JP2010008357A - Magnetic sensor - Google Patents

Abstract

An object of the present invention is to improve the detection sensitivity of an external magnetic field by effectively utilizing a planar area.
A magnetic film whose magnetic characteristics are changed by an external magnetic field J1 and a coil for applying a bias magnetic field to the magnetic film are arranged on a substrate so as to overlap each other via an insulator. The first coil part and the second coil part are composed of reverse spiral first coil part and second coil part, and the outer peripheral ends of the first coil part and the second coil part are connected to each other, and the inner peripheral end of each coil part is an induced voltage output. And the magnetic film is formed along a straight line passing through the vicinity of the inner peripheral end of the first coil portion and the vicinity of the inner peripheral end of the second coil portion, and the first coil portion and the second coil. Extending from a first area e1 located between the vicinity of the inner peripheral end of the section to second areas e21 and e22 located outside thereof, and having a current-carrying area at e21 and e22, the coil extending along its longitudinal direction Induced voltage H11, H1 , H21, H22 is the same orientation in e1 and e21, e22.
[Selection] Figure 2

Description

  The present invention relates to a magnetic sensor that detects a minute magnetic field with high accuracy, and more particularly to a magnetic sensor used as a fluxgate sensor or a high-frequency carrier type sensor.

  As a magnetic sensor for detecting a weak external magnetic field with high accuracy, there is one using a magnetic impedance element (magnetic film). However, since the magneto-impedance element has no sensitivity in the vicinity of the zero magnetic field, it is used as a high-frequency carrier type sensor by applying a bias magnetic field with a coil disposed in the vicinity of the element, or a flux gate with a coil disposed in the vicinity of the element. Must be used as a sensor.

  In recent years, there is a strong demand for thinning and miniaturization of magnetic sensors for mounting on mobile devices. For example, thin and small magnetic sensors composed of a magnetic film and a planar coil have been proposed (for example, patents). References 1 and 2).

  6 and 7 are diagrams showing examples of conventional magnetic sensors. 6A is a plan view, and FIG. 6B is a cross-sectional view taken along the line S11-S11 in FIG. Similarly, in FIG. 7, (a) is a plan view, and (b) is a cross-sectional view between S12 and S12 in (a).

  As shown in FIG. 6, the conventional magnetic sensor 100 includes a substrate 100A, an insulator 100B, a magnetic film 111 (111a, 111b), a magnetic film connection wiring 112 (112a, 112b, 112c), A magnetic film electrode pad 113 (113a, 113b), a coil 114 (114a, 114b), a coil connection wiring 115 (115a, 115b), and a coil electrode pad 116 (116a, 116b). (For example, refer to Patent Document 1).

As shown in FIG. 7, the conventional magnetic sensor 200 includes a substrate 200A, an insulator 200B, a magnetic film 211 (211a, 211b), and a magnetic film connection wiring 212 (212a, 212b, 212c). A magnetic film electrode pad 213 (213a, 213b), a coil 214 (214a, 214b), a coil connection wiring 215 (215a, 215b), and a coil electrode pad 216 (216a, 216b). (See, for example, Patent Document 2).
JP 2003-004831 A JP 2006-201123 A

  However, in the conventional magnetic sensor 100 shown in FIG. 6, the magnetic film 111 is provided only in the region near the inner peripheral end (region between the coil centers) e1 of the coil 114 composed of the coil portions 114a and 114b of the reverse spiral. Therefore, the outer regions e21 and e22 of the coil center-to-center region e1 are wasted.

  On the other hand, in the conventional magnetic sensor 200 shown in FIG. 7, the magnetic film 211 extends not only to the coil center region e <b> 1 but also to the outer regions e <b> 21 and e <b> 22 and is provided over the entire region of the coil 214. However, the magnetic films 211a and 211b are connected to the electrode pads 213a and 213b by the wirings 212a and 212b in the vicinity of the inner peripheral end of the coil part 214b, respectively, and by the wiring 212c in the vicinity of the inner peripheral end of the coil part 214a. Are connected to each other. Therefore, in the magnetic sensor 200, the magnetic film portions disposed in the outer regions e21 and e22 are not energized regions, and it is difficult to say that the outer regions e21 and e22 are effectively used. In the conventional magnetic sensor 200, when the energization region is expanded from the coil center region e1 to the outer regions e21 and e22, the following problem occurs, which becomes an obstacle to increasing the detection sensitivity of the external magnetic field (for example, (See paragraph [0009] of Patent Document 2 and FIG. 13).

(In the case of induction coil)
FIG. 8 is a schematic plan view for explaining a conventional problem when the magnetic sensor 200 having the energized region of the magnetic film 211 widened is used as a fluxgate sensor. In the magnetic sensor 200 in which the energization area is expanded, the coil 214 is used as an induction coil, the electrode pads 216a and 216b are used as magnetic detection (induced voltage) output terminals, the electrode pad 213a is used as a signal input terminal, and the electrode pad 213b is used as a GND terminal. .

  When a high-frequency signal or a pulse signal is passed from the electrode pad 213 to the magnetic film 211 and an external magnetic field in the direction of the arrow J1 in FIG. 8 exists at that time, for example, the magnetic film 211 is The magnetic field changes in the directions of arrows G11, G12, G21, and G22 in FIG. As a result, the coil 214 is positioned in the upper layer of the magnetic film 211, so that an induced voltage is generated in the direction of arrows H11 and H12 in FIG. 8 in the coil center region e1 and in the outer regions e21 and e22. An induced voltage is generated in the directions of arrows H21 and H22 in FIG.

  As described above, when used as a fluxgate sensor, the voltage induced in the coil 214 due to the change in the magnetic characteristics of the magnetic film 211 is the direction (symbol) H11, H12 in the coil center region e1 and the outside thereof. The directions (signs) H21 and H22 in the regions e21 and e22 are reversed. For this reason, the induced voltage cannot be increased and the detection sensitivity of the external magnetic field is lowered.

(For bias coil)
FIG. 9 is a schematic plan view for explaining a conventional problem when the magnetic sensor 200 in which the energization region of the magnetic film 211 is widened is used as a high frequency carrier type sensor. In the magnetic sensor 200 in which the energization region is expanded, the coil 214 is used as a bias coil, the electrode pads 213a and 213b are used as magnetic detection output terminals, the electrode pad 216b is used as a GND terminal, and the electrode pad 216a is used as a voltage input terminal.

  When a voltage is applied to the coil 214, a coil current flows in the directions of arrows E11, E12, E21, and E22 in FIG. 9, and the coil 214 generates a bias magnetic field. Thus, since the magnetic films 211a and 211b are located below the coil 214, the coil center region e1 receives the bias magnetic field from the coil 214 in the directions of arrows F11 and F12 in FIG. , E22, the bias magnetic field from the coil 214 is received in the directions of arrows F21 and F22 in FIG.

  Thus, when used as a high-frequency carrier type sensor, as viewed from the magnetic film 211, the direction of coil energization E11, E12 in the coil center-to-coil region e1 and the coil energization in the outer regions e21, e22. The directions E21 and E22 are reversed. For this reason, when the coil 214 is energized to apply a bias magnetic field, the direction F11, F12 of the bias magnetic field received by the magnetic film 211 in the inter-coil region e1 and the bias received by the magnetic film 211 in the outer regions e21, e22. The magnetic field directions F21 and F22 are opposite to each other. Accordingly, since a reverse bias magnetic field is applied to the magnetic film 211, the application efficiency of the bias magnetic field is deteriorated, and the decrease in the application efficiency becomes an obstacle to improving the detection sensitivity.

  As described above, the conventional magnetic sensor has a problem in that it cannot effectively improve the detection sensitivity by utilizing the planar area.

  The present invention has been made to solve the above-described conventional problems, and it is an object of the present invention to provide a magnetic sensor that can effectively improve the detection sensitivity of an external magnetic field by effectively using a planar region. is there.

  In order to solve the above problems, a first magnetic sensor of the present invention includes a magnetic film on a substrate whose magnetic characteristics change when a signal is applied while an external magnetic field is applied, and the magnetic film. A magnetic sensor in which an induced voltage changes due to a change in magnetic characteristics caused by energization of the magnetic sensor so as to overlap with each other via an insulator. 1st coil part and 2nd coil part which have the spiral shape of the same rotation direction toward the outer periphery end, The said 1st coil part and the said 2nd coil part are provided adjacent, and each outer periphery end is mutually Are connected to each other, and the inner peripheral ends of the respective coil portions form an induced voltage output end, and the magnetic film is disposed near the inner peripheral end of the first coil portion and the inner peripheral end of the second coil portion. Along the straight line passing through, the first Extending from a first region located between the coil portion and the inner peripheral end of the second coil portion to a second region located outside the first region, and has a current-carrying region in the second region. The coil is characterized in that the induced voltage generated along the longitudinal direction has the same direction in the first region and the second region.

  In the second magnetic sensor of the present invention, a magnetic film whose magnetic characteristics are changed by an external magnetic field and a coil for applying a bias magnetic field to the magnetic film are overlapped on a substrate via an insulator. The coil includes a first coil portion and a second coil portion having a spiral shape in the same rotational direction from the inner peripheral end toward the outer peripheral end when viewed from above the substrate. The first coil portion and the second coil portion are provided adjacent to each other, and the outer peripheral ends of the first coil portion and the second coil portion are connected to each other, and the inner peripheral end of each coil portion forms a signal input end. The film is located between the vicinity of the inner peripheral end of the first coil portion and the inner peripheral end of the second coil portion along a straight line passing through the vicinity of the inner peripheral end of the first coil portion and the vicinity of the inner peripheral end of the second coil portion. Positioned from the first area to the outside of the first area That to the second region is extended, the bias magnetic field generated along the longitudinal direction, characterized in that it is in the same direction in the first region and the second region.

  According to the first magnetic sensor of the present invention, the induced voltage generated along the longitudinal direction of the coil is in the same direction in the first region and the second region, so that the induced voltage is increased as compared with the conventional case. Therefore, there is an effect that the detection sensitivity of the external magnetic field can be improved by effectively utilizing the planar area of the sensor.

  Further, according to the second magnetic sensor of the present invention, the bias magnetic field generated along the longitudinal direction of the magnetic film is in the same direction in the first region and the second region. As a result, the detection sensitivity of the external magnetic field can be improved by effectively utilizing the planar area of the sensor.

  Hereinafter, the present invention will be described in detail with reference to the drawings. However, the present invention is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

Embodiment 1
1A and 1B are diagrams showing a first embodiment of a magnetic sensor according to the present invention, in which FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along line S1-S1 in FIG. As shown in FIG. 1, the magnetic sensor 10 according to the first embodiment of the present invention includes a substrate 10A, an insulator 10B, a magnetic film 11 (11a, 11b), and a magnetic film connection wiring 12 (12a, 12b, 12c), magnetic film electrode pads 13 (13a, 13b), coils 14 (14a, 14b), coil connection wires 15 (15a, 15b), and coil electrode pads 16 (16a, 16b). ).

  The substrate 10A is a substrate made of a nonmagnetic material or the like. As the substrate 10A, for example, a silicon (Si) substrate with an oxide film, a glass substrate, a ceramic substrate, or the like can be used. The magnetic sensor 10 according to the first embodiment is configured as a thin sensor formed on a substrate 10A as shown in FIG.

  The insulator 10B is provided on the substrate 10A, and ensures insulation between the magnetic film 11 and the coil 14 arranged close to each other or between these and other conductors, and the magnetic sensor 10. Ensures insulation. As this insulator 10B, one or two or more insulating materials can be appropriately selected and used. For example, an oxide film such as a silicon oxide film or an organic insulating film such as a resin by plasma CVD is used. Can be configured.

  In this Embodiment 1, as shown in FIG.1 (b), the magnetic body film 11 and the coil 14 are arrange | positioned on the board | substrate 10A so that it may overlap via the insulator 10B. The insulator 10B is provided with openings that expose the electrode pads 13a, 13b, 16a, and 16b. In addition, the insulator 10B may have a structure in which a sealing insulator is provided on the uppermost layer of the interlayer insulator.

  The magnetic film 11 changes its magnetic characteristics by an external magnetic field. Further, when a magnetic film 11 is energized with a signal (high frequency current or pulse current) while an external magnetic field is applied, the magnetic characteristics of the energized region change. The magnetic film 11 is made of a material whose magnetic properties change due to a magnetic field, such as a soft magnetic material having conductivity. As shown in FIG. 1, the magnetic film 11 of the first embodiment is composed of two linear magnetic films 11a and 11b. The magnetic films 11a and 11b are regions between the inner peripheral ends of the coil portions 14a and 14b, respectively, along the straight lines passing through the vicinity of the inner peripheral ends of the reverse spiral coil portions 14a and 14b constituting the coil 14. (Coil center region) extends from e1 (first region) to its outer regions e21, e22 (second region) (in FIG. 1, the magnetic films 11a, 11b are the lengths of the coil portions 14a, 14b). Are provided in the entire arrangement region of the coil 14 so as to protrude from the outer peripheral end in the direction).

  The magnetic films 11a and 11b are connected to the electrode pads 13a and 13b by the wirings 12a and 12b in the outer region e22 of the inter-coil region e1, respectively, and are connected to each other by the wiring 12c in the outer region e21 of the inter-coil region e1. Has been. Accordingly, the energization region f1 of the magnetic film 11 extends to the outer regions e21 and e22 of the inter-coil region e1. That is, the magnetic film 11 has the energization region f1 not only in the coil center region e1 but also in the outer regions e21 and e22. By setting the energized region f1 inside the regions q1 and q2 having strong demagnetizing fields near both ends in the longitudinal direction of the magnetic film 11, particularly excellent magnetic characteristics can be obtained.

  The coil 14 applies a bias magnetic field to the magnetic film 11. The coil 14 induces a change in magnetic characteristics due to energization of the energized magnetic film 11 as a change in voltage. The coil 14 is a conductor film made of a nonmagnetic metal material or the like.

  The coil 14 includes a coil part 14a (first coil part) and a coil part 14b (second coil part) having a spiral shape in the same rotational direction from the inner peripheral end to the outer peripheral end when viewed from above the substrate 10A. . The coil portions 14a and 14b are provided adjacent to each other, the outer peripheral ends thereof are connected to each other, and the inner peripheral ends of the respective coil portions form signal input ends.

  The wirings 12a and 12b connect the magnetic films 11a and 11b and the electrode pads 13a and 13b. The wiring 12a is connected to the magnetic film 11a in a region e22 outside the inter-coil center region e1, and the wiring 12b is connected to the magnetic film 11b in the region e22. The connection wiring 12c connects the two magnetic films 11a and 11b in the region e21 outside the inter-coil region e1. The connection wirings 15a and 15b connect the coil 14 and the electrode pads 16a and 16b. These wirings are preferably made of a nonmagnetic conductor such as copper (Cu) or aluminum (Al).

  The electrode pads 13a and 13b are provided in order to output a change in magnetic characteristics of the magnetic film 11 as a change in impedance. The electrode pads 13 a and 13 b are provided for flowing a high-frequency current or a pulse current through the magnetic film 11. On the other hand, the electrode pads 16 a and 16 b are provided for applying a voltage for generating a bias magnetic field in the coil 14. The electrode pads 16a and 16b are provided for outputting the induced voltage of the coil 14. These electrode pads are preferably made of a nonmagnetic conductor such as copper (Cu) or aluminum (Al).

(Operation as induction coil)
FIG. 2 is a schematic plan view for explaining the operation when the magnetic sensor 10 is used as a fluxgate sensor. In the magnetic sensor 10, the coil 14 is used as an induction coil of the fluxgate sensor, the electrode pads 16a and 16b are used as magnetic detection (induced voltage) output terminals, the electrode pad 13a is used as a signal input terminal, and the electrode pad 13b is used as a GND terminal.

  When a high frequency signal or a pulse signal is energized from the electrode pad 13a to the magnetic film 11, and an external magnetic field in the direction of the arrow J1 in FIG. 2 exists at that time, for example, the magnetic film 11 is Magnetic field changes occur in the directions of the arrows G11, G12, G21, and G22. Thereby, in the coil center area | region e1, since the coil 14 is located in the upper layer of the magnetic body film 11, an induced voltage is generate | occur | produced in the direction of the arrows H11 and H12 in FIG. On the other hand, in the outer regions e21 and e22, the coil 14 is located in the lower layer of the magnetic film 11, so that an induced voltage is generated in the directions of arrows H21 and H22 in FIG.

  That is, the direction of the magnetic field change seen from the coil 14 in the coil center-to-coil region e1 is the same as the direction of the magnetic field change seen from the coil 14 in the outer regions e21 and e22. The induced voltage in the same direction (symbol) is generated in the inter-coil center region e1 and the outer regions e21 and e22. Accordingly, the coil 14 generates an induced voltage in the same direction (symbol) over the entire energization region f1 of the magnetic film 11.

  As described above, according to the first embodiment, the direction (sign) of the voltage induced in the coil 14 due to the change in the magnetic characteristics of the magnetic film 11 that is energized while the external magnetic field is applied is substantially the same as the arrangement region of the coil 14. Since the same direction can be achieved in the entire region (the same direction can be achieved in the coil center-to-coil region e1 and its outer regions e21 and e22), the induced voltage can be made larger than that of a conventional magnetic sensor (flux gate sensor). High detection sensitivity can be obtained.

(Operation as a bias coil)
FIG. 3 is a schematic plan view for explaining the operation when the magnetic sensor 10 is used as a high-frequency carrier type sensor. In the magnetic sensor 10, the coil 14 is used as a bias coil, the electrode pads 13a and 13b are used as magnetic detection output terminals, the electrode pad 16b is used as a GND terminal, and the electrode pad 16a is used as a voltage input terminal.

  When a voltage is applied to the coil 14, a coil current flows in the directions of arrows E11, E12, E21, and E22 in FIG. 3, and the coil 14 generates a bias magnetic field. As a result, the magnetic films 11a and 11b are located in the lower layer of the coil 14 in the inter-coil center region e1, and thus receive the bias magnetic field from the coil 14 in the directions of arrows F11 and F12 in FIG. On the other hand, in the outer regions e21 and e22, since the magnetic films 11a and 11b are located in the upper layer of the coil 14, the bias magnetic field from the coil 14 is received in the directions of arrows F21 and F22 in FIG.

  That is, the direction of coil energization viewed from the magnetic film 11 in the coil center region e1 is the same as the direction of coil energization viewed from the magnetic film 11 in the outer regions e21 and e22. Bias magnetic fields in the same direction are applied to 11a and 11b in the coil center-to-coil region e1 and the outer regions e21 and e22. Therefore, the magnetic film 11 is applied with a bias magnetic field in the same direction in the longitudinal direction of the magnetic film 11 over the entire arrangement region of the coil 14.

  As described above, according to the first embodiment, the direction of the bias magnetic field received by the magnetic film 11 can be made the same in almost the entire area in the longitudinal direction of the magnetic film 11 (the coil center region e1 and the outer region). (e21 and e22 can be set in the same direction), the application efficiency of the bias magnetic field can be made higher than that of the conventional magnetic sensor (high-frequency carrier type sensor), and high detection sensitivity can be obtained.

  Furthermore, in the magnetic sensor 10 of the first embodiment, as shown in FIG. 1B, in the insulator 10B, the portion of the coil 14 disposed in the outer regions e21 and e22 is formed in the lower layer on the substrate 10A side. Then, the magnetic film 11 is formed as a single layer on the intermediate layer above it, and the portion of the coil 14 disposed in the coil center region e1 is formed on the upper layer thereon, and the lower coil portion and the upper coil are formed. The portion is connected by a contact hole or the like at the boundary between the coil center region e1 and the outer regions e21 and e22. That is, in the magnetic sensor 10, the magnetic film 11 has a single-layer structure, the coil 14 has a two-layer structure, and the insulator 10B has at least three layers (interlayer insulating layer of the substrate 10A and the lower coil portion, the lower coil portion and the magnetic layer). The laminated structure of the interlayer insulating layer of the body film 11, the magnetic film 11 and the interlayer insulating layer of the upper coil portion).

  Since the magnetic film 11 has a single-layer structure as described above, the magnetic film 11 can be flattened over the entire length, so that the magnetic film 11 having excellent magnetic characteristics can be provided. However, in the region where the magnetic film made of the thin film magnetic material is located above the coil, the insulator under the magnetic thin film needs to be flat.

  As described above, the first embodiment of the present invention is based on the magnetic film 11 in which the magnetic characteristics of the current-carrying region change when a signal is applied while an external magnetic field is applied on the substrate 10A, and the magnetic film 11 is energized. A magnetic sensor in which an induced voltage changes due to a change in magnetic characteristics and a coil 14 are arranged so as to overlap with each other through an insulator 10B. It consists of a coil part 14a and a coil part 14b having a spiral shape in the same rotational direction toward the ends, and the coil parts 14a and 14b are provided adjacent to each other, and the respective outer peripheral ends are connected to each other. The peripheral end forms an induced voltage output end, and the magnetic film 11 is formed along the straight line passing through the vicinity of the inner peripheral end of the coil portion 14a and the vicinity of the inner peripheral end of the coil 14b. The first region e1 located between the vicinity of the peripheral ends extends to the second region e21 or / and e22 located outside thereof, and has a current-carrying region in the second region. The induced voltage generated along the same direction is in the same direction in the first region and the second region. As a result, the energized region f1 of the magnetic film 11 can be made wider than the first region e1 and the induced voltage can be increased, so that the detection sensitivity of the external magnetic field can be improved by effectively using the planar region of the sensor. it can.

  In the first embodiment of the present invention, a magnetic film 11 whose magnetic characteristics are changed by an external magnetic field and a coil 14 that applies a bias magnetic field to the magnetic film 11 are provided on a substrate 10A via an insulator 10B. The coil 14 includes a coil portion 14a and a coil portion 14b having a spiral shape in the same rotational direction from the inner peripheral end toward the outer peripheral end when viewed from above the substrate 10A. The coil portions 14a and 14b are provided adjacent to each other, the outer peripheral ends thereof are connected to each other, the inner peripheral ends of the respective coil portions form signal input ends, and the magnetic film 11 includes the coil portion 14a. A first region e1 located between the vicinity of the inner peripheral ends of the coil portions 14a and 14b along a straight line passing through the vicinity of the inner peripheral end of the coil portion 14b and the vicinity of the inner peripheral end of the coil portion 14b. Others extends to / and e22, the bias magnetic field generated along the longitudinal direction is the same direction in the first region and the second region. Thereby, the arrangement area of the magnetic film 11 can be expanded more than the first area e1, and the application efficiency of the bias magnetic field can be increased. Therefore, the detection area sensitivity is improved by effectively using the planar area of the sensor. be able to.

  In the first embodiment, the coil is disposed in the upper layer of the magnetic film in the coil center region e1, and the coil is disposed in the lower layer of the magnetic film in the outer regions e21 and e22 (see FIG. 1B). . However, conversely, the coil may be arranged in the lower layer of the magnetic film in the inter-coil region e1 and the coil may be arranged in the upper layer of the magnetic film in the outer regions e21 and e22. Also in this case, the same effect as in the first embodiment can be obtained. It is also possible to position one end of the energizing region f1 in the vicinity of the inner peripheral end of the coil portion 14a, or position the other end of the energizing region f1 in the vicinity of the inner peripheral end of the coil portion 14b. Similarly, one end of the magnetic film 11 can be positioned near the inner peripheral end of the coil section 14a of the coil section 14a, or the other end of the magnetic film 11 can be positioned near the inner peripheral end of the coil section 14b. It is. In the first embodiment, the number of magnetic films can be one, or three or more.

Embodiment 2
4A and 4B are diagrams showing a second embodiment of the magnetic sensor of the present invention, in which FIG. 4A is a plan view and FIG. 4B is a cross-sectional view taken along S2-S2 in FIG. As shown in FIG. 4, the magnetic sensor 20 according to the second embodiment of the present invention includes a substrate 20A, an insulator 20B, magnetic films 21 (21a, 21b), and magnetic film connection wirings 22 (22a, 22b, 22c), electrode pads 23 (23a, 23b) of magnetic film, coils 24 (24a, 24b), coil connection wires 25 (25a, 25b), and coil electrode pads 26 (26a, 26b). ).

  In the magnetic sensor 20 of the second embodiment, similarly to the magnetic sensor 10 of the first embodiment (see FIG. 1), the region where the magnetic film 21 of one layer is arranged is a region between the inner peripheral ends (between the coil centers). (Region) It extends from both sides of e1, and is provided over the entire region where the coil 24 is disposed.

  However, in this magnetic sensor 20, unlike the magnetic sensor 10 of the first embodiment, the wires 22a and 22b are connected to the magnetic films 21a and 21b in the vicinity of the inner peripheral end of the coil portion 24b, respectively, and the wire 22c. Connects the magnetic films 21a and 21b in the vicinity of the inner peripheral end of the coil portion 24a. Accordingly, the energization region f2 of the magnetic film 21 is a region from the vicinity of the inner peripheral end of the coil portion 24a to the vicinity of the inner peripheral end of the coil portion 24b, and the length of the energization region f2 is substantially the same as that of the inter-coil region e1. The same.

  That is, this magnetic sensor 20 is the magnetic sensor 10 having a magnetic film having a single layer structure and a coil having a two layer structure, and the energization region f2 of the magnetic film is between the vicinity of the inner peripheral end of the coil portion. . Accordingly, the portions of the magnetic film disposed in the outer regions e21 and e22 of the coil center-to-center region e1 are non-conductive regions.

(Operation as a bias coil)
The operation when the magnetic sensor 20 is used as a high frequency carrier type magnetic sensor will be described below. The coil 24 is used as a bias coil, the electrode pads 23a and 23b are used as magnetic detection output terminals, the electrode pad 26b is used as a GND terminal, and the electrode pad 26a is used as a voltage input terminal.

  When a voltage is applied to the coil 24, a coil current flows in the directions of arrows E11, E12, E21, and E22 in FIG. 3, and the coil 24 generates a bias magnetic field. Thereby, in the coil center area | region e1, since the magnetic body films 21a and 21b are located in the lower layer of the coil 24, they receive the said bias magnetic field from the coil 24 in the direction of the arrows F11 and F12 in FIG. On the other hand, in the outer regions e21 and e22, since the magnetic films 21a and 21b are located in the upper layer of the coil 24, they receive the bias magnetic field from the coil 24 in the directions of arrows F21 and F22 in FIG.

  That is, the direction of coil energization viewed from the magnetic film 21 in the coil center-to-coil region e1 is the same as the direction of coil energization viewed from the magnetic film 21 in the outer regions e21 and e22. A bias magnetic field in the same direction is applied to 21a and 21b in the coil center-to-coil region e1 and the outer regions e21 and e22. Accordingly, the magnetic film 21 is applied with a bias magnetic field in the same direction in the longitudinal direction of the magnetic film 21 over the entire arrangement region of the coil 24.

  As described above, according to the second embodiment, as in the first embodiment, the direction of the bias magnetic field received by the magnetic film 21 can be made the same in substantially the entire longitudinal direction of the magnetic film 21. (The coil center region e1 and the outer regions e21 and e22 can be in the same direction), so that the bias magnetic field application efficiency can be made higher than that of a conventional magnetic sensor (high-frequency carrier type sensor), and high detection sensitivity. Can be obtained.

  Further, according to the second embodiment, similarly to the first embodiment, the magnetic film 21 can be flattened over the entire length by forming the magnetic film 21 in a single layer structure. A magnetic film 21 having excellent magnetic properties can be provided. However, in the region where the magnetic film is above the coil, the insulator under the magnetic film needs to be flat.

  As described above, according to the second embodiment of the present invention, the magnetic film 21 whose magnetic characteristics change due to the external magnetic field and the coil 24 that applies a bias magnetic field to the magnetic film 21 are formed on the substrate 20A. The coil 24 includes a coil portion 24a and a coil portion having a spiral shape in the same rotational direction from the inner peripheral end toward the outer peripheral end when viewed from above the substrate 20A. 24b, the coil portions 24a and 24b are provided adjacent to each other, and the outer peripheral ends of the respective coil portions are connected to each other, and the inner peripheral ends of the respective coil portions form signal input ends. A second region located outside the first region e1 located between the vicinity of the inner peripheral ends of the coil portions 24a and 24b along a straight line passing through the vicinity of the inner peripheral end of the portion 24a and the inner peripheral end of the coil portion 24b. Extends to 21 or / and e22, the bias magnetic field generated along the longitudinal direction is the same direction in the first region and the second region. Thereby, the arrangement area of the magnetic film 21 can be made wider than the coil center area e1 and the application efficiency of the bias magnetic field can be increased. Therefore, the sensing area of the sensor is effectively used to improve the detection sensitivity of the external magnetic field. Can be made.

  In the second embodiment, the coil is disposed in the upper layer of the magnetic film in the coil center region e1, and the coil is disposed in the lower layer of the magnetic film in the outer regions e21 and e22 (see FIG. 4B). . However, conversely, the coil may be arranged in the lower layer of the magnetic film in the inter-coil region e1 and the coil may be arranged in the upper layer of the magnetic film in the outer regions e21 and e22. Also in this case, the same effect as in the second embodiment can be obtained. Further, one end of the magnetic film 21 can be positioned near the inner peripheral end of the coil portion 24a, or the other end of the magnetic film 21 can be positioned near the inner peripheral end of the coil portion 24b. In the second embodiment, the number of magnetic films can be one, or three or more.

Embodiment 3
5A and 5B are diagrams showing Embodiment 3 of the magnetic sensor of the present invention, in which FIG. 5A is a plan view, and FIG. 5B is a cross-sectional view taken along S3-S3 in FIG. As shown in FIG. 5, the magnetic sensor 30 according to the third embodiment of the present invention includes a substrate 30A, an insulator 30B, magnetic films 31 (31a, 31b), and magnetic film connection wirings 32 (32a, 32b, 32c), electrode pads 33 (33a, 33b) of magnetic film, coils 34 (34a, 34b), coil connection wires 35 (35a, 35b), and coil electrode pads 36 (36a, 36b). ).

  In the magnetic sensor 30 according to the third embodiment, similarly to the magnetic sensor 20 according to the second embodiment (see FIG. 4), the arrangement area of the magnetic film 31 is changed from the inner peripheral edge vicinity area (coil center area) e1. The coil 34 is provided over the entire arrangement region of the coil 34, and the energization region f2 of the magnetic film 31 is a region from the vicinity of the inner peripheral end of the coil portion 34a to the vicinity of the inner peripheral end of the coil portion 34b.

  However, in this magnetic sensor 30, unlike the magnetic sensor 20 of the second embodiment (see FIG. 4), as shown in FIG. 5B, in the insulator 30B, the coil center is formed on the lower layer on the substrate 30A side. A portion of the magnetic film 31 disposed in the intermediate region e1 is formed, the coil 34 is formed as one layer on the intermediate layer thereon, and the magnetic film disposed in the outer regions e21 and e22 on the upper layer 31 is formed, and the lower magnetic film portion and the upper magnetic film portion are connected by a contact hole or the like at the boundary between the coil center region e1 and the outer regions e21 and e22.

  That is, this magnetic sensor 30 has the same structure as that of the magnetic sensor 20 in which the energization region f2 of the magnetic film is between the vicinity of the inner peripheral end. The coil 34 has a single-layer structure and the magnetic film 31 has a two-layer structure. Has a laminated structure of at least three layers (interlayer insulating layer of substrate 30A and lower magnetic film portion, lower magnetic film portion and interlayer insulating layer of coil 34, and interlayer insulating layer of coil 34 and upper magnetic film portion). Is.

  As described above, according to the third embodiment, since the coil 34 has a single-layer structure, it is not necessary to provide an inter-layer connection portion in the coil 34, so that the highly reliable coil 34 can be provided.

  In the magnetic sensor 30 having the magnetic film 31 having a two-layer structure, the magnetic films 31a and 31b are interlayer-connected at positions in the width direction passing through the centers of the coil portions 34a and 34b, respectively, and have bent portions. If this bent portion is included in the energization region, the magnetic properties of the magnetic film 31 may be deteriorated. For this reason, in this magnetic sensor 30, it is not a good idea to extend the energization region of the magnetic film 31 from the coil center region e1 to the outer regions e21 and e22.

(Operation as a bias coil)
The operation when the magnetic sensor 30 is used as a high frequency carrier type magnetic sensor will be described below. The coil 34 is used as a bias coil, the electrode pads 33a and 33b are used as magnetic detection output terminals, the electrode pad 36b is used as a GND terminal, and the electrode pad 36a is used as a voltage input terminal.

  When a voltage is applied to the coil 34, a coil current flows in the directions of arrows E11, E12, E21, and E22 in FIG. 3, and the coil 34 generates a bias magnetic field. As a result, in the inter-coil center region e1, the magnetic films 31a and 31b are positioned below the coil 34, and therefore receive the bias magnetic field from the coil 34 in the directions of arrows F11 and F12 in FIG. On the other hand, in the outer regions e21 and e22, since the magnetic films 31a and 31b are located in the upper layer of the coil 34, they receive the bias magnetic field from the coil 34 in the directions of arrows F21 and F22 in FIG.

  That is, the direction of coil energization viewed from the magnetic film 31 in the coil center region e1 is the same as the direction of coil energization viewed from the magnetic film 31 in the outer regions e21 and e22. A bias magnetic field in the same direction is applied to 31a, 31b in the coil center-to-coil region e1 and the outer regions e21, e22. Accordingly, the magnetic film 31 is applied with a bias magnetic field in the same direction in the longitudinal direction of the magnetic film 31 in the entire arrangement region of the coil 34.

  Thus, according to the third embodiment, as in the second embodiment, the direction of the bias magnetic field received by the magnetic film 31 can be made the same in substantially the entire longitudinal direction of the magnetic film 31. (The coil center region e1 and the outer regions e21 and e22 can be in the same direction), so that the bias magnetic field application efficiency can be made higher than that of a conventional magnetic sensor (high-frequency carrier type sensor), and high detection sensitivity. Can be obtained.

  As described above, in the third embodiment of the present invention, the magnetic film 31 whose magnetic characteristics are changed by the external magnetic field and the coil 34 that applies a bias magnetic field to the magnetic film 31 are formed on the substrate 30A by the insulator 30B. The coil 34 includes a coil portion 34a and a coil portion having a spiral shape in the same rotational direction from the inner peripheral end toward the outer peripheral end when viewed from above the substrate 30A. 34b, the coil portions 34a and 34b are provided adjacent to each other, the outer peripheral ends thereof are connected to each other, and the inner peripheral ends of the respective coil portions form signal input ends. A second region located outside the first region e1 located between the inner peripheral ends of the coil portions 34a and 34b along a straight line passing near the inner peripheral end of the portion 34a and the inner peripheral end of the coil portion 34b. Extends to 21 or / and e22, the bias magnetic field generated along the longitudinal direction is the same direction in the first region and the second region. Thereby, the arrangement area of the magnetic film 31 can be made wider than the area e1 between the coil centers and the application efficiency of the bias magnetic field can be increased. Therefore, the detection area sensitivity can be improved by effectively utilizing the planar area of the sensor. Can be made.

  In the third embodiment, the magnetic film is disposed in the lower layer of the coil in the coil center-to-coil region e1, and the magnetic film is disposed in the upper layer of the coil in the outer regions e21 and e22 (see FIG. 5B). . However, conversely, the magnetic film may be disposed in the upper layer of the coil in the coil center region e1 and the magnetic film may be disposed in the lower layer of the coil in the outer regions e21 and e22. Also in this case, the same effect as in the third embodiment can be obtained. Further, one end of the magnetic film 31 can be positioned near the inner peripheral end of the coil portion 34a, or the other end of the magnetic film 31 can be positioned near the inner peripheral end of the coil portion 34b. In the third embodiment, the number of magnetic films can be one, or three or more.

  A magnetic sensor 10 of the present invention (see FIG. 1) was created. The coil 14 had a thickness of 5 μm, and the lines / spaces of the coil portions 14a and 14b were 10 μm / 10 μm. For the magnetic films 11a and 11b, the line / space was 40 μm / 20 μm, the total length was 1.0 mm, the thickness was 1.5 μm, and the energization region length was 600 μm. The substrate 10A was a 1 mm square silicon substrate.

  A magnetic sensor 20 of the present invention (see FIG. 4) was created. The coil 24 was 5 μm thick, and the lines / spaces of the coil portions 24a and 24b were 10 μm / 10 μm. Regarding the magnetic films 21a and 21b, the line / space was 40 μm / 20 μm, the total length was 1.0 mm, the thickness was 1.5 μm, and the energization region length was 500 μm. The substrate 20A was a 1 mm square silicon substrate.

  A magnetic sensor 30 of the present invention (see FIG. 5) was created. The coil 34 made of a thin film magnetic material had a thickness of 5 μm, and the lines / spaces of the coil portions 34a and 34b were 10 μm / 10 μm. For the magnetic films 31a and 31b, the line / space was 40 μm / 20 μm, the total length was 1.0 mm, the thickness was 1.5 μm, and the energization region length was 500 μm. The substrate 30A was a 1 mm square silicon substrate.

It is a figure which shows Embodiment 1 of the magnetic sensor of this invention. It is a figure explaining the direction of the magnetic field change by a magnetic film, and the induced voltage of a coil at the time of using the magnetic sensor of this invention as a fluxgate type sensor. It is a figure explaining the direction of the electricity supply of a coil at the time of using the magnetic sensor of this invention as a high frequency carrier type sensor, and the direction of the bias magnetic field which a magnetic body film receives from a coil. It is a figure which shows Embodiment 2 of the magnetic sensor of this invention. It is a figure which shows Embodiment 3 of the magnetic sensor of this invention. It is a figure which shows an example of the conventional magnetic sensor. It is a figure which shows an example of the conventional magnetic sensor. In the conventional magnetic sensor shown in FIG. 7, the magnetic field change caused by the magnetic film and the induced voltage of the coil when the magnetic film energized region is longer than the center length of the spiral coil portion as a fluxgate type sensor. It is a figure explaining direction. In the conventional magnetic sensor of FIG. 7, the direction of energization of the coil and the magnetic film from the coil when the energized region of the magnetic film is longer than the center length of the spiral coil portion as a high frequency carrier type sensor. It is a figure explaining the direction of the bias magnetic field to receive.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10, 20, 30 ... Magnetic sensor, 10A, 20A, 30A ... Substrate, 10B, 20B, 30B ... Insulator, 11 (11a, 11b), 21 (21a, 21b), 31 (31a, 31b) ... Magnetic film , 12 (12a, 12b, 12c), 22 (22a, 22b, 22c), 32 (32a, 32b, 32c) ... connection wiring, 13 (13a, 13b), 23 (23a, 23b), 33 (33a, 33b) ) ... Electrode pad 14, 24, 34 ... Coil, 14a, 14b, 24a, 24b, 34a, 34b ... Coil part, 15 (15a, 15b), 25 (25a, 25b), 35 (35a, 35b) ... Connection Wiring, 16 (16a, 16b), 26 (26a, 26b), 36 (36a, 36b) ... electrode pads.

Claims (4)

Insulate a magnetic film whose magnetic characteristics change when a signal is applied while an external magnetic field is applied on the substrate, and a coil whose induced voltage changes due to a change in magnetic characteristics caused by the magnetic film. A magnetic sensor arranged so as to overlap through the body,
The coil is composed of a first coil part and a second coil part having a spiral shape in the same rotational direction from the inner peripheral end toward the outer peripheral end when viewed from above the substrate,
The first coil portion and the second coil portion are provided adjacent to each other, and the outer peripheral ends of each are connected, and the inner peripheral ends of the respective coil portions form an induced voltage output end,
The magnetic film is disposed in the vicinity of the inner peripheral ends of the first coil portion and the second coil portion along a straight line passing through the vicinity of the inner peripheral end of the first coil portion and the vicinity of the inner peripheral end of the second coil portion. Extending from a first region located between the first region to a second region located outside the first region, and having a current-carrying region in the second region,
The magnetic sensor, wherein the induced voltage generated along the longitudinal direction of the coil has the same direction in the first region and the second region. A magnetic sensor in which a magnetic film whose magnetic characteristics are changed by an external magnetic field and a coil for applying a bias magnetic field to the magnetic film are arranged on a substrate so as to overlap with each other through an insulator,
The coil is composed of a first coil part and a second coil part having a spiral shape in the same rotational direction from the inner peripheral end toward the outer peripheral end when viewed from above the substrate,
The first coil part and the second coil part are provided adjacent to each other, the outer peripheral ends of each are connected, and the inner peripheral ends of the respective coil parts form a signal input end,
The magnetic film is disposed in the vicinity of the inner peripheral ends of the first coil portion and the second coil portion along a straight line passing through the vicinity of the inner peripheral end of the first coil portion and the vicinity of the inner peripheral end of the second coil portion. The bias magnetic field that extends from the first region located between the first region to the second region located outside the first region and that occurs along the longitudinal direction thereof is the same in the first region and the second region. There is a magnetic sensor. The magnetic film is formed of a single layer,
The coil is formed in a lower layer that is closer to the substrate than the magnetic film in one of the first region and the second region, and is formed in an upper layer than the magnetic film in the other region. The magnetic sensor according to claim 1, wherein the magnetic sensor is provided. The coil is formed of a single layer,
The magnetic film is formed in a lower layer that is closer to the substrate than the coil in one of the first region and the second region, and is formed in an upper layer than the coil in the other region. The magnetic sensor according to claim 1, wherein the magnetic sensor is a magnetic sensor.

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