JP2006119087A - Magnetic field detection device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic field detection device and its manufacturing method capable of miniaturizing the device by arranging a magnetic field detection element in the unprojected state from a substrate. <P>SOLUTION: The second magnetic field detection device in this invention is a magnetic field detection device 100 equipped with three magnetic field detection elements 102, 103, 104 for detecting respectively the magnetic field in the mutually-orthogonal triaxial directions on the substrate 101'(101), and at least one 104 of the magnetic field detection elements is formed by using a magnetic material 107 filled in a through hole penetrating the substrate 101'(101). Figures 107a-107d show through holes filled with the magnetic material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a magnetic field detection device and a method for manufacturing the same, and more specifically, a magnetic field detection device in which a magnetic field detection element is built in the thickness direction of the substrate, and a magnetic field detection element using a through hole provided in the substrate. The present invention relates to a manufacturing method for forming a film.

  In recent years, high performance, miniaturization, thinning, and cost reduction of information equipment, measurement, and control equipment have progressed rapidly. With these rapid developments, the magnetic sensors used for them are also small, low cost, high sensitivity, etc. The demand for is getting higher.

  Known magnetic sensors include Hall elements, magnetoresistive elements (MR elements), giant magnetoresistive elements (GMR elements), fluxgate sensors, and the like. As a demand for miniaturization, high sensitivity, and wide range of these sensors, for example, a magnetic head used in a hard disk device as an external storage device of a computer is different from a conventional bulk type inductive magnetic head in MR. High performance has been advanced to the head, and research to apply the GMR element is being actively conducted now. Further, in a rotary encoder which is a rotation sensor of a motor, a magnetic flux leaking to the outside has become minute with the miniaturization of a magnet ring, and a highly sensitive magnetic sensor is required instead of the current MR element.

  In order to satisfy these requirements, a detection element called a magnetic impedance element (hereinafter also abbreviated as MI element), which detects the magnitude of the external magnetic field itself from the change in impedance as a function of the externally applied magnetic field and frequency, has been proposed. (For example, refer to Patent Document 1 and Patent Document 2).

  In addition, an apparatus for measuring two components having different magnetic field vectors using a high-frequency carrier type magnetic field detection element called a magnetic impedance element has been proposed (see, for example, Patent Document 3 and Patent Document 4).

  The magnetic field detection sensor can detect a uniaxial magnetic field component with one element. When two elements are used, they are arranged on the first magnetosensitive element arranged for detecting the first axis component of the external magnetic field, and on the plane having the common normal with the plane on which the first magnetosensitive element is arranged. By using it as a magnetic field detection device comprising a second magnetosensitive element arranged to detect at least another second component of the external magnetic field provided, the first axis and the second axis can be taken on a horizontal plane. For example, it can be used as an azimuth detecting device that detects the direction in the horizontal plane from the ratio of the magnitude of the geomagnetism in the first axis direction and the geomagnetism in the second axis direction in the horizontal component.

  However, up to two components of an arbitrary magnetic field vector can be detected by the above technique. Conventionally, only two magnetic sensors can detect only a two-dimensional direction or rotation angle of horizontal rotation. For accurate azimuth detection and attitude control, it is necessary to detect the third component of an arbitrary magnetic field vector.

  In order to detect the third component, for example, a magnetic field detection sensor that detects a magnetic field in one direction in advance is prepared, and then individually arranged as an element for detecting three components on the device substrate, or in-plane After an element for detecting two components is prepared, an element for detecting the remaining one component must be arranged. In the prior art, the elements that can be manufactured on the same substrate are up to two components parallel to the substrate surface (see Patent Document 3).

  5A and 5B are diagrams illustrating an example of a conventional magnetic field detection device, where FIG. 5A is a plan view and FIG. 5B is a cross-sectional view taken along line B-B ′. In FIG. 5, 200 is a magnetic field detection device, 201 is a first substrate, 202 is an X element (first magnetosensitive element arranged to detect a first axis component), and 203 is a Y element (second component). A second magnetosensitive element arranged for detection), 204 is a Z element (third magnetosensitive element arranged for detecting the third component), and 205 is a second substrate.

  As shown in FIG. 5, in order to detect three components, an X element 202 and a Y element 203 for detecting two components (for example, a first component and a second component) are arranged on one surface in advance. One substrate (also referred to as an apparatus substrate) 201 and a second substrate 205 including a Z element 204 for detecting the remaining one component (for example, a third component) are prepared, and the surface including the Z element 204 is the first surface. The second substrate 205 needs to be mounted on the first substrate 201 so as to be perpendicular to one surface of the substrate 201.

However, since the magnetic field detection element requires a length in the direction of the magnetic field to be detected, when the element (Z element 204) for detecting the magnetic field in the vertical direction is mounted on the first substrate 201, the height component increases. However, there is a problem that the size of the magnetic field detector becomes large because there is a limit to downsizing.
Japanese Patent Laid-Open No. 06-176930 Japanese Patent Laid-Open No. 06-281712 JP 2003-35757 A JP 2001-296127 A

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a magnetic field detection device and a method for manufacturing the same, in which a magnetic field detection element is arranged without protruding from a substrate, and the device can be reduced in size. And

  A magnetic field detection apparatus according to claim 1 of the present invention (hereinafter also referred to as a first magnetic field detection apparatus) includes a magnetic field detection element using a magnetic material filled in a through hole penetrating a substrate. And

  A magnetic field detection apparatus according to claim 2 of the present invention (hereinafter also referred to as a second magnetic field detection apparatus) includes a magnetic field detection device including three magnetic field detection elements for detecting magnetic fields in three axial directions orthogonal to each other. The apparatus is characterized in that at least one of the magnetic field detection elements is made of a magnetic material filled in a through hole penetrating the substrate.

  A magnetic field detection apparatus according to a third aspect of the present invention is the magnetic field detection device according to the first or second aspect, wherein the substrate includes detection means for detecting an output voltage of the magnetic field detection element.

  According to a fourth aspect of the present invention, there is provided a method for manufacturing a magnetic field detection device comprising at least a step of forming a magnetic field detection element by filling a through-hole penetrating a substrate with a magnetic material.

  The first magnetic field detection device according to the present invention includes a magnetic field detection element using a magnetic material filled in a through-hole penetrating the substrate. Therefore, the magnetic field detected by the main body of the magnetic field detection element, that is, the magnetic field detection element The length required in the direction can be stored in the thickness direction of the substrate. That is, the first magnetic field detection device can be provided without projecting the magnetic field detection element outside the substrate, so that the magnetic field detection device can be reduced in size, thickness, and weight.

A second magnetic field detection device according to the present invention is a magnetic field detection device comprising three magnetic field detection elements for detecting magnetic fields in three axial directions orthogonal to each other on a substrate, and at least one of the magnetic field detection elements. One uses a magnetic material filled in a through hole penetrating the substrate.
According to this configuration, the X element and the Y element for detecting two components (for example, the first component and the second component) are arranged on one surface of the substrate, and the remaining one component (for example, the third component) is disposed. The main body of the Z element for detection, that is, the length required in the magnetic field direction detected by the magnetic field detection element can be stored in the thickness direction of the substrate. Here, the form accommodated in the thickness direction of the substrate means a magnetic material filled in a through hole penetrating the substrate. Therefore, according to the present invention, the X element and the Y element for detecting the first component and the second component are within the surface of the substrate, and the Z element for detecting the third component is not projected outside the substrate. Therefore, a three-axis direction magnetic field detection device (second magnetic field detection device) that is reduced in size, thickness, and weight can be provided.

The manufacturing method of the magnetic field detection apparatus according to the present invention includes at least a step of forming a magnetic field detection element by filling a through hole penetrating the substrate with a magnetic material.
According to such a configuration, in the first or second magnetic field detection device described above, a magnetic field detection element having a form accommodated in the thickness direction of the substrate can be produced. Therefore, the production method including at least the above steps contributes to the provision of the first or second magnetic field detection device according to the present invention.

  Hereinafter, an embodiment of a magnetic field detection apparatus according to the present invention will be described with reference to the drawings.

1-4 is a figure which shows an example of the procedure which produces the magnetic field detection apparatus based on this invention, and has drawn the component exaggerated suitably for easy understanding.
FIG. 1 is a diagram showing an example of a state in which a through hole is provided in a substrate of a magnetic field detection device according to the present invention, where (a) is a plan view and (b) is a cross-sectional view taken along line AA ′. To express.
FIG. 2 is a cross-sectional view showing a state in which a first element (for example, a Z element) is formed by filling a through hole provided in a substrate with a magnetic material and linearly coupling the magnetic material.
FIG. 3 is a plan view showing a state where an insulating layer is provided on the substrate surface while securing openings for the second and third elements (for example, the X element and the Y element).
FIG. 4 is a plan view showing a state in which the second and third elements are formed on the insulating layer, and is a diagram showing an example of a three-axis direction magnetic field detection apparatus according to this example.

First, as shown in FIG. 1, a through hole 106 is formed in a magnetic field detecting element substrate 101 in which electronic circuits (not shown) of magnetic impedance elements (MI elements) are integrated.
When silicon is used as the substrate 101, a through hole can be provided at a specified location by using a photoelectrolytic polishing method as a method for forming the through hole. Details of the method of forming a through hole at a specified location by the photoelectrolytic polishing method are omitted here, but the method disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-161400 can be applied.
As a material constituting the substrate 101, in addition to silicon, a flat base material made of, for example, ceramics, PCB resin, glass or the like is preferably used. In addition to the photoelectrolytic polishing method, for example, a deep RIE method, a drill method, or a sand blast method may be used as a method for forming the through hole.

Next, the through hole 106 of the substrate 101 is filled with a magnetic material 107 such as CoNbZr using a molten metal suction method. Thereafter, the through holes 107a to 107d filled with the magnetic material are connected to the both surfaces of the substrate 101 by the conductive material 108b, 108c, and 108d by using photolithography using a photoresist and Cu plating, etc. The MI element in the direction is formed in a folded shape. In addition, conductive materials 108a and 108e are used to connect the input / output terminals 104a and 104b connected to the carrier wave signal circuit and the through holes 107a and 107d, respectively. Thereafter, the photoresist is removed by an alkali stripping solution or a plasma etching method.
As a result, a substrate 101 is obtained in which through holes 107 filled with a magnetic material as shown in FIG.
The conductive material produced here realizes a form in which the element length is extended by connecting individual magnetic materials filled in the through holes. This form causes an increase in the impedance of the magnetic detection element, which in turn contributes to an improvement in detection magnetic field sensitivity.

  The magnetic detection element according to the present invention is not limited to the magnetic material produced by the molten metal attraction method, but is effective for all magnetic materials. That is, the same applies to the case where an amorphous magnetic material or a crystalline magnetic material such as NiFe, FeCoSiB, or CoNbZr is used. Also, the through hole filling method is not limited at all, and sputtering, vacuum deposition, CVD, plating, and the like can be used. The material for connecting the through-holes is not limited to Cu, and the film formation method is not limited to Cu, such as Ag, Al, Ti, Nb, Cr, W, Ta, Au, Ni, Pt, etc. by using a sputtering method or the like. Materials can be used.

Next, as shown in FIG. 3, the MI element (X element) for detecting the X-axis direction and the MI element (Y element) for detecting the Y-axis direction are respectively aligned with the input / output terminals of the carrier wave signal. An insulating layer having openings 102a, 102b, 103a, and 103b is formed. In FIG. 3, 101 ′ represents a substrate in a state where an insulating layer is provided to insulate the surface.
In that case, as a material which comprises an insulating layer, silicon nitride, a silicon oxide, a polyimide resin, an epoxy resin, a silicone resin etc. are mentioned, for example. Such an insulating layer can be formed by, for example, a CVD method, a spin coating method, a printing method, a laminating method, or the like.
Further, the openings 102a, 102b, 103a, and 103b can be formed by, for example, forming a film of polyimide or the like constituting the resin layer on the entire surface and then patterning the film by a photolithography technique.

Next, an X element and a Y element are formed on the substrate 101 ′ in a state where an insulating layer is provided to insulate the surface. Examples of the formation method include a method of forming an amorphous magnetic thin film having a thickness of 1 μm to 10 μm by an RF sputtering method using an alloy target such as CoNbZr.
As a mask used when processing this amorphous magnetic thin film, for example, an arbitrary resist pattern provided on the magnetic thin film by a photolithography technique using a photosensitive resin is used. After the mask formation, the amorphous magnetic thin film may be finely processed along an arbitrary resist pattern using, for example, ion beam etching using the photosensitive resin as an etching mask. By this etching process, an X element or a Y element having a desired pattern can be formed.

  In the above description, the ion beam etching method is cited as a fine processing method of the amorphous magnetic thin film, but other dry etching methods such as a reactive ion etching method may be applied, a wet etching processing method, A processing method using a metal mask method may be used. Alternatively, a resist pattern reversed from the resist pattern described above may be formed, and an X element or a Y element having a desired pattern may be formed by a lift-off method.

  In the above description, CoNbZr is used as a magnetic material constituting the magnetic detection element. However, the present invention is not limited to this material, and is a material that is soft magnetic in the frequency band of the carrier wave signal and exhibits high permeability. Any material can be used as long as it is.

Finally, the X element 102 and the Y element 103 are obtained by removing the photosensitive resin with a stripping solution or plasma etching. Thereafter, the portions (102 ′, 102 ″, 103 ′, 103 ″) serving as the electrodes of the X element 102 and the Y element 103 and the carrier signal input / output terminals (102a, 102b, 103a, 103b) for the X element and the Y element ) In the same manner as the Z element 104 by a conductive material such as Cu produced by plating or sputtering. Alternatively, the magnetic thin film may be directly connected without particularly forming a conductive material.
By the above procedure, the three-axis direction magnetic field detection device having the external configuration shown in FIG.

  By the way, the magnetic field detection apparatus mentioned above may comprise a detection means for detecting an output voltage of a magnetic field detection element (for example, a Z element) on a substrate constituting the magnetic field detection apparatus. If the detection means is provided on the substrate, it is not necessary to attach the detection means to the substrate as a separate body, which is preferable because the magnetic field detection device is not reduced in size, thickness, and weight.

  In addition, you may use the amorphous magnetic material which provided the magnetic anisotropy to the X element based on the example of an aspect mentioned above, and / or the Z element, or gave heat processing.

  Further, a bias magnetic field may be applied in the magnetic field detection direction of each element by arranging a coil or a magnet in the vicinity of each element or around each element. By applying a bias magnetic field, the operating point of each element can be set to the most sensitive position, and the linearity of the detection output in each element can be improved.

  Further, in the above-described embodiment example, the case where three elements (X element, Y element, and Z element) are formed on a single substrate 101 has been described as an example, but the Z element using a through hole is provided. A triaxial magnetic field detection device may be formed by mounting an X element and a Y element separately manufactured on a substrate.

  In the above-described embodiment, the case where the magnetic impedance element (MI element) is provided as the magnetic field detection element has been described as an example. However, instead of the MI element, a Hall element, a magnetoresistive effect element (MR element), a giant magnetoresistance Needless to say, even if an effect element (GMR element), a fluxgate sensor, or the like is applied, the functions and effects of the present invention can be obtained.

  According to the present invention, the magnetic field detection element can be provided without projecting outside the substrate, so that the magnetic field detection device can be reduced in size, thickness, and weight. Further, in addition to the element (for example, Z element) built in the substrate, the X element and the Y element are provided on one surface or both surfaces of the substrate, thereby reducing the size, thickness, and weight. An axial magnetic field detection device can be provided.

  Therefore, the magnetic field detection device according to the present invention can be made particularly thin and lightweight as compared with the conventional device, so that various devices such as mobile phones, PDAs, watches, GPS, etc., on which this device is mounted. Contributes to the miniaturization of equipment.

It is a figure which shows an example of the state which provided the through-hole in the board | substrate of a magnetic field detection apparatus, (a) represents a top view, (b) represents sectional drawing in line segment A-A '. It is sectional drawing which shows the state which filled the through-hole provided in the board | substrate of the magnetic field detection apparatus with the magnetic material, and combined the magnetic material linearly and formed the 1st element. It is a top view which shows the state which provided the insulating layer in the board | substrate surface, ensuring the opening part for 2nd and 3rd elements in the board | substrate of a magnetic field detection apparatus. It is a top view which shows the state which formed the 2nd and 3rd element on the insulating layer, and is a figure which shows an example of the 3-axis direction magnetic field detection apparatus which concerns on this invention. It is a figure which shows an example of the conventional magnetic field detection apparatus, (a) is a top view, (b) represents sectional drawing in line segment B-B '.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Magnetic field detection apparatus, 101 board | substrate, 101 'board | substrate in the state which aimed at insulation, 102 Magnetic field detection element (X element), 102', 102 '' X element electrode part, 102a, 102b The opening part for X element, 103 Magnetic field detection element (Y element), 103 ′, 103 ″ Y element electrode part, 103a, 103b Y element opening, 104 Magnetic field detection element (Z element), 106 Through hole, 107 Magnetic material, 107a to 107d Through hole filled with magnetic material, 108 conductive material.

Claims (4)

  A magnetic field detection device comprising a magnetic field detection element using a magnetic material filled in a through hole penetrating a substrate. A magnetic field detection device comprising three substrates for detecting magnetic fields in three axial directions orthogonal to each other on a substrate,
At least one of the magnetic field detection elements is made of a magnetic material filled in a through hole that penetrates the substrate.   The magnetic field detection apparatus according to claim 1, wherein the substrate includes detection means for detecting an output voltage of the magnetic field detection element. A method of manufacturing a magnetic field detection device comprising at least a step of forming a magnetic field detection element by filling a through-hole penetrating a substrate with a magnetic material.

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