowest in the plane direction of the magnetic layers 26a and 26b. Therefore, the influence of the demagnetizing field when the external magnetic field is applied in the plane direction of the magnetic layers 26a and 26b is small, and the detection sensitivity of the external magnetic field is improved. Can be.

FIG. 4 is a plan view of the magnetic layers 26a and 26b, the excitation coil 23, and the detection coil 24 of the flux gate sensor of FIG. 1 as viewed from above in FIG. FIG.
FIG. 2 is a plan view of an excitation coil 28 and detection coils 29a and 29b of the fluxgate sensor of FIG. 1 as viewed from below in FIG. That is, in the fluxgate sensor shown in FIG. 1, the surfaces shown in FIGS. 4 and 5 face each other.

The detection coil 24 shown in FIG. 4 is formed by connecting a first detection coil 24a and a second detection coil 24b so as to form a figure eight coil. In both the first detection coil 24a and the second detection coil 24b, the winding direction from the inner peripheral side is left-handed.

The winding directions of the detection coil 29a and the detection coil 29b from the inner circumferential side are both clockwise in FIG. 5, but this is because FIG. 5 is a plan view of the fluxgate sensor of FIG. This is because it is a diagram. Detection coil 29
a and the detection coil 29b are both left-handed when viewed from above, and the first detection coil 24a and the detection coil 29b and the second detection coil 24b and the detection coil 29a are:
Each overlaps with the same winding direction.

The end 24 of the first detection coil 24a
a1 and the end portion 29b1 of the detection coil 29b are connected by forming a connection layer (not shown) on the insulating layers 25 and 27 in FIG. 1, and are connected to the end portion 24b1 of the second detection coil 24b. The end portion 29a1 of the detection coil 29a is connected to the insulating layers 25 and 27 of FIG. 1 by forming a connection layer (not shown). Therefore, the detection coil 29
a, 24 and 29b are connected in series.

The end 23a of the exciting coil 23 and the end 28a of the exciting coil 28 are connected to the insulating layers 25 and 2 of FIG.
7 is connected by forming a connection layer (not shown), and the exciting coils 23 and 28 are connected in series.

The AC current for AC excitation is inputted from the end 23b of the exciting coil 23 and the end 28b of the exciting coil 28, and the output voltage is supplied to the end 29a of the detecting coil 29a.
2 and the end portion 29b2 of the detection coil 29b.

As shown in FIG. 4, the magnetic layer 26a is disposed above the side 23c of the exciting coil 23,
“b” is disposed above the side 23 d facing the side 23 c of the exciting coil 23. When the edges 23c the arrow I ₁ direction of the current is flowing, the side 23d is flowing the arrow I ₂ direction of the current facing the direction opposite to the arrow I _1. Also,
The excitation coil 28 is overlaid on the magnetic layers 26a and 26b.

The opposed magnetic layers 26a
And 26b, a first detection coil 24a
And the second detection coil 24b. Also,
The detection coil 29b and the detection coil 29a are overlaid on each of the magnetic layers 26a and 26b.

FIG. 6 is a state diagram at a certain moment when an external magnetic field Hex is applied to the flux gate sensor of FIG. 1 from the X direction in the drawing.

In the state shown in FIG. 6, an alternating current is applied to the exciting coils 23 and 28 to generate an alternating magnetic field H, and the magnetic layers 26a and 26b are excited. As shown in FIG. 6, the directions of the alternating magnetic field H applied to the magnetic layers 26a and 26b are opposite. Here, when an external magnetic field Hex is applied from the lateral direction in FIG.
ex and the AC magnetic field H are strengthened and weakened in the magnetic layer 26b.

The magnetic flux leaking from the ends of the magnetic layers 26a and 26b is detected as magnetic flux voltage by the detecting coils 24, 29a and 29b.

The first detection coil 24a and the second detection coil 24b, the detection coil 29a and the detection coil 2
9b, the asymmetry of the intersecting magnetic flux density can be increased. Since the detection coil 29a and the detection coil 29b are differentially connected between the first detection coil 24a and the second detection coil 24b, the output voltage can be increased by increasing the asymmetry of the intersecting magnetic flux density. Can be. That is, the detection sensitivity of the external magnetic field can be improved.

When the first detection coil 24a and the second detection coil 24b and the detection coil 29a and the detection coil 29b are connected so as to form a figure-eight coil shape, the fundamental voltage component is removed from the output voltage. Will be able to

FIG. 2 is a sectional view showing a second embodiment of the present invention. A spiral excitation coil 33 and a figure-eight coil-shaped detection coil 34 are formed on the same plane on a substrate 31 via an insulating layer 32 to form a coil layer C1, and an insulating layer 35 is formed on the coil layer C1. Through the magnetic layer 36
After the formation of the multilayer films A, the gaps between the magnetic layers 36a and 36b are filled with the insulating material 37. Note that the magnetic layers 36a and 36b are
And the detection coil 34.

On the other hand, an insulating layer 42 is laminated on a coil layer C2 in which a spiral exciting coil 40, a detecting coil 41a and a detecting coil 41b are formed on the same plane on a substrate 38 via an insulating layer 39. Thus, a multilayer film B is formed.

The multilayer film A and the multilayer film B are combined with the magnetic layers 36a and 36a.
6b and the insulating layer 42, the magnetic layers 36a and 36b and the exciting coil 40 overlap, and the magnetic layer 36a and the detecting coil 41a
The flux gate sensor shown in FIG. 2 is bonded to the magnetic layer 36b and the detection coil 41b so that the magnetic layer 36b and the detection coil 41b overlap.

The substrates 31, 38 are made of glass, Si, Si
O ₂ , Al ₂ O _3, etc., insulating layers 32, 35, 3
9, 42 and the insulating material 37 are formed of an organic material such as a polyimide resin or an inorganic material such as SiO ₂ or Al ₂ O ₃ .

The excitation coils 33, 40 and the detection coil 34,
41a and 41b are made of a conductive material such as Cu or Al.

The magnetic layers 36a and 36b are formed by a soft magnetic thin film or a ribbon described later.

In the flux gate sensor of FIG. 2, the coil layer C1, the magnetic layers 36a and 36b, the coil layer C
The shape and positional relationship of 2 are the same as those of the flux gate sensor of the first embodiment shown in FIG. 1, FIG. 4, and FIG. Therefore, the fluxgate sensor of FIG. 2 can also achieve the same operation and effect as the fluxgate sensor of the first embodiment.

FIG. 3 is a sectional view showing a third embodiment of the present invention. On a substrate 51, a spiral excitation coil 52 and a figure-eight coil-shaped detection coil 53 are formed on the same plane to form a coil layer C1, and a coil layer C1 is formed.
An insulating layer 54 is stacked thereon to form a multilayer film A.

On the other hand, a multilayer film B is formed by laminating an insulating layer 58 on a coil layer C2 in which a spiral exciting coil 56, a detecting coil 57a and a detecting coil 57b are formed on the same plane on a substrate 55. Is done.

The multilayer film A and the multilayer film B are
5 and a magnetic layer 59 between the substrate 51 and the substrate 55.
The fluxgate sensor shown in FIG. 3 is obtained by affixing a and 59b. Magnetic layers 59a, 5
9b is arranged at a position overlapping the excitation coil 52 and the detection coil 53. In the magnetic layers 59a and 59b, the magnetic layers 59a and 59b and the excitation coil 56 overlap, the magnetic layer 59a and the detection coil 57a overlap, and the magnetic layers 59a and 59b further overlap.
b and the detection coil 57b are arranged so as to overlap with each other.

The substrates 51 and 55 and the insulating layers 54 and 58 are made of an organic material such as polyimide resin or SiO ₂ or Al ₂ O _3.
And the like.

The excitation coils 52, 56 and the detection coil 53,
57a and 57b are made of a conductive material such as Cu or Al. Note that the magnetic layers 59a and 59b are formed of a soft magnetic thin film or a ribbon described later.

In the flux gate sensor of FIG. 3, the coil layer C1, the magnetic layers 59a and 59b, and the coil layer C
The shape and positional relationship of 2 are the same as those of the flux gate sensor of the first embodiment shown in FIG. 1, FIG. 4, and FIG. Therefore, the fluxgate sensor of FIG. 3 can also achieve the same operation and effect as the fluxgate sensor of the first embodiment.

FIG. 7 is a sectional view showing a fourth embodiment of the present invention. In the fluxgate sensor shown in FIG. 7, a spiral excitation coil 63 and a figure-eight coil detection coil 64 are formed on a substrate 61 via an insulating layer 62 on the same plane, and a coil layer C1 is formed. Is formed. The detection coil 64 is formed on the inner peripheral side of the exciting coil 63.

Further, magnetic layers 66a and 66b forming a magnetic layer are formed on the coil layer C1 with an insulating layer 65 interposed therebetween. The magnetic layers 66a and 66b are arranged at positions overlapping the excitation coil 63 and the detection coil 64. Magnetic layer 66
a, 66b, an insulating layer 67 is laminated on the magnetic body 66a,
66b is protected.

The substrate 61 is made of glass, Si, SiO ₂ , Al ₂
O ₃ is formed in such insulating layer 62,65,67 is formed of an inorganic material such as an organic material or SiO _2, Al ₂ O _3, such as a polyimide resin.

The exciting coil 63 and the detecting coil 64 are made of Cu,
It is made of a conductive material such as Al. Note that the magnetic layers 66a,
66b is formed by a soft magnetic thin film or a ribbon described later.

The fluxgate sensor of FIG. 7 is different from the fluxgate sensors shown in FIGS.
It has a structure in which only one coil layer is formed. The shape and positional relationship between the coil layer C1 and the magnetic layers 66a and 66b are as follows.
It is the same as FIG.

The flux gate sensor of FIG. 7 is different from the flux gate sensor of FIGS. 1 to 3 in that the total number of turns of the detection coil and the excitation coil is smaller than that of the flux gate sensor of FIGS. In the same manner, the pattern can be easily and accurately formed, and the direction in which the external magnetic field is applied can be set to a direction less affected by the demagnetizing field.

To detect the direction and magnitude of the external magnetic field simultaneously, a two-axis fluxgate sensor is used. The present invention can also constitute a two-axis fluxgate sensor.

FIG. 8 shows the magnetic layers 74a, 74b, 74 of the biaxial fluxgate sensor according to the fifth embodiment of the present invention.
It is the top view which looked at c, 74d, the excitation coil 71, the Y-axis detection coil 72, and the X-axis detection coil 73 from above. FIG. 9 shows an excitation coil 75 and a Y-axis detection coil 76 of a two-axis fluxgate sensor according to a fifth embodiment of the present invention.
It is the top view which looked at a, 76b and the X-axis detection coil 77a, 77b from below.

In the biaxial fluxgate sensor according to the fifth embodiment of the present invention, the surfaces shown in FIGS. 8 and 9 face each other via an insulating layer.

The Y-axis detection coil 72 shown in FIG. 8 is formed by connecting a first detection coil 72a and a second detection coil 72b so as to form a figure eight coil. Also, X
The axis detection coil 73 is formed by connecting the first detection coil 73a and the second detection coil 73b so as to form a figure eight coil shape.

First detection coil 7 of Y-axis detection coil 72
2a overlaps the Y-axis detection coil 76a of FIG. 9, and the second detection coil 72b overlaps the Y-axis detection coil 76b of FIG. Further, the first detection coil 73a of the X-axis detection coil 73 overlaps the X-axis detection coil 77a of FIG. 9, and the second detection coil 73b is the same as the X-axis detection coil 77b of FIG.
Overlap with

The end 72a1 of the first detection coil 72a of the Y-axis detection coil 72 is electrically connected to the end 76a1 of the Y-axis detection coil 76a, and the end of the second detection coil 72b. 72b1 and the end 76b1 of the Y-axis detection coil 76b are electrically connected. Therefore, the Y-axis detection coils 76a, 72, 76b are connected in series.

The end 73a1 of the first detection coil 73a of the X-axis detection coil 73 is electrically connected to the end 77a1 of the X-axis detection coil 77a, and the end of the second detection coil 73b is connected to the end 73a1 of the X-axis detection coil 77a. 73b1 and the end 77b1 of the X-axis detection coil 77b are electrically connected. Therefore, the X-axis detection coils 77a, 73, 77b are connected in series.

The end 71a of the exciting coil 71 and the end 75a of the exciting coil 75 are electrically connected, and the exciting coils 71 and 75 are connected in series.

As shown in FIG. 8, the magnetic layer 74a is disposed above the side 71c of the exciting coil 71,
“b” is arranged above the side 71d opposite to the side 71c of the exciting coil 71. The magnetic layer 74c is arranged above the side 71e of the exciting coil 71, and the magnetic layer 74d is arranged above the side 71f facing the side 71e of the exciting coil 71.

The magnetic layers 74 arranged opposite to each other
a, 74b, 74c, and 74d, a first detection coil 72a, a second detection coil 72b,
And the second detection coil 73b are overlapped. Also, the magnetic layers 74a, 74b, 74c,
The Y-axis detection coils 76a, 76
b, X-axis detection coils 77a and 77b are overlapped.

The excitation coil 75 is superposed on the magnetic layers 74a, 74b, 74c and 74d.

The AC current for AC excitation is input from the end 71b of the exciting coil 71 and the end 75b of the exciting coil 75, and the output voltage in the Y-axis direction is
a and the end 76b of the Y-axis detection coil 76b
2 and the output voltage in the X-axis direction is extracted from the end 77a2 of the X-axis detection coil 77a and the end 77b2 of the X-axis detection coil 77b.

In the two-axis flux gate sensor, an external magnetic field is applied from an arbitrary direction shown in FIG. 8, and even-order harmonic components of the fundamental wave are extracted from the output voltages in the X-axis direction and the Y-axis direction. The magnitude and direction of the external magnetic field can be detected by detecting the magnitude of the external magnetic field in the direction and the Y-axis direction and calculating the vector sum.

The above-mentioned magnetic layers 26a, 26b, 36
a, 36b, 59a, 59b, 66a, 66b, 74
It is preferable that a, 74b, 74c, and 74d be made of a magnetic material having a magnetic permeability of 1000 or more at 1 MHz.

More specifically, the magnetic layers 26a, 26b, 36
a, 36b, 59a, 59b, 66a, 66b, 74
a, 74b, 74c, and 74d can be formed as the following soft magnetic thin films.

1. A soft magnetic thin film whose composition formula is represented by Fe _h M _i O _j , wherein 50% or more of the entire structure is an amorphous phase, and the remainder is Fe crystal grains having a bcc structure with an average crystal grain size of 30 nm or less.

Here, M is Ti, Zr, Hf, V, N
one or two selected from b, Ta, W and a rare earth element
H, i, j are at% and 45 ≦ h
≦ 70, 5 ≦ i ≦ 30, 10 ≦ j ≦ 40, h + i + j =
100 are satisfied.

[0112] 2. Represented by a compositional formula of _{(Co 1-c T c)} x M y X z O w, and an amorphous phase containing a large amount of oxide of the element M, bcc structure mainly composed of Co and element T, the fcc structure 1 A soft magnetic thin film in which a microcrystalline phase composed of seeds or two or more kinds of crystal grains is mixed.

Here, the element T is an element containing one or both of Fe and Ni, and the element M is
i, Zr, Hf, V, Nb, Ta, Cr, Mo, Si,
P, C, W, B, Al, Ga, Ge and one or more elements selected from rare earth elements, and X is Au,
Ag, Cu, Ru, Rh, Os, Ir, Pt, Pd, and at least one element selected from the group consisting of: 0 ≦ c ≦ 0.7, x, y, z, w is atomic%
Where 3 ≦ y ≦ 30, 0 ≦ z ≦ 20, 7 ≦ w ≦ 40, 20
<Y + z + w ≦ 60 is satisfied, and the balance is x.

3. Represented by a compositional formula of Co _l Ta _m Hf _n,
Soft magnetic thin film mainly composed of amorphous phase.

Here, l, m and n are at% and 70 ≦ l
≦ 90, 5 ≦ m ≦ 21, 6.6 ≦ n ≦ 15, 1 ≦ m / n
<2.5 is satisfied.

In addition, Co-Fe-Si-B based Co-based amorphous soft magnetic ribbons are preferably used.

Hereinafter, a method of manufacturing the fluxgate sensor shown in FIG. 1 will be described. First, an exciting coil 23 is formed in a spiral pattern on a substrate 21 with an insulating layer 22 interposed therebetween. At the same time, a detecting coil 24 is formed on the inner peripheral side of the exciting coil 23 and a pattern is formed on the same plane as the exciting coil 23. The layer C1 is formed. The excitation coil 23 and the detection coil 24 can be formed by using a method such as a plating method or a sputtering method. Further, the detection coil 24 may be formed on the outer peripheral side of the exciting coil 23.

The first detection coil 24a has a figure-eight coil shape as shown in FIG.
And the second detection coil 24b are formed as connected to each other.

Further, magnetic layers 26a and 26b forming a magnetic layer on the coil layer C1 via the insulating layer 25 are formed by a sputtering method, a plating method, or the like.

As shown in FIG. 4, the magnetic layers 26a and 26b are arranged above the opposing sides of the exciting coil 23. In addition, the magnetic layers 26a and 26b are disposed so as to overlap the first detection coil 24a and the second detection coil 24b, respectively.

Further, an insulating layer 27 is laminated on the magnetic layers 26a and 26b. On the insulating layer 27, the exciting coil 28 as another exciting coil and the detecting coils 29a and 29b as other detecting coils are simultaneously patterned on the same plane to form a coil layer C2. The exciting coil 28 is formed at a position overlapping the exciting coil 23. Detection coil 29
a and 29b are formed on the inner peripheral side of the exciting coil 28 so as to overlap the detection coil 24.

The excitation coil 28 is overlaid on the magnetic layers 26a and 26b. Further, the detection coil 29a is overlaid on the magnetic layer 26a, and the detection coil 29b is overlaid on the magnetic layer 26b.

It should be noted that when the insulating layer 27 is laminated and the coil layer is not laminated any further, the flux gate sensor shown in FIG. 7 is obtained.

The detection coil 24 and the detection coil 29
a and a connection layer (not shown) for connecting the detection coil 24 and the detection coil 29b to the insulating layers 25 and 27.
And the detection coils 29a, 24 and 29b are connected in series.

The exciting coil 23 and the exciting coil 28
A connection layer (not shown) for connecting to the coils is also formed on the insulating layers 25 and 27, and the exciting coils 23 and 28 are connected in series. Further, the coil layer C2 is covered with the insulating layer 30.

The substrate 21 is made of glass, Si, SiO ₂ , Al ₂
O ₃ is formed in such insulating layers 22,25,27,30 organic material or SiO _2, such as a polyimide resin, Al ₂
It is formed of an inorganic material such as O ₃ .

The exciting coils 23, 28 and the detecting coil 24,
Reference numerals 29a and 29b are made of a conductive material such as Cu or Al.

Incidentally, the magnetic layers 26a and 26b are formed of a soft magnetic thin film or a ribbon described later.

A method for manufacturing the fluxgate sensor shown in FIG. 2 will be described. First, a spiral excitation coil 33 and a detection coil 34 are simultaneously patterned on a substrate 31 via an insulating layer 32 on the same plane to form a coil layer C1. Excitation coil 33 and detection coil 34
Can be formed by a method such as a plating method or a sputtering method. Further, the detection coil 34 is connected to the exciting coil 33.
May be formed on the outer peripheral side of the.

The detection coil 34 is formed so as to have a figure eight coil shape as shown in FIG.

Further, on the coil layer C1, the magnetic layers 36a and 36b forming the magnetic layer via the insulating layer 35 are formed by a sputtering method, a plating method, or the like.

The magnetic layers 36a and 36b are formed so as to overlap on the opposite side of the exciting coil 33 similarly to the flux gate sensor in FIG.

After the formation of the magnetic layers 36a and 36b, the gap between the magnetic layers 36a and 36b is filled with an insulating material 37 to form a multilayer film A.

On the other hand, an excitation coil 40 as another excitation coil and detection coils 41a and 41b as other detection coils are simultaneously placed on a substrate 38 as another substrate via an insulating layer 39 on the same plane. The pattern is formed to form the coil layer C2. Excitation coil 40 and detection coils 41a and 41b
Can be formed by a method such as a plating method or a sputtering method. The insulating layer 42 is laminated on the coil layer C2 to form the multilayer film B.

Further, the multilayer film A and the multilayer film B are
6a and 36b and the insulating layer 42 are bonded to face each other,
The flux gate sensor shown in FIG. 2 is formed.

When the multilayer film A and the multilayer film B are bonded, the excitation coil 33 is superimposed on the excitation coil 40, and the detection coils 41a and 41b are superimposed on the detection coil.

The multilayer films A and B are bonded so that the magnetic layers 36a and 36b and the excitation coil 40 overlap, the magnetic layer 36a and the detection coil 41a overlap, and the magnetic layer 36b and the detection coil 41b overlap.

The detection coil 34 and the detection coil 41
a, and a connection layer (not shown) for connecting the detection coil 34 and the detection coil 41b to the insulating layer 35, the insulating material 37, and the insulating layer 42.
34 and 41b are connected in series.

The exciting coil 33 and the exciting coil 40
A connection layer (not shown) for connecting to the excitation coil 33 is also formed on the insulating layer 35, the insulating material 37, and the insulating layer 42.
And the exciting coil 40 are connected in series.

The substrates 31, 38 are made of glass, Si, Si
O ₂ , Al ₂ O _3, etc., insulating layers 32, 35, 3
9, 42 and the insulating material 37 are formed of an organic material such as a polyimide resin or an inorganic material such as SiO ₂ or Al ₂ O ₃ .

The excitation coils 33, 40 and the detection coil 34,
41a and 41b are made of a conductive material such as Cu or Al.

Note that the magnetic layers 36a and 36b are formed of a soft magnetic thin film or a ribbon described later.

A method for manufacturing the flux gate sensor shown in FIG. 3 will be described. A spiral excitation coil 52 and a detection coil 53 are simultaneously patterned on a substrate 51 on the same plane to form a coil layer C1. The multilayer film A is formed by laminating the insulating layer 54 on the coil layer C1.

The excitation coil 52 and the detection coil 53 can be formed by a method such as a plating method or a sputtering method. Further, the detection coil 53 may be formed on the outer peripheral side of the exciting coil 52.

The detecting coil 53 is formed so as to have a figure eight coil shape as shown in FIG.

On the other hand, the exciting coil 56 as another exciting coil is formed in a spiral pattern on the substrate 55, and at the same time, the detecting coils 57a and 57b are formed on the same plane as the exciting coil 56 to form the coil layer C2. I do. An insulating layer 58 is stacked on the coil layer C2 to form a multilayer film B.

The multilayer film A and the multilayer film B are
5 and a magnetic layer 59 between the substrate 51 and the substrate 55.
The fluxgate sensor of FIG. 3 is formed by bonding the substrates a and 59b.

When the multilayer film A and the multilayer film B are bonded, the magnetic layers 59a and 59b are made to overlap with the upper side of the opposite side of the exciting coil 52 similarly to the flux gate sensor of FIG. Further, the magnetic layers 59a and 59b are made to overlap the upper part of the detection coil 53.

The magnetic layers 59a and 59b and the excitation coil 56 overlap, the magnetic layer 59a and the detection coil 57a overlap, and the magnetic layer 59b and the detection coil 57b overlap.

When the multilayer film A and the multilayer film B are bonded, the exciting coil 56 is superposed on the exciting coil 52, and the detection coils 57a and 57b are superposed on the detection coil 53.

The detection coil 53 and the detection coil 57
a, a connection layer (not shown) for connecting the detection coil 53 and the detection coil 57b is formed on the insulating layer 51 and the insulating layer 55, and the detection coils 57a, 53, and 57b are connected in series.

The excitation coil 52 and the excitation coil 56
Are also formed on the substrate 51 and the substrate 55, and the exciting coil 52 and the exciting coil 56 are connected in series.

The substrates 51 and 55 and the insulating layers 54 and 58 are made of an organic material such as polyimide resin or SiO ₂ or Al ₂ O _3.
And the like.

The exciting coils 52, 56 and the detecting coil 53,
57a and 57b are made of a conductive material such as Cu or Al.

Incidentally, the magnetic layers 59a and 59b are formed of a soft magnetic thin film or a ribbon described later.

Further, the coil layers C1 and C2 of the flux gate sensor shown in FIGS. 1 to 3 and 7 are formed by the coil for the biaxial flux gate sensor shown in FIGS. 8 and 9, and the magnetic layer is formed as shown in FIG. In this case, a two-axis fluxgate sensor capable of detecting the direction and magnitude of the external magnetic field can be formed.

The above-described magnetic layers 26a, 26b, 36
a, 36b, 59a, 59b, 66a, 66b, 74
It is preferable that a, 74b, 74c, and 74d be formed of a magnetic material having a magnetic permeability of 1 or more at 1 MHz.

More specifically, the magnetic layers 26a, 26b, 36
a, 36b, 59a, 59b, 66a, 66b, 74
a, 74b, 74c and 74d can be formed as the following soft magnetic thin films.

1. A soft magnetic thin film whose composition formula is represented by Fe _h M _i O _j , wherein 50% or more of the entire structure is an amorphous phase, and the remainder is Fe crystal grains having a bcc structure with an average crystal grain size of 30 nm or less.

However, M is Ti, Zr, Hf, V, N
one or two selected from b, Ta, W and a rare earth element
H, i, j are at% and 45 ≦ h
≦ 70, 5 ≦ i ≦ 30, 10 ≦ j ≦ 40, h + i + j =
100 are satisfied.

[0161] 2. Represented by a compositional formula of _{(Co 1-c T c)} x M y X z O w, and an amorphous phase containing a large amount of oxide of the element M, bcc structure mainly composed of Co and element T, the fcc structure 1 A soft magnetic thin film in which a microcrystalline phase composed of seeds or two or more kinds of crystal grains is mixed.

The element T is an element containing one or both of Fe and Ni, and the element M is
i, Zr, Hf, V, Nb, Ta, Cr, Mo, Si,
P, C, W, B, Al, Ga, Ge and one or more elements selected from rare earth elements, and X is Au,
Ag, Cu, Ru, Rh, Os, Ir, Pt, Pd, and at least one element selected from the group consisting of: 0 ≦ c ≦ 0.7, x, y, z, w is atomic%
Where 3 ≦ y ≦ 30, 0 ≦ z ≦ 20, 7 ≦ w ≦ 40, 20
<Y + z + w ≦ 60 is satisfied, and the balance is x.

3. Represented by a compositional formula of Co _l Ta _m Hf _n,
Soft magnetic thin film mainly composed of amorphous phase. Where l,
m and n are at%, 70 ≦ l ≦ 90, 5 ≦ m ≦ 21,
It satisfies the relationship of 6.6 ≦ n ≦ 15 and 1 ≦ m / n ≦ 2.5.

In addition, a Co-based amorphous soft magnetic ribbon based on Co-Fe-Si-B may be used.

The fluxgate sensor of the present invention can be widely used for measurement of geomagnetism, aerial exploration, and the like. Specifically, magnetic flaw detection, position and angle measurement of the rotating body, displacement measurement,
It can be used for vehicle detection, iron piece detection, current measurement, remanence measurement, and the like.

[0166]

FIG. 10 is a block diagram of an apparatus for detecting an external magnetic field using a flux gate sensor. An AC power supply 80 at the fundamental frequency supplies an AC current for excitation to the flux gate sensor 82 via the amplifier 81, and an external magnetic field Hex is applied in the excitation direction of the flux gate sensor. The output of the flux gate sensor is extracted as a differential voltage, and the band-pass filter 83 extracts only the even-order harmonic component with respect to the fundamental frequency. The magnitude of the even-order harmonic component with respect to the fundamental frequency corresponds to the magnitude of the external magnetic field.

FIG. 11 is a graph showing the result of detecting the external magnetic field by configuring the apparatus of FIG. 10 using the fluxgate sensor of the present invention shown in FIG.

Frequency of AC current for excitation (fundamental frequency)
Is 5.6 MHz, and the excitation current amplitude is 20 mA, 40 m
A, was changed to 60 mA.

It can be seen from FIG. 11 that the output increases as the alternating current increases. The sensitivity when the exciting current amplitude is 60 mA is about 0.006 (Vm / A).

[0170]

According to the present invention described in detail above, since the detection coil is formed on the same plane as the excitation coil, the detection coil and the excitation coil are formed in a structure having a step. There is no need. Accordingly, the detection coil and the excitation coil can be easily formed, and the pattern can be accurately formed, so that a manufacturing error can be reduced and a defective product occurrence rate can be suppressed.

In the present invention, the exciting coil is formed in a spiral shape, and the magnetic layer is formed above or below the exciting coil.
The magnetic layer is excited in a plane direction by a magnetic field generated from the excitation coil. Therefore, when an external magnetic field to be detected is applied in the surface direction of the magnetic layer, the detection sensitivity of the external magnetic field is highest. Since the plane direction of the magnetic layer is the direction in which the demagnetizing coefficient is the lowest, the influence of the demagnetizing field when an external magnetic field is applied in the plane direction of the magnetic layer is small, and the detection sensitivity of the external magnetic field can be improved. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the present invention.

FIG. 4 is a magnetic layer 26 of the flux gate sensor of FIG.
a, 26b, the excitation coil 23, and the detection coil 24 seen from above in FIG.

5 is a plan view of the excitation coil 28 and detection coils 29a and 29b of the flux gate sensor of FIG. 1 as viewed from below in FIG.

FIG. 6 is a state diagram at a certain moment when an external magnetic field Hex is applied to the flux gate sensor of FIG. 1 from the X direction in the drawing.

FIG. 7 is a sectional view showing a fourth embodiment of the present invention.

FIG. 8 is a plan view of the magnetic layer, the excitation coil, and the detection coil of the two-axis fluxgate sensor as viewed from above.

FIG. 9 is a plan view of the magnetic layer, the excitation coil, and the detection coil of the two-axis flux gate sensor as viewed from below.

FIG. 10 is a block diagram of a circuit for detecting an external magnetic field using a flux gate sensor.

FIG. 11 is a graph showing the result of detecting an external magnetic field using the fluxgate sensor of the present invention.

FIG. 12 is a conceptual diagram of a flux gate sensor.

FIG. 13 is a view for explaining the principle of magnetic field detection by a flux gate sensor.

FIG. 14 is a view for explaining the principle of magnetic field detection by a flux gate sensor.

FIG. 15 shows a conventional fluxgate sensor.

FIG. 16 shows a conventional fluxgate sensor.

[Explanation of symbols]

 21 Substrate 22, 25, 27, 30 Insulating layer 23, 28 Exciting coil 24, 29a, 29b Detection coil 26a, 26b Magnetic layer C1, C2 Coil layer Hex External magnetic field

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshito Sasaki 1-7 Yukitani Otsukacho, Ota-ku, Tokyo Alps Electric Co., Ltd. (72) Inventor Takashi Hatanai 1-7 Yukitani-Otsukacho, Ota-ku, Tokyo Alps Electric Co., Ltd.

Claims (26)

[Claims] 1. A flux comprising: an excitation coil to which an alternating current flows to generate an induction magnetic field; a magnetic layer through which the induction magnetic field flows; and a detection coil whose voltage is induced by the induction magnetic field flowing through the magnetic layer. In the gate sensor, the excitation coil is formed by being wound on a substrate in a spiral shape, and the detection coil is formed on the same plane on the inner peripheral side or the outer peripheral side of the excitation coil, and is formed together with the excitation coil. A flux gate sensor, wherein a coil layer is formed, and the magnetic layer is formed above or below the excitation coil and the detection coil. 2. The flux gate sensor according to claim 1, wherein a coil layer including the excitation coil and the detection coil is formed above and below the magnetic layer. 3. The excitation coils positioned above and below each other,
The fluxgate sensor according to claim 2, wherein the detection coils are connected in series with each other. 4. The flux gate sensor according to claim 1, wherein a plurality of the magnetic layers are provided, and each of the magnetic layers is arranged at a position overlapping the excitation coil and the detection coil. 5. The plurality of magnetic layers are superimposed on an upper or lower portion of a portion of the exciting coil wound in a plane and opposed on the plane, and the inner or outer periphery of the exciting coil is provided. 5. The plurality of detection coils formed on the side are formed in the same winding direction, and each of the detection coils faces a different one of the magnetic layers.
7. A fluxgate sensor according to item 1. 6. The fluxgate sensor according to claim 5, wherein the plurality of detection coils are connected to each other so as to form a figure-eight coil shape. 7. A pair of the detection coil on an inner peripheral side or an outer peripheral side of a portion of the exciting coil formed in a plane and opposed on the plane, and another portion of the exciting coil opposed on the plane. The fluxgate sensor according to claim 5, wherein a pair of the detection coils is further provided on the inner peripheral side or the outer peripheral side of the sensor. 8. The magnetic layer has a magnetic permeability of 1 at 1 MHz.
The fluxgate sensor according to any one of claims 1 to 7, comprising at least 000 magnetic materials. Wherein said magnetic layer is represented by a compositional formula of Fe _h M _i O _j, over 50% of the total tissue is amorphous phase,
The remainder is Fe of a bcc structure having an average crystal grain size of 30 nm or less.
2. A soft magnetic thin film formed of crystal grains.
9. The flux gate sensor according to any one of claims 8 to 8.
Here, M is Ti, Zr, Hf, V, Nb, Ta, W
And one or more elements selected from rare earth elements, and h, i, and j are at% and 45 ≦ h ≦ 70, 5 ≦
i ≦ 30, 10 ≦ j ≦ 40, and h + i + j = 100. 10. The magnetic layer has a composition formula (Co)
_{1-c T c) x M} y X z O w is represented by, and an amorphous phase containing a large amount of oxide of the element M, bc composed mainly of Co and element T
The fluxgate sensor according to any one of claims 1 to 8, wherein the fluxgate sensor is formed as a soft magnetic thin film in which a microcrystalline phase composed of one or more kinds of crystal grains having a c structure and an fcc structure is mixed. Here, the element T is an element containing one or both of Fe and Ni, and the element M is
i, Zr, Hf, V, Nb, Ta, Cr, Mo, Si,
P, C, W, B, Al, Ga, Ge and one or more elements selected from rare earth elements, and X is Au,
Ag, Cu, Ru, Rh, Os, Ir, Pt, Pd, and at least one element selected from the group consisting of: 0 ≦ c ≦ 0.7, x, y, z, w is atomic%
Where 3 ≦ y ≦ 30, 0 ≦ z ≦ 20, 7 ≦ w ≦ 40, 20
<Y + z + w ≦ 60 is satisfied, and the balance is x. Wherein said magnetic layer has a composition formula Co _l Ta _m H
It is represented by f _n, fluxgate sensor according to any one of claims 1 to 8 is formed as a soft magnetic thin film mainly composed of amorphous phases. Where l, m and n are a
At t%, 70 ≦ l ≦ 90, 5 ≦ m ≦ 21, 6.6 ≦ n ≦
15, 1 ≦ m / n ≦ 2.5. 12. A step of forming the exciting coil on a substrate by winding the same in a spiral shape, and (b) forming the detecting coil on the same plane on the inner peripheral side or outer peripheral side of the excitation coil. And (c) laminating a magnetic layer on a coil layer comprising the excitation coil and the detection coil. 13. After the step (c), (d) forming another exciting coil in a spiral shape on the magnetic layer, and (e) inner circumference of the other exciting coil. 13. A step of forming another detection coil on the same plane on the side or the outer side so as to overlap with the magnetic layer.
3. The method for manufacturing a fluxgate sensor according to item 1. 14. After the step (c), (f) forming another exciting coil on another substrate by winding it in a spiral shape; and (g) forming an inner periphery of the other exciting coil. Forming another detection coil on the same plane on the side or outer circumference side, (h) laminating an insulating layer on the other excitation coil and another detection coil, and (i) the above (c). Bonding the magnetic layer formed in the step and the insulating layer formed in the step (h) such that the other excitation coil and the other detection coil overlap the magnetic layer. The method for manufacturing a flux gate sensor according to claim 12, comprising: 15. After the step (b), (j) a step of winding another exciting coil on another substrate in a spiral shape, and (k) an inner periphery of the other exciting coil. Forming another detection coil on the same plane on the side or the outer circumference; and (l) sandwiching a magnetic layer between the substrate and the other substrate, and forming the excitation coil formed in the step (a). A coil and the detection coil formed in the step (b), the other excitation coil formed in the step (j), and the other detection coil formed in the step (k). The method of manufacturing a flux gate sensor according to claim 12, further comprising: bonding the substrate and the other substrate so as to overlap the magnetic layer. 16. The method according to claim 12, wherein the exciting coil in the step (a) and the detection coil in the step (b) are simultaneously formed. 17. The method of manufacturing a flux gate sensor according to claim 13, wherein said another exciting coil and another detecting coil are formed simultaneously. 18. The method according to claim 13, further comprising the step of connecting the exciting coil and the other exciting coil in series, and further connecting the detecting coil and the other detecting coil in series. Of manufacturing a flux gate sensor. 19. The method according to claim 12, wherein in the step (c), the plurality of magnetic layers are arranged on a plane, and each of the plurality of magnetic layers is arranged at a position overlapping the exciting coil and the detecting coil. 15. The method for manufacturing a flux gate sensor according to any one of items 14 to 14. 20. In the step (c), a plurality of the magnetic layers arranged on a plane are provided, and each of the plurality of magnetic layers is arranged at a position overlapping the excitation coil and the detection coil. 14. The method according to claim 13, wherein in the step e), the other excitation coil and the other detection coil are arranged so as to overlap each of the plurality of magnetic layers. 21. In the step (c), a plurality of the magnetic layers arranged on a plane are provided, and each of the plurality of magnetic layers is arranged at a position overlapping the exciting coil and the detecting coil. The method of manufacturing a flux gate sensor according to claim 14, wherein in the step (i), the other excitation coil and the other detection coil are arranged so as to overlap each of the plurality of magnetic layers. 22. In the step (1), a plurality of the magnetic layers arranged on a plane are provided, each of the plurality of magnetic layers is arranged at a position overlapping the exciting coil and the detecting coil, and The method for manufacturing a flux gate sensor according to claim 15, wherein another excitation coil and the other detection coil are arranged so as to overlap each of the plurality of magnetic layers. 23. The method of manufacturing a flux gate sensor according to claim 12, wherein the magnetic layer is formed of a magnetic material having a magnetic permeability at 1 MHz of 1000 or more. The method according to claim 24, wherein said magnetic layer, composition formula Fe _h M _i O _j
Wherein at least 50% of the entire structure is an amorphous phase, and the remainder is formed as a soft magnetic thin film of Fe crystal grains having a bcc structure with an average crystal grain size of 30 nm or less.
24. The method of manufacturing a flux gate sensor according to any one of claims 23 to 23. Here, M is Ti, Zr, Hf, V, N
one or two selected from b, Ta, W and a rare earth element
H, i, j are at% and 45 ≦ h
≦ 70, 5 ≦ i ≦ 30, 10 ≦ j ≦ 40, h + i + j =
100 are satisfied. 25. The magnetic layer according to claim 1, wherein the composition formula is (Co)
_{1-c T c) x M} y X z O w is represented by, and an amorphous phase containing a large amount of oxide of the element M, bc composed mainly of Co and element T
24. The method of manufacturing a flux gate sensor according to claim 12, wherein the soft magnetic thin film is formed as a soft magnetic thin film in which a microcrystalline phase composed of one or more crystal grains having a c structure and an fcc structure is mixed. Here, the element T is an element containing one or both of Fe and Ni, and the element M
Are Ti, Zr, Hf, V, Nb, Ta, Cr, Mo,
X is one or more elements selected from Si, P, C, W, B, Al, Ga, Ge and rare earth elements;
Au, Ag, Cu, Ru, Rh, Os, Ir, Pt, P
d is one or two or more elements, and the composition ratio is such that c is 0 ≦ c ≦ 0.7, x, y, z, and w are atomic%, 3 ≦ y ≦ 30, 0 ≦ z ≦ 20, 7 ≦ w ≦ 40, 2
The relationship of 0 ≦ y + z + w ≦ 60 is satisfied, and the balance is x. The method according to claim 26, wherein said magnetic layer, composition formula Co _l Ta _m H
represented by f _n, the production method of the flux gate sensor according to any one of claims 12 to 23 to form a soft magnetic thin film mainly composed of amorphous phases. Where l,
m and n are at%, 70 ≦ l ≦ 90, 5 ≦ m ≦ 21,
It satisfies the relationship of 6.6 ≦ n ≦ 15 and 1 ≦ m / n ≦ 2.5.