JP2004333247A - Magnetic impedance element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simply and easily apply a bias magnetic field to a magnetic impedance element utilizing the magnetic impedance effect. <P>SOLUTION: A hard magnetic body or hard magnetic thin film 4 is formed on a substrate 5 of piezoelectric material. A magnetic thin film 1 is formed on a non-magnetic substrate 3. The magnetic body or thin film 4 and the thin film 1 are bonded together so as to stand opposite to each other with a support material 7 in between as shown in Fig.(c). Since the distance between the two can be changed by impressing a voltage across the magnetic body or thin film 4 and the thin film 1, the bias magnetic field can be changed without using a coil particularly, potentiating structure simplification, price reduction, etc. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a magnetic sensor for detecting a magnetic field and a current sensor using the same, and more particularly, to a high-sensitivity magnetic impedance element utilizing a magnetic impedance effect.
[0002]
[Prior art]
In recent years, information devices and measurement / control devices have been rapidly becoming more sophisticated, smaller, thinner, and lower in cost. With these rapid developments, magnetic sensors, current sensors, and the like used in them have become smaller and less costly. Demands for high sensitivity and the like are increasing.
Conventionally used magnetic sensors include a Hall element, a magnetoresistive element (MR element), a giant magnetoresistive element (GMR element), a flux sensor, and the like. A current transformer uses a current transformer as a current sensor. Known methods are known.
[0003]
For example, the performance of magnetic heads used in hard disk devices as external storage devices of computers has been improved from conventional bulk-type inductive magnetic heads to MR heads, and the giant magnetoresistive effect (GMR) has now been developed. The research to be applied is active. Further, in a rotary encoder which is a rotation sensor of a motor, a magnetic flux leaking to the outside is weakened due to miniaturization of a magnet ring, and a high-sensitivity magnetic sensor is required instead of a current MR element. Electronic breakers, etc. using current sensors have been developed instead of conventional mechanical breakers. However, it is difficult to reduce the size of conventional breakers using current transformers, and in terms of sensitivity, detection range, etc. There is a demand for higher sensitivity and larger range of magnetic sensors.
[0004]
In order to satisfy these requirements, a magnetic impedance sensor using a magnetic impedance effect (also referred to as an MI effect) of an amorphous wire has been proposed in, for example, Patent Document 1. The magnetic impedance effect means that when an external magnetic field changes while a high-frequency current is applied to a magnetic material, the magnetic permeability of the magnetic material changes, and the impedance of the magnetic material accordingly increases by several tens to several times compared to when the magnetic field is zero. It is a phenomenon that changes by 100%. A sensor utilizing such an effect can detect a minute change in the external magnetic field of about several hundred microtesla (μT) by measuring the voltage across the magnetic material. The above-described magnetic impedance effect can be seen not only in amorphous wires but also in magnetic ribbons and thin films. In particular, thin films can be made small and thin, and have excellent reliability and mass productivity. Some of them have been proposed, and one of them is disclosed in Patent Document 2, for example.
[0005]
A magnetic impedance element using a thin film is formed of a magnetic thin film pattern obtained by processing a high magnetic permeability soft magnetic film having magnetic anisotropy and inducing uniaxial anisotropy into a strip shape. The magnetic anisotropy is performed by applying a magnetic field during the formation of the magnetic film, and is further induced by performing a heat treatment at about 150 to 400 ° C. in a rotating magnetic field or a static magnetic field. The direction of the axis of easy magnetization is generally the direction of the short axis (line width) of the strip-shaped structure. The magneto-impedance element has a characteristic that the impedance is changed by the magnetic field of the longitudinal component. The magnetic impedance characteristic at this time shows that when the axis of easy magnetization has a line width, the impedance peaks at positive and negative magnetic fields, respectively, and is symmetrical at positive and negative magnetic fields. The rate of change shows a very large change of several tens to several hundreds of percent.
[0006]
Even if magnetic anisotropy is provided in the length direction, the magnetic impedance characteristic is exhibited. The characteristic at that time is such that the impedance is the largest when the magnetic field is 0, and decreases as the absolute value of the magnetic field increases. Also in this case, the impedance is symmetric with respect to the positive and negative of the magnetic field. The direction of the detected magnetic field in this case is also a component in the length direction of the magnetic thin film pattern.
The change in impedance in these magnetic impedance characteristics is caused by a change in magnetic permeability in a state where a high-frequency current is applied to the magnetic thin film pattern. When the impedance is separated into a resistance component and an inductance component, both change due to a change in magnetic permeability, but the resistance component having a large absolute value is dominant in the change. The change in resistance due to the change in magnetic permeability is basically caused by the skin effect that occurs when a high-frequency current flows in a magnetic material.To increase the skin effect, increase the frequency of the high-frequency current or use a magnetic thin film. It is effective to increase the thickness of the magnetic material that is the pattern.
[0007]
As described above, the characteristic of the magnetic impedance element is that the impedance greatly changes with respect to the magnetic field, but by applying a bias magnetic field to the element and operating at a point where the impedance changes greatly with respect to the magnetic field, The sensor responds with high sensitivity to a magnetic field. In order to apply the bias magnetic field, it is necessary to form a coil (bias coil) around the element and generate a magnetic field by applying a current to the coil. Also, a coil is required for a method of applying a negative feedback magnetic field for the purpose of improving the linearity of sensitivity. When an amorphous wire is used, a coil is formed by winding a Cu wire directly around the wire, but a coil is formed in a thin film on the same substrate as a magnetic impedance element formed in a thin film. (See, for example, Patent Document 3).
[0008]
[Patent Document 1]
JP-A-06-281712 (pages 2-4, FIG. 1)
[Patent Document 2]
JP-A-08-075835 (page 4, FIG. 1)
[Patent Document 3]
JP-A-11-109006 (page 3-4, FIG. 1)
[0009]
[Problems to be solved by the invention]
As described above, there are two types of magneto-impedance elements, one using an amorphous wire and the other using a thin film. The use of a thin film is better in terms of reproducibility (stability), reliability, and mass productivity of characteristics. It can be said to be advantageous. When a thin film is used, a thin film is formed on a non-magnetic substrate such as glass using a sputtering method, a fine pattern is formed using a photosensitive material such as a resist, and dry etching such as wet etching or ion beam etching is performed. And processed into a fine pattern.
[0010]
By the way, as shown in FIG. 11, for example, the magnetic impedance characteristic has a symmetrical shape around a zero magnetic field. When measuring a magnetic field using such characteristics, it is necessary to apply a bias magnetic field in advance in order to bring the operating point to point b in FIG. As a method of applying the bias magnetic field, there are a method of forming a thin film coil and a method of using a thin film magnet. However, when a thin film coil is formed, it has a three-dimensional structure, and the process is complicated. Further, when a permanent magnet is formed, the bias is fixed, and there is no flexibility.
Therefore, an object of the present invention is to make it possible to apply a bias magnetic field to a magnetic impedance element simply and inexpensively.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention of claim 1 is to form a strip-shaped magnetic thin film having high magnetic permeability or a magnetic thin film pattern by alternately connecting these magnetic thin films on a non-magnetic substrate. An element that utilizes the magnetic impedance effect, in which the impedance of a magnetic substance changes when applied,
A non-magnetic substrate on which the magnetic thin film is formed and a substrate on which a hard magnetic material is formed on a piezoelectric material substrate are combined using a support so that the magnetic thin film and the hard magnetic material face each other.
[0012]
In the first aspect of the present invention, a hard magnetic material can be disposed under the magnetic thin film (the second aspect of the invention). In the first or second aspect, the substrate supporting the magnetic thin film is provided. A piezoelectric material substrate can be used for the invention (the invention of claim 3), and in any one of the inventions of claims 1 to 3, the voltage applied to the piezoelectric material substrate can be made in three directions (claim) Invention 4).
[0013]
According to a fifth aspect of the present invention, a strip-shaped magnetic thin film of high magnetic permeability or a magnetic thin-film pattern is formed by alternately connecting these magnetic thin films to a non-magnetic substrate, and a high-frequency current is applied to the thin magnetic thin-film pattern. Is an element utilizing the magneto-impedance effect,
A substrate having a hard magnetic material or a hard magnetic thin film formed on a bimetal and a non-magnetic substrate having a magnetic thin film formed thereon are fixed by a support material such that the hard magnetic material or the hard magnetic thin film and the magnetic thin film face each other. It is characterized by.
[0014]
According to the fifth aspect of the present invention, the hard magnetic material or the hard magnetic thin film can be arranged on the high thermal expansion body side of the bimetal (the sixth aspect of the invention). The magnetic sensing direction of the thin film can be arranged in a direction orthogonal to the warping direction of the bimetal (the invention of claim 7).
Further, in the invention of claim 5, the movable portion of the thermal expansion actuator can be used instead of the bimetal (the invention of claim 8), or the movable portion of the electrostatic actuator is used instead of the bimetal. (Invention of claim 9).
[0015]
According to a tenth aspect of the present invention, a strip-shaped magnetic thin film of high magnetic permeability or a magnetic thin-film pattern is formed by alternately connecting these magnetic thin films to a non-magnetic substrate, and a high-frequency current is applied to the thin magnetic thin-film pattern. Is an element utilizing the magneto-impedance effect,
A substrate having a magnetic thin film disposed on a bimetal and a substrate having an object to be detected are fixed by a support so that the magnetic thin film and the object to be detected face each other.
[0016]
In the tenth aspect of the present invention, the magnetic thin film can be arranged on the high thermal expansion body side on the bimetal (the eleventh aspect of the invention), and a piezoelectric material substrate can be used instead of the bimetal (the claim). 12) The movable part of the thermal expansion actuator can be used instead of the bimetal (the invention of claim 13), or the movable part of the electrostatic actuator can be used instead of the bimetal ( The invention of claim 14).
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment of the present invention will be described.
Example 1-1
FIG. 1 is a configuration diagram showing a first example of the first embodiment.
This is because the substrate 30 having the hard magnetic thin film 4 formed on the piezoelectric material substrate 5 and the substrate 20 having the magnetic thin film 1 formed on the non-magnetic substrate 3 are arranged such that the magnetic thin film 1 and the hard magnetic thin film 4 face each other. Next, an example of a magneto-impedance element combined using the support member 7 is shown. The manufacturing process will be described below.
A metal electrode film 6 is formed on the front and back of a PZT substrate 5 (thickness 0.5 mm), which is a piezoelectric material, and an SmCo hard magnetic thin film 4 is formed on one surface by RF magnetron sputtering, and a photosensitive material such as a resist is formed. Then, the SmCo hard magnetic thin film 4 was processed into a desired pattern by ion beam etching. This is referred to as a substrate 30. FIG. 1 (a) shows a side view thereof, and FIG. 8 (a) shows a plan view thereof.
[0018]
Next, an insulating organic material to be used as the adhesion layer 2 is formed on the non-magnetic substrate 3, and then the amorphous magnetic thin film 1 is formed by using an RF magnetron sputtering method, and finely divided by using a photosensitive material such as a resist. A pattern was formed, and after the magnetic field heat treatment, the amorphous magnetic thin film 1 was processed into a fine pattern by, for example, ion beam etching. This is referred to as a substrate 20. FIG. 1 (b) shows a side view thereof, and FIG. 8 (c) shows a plan view thereof.
[0019]
Next, as shown in FIG. 1C, the SmCo hard magnetic thin film 4 of the substrate 30 and the amorphous magnetic thin film 1 of the substrate 20 are combined using the support material 7 so as to face each other to produce a desired magnetic impedance element. I do. At this time, the distance between the amorphous magnetic thin film 1 and the SmCo hard magnetic thin film 4 was 2 μm. Here, the axis of easy magnetization of the SmCo hard magnetic thin film 4 is aligned with the in-plane longitudinal direction of the amorphous magnetic thin film 1 so that a magnetic field is applied in the in-plane longitudinal direction of the amorphous magnetic thin film 1.
[0020]
FIG. 9 shows a characteristic example of the magnetic impedance element manufactured as described above. The curve becomes asymmetric with respect to the zero magnetic field, and a bias magnetic field of about 320 A / m is applied. When a voltage of 50 V was applied to the PZT piezoelectric material substrate 5 of this element, the bias magnetic field increased by about 56 A / m, and when 100 V was applied, the bias magnetic field increased by about 110 A / m. As described above, by changing the voltage applied to the piezoelectric material, the distance between the magnetic thin film and the hard magnetic thin film can be changed, and the bias magnetic field applied to the magnetic thin film can be changed.
In this example, the amorphous magnetic thin film 1 is formed in a strip shape. However, it may be a broken pattern or a structure in which strip-shaped magnetic thin films are arranged in parallel. Further, although PZT was used as the piezoelectric material substrate, other piezoelectric materials may be used, and a material other than SmCo may be used as the hard magnetic material.
[0021]
Example 1-2
FIG. 2 is a block diagram showing the second embodiment.
This is because the substrate 30 as shown in FIG. 2A in which the hard magnetic thin film 4 is formed on the piezoelectric material substrate 5 on which the electrode 6 is formed, the amorphous magnetic thin film 1 formed on the non-magnetic substrate 3 and the adhesion layer 2 The substrate 21 having the SmCo hard magnetic thin film 4 formed therebetween as shown in FIG. 2B is placed on the support member 7 such that the SmCo hard magnetic thin film 4 of the substrate 30 and the amorphous magnetic thin film 1 of the substrate 21 face each other. This is an example of a magneto-impedance element manufactured by combining the elements as shown in FIG. FIG. 8D is a plan view of the substrate 21. Thereby, since a bias magnetic field by the SmCo hard magnetic thin film 4 formed on the substrate 21 is also applied, a strong bias magnetic field can be applied.
In this example, the amorphous magnetic thin film 1 is formed in a strip shape. However, it may be a broken pattern or a structure in which strip-shaped magnetic thin films are arranged in parallel. Further, although PZT was used as the piezoelectric material substrate, other piezoelectric materials may be used, and a material other than SmCo may be used as the hard magnetic material.
[0022]
FIG. 3 is a block diagram showing a third embodiment.
Example 1-3
3 (a) in which an SmCo hard magnetic thin film 4 is formed on a piezoelectric material substrate 5 on which an electrode 6 is formed, and a PZT piezoelectric material substrate 5 as a non-magnetic substrate for supporting the amorphous magnetic thin film 1. The substrate 22 as shown in FIG. 3B is used by using the support member 7 so that the SmCo hard magnetic thin film 4 of the substrate 30 and the amorphous magnetic thin film 1 of the substrate 22 face each other. This is an example of a magneto-impedance element manufactured in such a combination. Thus, by applying a voltage to the piezoelectric material substrate 5 of the substrate 22, the amorphous magnetic thin film 1 side also becomes movable, so that the distance between the SmCo hard magnetic thin film 4 and the magnetic thin film 1 can be changed over a wide range. .
In this example, the amorphous magnetic thin film 1 is formed in a strip shape. However, it may be a broken pattern or a structure in which strip-shaped magnetic thin films are arranged in parallel. Further, although PZT was used as the piezoelectric material substrate, other piezoelectric materials may be used, and a material other than SmCo may be used as the hard magnetic material.
[0023]
Example 1-4
FIG. 4 is a block diagram showing a fourth embodiment.
This is because, on a substrate 31 as shown in FIG. 4A in which an SmCo hard magnetic thin film 4 is formed on a PZT piezoelectric material substrate 5, electrodes are formed in three directions so that voltages can be applied in three directions of the PZT substrate. It is an example of an impedance element. An example of a plan view of the substrate 31 is shown in FIG. The substrate 20 is the same as in FIG. By making it possible to control the voltage applied to the piezoelectric material substrate of the substrate 31 in three directions, it becomes possible to accurately control the amount and the manner of distortion of the piezoelectric material.
In this example, the amorphous magnetic thin film 1 is formed in a strip shape. However, it may be a broken pattern or a structure in which strip-shaped magnetic thin films are arranged in parallel. Further, although PZT was used as the piezoelectric material substrate, other piezoelectric materials may be used, and a material other than SmCo may be used as the hard magnetic material.
[0024]
FIG. 5 is a configuration diagram showing a second embodiment of the present invention.
Example 2
This is as shown in FIG. 5A in which a hard magnetic thin film 4 is formed on a bimetallic material 51 and a magnetic thin film 1 as a magnetic sensing part is formed on a glass substrate 3a as shown in FIG. 5B. This is an example of a magnetic impedance element in which a simple substrate 60 is combined as shown in FIGS. 5C and 5D using a support member 7c such that the magnetic thin film 1 and the hard magnetic thin film 4 face each other. The manufacturing process will be described below. 5C is a longitudinal sectional view of the magnetic thin film 1, and FIG. 5D is a longitudinal sectional view of the glass substrate 3a.
[0025]
After an insulating organic material to be used as the adhesion layer 2b is formed on a glass substrate 3b, an SmCo hard magnetic thin film 4 is formed using an RF magnetron sputtering method, and is formed into a desired size using a photosensitive material such as a resist. A pattern is formed, and the SmCo hard magnetic thin film 4 is processed into a desired pattern by ion beam etching. The glass substrate 3b is bonded on the bimetal material 51, and this is used as a substrate 70 shown in FIG. Here, the hard magnetic thin film 4 was joined to the high thermal expansion material side of the bimetal material 51.
Further, a heater wiring 8 for heating the bimetal is formed on one side of the substrate 70 (the side without the hard magnetic thin film) by a thin film pattern technique. The heater wiring 8 may be formed on either the front or back surface of the bimetal material 51, but is formed here on the surface where the substrate 3b having the hard magnetic thin film 4 is bonded. Further, a supporting member 7c for bonding to the substrate 60 was formed on the same surface.
[0026]
Next, after an insulating organic material used as the adhesion layer 2 is formed on the glass substrate 3a, the amorphous magnetic thin film 1 is formed using an RF magnetron sputtering method, and a fine pattern is formed using a photosensitive material such as a resist. The amorphous magnetic thin film 1 was formed into a fine pattern by ion beam etching after magnetic field heat treatment. Here, the magnetic sensing direction of the amorphous magnetic thin film 1 is the short axis direction of the glass substrate 3a as shown in FIG. 5C, and this is the substrate 60 shown in FIG. 5B. On this substrate 60, pads 7b for supporting material bonding were formed.
[0027]
Next, the support material 7c of the substrate 70 and the pad 7b for bonding the support material of the substrate 60 are moved so that the SmCo hard magnetic thin film 4 of the substrate 70 and the amorphous magnetic thin film 1 of the substrate 60 face each other, as shown in FIG. To form a desired magnetic impedance element. At this time, the distance between the amorphous magnetic thin film 1 and the SmCo hard magnetic thin film 4 was set to about 2 μm. Here, the axis of easy magnetization of the hard magnetic thin film 4 is made to coincide with the in-plane longitudinal direction of the amorphous magnetic thin film 1.
[0028]
FIG. 10 shows a characteristic example of the magnetic impedance element manufactured as described above.
As shown in the drawing, the curve was asymmetric with respect to the zero magnetic field, and a bias magnetic field of about 320 A / m was applied. When a direct current is applied to the heater 8 of this element, the heat generated in the heater 8 causes the bimetal 51 to warp, increasing the distance between the amorphous magnetic thin film 1 and the SmCo hard magnetic thin film 4. The applied bias magnetic field decreases, and the magnetic impedance characteristic shifts as shown in FIG.
[0029]
As described above, by heating the bimetal material, the distance between the magnetic thin film 1 and the hard magnetic thin film 4 can be changed, and the bias magnetic field applied to the magnetic thin film can be changed.
In FIG. 5, one support member 7c is used as a cantilever, but a structure in which both ends are supported and the bimetal is bent may be used. Further, although the amorphous magnetic thin film 1 is formed in a strip shape, it may be formed in a zigzag pattern or a structure in which a plurality of strip-shaped magnetic thin films are arranged in parallel. Further, a material other than SmCo may be used as the magnetic thin film, or a bulk magnet may be used. Further, the substrate 70 has a structure in which a glass substrate is bonded on a bimetal material, but a structure in which an SiO2 thin film is formed on a bimetal, and then the adhesion layer 2b and the hard magnetic thin film 4 are formed.
[0030]
Although the hard magnetic thin film 4 is disposed on the bimetal, the same effect as described above can be obtained by a structure in which the hard magnetic thin film or the bulk magnet is disposed on the movable portion of the piezoelectric material, the thermal expansion actuator, or the electrostatic actuator. be able to.
According to the configuration of FIG. 5, the temperature characteristic of the magnetic impedance characteristic can be corrected. In this case, a heater for heating the bimetal material is not required. That is, in FIG. 5, the high thermal expansion material side is warped convexly, and the interval between the amorphous magnetic thin film 1 and the hard magnetic thin film 4 is widened, so that the bias magnetic field is reduced and the change of the magnetic impedance characteristic due to the temperature rise to the low magnetic field side is corrected. be able to.
[0031]
FIG. 6 is a configuration diagram showing a third embodiment of the present invention.
Example 3
This is because a substrate 71 as shown in FIG. 6A in which an amorphous magnetic thin film 1 is formed on a bimetal material 51 and a substrate 61 as shown in FIG. 6B in which a wiring pattern 9 to be measured is formed. This is an example of a magneto-impedance element joined as shown in FIG. 6C via a supporting member 7c so that the amorphous magnetic thin film 1 and the wiring pattern 9 face each other. The fabrication process is as follows.
[0032]
After an insulating organic material to be used as the adhesion layer 2 is formed on the glass substrate 3b, the amorphous magnetic thin film 1 is formed using an RF magnetron sputtering method, and a fine pattern is formed using a photosensitive material such as a resist. After the magnetic field heat treatment, the amorphous magnetic thin film 1 is processed into a fine pattern by ion beam etching, and this is used as a substrate 71 shown in FIG. Further, a support member 7c and a heater wiring 8 were formed on the substrate 71.
The amorphous magnetic thin film 1 of the substrate 71 is joined as shown in FIG. 6C via a supporting member 7c so as to face the wiring pattern 9 of the substrate 61 shown in FIG. Is prepared.
[0033]
With the above-described configuration, the bimetal material 51 is warped by applying a current to the heater wiring 8 and heating the bimetal material 51, and the distance between the amorphous magnetic thin film 1 and the wiring pattern 9 changes. Since the amount of warpage can be controlled by the heating temperature, that is, the current flowing, the distance between the amorphous magnetic thin film 1 and the wiring pattern 9 can be controlled with high accuracy.
[0034]
In FIG. 6, a single support member 7c is used as a cantilever, but a structure in which both ends are supported and the bimetal is bent may be used. Further, although the amorphous magnetic thin film 1 is formed in a strip shape, it may be formed in a zigzag pattern or a structure in which a plurality of strip-shaped magnetic thin films are arranged in parallel. Further, the substrate 71 has a structure in which a glass substrate is bonded on a bimetal material, but a structure in which an SiO2 thin film is formed on a bimetal, and then the adhesion layer 2 and the amorphous magnetic thin film 1 are formed.
[0035]
FIG. 7 is a configuration diagram showing a modification of FIG.
Example 3-1
This is because a substrate 72 on which an organic insulating thin film as an adhesion layer 2 and an amorphous magnetic thin film 1 as a magnetic sensing part are formed on a piezoelectric material substrate 5 on which a metal electrode 11 is formed, and a wiring pattern 9 as a magnetic field measurement target. Is formed by using a support member 7 formed around a substrate 72 so that the amorphous magnetic thin film 1 and the wiring pattern 9 are opposed to each other. It is an example of an element.
[0036]
With the above configuration, the distance between the wiring pattern and the magnetic thin film can be adjusted with high accuracy by the voltage applied to the piezoelectric material substrate 5. The same effect can be obtained by using a movable portion of a thermal expansion actuator or an electrostatic actuator instead of the piezoelectric material substrate and forming a magnetic thin film thereon.
[0037]
【The invention's effect】
According to the invention of claims 1 to 4, a non-magnetic substrate on which a magnetic thin film is formed, a substrate on which a hard magnetic material is formed on a piezoelectric material substrate, and a support material are used so that the magnetic thin film and the hard magnetic material face each other. In this case, the distance between the magnetic thin film and the hard magnetic material can be controlled by the voltage applied to the piezoelectric material, thereby providing an advantage that the bias magnetic field can be easily changed.
According to the invention of claims 5 to 14, a non-magnetic substrate on which a magnetic thin film which is a magnetic sensing part of a magnetic impedance element is formed, and a non-magnetic substrate on which a hard magnetic material or a thin film is formed are arranged on a bimetal. Since the magnetic thin film and the hard magnetic material or the thin film are combined using a support material so as to face each other, the distance between the magnetic thin film and the hard magnetic material or the thin film can be controlled by the warpage of the bimetal. And the bias magnetic field can be changed. Furthermore, the magnetic thin film, which is the magnetic sensing part of the magneto-impedance element, is formed on a bimetal and joined using a support so as to face the object to be detected. Can be adjusted with high precision.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a first embodiment (No. 1) of the present invention; FIG. 2 is a configuration diagram showing a first embodiment (No. 2) of the present invention; FIG. FIG. 4 is a configuration diagram showing a first embodiment (part 3). FIG. 4 is a configuration diagram showing a first embodiment (part 4) of the present invention. FIG. 5 is a configuration showing a second embodiment of the present invention. FIG. 6 is a configuration diagram showing a third embodiment of the present invention. FIG. 7 is a configuration diagram showing a modification of FIG. 6. FIG. 8 is a plan view showing various substrates used in the present invention. FIG. 10 is an example of the magnetic impedance characteristic of the element according to the first invention. FIG. 10 is an example of the magnetic impedance characteristic of the element according to the second invention. FIG. 11 is an explanatory diagram of the bias point.
DESCRIPTION OF SYMBOLS 1 ... Magnetic thin film, 2, 2b ... Adhesion layer, 3 ... Non-magnetic substrate, 3a, 3b ... Glass substrate, 4 ... Hard magnetic thin film, 5 ... Piezoelectric material, 6, 11 ... Electrode, 7, 7c ... Support material, 7b ... Pads for joining supporting materials, 8 ... heater wiring, 9 ... wiring pattern, 10, 20, 21, 22, 30, 31, 32, 60, 61, 70, 71, 72 ... substrate, 51 ... bimetal.

Claims (14)

A magnetic impedance effect in which the impedance of a magnetic material changes by applying a high-frequency current to a non-magnetic substrate, forming a strip-shaped magnetic thin film of high magnetic permeability or alternately connecting these to form a skewing magnetic thin film pattern An element utilizing
Magneto-impedance wherein a non-magnetic substrate on which the magnetic thin film is formed and a substrate on which a hard magnetic material is formed on a piezoelectric material substrate are combined using a support so that the magnetic thin film and the hard magnetic material face each other. element. 2. The magneto-impedance element according to claim 1, wherein a hard magnetic material is disposed under the magnetic thin film. 3. The magneto-impedance element according to claim 1, wherein a piezoelectric material substrate is used as a substrate supporting the magnetic thin film. 4. The magneto-impedance element according to claim 1, wherein the voltage applied to the piezoelectric material substrate is set in three directions. A magnetic impedance effect in which the impedance of a magnetic material changes by applying a high-frequency current to a non-magnetic substrate, forming a strip-shaped magnetic thin film of high magnetic permeability or alternately connecting these to form a skewing magnetic thin film pattern An element utilizing
A substrate having a hard magnetic material or a hard magnetic thin film formed on a bimetal and a non-magnetic substrate having a magnetic thin film formed thereon are fixed by a support material such that the hard magnetic material or the hard magnetic thin film and the magnetic thin film face each other. A magneto-impedance element characterized by the following. 6. The magneto-impedance element according to claim 5, wherein the hard magnetic material or the hard magnetic thin film is disposed on the high thermal expansion body side of the bimetal. 7. The magneto-impedance element according to claim 5, wherein a magnetic sensing direction of the magnetic thin film is arranged in a direction orthogonal to a warping direction of the bimetal. The magneto-impedance element according to claim 5, wherein a movable portion of a thermal expansion actuator is used instead of the bimetal. The magneto-impedance element according to claim 5, wherein a movable portion of an electrostatic actuator is used instead of the bimetal. A magnetic impedance effect in which the impedance of a magnetic material changes by applying a high-frequency current to a non-magnetic substrate, forming a strip-shaped magnetic thin film of high magnetic permeability or alternately connecting these to form a skewing magnetic thin film pattern An element utilizing
A magnetic impedance element, wherein a substrate having a magnetic thin film disposed on a bimetal and a substrate having an object to be detected are fixed by a support so that the magnetic thin film and the object to be detected face each other. The magneto-impedance element according to claim 10, wherein the magnetic thin film is disposed on a side of the high thermal expansion body on the bimetal. The magneto-impedance element according to claim 10, wherein a piezoelectric material substrate is used instead of the bimetal. The magneto-impedance element according to claim 10, wherein a movable portion of a thermal expansion actuator is used instead of the bimetal. The magneto-impedance element according to claim 10, wherein a movable part of an electrostatic actuator is used instead of the bimetal.

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