JP2019211385A - Magnetic detection device and magnetic bias device - Google Patents

Abstract

To provide a magnetic detection device capable of correctly applying a bias magnetic field while suppressing enlarging of the device, and a magnetic bias device thereof.SOLUTION: A magnetic detection device 1 includes an MI element 21, an upper conduction member 33A, and a lower conduction member 33B. The MI element 21 detects an external magnetic field. The upper conduction member 33A is formed in a planar shape and stacked on one side of the stacking direction of the MI element 21. The lower conduction member 33B is formed in a planar shape, stacked on the other side of the stacking direction of the MI element 21, and faces the upper conduction member 33A along the stacking direction. A current is applied to the upper conduction member 33A and the lower conduction member 33B, and a bias magnetic field is applied to the MI element 21.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a magnetic detection device and a magnetic bias device.

  Conventionally, as a magnetic detection device, for example, Patent Document 1 discloses a magnetic sensor that detects an external magnetic field. The magnetic sensor includes a magnetic core as a magnetic detection element and a solenoid coil that applies a bias magnetic field to the magnetic core.

JP 2008-275578 A

  Incidentally, the magnetic sensor described in Patent Document 1 described above is desired to apply a predetermined bias magnetic field to the magnetic core, for example, while suppressing an increase in the size of the solenoid coil.

  Therefore, the present invention has been made in view of the above, and an object thereof is to provide a magnetic detection device and a magnetic bias device that can appropriately apply a bias magnetic field while suppressing an increase in size of the device. To do.

  In order to solve the above-described problems and achieve the object, a magnetic detection device according to the present invention includes a magnetic detection element that detects an external magnetic field, and is laminated on one side in the stacking direction of the magnetic detection element. And a second conductive member formed in a planar shape and stacked on the other side in the stacking direction of the magnetic sensing element and facing the first conductive member along the stacking direction, A current is applied to the first conductive member and the second conductive member to apply a bias magnetic field to the magnetic detection element.

  In the magnetic detection device, the first conductive member and the second conductive member have a current flowing in a direction intersecting with a magnetic field detection direction in which the magnetic detection element detects the external magnetic field, and in the opposite directions. It is preferable that a current flows.

  In the magnetic detection device, the first conductive member and the second conductive member have a current flowing along a magnetic field detection direction in which the magnetic detection element detects the external magnetic field, and a current flows in the opposite direction. Is preferred.

  In the magnetic detection device, the magnetic detection element is formed to extend along a first extending direction, and a magnetic field detection direction in which the magnetic detection element detects the external magnetic field is along the first extending direction. It is preferable that a current flows through the first conductive member and the second conductive member along a direction intersecting the first extending direction.

  In the magnetic detection device, the magnetic detection element extends along a second extending direction, and a magnetic field detection direction in which the magnetic detection element detects the external magnetic field intersects the second extending direction. It is preferable that a current flows through the first conductive member and the second conductive member along the second extending direction.

  In the magnetic detection apparatus, the first conductive member includes a first base material formed on a first outer surface, and a second base member formed on the second outer surface of the second conductive member, The base material and the second base material are a first inner surface that is a surface opposite to the first outer surface side of the first base material, or a side opposite to the second outer surface side of the second base material. A recess is formed in at least one of the second inner surfaces, which is a surface of the magnetic detection element, and the magnetic detection element is accommodated in the recess in a state where the first inner surface and the second inner surface are combined along the stacking direction. preferable.

  The magnetic detection device includes a third base material on which a power supply wiring pattern is formed, the second base material is laminated on the third base material, and the second conductive member is formed on the wiring pattern. A direct connection is preferred.

  A magnetic bias device according to the present invention is a conductive member formed in a planar shape and is laminated on one side in the stacking direction of a magnetic detection element that detects an external magnetic field, and a conductive material formed in a planar shape. A second conductive member that is a member and is laminated on the other side of the lamination direction of the magnetic detection element and faces the first conductive member along the lamination direction, and includes the first conductive member and the second conductive member. The member is characterized in that a current is applied to apply a bias magnetic field to the magnetic detection element.

  In the magnetic detection device and the magnetic bias device according to the present invention, the planar first conductive member and the planar second conductive member are applied with a current to apply a bias magnetic field to the magnetic detection element. With this configuration, the magnetic detection device and the magnetic bias device can form a pseudo solenoid coil, and the member to which the bias magnetic field is applied can be reduced in size. As a result, the magnetic detection device and the magnetic bias device can appropriately apply the bias magnetic field.

FIG. 1 is a perspective view illustrating a configuration example of a main part of the magnetic detection device according to the first embodiment. FIG. 2 is a perspective view illustrating a configuration example of a main part of the magnetic detection device according to the first embodiment. FIG. 3 is a plan view showing a bias magnetic field by the magnetic bias device according to the first embodiment. FIG. 4 is a diagram illustrating how current flows in the solenoid coil according to the comparative example. FIG. 5 is a diagram illustrating a current flow of the pseudo solenoid coil according to the first embodiment. FIG. 6 is a diagram illustrating the magnetic field strength of the solenoid coil according to the comparative example. FIG. 7 is a diagram illustrating the magnetic field strength of the pseudo solenoid coil according to the first embodiment. FIG. 8 is a diagram illustrating a magnetic field distribution of the solenoid coil according to the comparative example. FIG. 9 is a diagram illustrating a magnetic field distribution of the solenoid coil according to the comparative example. FIG. 10 is a cross-sectional view illustrating a configuration example of a magnetic detection device according to a modification of the first embodiment. FIG. 11 is a cross-sectional view illustrating a configuration example of a magnetic detection device according to a modification of the first embodiment. FIG. 12 is a cross-sectional view illustrating a configuration example of a magnetic detection device according to a modification of the first embodiment. FIG. 13 is a plan view showing a bias magnetic field by the magnetic bias device according to the second embodiment. FIG. 14 is a diagram illustrating the relationship between the magnetic field detection direction and the bias magnetic field according to the third embodiment. FIG. 15 is a diagram illustrating a relationship among the magnetic field detection direction, the bias magnetic field, and the external magnetic field according to the third embodiment. FIG. 16 is a diagram illustrating a relationship between the magnetic field detection direction and the combined magnetic field according to the third embodiment. FIG. 17 is a diagram showing the relationship between the magnetic field strength (synthetic magnetic field angle) and the resistance value of the MR element according to the third embodiment.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the structures described below can be combined as appropriate. Various omissions, substitutions, or changes in the configuration can be made without departing from the scope of the present invention.

[First Embodiment]
The magnetic detection device 1 and the magnetic bias device 30 according to the first embodiment will be described with reference to the drawings. The magnetic detection device 1 is configured to include a magnetic bias device 30 and detects an external magnetic field. The magnetic bias device 30 is a device that applies a bias magnetic field to an MI element 21 (Magneto-Impedance element) that is a magnetic detection element. Hereinafter, the magnetic detection device 1 and the magnetic bias device 30 will be described in detail. For example, as shown in FIGS. 1, 2, and 3, the magnetic detection device 1 includes a base material 10, a magnetic detection unit 20, and a magnetic bias device 30.

  Here, FIG. 1 shows a configuration example of a main part of the magnetic detection device 1, and some components such as the wiring of the base material 10 and the pseudo solenoid coil 33 are omitted. In FIG. 2, the structural example of the principal part of the magnetic detection apparatus 1 is shown, and the electrode 22 and the like of the MI element 21 are omitted. FIG. 3 illustrates a configuration in which a plurality of MI elements 21 are connected in a meander shape.

  In the following description, the direction in which the MI element 21 extends is referred to as a first extending direction. A direction in which the upper conductive member 33A (lower conductive member 33B) of the magnetic bias device 30 and the MI element 21 are stacked is referred to as a stacking direction. A direction in which a current flows through the upper conductive member 33A and the lower conductive member 33B is referred to as an energization direction. Typically, the first extending direction, the stacking direction, and the energizing direction are orthogonal to each other, but are not limited thereto.

  The base material 10 is made of an insulating material and is formed in a rectangular shape. The base material 10 has a mounting surface 10a, and the MI element 21 is formed on the mounting surface 10a.

  The magnetic detection unit 20 detects an external magnetic field. The magnetic detection unit 20 includes a plurality of MI elements 21, electrodes 22, and bypass wirings 23 (see FIG. 3). The MI element 21 is an element formed in a thin film shape. The impedance of the MI element 21 is changed by an external magnetic field. The MI element 21 is applied with a high frequency current and outputs an impedance changed by an external magnetic field. The MI element 21 is formed extending along the first extending direction. The MI element 21 detects an external magnetic field in a certain direction (magnetic field detection direction). That is, the MI element 21 has a constant direction of sensitivity (magnetic field detection direction) that reacts to an external magnetic field. The magnetic field detection direction of the MI element 21 is a direction along the first extending direction in which the MI element 21 extends. The MI element 21 detects the magnitude and direction of the external magnetic field in the magnetic field detection direction. The MI element 21 outputs the detected magnitude and direction of the external magnetic field as a change in impedance.

  The electrode 22 is applied with a high-frequency current. The electrode 22 includes an electrode 22A connected to a terminal of one MI element 21 connected in a meander shape and an electrode 22B connected to a terminal of the other MI element 21 connected in a meander shape. Composed. The electrodes 22 </ b> A and 22 </ b> B are connected to a high frequency power source (not shown), and a high frequency current is applied from the high frequency power source to cause the MI element 21 to flow.

  The bypass wiring 23 is for electrically connecting the MI elements 21 to each other (see FIG. 3). The bypass wiring 23 connects, for example, adjacent MI elements 21 and connects each MI element 21 in a meander shape.

  The magnetic bias device 30 applies a bias magnetic field to the MI element 21. 1 and 2, the magnetic bias device 30 includes a first wiring pattern group 31A, a second wiring pattern group 31B, a first wire group 32A, a second wire group 32B, and a pseudo solenoid coil 33. It is comprised including.

  The first wiring pattern group 31A is provided on one side of the energizing direction of the pseudo solenoid coil 33 (upper conductive member 33A). The first wiring pattern group 31A includes, for example, three wiring patterns 31a to 31c. Each of the wiring patterns 31a to 31c is arranged at a constant interval along the width direction (first extending direction) orthogonal to the energization direction. Each of the wiring patterns 31a to 31c is electrically connected to one side in the energizing direction of the upper conductive member 33A via a first wire group 32A (bonding wire). For example, the wiring pattern 31a is connected to one side in the energization direction of the upper conductive member 33A via the wire 32a. The wiring pattern 31b is connected to one side in the energization direction of the upper conductive member 33A via the wire 32b. The wiring pattern 31c is connected to one side in the energization direction of the upper conductive member 33A via the wire 32c.

  The second wiring pattern group 31B is provided on the other side of the energizing direction of the pseudo solenoid coil 33 (upper conductive member 33A). The second wiring pattern group 31B includes, for example, three wiring patterns 31d to 31f. Each of the wiring patterns 31d to 31f is arranged at a constant interval along the width direction (first extending direction) orthogonal to the energization direction. Each of the wiring patterns 31d to 31f is electrically connected to the other side in the energizing direction of the upper conductive member 33A via the second wire group 32B (bonding wire). For example, the wiring pattern 31d is connected to the other side in the energization direction of the upper conductive member 33A via the wire 32d. The wiring pattern 31e is connected to the other side in the energization direction of the upper conductive member 33A via the wire 32e. The wiring pattern 31f is connected to the other side in the energization direction of the upper conductive member 33A via the wire 32f.

  The first wire group 32A electrically connects one side of the upper conductive member 33A and the first wiring pattern group 31A. The first wire group 32A includes, for example, three wires 32a to 32c. Each of the wires 32a to 32c electrically connects one side of the upper conductive member 33A in the energization direction to each of the wiring patterns 31a to 31c. The wires 32a to 32c are connected to each other on the one side in the energizing direction of the upper conductive member 33A with a certain interval along the width direction (first extending direction) orthogonal to the energizing direction.

  The second wire group 32B is for electrically connecting the other side of the upper conductive member 33A and the second wiring pattern group 31B. The second wire group 32B includes, for example, three wires 32d to 32f. The wires 32d to 32f electrically connect the other side in the energizing direction of the upper conductive member 33A and the wiring patterns 31d to 31f, respectively. The wires 32d to 32f are connected to each other on the other side in the energizing direction of the upper conductive member 33A with a certain interval along the width direction (first extending direction) orthogonal to the energizing direction.

  The connection point between the first wire group 32A and the upper conductive member 33A and the connection point between the second wire group 32B and the upper conductive member 33A are located on substantially the same straight line in the energization direction. That is, the connection point between the wire 32a and the upper conductive member 33A and the connection point between the wire 32d and the upper conductive member 33A are located on substantially the same straight line in the energization direction. Further, the connection point between the wire 32b and the upper conductive member 33A and the connection point between the wire 32e and the upper conductive member 33A are located on substantially the same straight line in the energization direction. Further, the connection point between the wire 32c and the upper conductive member 33A and the connection point between the wire 32f and the upper conductive member 33A are located on substantially the same straight line in the energization direction. With this configuration, the magnetic bias device 30 can flow a parallel current I1 from one side to the other side in the energization direction of the upper conductive member 33A. In the magnetic bias device 30, the lower conductive member 33B is configured similarly to the upper conductive member 33A.

  The pseudo solenoid coil 33 applies a bias magnetic field to the MI element 21. The pseudo solenoid coil 33 is a pseudo configuration of the solenoid coil 100 (see FIG. 4) formed by spirally winding the linear conductor 101. The pseudo solenoid coil 33 includes an upper conductive member 33A and a lower conductive member 33B. The upper conductive member 33A is a conductive member formed in a planar shape (sheet shape). The upper conductive member 33A is, for example, a wiring pattern formed in a thin film shape. The upper conductive member 33 </ b> A is formed in a rectangular shape and is stacked on one side of the MI element 21 in the stacking direction. In the upper conductive member 33A, a current flows along a direction intersecting the magnetic field detection direction (first extending direction) in which the MI element 21 detects an external magnetic field. Typically, current flows in the upper conductive member 33A along a direction orthogonal to the magnetic field detection direction (first extending direction).

  The lower conductive member 33B is a conductive member formed in a planar shape (sheet shape). The lower conductive member 33B is, for example, a wiring pattern formed in a thin film shape. The lower conductive member 33B is formed in a rectangular shape having the same size as the upper conductive member 33A. The lower conductive member 33B is stacked on the other side of the MI element 21 in the stacking direction, and faces the upper conductive member 33A along the stacking direction. In the lower conductive member 33B, a current flows along a direction intersecting the magnetic field detection direction (first extending direction) in which the MI element 21 detects an external magnetic field. Typically, in the lower conductive member 33B, a current flows along a direction orthogonal to the magnetic field detection direction (first extending direction).

  The upper conductive member 33A and the lower conductive member 33B flow in opposite directions. For example, in the upper conductive member 33A, a current flows from one side in the energizing direction to the other side, and in the lower conductive member 33B, a current flows from the other side in the energizing direction toward the one side. That is, the upper conductive member 33A has a current flowing from the first wiring pattern group 31A side to the second wiring pattern group 31B side in the energization direction, and the lower conductive member 33B is first from the second wiring pattern group 31B side. A current flows toward the wiring pattern group 31A. Thus, the upper conductive member 33A and the lower conductive member 33B can pseudo-configure the solenoid coil 100 formed by winding the linear conductor 101 in a spiral. That is, the upper conductive member 33A and the lower conductive member 33B can reduce the interval between the upper conductive member 33A and the lower conductive member 33B to the order of μm because the MI element 21 is in a thin film shape. The solenoid coil 100 can be configured in a pseudo manner. As a result, the magnetic bias device 30 can apply the bias magnetic field H1 along the magnetic field detection direction of the MI element 21, as shown in FIG. With this bias magnetic field H1, the magnetic detection device 1 can set the output impedance of the MI element 21 within a predetermined range, and thus can properly detect the external magnetic field in the positive and negative directions.

  Here, as shown in FIG. 4, the solenoid coil 100 of the comparative example is formed by spirally winding the linear conductor 101, so it is necessary to provide an insulating portion between the adjacent linear conductors 101. is there. In contrast, the pseudo solenoid coil 33 according to the first embodiment does not need to provide an insulating portion between the adjacent linear conductors 101 unlike the solenoid coil 100 as shown in FIG. For this reason, the pseudo solenoid coil 33 can have a larger cross-sectional area, and the current value of the current I1 can be made larger than the current value of the current I2 flowing through the solenoid coil 100. When the solenoid coil 100 has a large cross-sectional area, it is necessary to increase the number of turns of the linear conductor 101. However, in this case, there is a problem in that the resistance value increases and power consumption and heat generation increase.

  FIG. 6 illustrates the magnetic field strength in the thin solenoid coil 100 according to the comparative example. The solenoid coil 100 applies a bias magnetic field H2 to the inside of the solenoid coil 100 from the long side and the short side when the current I2 flows. The bias magnetic field H2 applied by the short side of the solenoid coil 100 is smaller than the bias magnetic field H2 applied by the long side of the solenoid coil 100, and the influence on the magnetic field strength inside the solenoid coil 100 is very small.

  FIG. 7 illustrates the magnetic field strength in the pseudo solenoid coil 33 according to the first embodiment. The pseudo solenoid coil 33 applies a bias magnetic field H1 to the inside of the solenoid coil 100 by the upper conductive member 33A and the lower conductive member 33B when the current I1 flows. The pseudo solenoid coil 33 does not include the bias magnetic field H <b> 2 applied by the short side of the solenoid coil 100. However, as described above, the bias magnetic field H2 applied from the short side of the solenoid coil 100 has a small influence on the magnetic field strength inside the solenoid coil 100. As a result, the pseudo solenoid coil 33 can apply a bias magnetic field H 1 equivalent to the bias magnetic field H 2 of the solenoid coil 100.

  FIG. 8 illustrates a magnetic field distribution of the solenoid coil 103 according to the comparative example. The solenoid coil 103 has an opening formed in the positive direction. The solenoid coil 103 has a magnetic field distributed concentrically.

  FIG. 9 illustrates the magnetic field distribution of the solenoid coil 100 according to the comparative example. The solenoid coil 100 has an opening formed in a rectangular shape (a rectangle having an aspect ratio of 1: 2). In the solenoid coil 100, the magnetic field is distributed as if the concentric magnetic field was crushed up and down. The rectangular solenoid coil 100 and the square solenoid coil 103 show almost no difference in the strength of the magnetic field at the center. It can be estimated that the pseudo solenoid coil 33 according to the first embodiment distributes a magnetic field in the same manner as the rectangular solenoid coil 100 (see FIGS. 6 and 7).

  As described above, the magnetic detection device 1 according to the first embodiment includes the MI element 21, the upper conductive member 33A, and the lower conductive member 33B. The MI element 21 detects an external magnetic field. The upper conductive member 33 </ b> A is formed in a planar shape and is stacked on one side of the MI element 21 in the stacking direction. The lower conductive member 33B is formed in a planar shape, is stacked on the other side of the MI element 21 in the stacking direction, and opposes the upper conductive member 33A along the stacking direction. The upper conductive member 33A and the lower conductive member 33B apply a bias magnetic field to the MI element 21 by applying a current.

  With this configuration, the magnetic detection device 1 can form the pseudo solenoid coil 33 by the upper conductive member 33 </ b> A and the lower conductive member 33 </ b> B, and can apply a bias magnetic field to the MI element 21. With this bias magnetic field, the magnetic detection device 1 can determine the magnitude and direction of the external magnetic field based on the change in impedance output from the MI element 21.

  In the magnetic detection device 1, the pseudo solenoid coil 33 is formed by the planar upper conductive member 33 </ b> A and the lower conductive member 33 </ b> B, so that the current value can be made larger than that of the solenoid coil 100 formed by the linear conductor 101, for example. . Thereby, the magnetic detection apparatus 1 can reduce the size of the member to which the bias magnetic field is applied. As a result, the magnetic detection device 1 can appropriately apply a bias magnetic field.

  The magnetic detection device 1 is mounted as, for example, a MEMS (Micro Electro Mechanical Systems) integrated by a fine processing technique. In a MEMS, in a three-dimensional structure using a lamination process, it is difficult to form a multi-layer winding shape of the linear conductor 101 due to the thickness increase of the conventional linear conductor 101 or difficulty in step processing. There was a limit to the bias magnetic field. In contrast, in the magnetic detection device 1 according to the first embodiment, since the pseudo solenoid coil 33 is configured by the upper conductive member 33A and the lower conductive member 33B, the manufacturing process is simplified by eliminating the need for a multilayer winding shape. Can be Further, since the magnetic detection device 1 does not need to provide an insulating portion between the adjacent linear conductors 101, the cross-sectional area can be increased, and a predetermined bias magnetic field can be obtained while suppressing an increase in size of the device. Can do. Further, the magnetic detection device 1 can form a laminated structure by laminating a plurality of upper conductive members 33A and lower conductive members 33B in the laminating direction, and the bias magnetic field can be easily strengthened.

  In the magnetic detection device 1, the upper conductive member 33 </ b> A and the lower conductive member 33 </ b> B have a current flowing along the direction intersecting the magnetic field detection direction in which the MI element 21 detects the external magnetic field, and the currents flow in opposite directions. Flowing. With this configuration, the magnetic detection device 1 can apply the bias magnetic field H1 to the MI element 21 along the magnetic field detection direction.

  In the magnetic detection device 1, the MI element 21 is formed extending along the first extending direction, and the magnetic field detection direction is a direction along the first extending direction. In the upper conductive member 33A and the lower conductive member 33B, a current flows along a direction intersecting the first extending direction. With this configuration, the magnetic detection device 1 can apply a bias magnetic field to the MI element 21 by the pseudo solenoid coil 33.

  The magnetic bias device 30 according to the first embodiment includes an upper conductive member 33A and a lower conductive member 33B. The upper conductive member 33A is a conductive member formed in a planar shape, and is stacked on one side in the stacking direction of the MI element 21 that detects an external magnetic field. The lower conductive member 33B is a conductive member formed in a planar shape, is stacked on the other side of the MI element 21 in the stacking direction, and opposes the upper conductive member 33A along the stacking direction. The upper conductive member 33A and the lower conductive member 33B apply a bias magnetic field to the MI element 21 by applying a current. With this configuration, the magnetic bias device 30 can achieve the same effects as the magnetic detection device 1 described above.

[Modification of First Embodiment]
Next, a magnetic detection device 1A according to a modification of the first embodiment will be described. The magnetic detection device 1A has the magnetic detection according to the first embodiment in that the lower conductive member 33B is stacked not on the bonding wire but on the wiring board 50 (see FIG. 12) and electrically connected to the power supply unit (not shown). Different from device 1. In addition, in the modification of 1st Embodiment, the same code | symbol is attached | subjected to the component equivalent to 1st Embodiment, and the detailed description is abbreviate | omitted.

  As shown in FIGS. 10, 11, and 12, the magnetic detection device 1 </ b> A according to the modification includes a magnetic detection unit 20, a magnetic bias device 30, a lower base material 41 as a second base material, And an upper substrate 42 as a substrate. The upper base material 42 is formed of an insulating material, and is formed in a rectangular shape when viewed from the stacking direction. The upper base material 42 includes a main body portion 42a, an upper base material outer surface (first outer surface) 42g formed on one side (upper side) in the stacking direction of the main body portion 42a, and the other side of the main body portion 42a in the stacking direction ( And the upper base material inner surface (first inner surface) 42h formed on the lower side. The upper base member 42 has an upper conductive member 33A formed on the upper base member outer surface 42g. The upper base member 42 has a recess (bowl) 42b formed on the upper base member inner surface 42h. The recess 42b is formed in a groove shape, for example. The concave portion 42b forms an accommodating space portion sandwiched between the standing portions 42c provided on both sides of the main body portion 42a. Each standing portion 42c has a joint surface 42d that is joined to the lower base material inner surface (second inner surface) 41a. Each bonding surface 42d is bonded and fixed to the lower base material inner surface 41a with, for example, an adhesive 42e.

  The lower base material 41 is formed of an insulating material, and is formed in a rectangular shape having the same size as the upper base material 42 when viewed from the stacking direction. The lower base 41 includes a main body 41c, a lower base outer surface (second outer surface) 41b formed on one side (lower side) in the stacking direction of the main body 41c, and a stacking direction of the main body 41c. And a lower substrate inner surface 41a formed on the other side (upper side). In the lower base material 41, a lower conductive member 33B is formed on the lower base material outer surface 41b. In the lower base 41, the MI element 21 is formed on the lower base inner surface 41a opposite to the lower base outer surface 41b. As shown in FIG. 11, the MI element 21 is accommodated in the recess 42b in a state where the upper base material inner surface 42h and the lower base material inner surface 41a are combined along the stacking direction. That is, the MI element 21 is accommodated in an accommodation space surrounded by the standing portions 42c of the recess 42b and the lower base inner surface 41a in a state where the upper base inner surface 42h and the lower base inner surface 41a are combined. . The upper conductive member 33A and the lower conductive member 33B constitute the pseudo solenoid coil 33 in a state where the upper base material inner surface 42h and the lower base material inner surface 41a are combined.

  As shown in FIG. 12, the pseudo solenoid coil 33 (33 </ b> A, 33 </ b> B) stacks the lower conductive member 33 </ b> B on the wiring board 50 instead of the bonding wire and electrically connects to the power supply unit. The wiring board 50 includes power supply wiring patterns 51, 52, 55, 56, 59, a base substrate 53, substrates 54 a, 54 b, and wires 57, 58. In the wiring substrate 50, wiring patterns 51 and 52 are formed on a base substrate 53. In the wiring board 50, a base material 54 a is erected on the wiring pattern 51, and a base material 54 b is erected on the wiring pattern 52. In the wiring board 50, a wiring pattern 55 is formed on the side opposite to the wiring pattern 51 side of the base material 54a, and a wiring pattern 56 is formed on the side opposite to the wiring pattern 52 side of the base material 54b. The wiring pattern 51 and the wiring pattern 55 are electrically connected via the wiring pattern 59. In the wiring board 50, the positive electrode side of the power supply unit is connected to the wiring pattern 52, and the negative electrode side of the power supply unit is connected to the wiring pattern 56.

  In the pseudo solenoid coil 33, the lower base member 41 is laminated on the base base member 53, whereby the lower conductive member 33 </ b> B is electrically connected directly to the wiring patterns 51 and 52. In the pseudo solenoid coil 33, for example, one side in the energization direction of the lower conductive member 33B is directly connected to the wiring pattern 51, and the other side in the energization direction of the lower conductive member 33B is directly connected to the wiring pattern 52. In the pseudo solenoid coil 33, the upper conductive member 33 </ b> A is connected to the wiring patterns 55 and 56 via the wires 57 and 58. In the pseudo solenoid coil 33, for example, one side in the energization direction of the upper base material 42 is connected to the wiring pattern 55 through the wire 57, and the other side in the energization direction of the upper base material 42 is connected to the wiring pattern 56 through the wire 58. Is done. In the pseudo solenoid coil 33, when a current is applied to the wiring pattern 52 by the power supply unit, reverse currents flow through the lower conductive member 33B and the upper conductive member 33A, respectively. In the pseudo solenoid coil 33, for example, a current flows from the wiring pattern 52 side of the lower conductive member 33B to the wiring pattern 51 side, and a current flows from the wire 57 side of the upper conductive member 33A to the wire 58 side. That is, the current flows in the order of the wiring pattern 52, the lower conductive member 33B, the wiring pattern 51, the wiring pattern 59, the wiring pattern 55, the wire 57, the upper conductive member 33A, the wire 58, and the wiring pattern 56.

  As described above, the magnetic detection device 1 </ b> A according to the modification of the first embodiment includes the upper base material 42 and the lower base material 41. The upper base member 42 has an upper conductive member 33A formed on the upper base member outer surface 42g. In the lower base material 41, the lower conductive member 33B is formed on the lower base material outer surface 41b. The upper base material 42 and the lower base material 41 are the upper base material inner surface 42h that is the surface opposite to the upper base material outer surface 42g side of the upper base material 42, or the lower base material outer surface of the lower base material 41. A recess 42b is formed on at least one of the lower substrate inner surface 41a, which is the surface opposite to the 41b side. In the first embodiment, the recess 42 b is formed on the upper base inner surface 42 h of the upper base 42. The MI element 21 is accommodated in the recess 42b in a state where the upper base material inner surface 42h and the lower base material inner surface 41a are combined in the stacking direction. With this configuration, the magnetic detection device 1A can sandwich the MI element 21 along the stacking direction between the upper conductive member 33A and the lower conductive member 33B. In the magnetic detection device 1A, the pseudo solenoid coil 33 can be constituted by the upper conductive member 33A and the lower conductive member 33B, so that the bias magnetic field can be applied to the MI element 21 by the pseudo solenoid coil 33.

  The magnetic detection device 1A includes a base substrate 53 on which wiring patterns 51 and 52 for supplying power are formed. The lower base material 41 is laminated on the base base material 53. The lower conductive member 33B is directly connected to the wiring patterns 51 and 52. With this configuration, the magnetic detection device 1 </ b> A can supply power to the lower conductive member 33 </ b> B via the wiring patterns 51 and 52.

[Second Embodiment]
Next, a magnetic detection device 1B according to the second embodiment will be described. The magnetic detection device 1B is different from the magnetic detection device 1 according to the first embodiment in that an external magnetic field is detected using an MR element 61 instead of the MI element 21. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 13, the magnetic detection device 1 </ b> B according to the second embodiment includes a magnetic detection unit 60 and a magnetic bias device 70.

  The magnetic detection unit 60 detects an external magnetic field. The magnetic detection unit 60 includes a plurality of MR (Magneto Resistive) elements 61 serving as magnetic detection elements, an electrode 62, and a bypass wiring 63. The MR element 61 is an element whose resistance is changed by an external magnetic field, such as an AMR (anisotropic magnetoresistive element) element. The MR element 61 is applied with a current and outputs a resistance value changed by an external magnetic field. The MR element 61 is formed extending along the second extending direction. The MR element 61 detects an external magnetic field in a certain direction (magnetic field detection direction). That is, the MR element 61 has a constant sensitivity direction (magnetic field detection direction) that reacts to an external magnetic field. The magnetic field detection direction of the MR element 61 is a direction that intersects (for example, is orthogonal to) the second extending direction in which the MR element 61 extends. The MR element 61 detects the magnitude and direction of the external magnetic field in the magnetic field detection direction. The MR element 61 outputs the detected magnitude and direction of the external magnetic field as a change in resistance value.

  The electrode 62 is applied with a current. The electrode 62 includes an electrode 62A connected to a terminal of one MR element 61 connected in a meander shape and an electrode 62B connected to a terminal of the other MR element 61 connected in a meander shape. Composed. The electrodes 62A and 62B preferably do not overlap the upper conductive member 71A and the lower conductive member (not shown) of the pseudo solenoid coil 71. With this configuration, the electrodes 62 </ b> A and 62 </ b> B can suppress interference with the pseudo solenoid coil 71. The electrodes 62 </ b> A and 62 </ b> B are connected to a power source (not shown), and a current is applied from the power source to flow the current through the MR element 61.

  The bypass wiring 63 is for electrically connecting the MR elements 61 to each other (see FIG. 13). The bypass wiring 63 connects, for example, adjacent MR elements 61 and connects each MR element 61 in a meander shape.

  The magnetic bias device 70 applies a bias magnetic field to the MR element 61. The magnetic bias device 70 includes a pseudo solenoid coil 71. The pseudo solenoid coil 71 applies a bias magnetic field to the MR element 61. The pseudo solenoid coil 71 is a pseudo configuration of the solenoid coil 100 (see FIG. 4). The pseudo solenoid coil 71 includes an upper conductive member 71A and a lower conductive member. The upper conductive member 71A is a conductive member formed in a planar shape (sheet shape). The upper conductive member 71A is, for example, a wiring pattern formed in a thin film shape. The upper conductive member 71A is formed in a rectangular shape, and is laminated on one side of the MR element 61 in the lamination direction. In the upper conductive member 71A, a current flows along the direction intersecting the magnetic field detection direction in which the MR element 61 detects an external magnetic field. Typically, current flows through upper conductive member 71A along a direction orthogonal to the magnetic field detection direction.

  The lower conductive member is a conductive member formed in a planar shape (sheet shape). The lower conductive member is, for example, a wiring pattern formed in a thin film shape. The lower conductive member is formed in a rectangular shape having the same size as the upper conductive member 71A. The lower conductive member is stacked on the other side of the MR element 61 in the stacking direction, and faces the upper conductive member 71A along the stacking direction. In the lower conductive member, a current flows along the direction intersecting the magnetic field detection direction in which the MR element 61 detects the external magnetic field. Typically, a current flows through the lower conductive member along a direction orthogonal to the magnetic field detection direction.

  A current flows through the upper conductive member 71A and the lower conductive member in opposite directions. For example, in the upper conductive member 71A, a current flows from one side in the energizing direction to the other side, and in the lower conductive member, a current flows from the other side in the energizing direction toward the one side. Thus, the upper conductive member 71A and the lower conductive member can pseudo-configure the solenoid coil 100 formed by winding the linear conductor 101 in a spiral. As a result, the magnetic bias device 70 can apply the bias magnetic field H3 along the magnetic field detection direction of the MR element 61 as shown in FIG. With this bias magnetic field H3, the magnetic detection device 1B can set the output resistance value of the MR element 61 within a predetermined range, so that it can properly detect the external magnetic field in the positive and negative directions.

  As described above, in the magnetic detection device 1B according to the second embodiment, the MR element 61 is formed to extend along the second extending direction, and the direction in which the magnetic field detection direction intersects the second extending direction. It is. Current flows through the upper conductive member 71A and the lower electric member along the second extending direction. With this configuration, the magnetic detection device 1 </ b> B can apply a bias magnetic field to the MR element 61 by the pseudo solenoid coil 71.

[Third Embodiment]
Next, a magnetic detection apparatus 1C according to the third embodiment will be described. The magnetic detection device 1C is different from the first and second embodiments in that a bias magnetic field H4 is applied in a direction orthogonal to the magnetic field detection direction (sensitivity direction) P of the MR element 61A. Note that, in the third embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  The MR element 61A is, for example, a spin valve GMR (Giant Magnetic Resistance) element or a spin valve TMR (Tunnel Magneto Resistance) element. As shown in FIG. 17, the MR element 61A has a characteristic that the resistance value changes with respect to the magnetic field strength (synthetic magnetic field angle) at a certain threshold, and is used as, for example, a memory reading element. Here, FIG. 17 is a diagram showing the relationship between the magnetic field strength (synthetic magnetic field angle) and the resistance value of the MR element 61A, and the vertical axis represents each parameter value of the magnetic field strength (synthetic magnetic field angle) and the resistance value. The horizontal axis represents the strength of the external magnetic field. The MR element 61A detects the magnitude of the external magnetic field (detected magnetic field) Q by detecting the angle of the magnetic field using the bias magnetic field H4. The resistance value of the MR element 61A varies depending on the relationship between the magnetization direction of the fixed layer and the magnetization direction of the free layer. The fixed layer is a layer whose magnetization direction is not changed by the external magnetic field Q, and the free layer is a layer whose magnetization direction is changed by the external magnetic field Q. The change in the magnetization direction of the free layer changes abruptly at a certain threshold with respect to the magnetic field strength in the same direction as the magnetization direction of the fixed layer, while the magnetic field strength exceeding a certain threshold value changes. It changes continuously with the direction of the magnetic field.

  Here, in the magnetic detection device 1 </ b> C, the upper conductive member 33 </ b> A and the lower conductive member 33 </ b> B have a current flowing along the magnetic field detection direction (sensitivity direction) P in which the MR element 61 </ b> A detects the external magnetic field Q and vice versa. Current flows in the direction. Thereby, the magnetic detection device 1C applies a bias magnetic field H4 along the crossing direction (orthogonal direction) with respect to the magnetic field detection direction (sensitivity direction) P as shown in FIG. As shown in FIG. 15, when the external magnetic field Q is detected along the magnetic field detection direction (sensitivity direction) P as shown in FIG. 15, the magnetic detection device 1C generates a bias magnetic field H4 as shown in FIG. And the combined magnetic field H5 obtained by combining the external magnetic field Q. The MR element 61A increases the composite magnetic field H5 as the external magnetic field Q increases, and can detect the external magnetic field Q based on a resistance value corresponding to the strength of the composite magnetic field H5. It should be noted that AMR elements and MI elements other than the MR element 61A can also be applied because they have angle dependency due to the composite magnetic field H5.

  As described above, in the magnetic detection device 1C, the upper conductive member 33A and the lower conductive member 33B have a current flowing along the magnetic field detection direction P in which the MR element 61A detects the external magnetic field Q, and in the opposite directions. Current flows. With this configuration, the magnetic detection device 1 </ b> C can apply the bias magnetic field H <b> 4 to the MR element 61 </ b> A along the direction intersecting (orthogonal) with the magnetic field detection direction P. As a result, the magnetic detection device 1C can detect the external magnetic field Q based on the resistance value corresponding to the strength of the combined magnetic field H5 formed by the bias magnetic field H4 and the external magnetic field Q.

[Modification of the first to third embodiments]
Next, modified examples of the first to third embodiments will be described. The magnetic detection element has been described using the MI element 21 or the MR element 61. However, the present invention is not limited to this, and other elements may be used as long as they can detect an external magnetic field.

  Although the recessed part 42b demonstrated the example formed in 42 h of upper base material inner surfaces of the upper base material 42, it is not limited to this. The recess 42b may be formed on the lower base material inner surface 41a of the lower base material 41, or both the lower base material inner surface 41a of the lower base material 41 and the upper base material inner surface 42h of the upper base material outer surface 42g. May be formed.

  Although the lower conductive member 33 </ b> B has been described with respect to the example in which the lower base 41 is laminated on the base base 53 and electrically connected to the wiring patterns 51 and 52, the present invention is not limited thereto. The upper conductive member 33 </ b> A may be electrically connected directly to the wiring patterns 51 and 52 by laminating the upper substrate 42 on the base substrate 53. In this case, the lower conductive member 33 </ b> B is connected to the wiring patterns 55 and 56 via the wires 57 and 58.

1, 1A, 1B Magnetic detection device 21 MI element (magnetic detection element)
33A Upper conductive member (first conductive member)
33B Lower conductive member (second conductive member)
30, 70 Magnetic bias device 61, 61A MR element (magnetic detection element)
41 Lower substrate (second substrate)
42 Upper substrate (first substrate)
42g Upper base material outer surface (first outer surface)
42h Upper base material inner surface (first inner surface)
41b Lower substrate outer surface (second outer surface)
41a Lower base inner surface (second inner surface)
42b Recess 53 Base base material (third base material)
51, 52 Wiring pattern

Claims (8)

A magnetic detection element for detecting an external magnetic field;
A first conductive member formed in a planar shape and stacked on one side in the stacking direction of the magnetic detection elements;
A second conductive member formed in a planar shape and stacked on the other side of the stacking direction of the magnetic detection element and facing the first conductive member along the stacking direction,
The magnetic detection device according to claim 1, wherein a current is applied to the first conductive member and the second conductive member to apply a bias magnetic field to the magnetic detection element.   The current flows through the first conductive member and the second conductive member along a direction intersecting a magnetic field detection direction in which the magnetic detection element detects the external magnetic field, and a current flows in the opposite direction. The magnetic detection apparatus described in 1.   2. The magnetism according to claim 1, wherein a current flows in the first conductive member and the second conductive member along a magnetic field detection direction in which the magnetic detection element detects the external magnetic field, and a current flows in the opposite direction. Detection device. The magnetic detection element is formed extending along a first extending direction, and a magnetic field detection direction in which the magnetic detection element detects the external magnetic field is a direction along the first extending direction,
The magnetic detection device according to claim 1, wherein a current flows through the first conductive member and the second conductive member along a direction intersecting the first extending direction. The magnetic detection element is formed to extend along a second extending direction, and a magnetic field detection direction in which the magnetic detection element detects the external magnetic field intersects the second extending direction,
3. The magnetic detection device according to claim 1, wherein current flows through the first conductive member and the second conductive member along the second extending direction. A first base material having the first conductive member formed on a first outer surface;
A second base member formed on the second outer surface of the second conductive member,
The first base material and the second base material are a first inner surface that is a surface opposite to the first outer surface side of the first base material, or the second outer surface side of the second base material. Is formed with a recess in at least one of the second inner surface, which is the opposite surface,
The magnetic detection device according to claim 1, wherein the magnetic detection element is housed in the recess in a state where the first inner surface and the second inner surface are combined along the stacking direction. A third substrate on which a wiring pattern for power supply is formed;
The second base material is laminated on the third base material,
The magnetic detection device according to claim 6, wherein the second conductive member is directly connected to the wiring pattern. A first conductive member that is laminated on one side in the laminating direction of a magnetic sensing element that is a planar conductive member that detects an external magnetic field;
A conductive member formed in a planar shape and stacked on the other side of the stacking direction of the magnetic sensing element and facing the first conductive member along the stacking direction,
A magnetic bias device, wherein a current is applied to the first conductive member and the second conductive member to apply a bias magnetic field to the magnetic detection element.

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