JP6822127B2 - Magnetic sensor - Google Patents

Description

The present invention relates to a magnetic sensor, and more particularly to a magnetic sensor provided with a magnetic material for collecting magnetic flux in a magnetic sensing element.

Magnetic sensors using magnetic sensitive elements are widely used in ammeters, magnetic encoders, and the like. For example, the magnetic sensor described in Patent Document 1 is provided with a magnetic material for collecting magnetic flux in a magnetic sensing element, whereby the detection accuracy of magnetic flux is improved.

Japanese Patent No. 5500785

However, the magnetic sensor described in Patent Document 1 does not have sufficient magnetic force collection because the shape of the magnetic material is a simple block shape, and therefore, it is necessary to realize extremely high detection accuracy required in recent years. It is difficult.

As a method of improving the detection accuracy of the magnetic sensor, it is conceivable to devise the shape of the magnetic material and increase the diameter in the portion far from the magnetic sensing element rather than the diameter in the vicinity of the magnetic sensing element. However, when a magnetic material having such a shape is used, the detection accuracy varies for each magnetic sensor when a plurality of magnetic sensors are arranged in an array and used, and as a result, each magnetism even in a uniform magnetic field. There was a phenomenon that the output from the sensor was different.

Therefore, the present invention provides a magnetic sensor capable of obtaining extremely high detection accuracy and suppressing variation in detection accuracy even when a plurality of magnetic sensors are arranged and used in an array. The purpose is.

The magnetic sensor according to the present invention includes a magnetic sensitive element and a magnetic material that collects magnetic flux in the magnetic sensitive element, and the magnetic material includes a first magnetic material, the magnetic sensitive element, and the first magnetic material. The cross-sectional areas of the first and second magnetic materials in the cross section perpendicular to the magnetic collection direction are S1 and S2, respectively, including the second magnetic material located between the first and second magnetic materials. When the lengths of the magnetic material in the magnetic collection direction are L1 and L2, respectively,
S1> S2 and L1 / L2 ≦ 2
It is characterized by satisfying.

According to the present invention, since the first magnetic material has a larger cross-sectional area than the second magnetic material, it is possible to collect more magnetic flux, thereby obtaining extremely high detection accuracy. Is possible. Moreover, since the length of the first magnetic material is not twice the length of the second magnetic material, even when a plurality of magnetic sensors are arranged in an array and used, the magnetic materials are interfering with each other. As a result, it is possible to suppress the variation in the sensitivity distribution to, for example, 20% or less.

In the present invention, it is preferable that the centers of the first and second magnetic materials in the cross section are substantially on the same axis as each other. According to this, the flow of the magnetic flux from the first magnetic material to the second magnetic material becomes smooth, so that the detection accuracy can be improved. Further, since the magnetic field distribution around the central axis is made uniform, the sensitivity distribution is less likely to be distorted when a plurality of magnetic sensors are arranged and used in an array.

In the present invention, the magnetic sensing element preferably includes a plurality of magnetic sensing elements connected by a bridge. According to this, it is possible to improve the detection accuracy by the bridge connection. In this case, it is preferable that the plurality of magnetic sensitive elements are formed on the element forming surface of the sensor substrate, and the element forming surface of the sensor substrate is covered with a magnetic material layer. According to this, since the magnetic resistance is lowered, it is possible to further improve the detection accuracy.

In the present invention, the sensitivity direction of the magnetic sensitive element may be substantially parallel to the magnetic collection direction, and the sensitivity direction of the magnetic sensitive element is substantially perpendicular to the magnetic collection direction, and the second The magnetic material may be arranged offset with respect to the magnetic sensing element when viewed from the magnetic collection direction. In the former case, the magnetic sensing elements preferably include a plurality of magnetic sensing elements having different sensitivity directions by 180 °, and in the latter case, the second magnetic material is the magnetic sensing element when viewed from the magnetic collecting direction. It is preferable that it does not overlap with.

In the present invention, the magnetic material further includes a third magnetic material, and the magnetic sensitive element may be located between the second magnetic material and the third magnetic material when viewed from the magnetic collection direction. preferable. According to this, since the density of the magnetic flux passing through the magnetic sensing element is increased, it is possible to further improve the detection accuracy.

In the present invention, the magnetic material further includes a fourth magnetic material and a fifth magnetic material located between the magnetic sensory element and the fourth magnetic material, and the magnetic material is said to be the magnetic material. The cross-sectional area of the fourth and fifth magnetic materials in the cross section perpendicular to the magnetic collection direction, which is located between the first and second magnetic materials and the fourth and fifth magnetic materials, is S4, respectively. And S5, and when the lengths of the fourth and fifth magnetic materials in the magnetic collection direction are L4 and L5, respectively.
S4> S5 and L4 / L5 ≦ 2
It is preferable to satisfy. According to this, it becomes possible to further enhance the selectivity of the magnetic flux in the vertical direction. In this case, it is preferable that the first magnetic material and the fourth magnetic material have substantially the same shape as each other, and the second magnetic material and the fifth magnetic material have substantially the same shape as each other. According to this, the accuracy for the magnetic flux from the first magnetic body side and the accuracy for the magnetic flux from the fourth magnetic body side can be made substantially equal.

In the present invention, the magnetic sensing element is preferably a magnetoresistive element. In this case, the magnetoresistive element constituting the magnetic sensing element is more preferably a spin valve type GMR element.

The magnetic sensor according to the present invention further includes a sensor substrate having an element forming surface on which the magnetic sensitive element is formed, and a circuit board having a mounting surface on which the sensor substrate and the second magnetic material are mounted. It is preferable that the sensor board is mounted on the circuit board so that the element forming surface is substantially orthogonal to the mounting surface of the circuit board. According to this, since the sensor board and the second magnetic material are mounted on the circuit board in a laid state, they can be stably supported even when the length of the second magnetic material is long. It becomes possible to do.

In the present invention, the magnetic sensitive element may include a magnetic material extending in the magnetic collection direction and a coil conductor wound around the magnetic material. In this case, the magnetic material may be in the form of a bulk or may be formed on a substrate.

As described above, according to the present invention, it is possible to obtain extremely high detection accuracy, and it is possible to suppress variations in detection accuracy even when a plurality of magnetic sensors are arranged and used in an array. It will be possible.

FIG. 1 is a schematic perspective view showing the appearance of the magnetic sensor 10A according to the first embodiment of the present invention. FIG. 2 is an exploded perspective view of the magnetic sensor 10A. FIG. 3 is a schematic perspective view for explaining the shape of the magnetic body 40. FIG. 4A is a cross-sectional view of the magnetic body 40 in xz, and FIG. 4B is a top view of the magnetic body 40 as viewed from the z direction. FIG. 5 is a cross-sectional view of the sensor substrate 30. FIG. 6 is a circuit diagram for explaining the connection relationship between the magnetic sensing elements R1 to R4 and the terminal electrodes E11 to E14. FIG. 7 is a simulation model in which a plurality of magnetic sensors 10A are arranged in an array. FIG. 8A is a schematic perspective view of the measurement region 4 of the model A, and FIG. 8B is a schematic perspective view of the measurement region 4 of the model B. FIG. 9 is a diagram showing a simulation result. FIG. 10 is a simulation result showing the relationship between the L1 / L2 value and the variation in the sensitivity distribution. It is a schematic perspective view which shows the structure of the magnetic body 40 by the modification. FIG. 12 is a schematic perspective view showing the configuration of the magnetic sensor 10B according to the second embodiment of the present invention. FIG. 13 is a schematic perspective view showing the configuration of the magnetic sensor 10C according to the third embodiment of the present invention. FIG. 14 is a schematic perspective view showing the configuration of the magnetic sensor 10D according to the fourth embodiment of the present invention. FIG. 15 is a schematic perspective view showing the configuration of the magnetic sensor 10E according to the fifth embodiment of the present invention. FIG. 16 is a schematic perspective view showing the configuration of the magnetic sensor 10F according to the sixth embodiment of the present invention. FIG. 17 is a schematic perspective view showing the configuration of the magnetic sensor 10G according to the seventh embodiment of the present invention. FIG. 18 is a schematic perspective view showing the configuration of the magnetic sensor 10H according to the eighth embodiment of the present invention. FIG. 19 is a substantially exploded perspective view for explaining the structure of the main part of the sensor substrate 80.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view showing the appearance of the magnetic sensor 10A according to the first embodiment of the present invention. Further, FIG. 2 is an exploded perspective view of the magnetic sensor 10A.

As shown in FIGS. 1 and 2, the magnetic sensor 10A according to the present embodiment is connected to the circuit board 20, the sensor board 30 mounted on the mounting surface 21 of the circuit board 20, and the element forming surface 31 of the sensor board 30. It is composed of the magnetic material 40.

The circuit board 20 is a board in which a wiring pattern is formed on an insulating substrate such as resin, and a general printed circuit board, an interposer board, or the like can be used. The mounting surface 21 of the circuit board 20 forms an xz plane, and a part of the sensor board 30 and the magnetic body 40 is mounted on the mounting surface 21. Four land patterns E21 to E24 are provided on the mounting surface 21 of the circuit board 20, and a constant voltage source and a voltage detection circuit described later are connected to these land patterns E21 to E24. The constant voltage source and the voltage detection circuit may be provided on the circuit board 20 itself, or may be provided on a board different from the circuit board 20.

The sensor substrate 30 has a substantially rectangular parallelepiped shape, and four magnetic sensitive elements R1 to R4 are formed on the element forming surface 31. As shown in FIGS. 1 and 2, the element forming surface 31 constitutes an xy surface. That is, the sensor board 30 is mounted on the mounting area 22 of the circuit board 20 so that the element forming surface 31 is substantially orthogonal to the mounting surface 21 of the circuit board 20. As a method for manufacturing the sensor substrate 30, a method in which a large number of sensor substrates 30 are simultaneously formed on an assembly substrate and a large number of the sensor substrates 30 are separated from each other is generally used, but the present invention is not limited thereto. Instead, the individual sensor substrates 30 may be manufactured separately.

The magnetic sensing elements R1 to R4 are not particularly limited as long as they are elements whose physical characteristics change depending on the magnetic flux density, but in the present embodiment, a magnetoresistive element whose electrical resistance changes according to the direction of the magnetic field is used, and spin. It is particularly preferable to use a valve type GMR element. In the present embodiment, the sensitivity directions (fixed magnetization directions) of the magnetic sensing elements R1 to R4 are all aligned in the direction indicated by the arrow P in FIG. 2 (plus side in the x direction).

Further, four terminal electrodes E11 to E14 are provided on the element forming surface 31 of the sensor substrate 30. These terminal electrodes E11 to E14 are connected to land patterns E21 to E24, respectively, via solder S. The connection relationship between the terminal electrodes E11 to E14 and the magnetic sensitive elements R1 to R4 will be described later. The central region 32 located between the magnetic sensing elements R1 and R3 and the magnetic sensing elements R2 and R4 is covered with the magnetic body 40.

The magnetic body 40 is a block made of a high magnetic permeability material such as ferrite, and in this embodiment, it is composed of a first magnetic body 41 and a second magnetic body 42. The first magnetic body 41 is located outside the circuit board 20, while the second magnetic body 42 is mounted on the circuit board 20. The second magnetic body 42 is located between the first magnetic body 41 and the magnetic sensitive elements R1 to R4, and the magnetic flux in the z direction collected by the first magnetic body 41 is applied to the magnetic flux elements R1 to R1. It plays a role of concentrating on R4. The second magnetic body 42 is arranged so as to abut the central region 32 of the sensor substrate 30. The central region 32 is a portion where the magnetic sensing elements R1 to R4 are not provided. Therefore, the magnetic sensing elements R1 to R4 are arranged offset in the x direction so as not to overlap with the second magnetic body 42 when viewed from the z direction.

The magnetic body 40 may be composed of a single block, or the first magnetic body 41 and the second magnetic body 42 may be composed of different blocks, but it is easy to manufacture. In consideration of the above, it is preferable that the first magnetic body 41 and the second magnetic body 42 are composed of different blocks. In this case, it is preferable to bring them into close contact with each other in order to reduce the magnetic resistance between the first magnetic body 41 and the second magnetic body 42.

FIG. 3 is a schematic perspective view for explaining the shape of the magnetic body 40. Further, FIG. 4A is a cross-sectional view taken along the line xz of the magnetic body 40, and FIG. 4B is a top view of the magnetic body 40 as viewed from the z direction.

As shown in FIGS. 3 and 4, both the first magnetic body 41 and the second magnetic body 42 have a substantially rectangular parallelepiped shape. Although not particularly limited, it is preferable that the second magnetic body 42 is connected to a substantially central portion of the xy plane of the first magnetic body 41. In this case, as shown in FIG. 4, it is preferable that the central axes C of the first magnetic body 41 and the second magnetic body 42 coincide with each other. According to this, the flow of the magnetic flux from the first magnetic body 41 to the second magnetic body 42 becomes smooth, so that the detection accuracy is improved. Further, even when a large number of magnetic sensors 10A are arranged in an array and used, it is possible to suppress variations in detection accuracy for each magnetic sensor 10A.

Here, when the xy cross sections of the first and second magnetic bodies 41 and 42, that is, the cross sections in the cross sections perpendicular to the z direction, which is the magnetic collection direction, are S1 and S2, respectively.
S1> S2
Meet. Further, when the lengths of the first and second magnetic bodies 41 and 42 in the z direction, which is the magnetic collection direction, are L1 and L2, respectively.
L1 / L2 ≦ 2
Meet.

As described above, since the cross-sectional area S1 of the first magnetic body 41 is larger than the cross-sectional area S2 of the second magnetic body 42, the magnetic fluxes in the z direction are selectively collected and concentrated on the magnetic sensing elements R1 to R4. be able to. Further, since the length L1 of the first magnetic body 41 in the z direction is twice or less the length of the second magnetic body 42 in the z direction, a plurality of magnetic sensors 10A are arranged in an array as described later. Interference between magnetic materials can be suppressed even when they are used by arranging them in the same manner.

Although not particularly limited, in the present embodiment, the second magnetic body 42 is laid down on the mounting surface 21 of the circuit board 20. As a result, the positional relationship between the end surface of the second magnetic body 42 and the central region 32 of the sensor substrate 30 can be fixed on the circuit board 20. The first magnetic body 41 is located outside the circuit board 20, so that the first magnetic body 41 having a large cross-sectional area S1 does not interfere with the circuit board 20.

FIG. 5 is a cross-sectional view of the sensor substrate 30.

As shown in FIG. 5, magnetic material layers 51 to 53 are formed on the element forming surface 31 of the sensor substrate 30. The magnetic material layer 51 is located substantially in the center of the element forming surface 31, and the magnetic material layers 52 and 53 are arranged on both sides in the x direction thereof. Then, the magnetic sensitive elements R1 and R3 are arranged in the gap formed by the magnetic material layer 51 and the magnetic material layer 52, and the magnetic sensitive elements R2 and R4 are arranged in the gap formed by the magnetic material layer 51 and the magnetic material layer 53. Will be done. Although not particularly limited, the magnetic material layers 51 to 53 may be a film made of a composite magnetic material in which a magnetic filler is dispersed in a resin material, or may be made of a soft magnetic material such as nickel or permalloy. It may be a thin film or a foil, or a thin film or a bulk sheet made of ferrite or the like.

Although it is not essential to provide such magnetic material layers 51 to 53 in the present invention, the magnetic resistance is reduced by providing the magnetic material layers 51 to 53, and the magnetic flux φ supplied from the magnetic material 40 is efficiently magnetized. Since it passes through the elements R1 to R4, it is possible to improve the detection accuracy.

FIG. 6 is a circuit diagram for explaining the connection relationship between the magnetic sensing elements R1 to R4 and the terminal electrodes E11 to E14.

As shown in FIG. 6, the ground potential Gnd and the power supply potential Vdd are supplied to the terminal electrodes E11 and E14 from the constant voltage source, respectively. Further, the magnetic sensing elements R1 and R2 are connected in series between the terminal electrodes E11 and E14, and the magnetic sensing elements R4 and R3 are connected in series. Then, the connection points of the magnetic sensitive elements R3 and R4 are connected to the terminal electrode E12, and the connection points of the magnetic sensitive elements R1 and R2 are connected to the terminal electrode E13. With such a bridge connection, by referring to the potential Va appearing at the terminal electrode E13 and the potential Vb appearing at the terminal electrode E12, changes in the electrical resistance of the magnetically sensitive elements R1 to R4 according to the magnetic flux density can be detected with high accuracy. It becomes possible.

Specifically, since the magnetic sensing elements R1 to R4 all have the same magnetization fixing direction (P direction shown in FIG. 2), the magnetic sensing element located on one side of the second magnetic body 42. There is a difference between the amount of change in resistance of R1 and R3 and the amount of change in resistance of the magnetic sensitive elements R2 and R4 located on the other side of the second magnetic body 42. This difference is amplified twice by the differential bridge circuit shown in FIG. 6 and appears at the terminal electrodes E12 and E13. A voltage detection circuit is provided on the circuit board 20 or a motherboard (not shown), and the magnetic flux density can be measured by detecting the difference between the potentials Va and Vb appearing on the terminal electrodes E12 and E13 by the voltage detection circuit. Become.

In the magnetic sensor 10A according to the present embodiment, the magnetic body 40 is composed of a first magnetic body 41 having a large cross-sectional area S1 and a second magnetic body 42 having a small cross-sectional area S2, and the first magnetic body 41 Since the magnetic flux collected in the second magnetic body 42 is distributed to the magnetic sensitive elements R1 to R4, it is possible to obtain higher detection accuracy than in the case where the magnetic body 40 has a simple block shape. Become.

Moreover, since the length L1 of the first magnetic body 41 in the z direction is less than twice the length of the second magnetic body 42 in the z direction, a plurality of magnetic sensors 10A are arranged and used in an array. Even in this case, interference between magnetic materials can be suppressed.

FIG. 7 is a simulation model in which a plurality of magnetic sensors 10A are arranged in an array. In the model shown in FIG. 7, six magnetic sensors 10A are arranged in an array in the x direction and six in the y direction. Using such a model, the distribution of the magnetic flux density detected when the uniform magnetic field in the z direction was measured by a plurality of magnetic sensors 10A was simulated. Since the results of the simulation should be common in the measurement areas 1 to 4, only the data in the measurement area 4 was evaluated.

Here, in the model A, as shown in FIG. 8A, the length L1 of the first magnetic body 41 in the z direction is short.
L1 / L2 = 0.14
Is. On the other hand, in the model B, as shown in FIG. 8B, the length L1 of the first magnetic body 41 in the z direction is long and L1 / L2 = 3
Is. That is, the model A satisfies the conditions specified in the present invention, while the model B does not satisfy the conditions specified in the present invention. Both models A and B have the same cross-sectional areas S1 and S2, and both have S1> S2.
Is.

Further, in both models A and B, 36 magnetic sensors 10A were mirror-arranged in the z direction, whereby a total of 72 magnetic sensors 10A were configured.

The simulation results are shown in FIG. Since the simulation results are common to the measurement areas 1 to 4 shown in FIG. 7, only the simulation results in the measurement area 4 are shown in FIG.

It can be seen that the value of the magnetic flux density shown in FIG. 9A, which is the simulation result of the model A, has a smaller variation than the value of the magnetic flux density shown in FIG. 9B, which is the simulation result of the model B. Here, when the maximum magnetic flux density in each model is Bmax, the minimum magnetic flux density is Bmin, and the average magnetic flux density is Bave,
(Bmax-Bmin) / Bave
The value obtained by is defined as the variation of the sensitivity distribution.

As a result, the variation in the sensitivity distribution in the model A was suppressed to about 14%, while the variation in the sensitivity distribution in the model B reached about 24%. Moreover, as shown in FIG. 9, it can be confirmed that there is almost no difference between the model A and the model B in terms of the maximum magnetic flux density Bmax.

The reason why the sensitivity distributions vary in models A and B is that even in a uniform magnetic field in the z direction, the magnetic sensor 10A closer to the center has a large amount of magnetic flux sucked into the other magnetic sensors 10A. This is because the detected magnetic flux density tends to decrease, while the magnetic flux density of the magnetic sensor 10A closer to the end is less likely to decrease because the magnetic flux sucked into the other magnetic sensor 10A is small. Therefore, in order to reduce the variation in the sensitivity distribution, it is necessary to reduce the magnetic flux sucked into the other magnetic sensor 10A as much as possible, and for that purpose, it is effective to reduce the values of S1 and L1. However, if the value of S1 is reduced, the magnetic flux that can be collected decreases, so that it becomes difficult to obtain high detection accuracy. Therefore, in the present invention, the value of L1 is reduced to ensure high detection accuracy and suppress variations in the sensitivity distribution.

However, if the value of L2 is reduced according to the value of L1, the selectivity for the magnetic flux in the z direction is lowered. Therefore, in order to ensure the selectivity for the magnetic flux in the z direction, it is necessary to reduce the value of L1 without reducing the value of L2.

FIG. 10 is a simulation result showing the relationship between the L1 / L2 value and the variation in the sensitivity distribution. As shown in FIG. 10, the variation in the sensitivity distribution tends to decrease as the value of L1 / L2 decreases, and when the value is 2 or less, the variation in the sensitivity distribution becomes 20% or less.

When arranging the magnetic sensors in an array, it is not realistic to make the variation in the sensitivity distribution zero, and no matter what layout is adopted, the sensitivity distribution will vary to some extent. Such variations can be corrected to some extent by signal processing, but if the variations exceed 20%, distortion tends to remain in the sensitivity distribution even when corrected by signal processing, making it difficult to obtain correct measurement results. .. On the other hand, if the variation in the sensitivity distribution is 20% or less, it is possible to obtain a fairly accurate measurement result by signal processing.

Then, in the present embodiment, since the lengths of the first magnetic body 41 and the second magnetic body 42 are designed so that the values of L1 / L2 are 2 or less, the variation in the sensitivity distribution is 20. It can be less than or equal to%, which makes it possible to obtain an accurate measurement result.

The cross-sectional area S1 of the first magnetic body 41 is not particularly limited as long as it is larger than the cross-sectional area S2 of the second magnetic body 42. Further, it is not essential that the cross-sectional area S1 of the first magnetic body 41 is constant in the z direction, and as shown in FIG. 11, the tapered shape becomes smaller as the position in the z direction approaches the second magnetic body 42. It doesn't matter. As described above, when the cross-sectional area S1 of the first magnetic body 41 has a shape that changes depending on the position in the z direction, the cross-sectional area S1 of the first magnetic body 41 refers to the maximum cross-sectional area.

Similarly, the cross-sectional area S2 of the second magnetic body 42 does not have to be constant in the z direction, and may have a tapered shape that becomes smaller as the position in the z direction approaches the sensor substrate 30. Even in such a case, the cross-sectional area S2 of the second magnetic body 42 refers to the maximum cross-sectional area.

Hereinafter, the magnetic sensor according to some other embodiments of the present invention will be described.

FIG. 12 is a schematic perspective view showing the configuration of the magnetic sensor 10B according to the second embodiment of the present invention.

The magnetic sensor 10B shown in FIG. 12 differs from the magnetic sensor 10A according to the first embodiment shown in FIG. 1 in that the magnetic body 40 includes a third magnetic body 43. Since the other configurations are the same as those of the magnetic sensor 10A according to the first embodiment shown in FIG. 1, the same elements are designated by the same reference numerals, and redundant description will be omitted.

Like the first and second magnetic bodies 41 and 42, the third magnetic body 43 is a block made of a high magnetic permeability material such as ferrite, and is located on the side opposite to the element forming surface 31 of the sensor substrate 30. It has a U-shape so as to cover the xy surface and the pair of yz surfaces. Therefore, the magnetic sensitive elements R1 and R3 are located between the second magnetic body 42 and a part of the third magnetic body 43 when viewed from the z direction, and the magnetic sensitive elements R2 and R4 are located when viewed from the z direction. It will be located between the second magnetic body 42 and another part of the third magnetic body 43. With this configuration, the magnetic flux input to the element forming surface 31 of the sensor substrate 30 via the first and second magnetic bodies 41 and 42 tends to bend in the x direction, so that the detection sensitivities of the magnetic sensing elements R1 to R4 Can be increased.

FIG. 13 is a schematic perspective view showing the configuration of the magnetic sensor 10C according to the third embodiment of the present invention.

The magnetic sensor 10C shown in FIG. 13 differs from the magnetic sensor 10A according to the first embodiment shown in FIG. 1 in that the magnetic body 40 includes the fourth and fifth magnetic bodies 44 and 45. Since the other configurations are the same as those of the magnetic sensor 10A according to the first embodiment shown in FIG. 1, the same elements are designated by the same reference numerals, and redundant description will be omitted.

The fourth and fifth magnetic bodies 44 and 45 are blocks made of a high magnetic permeability material such as ferrite, like the first and second magnetic bodies 41 and 42, and the first and first magnetic bodies 44 and 45 pass through the sensor substrate 30. It is arranged symmetrically with the magnetic bodies 41 and 42 of 2. In the present embodiment, the second and fifth magnetic bodies 42 and 45 are mounted on the circuit board 20, while the first and fourth magnetic bodies 41 and 44 are arranged outside the circuit board 20. There is. If the fourth and fifth magnetic bodies 44 and 45 are used, the magnetic flux from the side opposite to the first magnetic body 41 as viewed from the sensor substrate 30 is also collected, so that the magnetic flux in the z direction can be collected. It becomes possible to further enhance the selectivity.

Here, when the xy cross sections of the fourth and fifth magnetic bodies 44 and 45, that is, the cross sections in the cross sections perpendicular to the z direction, which is the magnetic collection direction, are S4 and S5, respectively.
S4> S5
It is preferable that Further, when the lengths of the fourth and fifth magnetic bodies 44 and 45 in the z direction, which are the magnetic collection directions, are L4 and L5, respectively.
L4 / L5 ≦ 2
It is preferable that According to this, it is possible to further improve the detection accuracy for the magnetic flux in the z direction, and even when a plurality of magnetic sensors 10C are arranged in an array and used, interference between magnetic materials can be suppressed. Can be done.

In the present embodiment, the first magnetic body 41 and the fourth magnetic body 44 have substantially the same shape as each other, and the second magnetic body 42 and the fifth magnetic body 45 have substantially the same shape as each other. Is preferable. According to this, it is possible to make the detection accuracy for the magnetic flux from the first magnetic body 41 side and the detection accuracy for the magnetic flux from the fourth magnetic body 44 side substantially equal. Further, it is not necessary to separate the first magnetic body 41 and the fourth magnetic body 44, and it is not necessary to separately prepare the second magnetic body 42 and the fifth magnetic body 45, so that the manufacturing cost is reduced. It is also possible.

FIG. 14 is a schematic perspective view showing the configuration of the magnetic sensor 10D according to the fourth embodiment of the present invention.

The magnetic sensor 10D shown in FIG. 14 differs from the magnetic sensor 10C according to the third embodiment shown in FIG. 13 in that the magnetic body 40 includes the third magnetic body 43. Since the other configurations are the same as those of the magnetic sensor 10C according to the third embodiment shown in FIG. 13, the same elements are designated by the same reference numerals, and duplicate description will be omitted.

The third magnetic body 43 is the same as that used in the second embodiment, and covers the xy surface and the pair of yz surfaces located on the opposite side of the sensor substrate 30 from the element forming surface 31. It has a character shape. By adding such a third magnetic material 43, it is possible to further increase the detection sensitivity by the magnetic sensitive elements R1 to R4.

FIG. 15 is a schematic perspective view showing the configuration of the magnetic sensor 10E according to the fifth embodiment of the present invention.

The magnetic sensor 10E shown in FIG. 15 is different from the magnetic sensor 10C according to the third embodiment shown in FIG. 13 in that the mounting angle of the sensor substrate 30 is different by 90 °. Two magnetic sensitive elements R5 and R6 are arranged side by side in the z direction on the element forming surface 31 of the sensor substrate 30, and their fixed magnetization directions are the directions indicated by the arrows P1 and P2 (minus side in the z direction, respectively). And the plus side). That is, the fixed magnetization directions of the magnetic sensing elements R5 and R6 are different from each other by 180 °. Since the other configurations are the same as those of the magnetic sensor 10C according to the third embodiment shown in FIG. 3, the same elements are designated by the same reference numerals, and redundant description will be omitted.

In the present embodiment, the magnetic collecting direction (z direction) by the magnetic body 40 and the fixed magnetization direction (z direction) of the magnetic sensing elements R5 and R6 are the same, but the fixed magnetization directions of the magnetic sensing elements R5 and R6 are Since they differ by 180 ° from each other, the resistance values of the magnetic sensing elements R5 and R6 differ depending on the magnetic flux density in the z direction. Thereby, the magnetic flux density in the z direction can be detected.

As described above, in the present invention, the element forming surface 31 of the sensor substrate 30 does not have to be substantially perpendicular to the magnetic collection direction (z direction), and as illustrated in the present embodiment, the element forming surface of the sensor substrate 30 is formed. 31 may be substantially parallel to the magnetic collection direction (z direction).

FIG. 16 is a schematic perspective view showing the configuration of the magnetic sensor 10F according to the sixth embodiment of the present invention.

The magnetic sensor 10F shown in FIG. 16 differs from the magnetic sensor 10E shown in FIG. 15 in that it includes a bulk-shaped magnetic body 60 extending in the z direction instead of the sensor substrate 30. The magnetic material 60 is made of a high magnetic permeability magnetic material such as an amorphous magnetic material, and an exciting coil 61 and a detection coil 62 are wound around the magnetic material 60. Since the other configurations are the same as those of the magnetic sensor 10E according to the fifth embodiment shown in FIG. 15, the same elements are designated by the same reference numerals, and redundant description will be omitted.

The exciting coil 61 and the detection coil 62 are connected to an exciting circuit and a detection circuit (not shown, respectively). As a result, the magnetic body 60, the exciting coil 61, and the detection coil 62 form a fluxgate type magnetic sensing element.

As illustrated by the present embodiment, it is not essential that the magnetically sensitive element used in the present invention is a magnetoresistive element, and a fluxgate type magnetically sensitive element can also be used.

FIG. 17 is a schematic perspective view showing the configuration of the magnetic sensor 10G according to the seventh embodiment of the present invention.

The magnetic sensor 10G shown in FIG. 17 differs from the magnetic sensor 10F shown in FIG. 16 in that it includes a bulk amorphous wire 70 extending in the z direction instead of the magnetic body 60. A pulsed voltage is applied to both ends of the amorphous wire 70 by a drive circuit (not shown), and a detection coil 71 is wound around the amorphous wire 70. Since the other configurations are the same as those of the magnetic sensor 10F according to the sixth embodiment shown in FIG. 16, the same elements are designated by the same reference numerals, and redundant description will be omitted.

As described above, a pulsed voltage is applied to both ends of the amorphous wire 70 by a drive circuit (not shown). Further, the detection coil 71 is connected to a detection circuit (not shown). As a result, the amorphous wire 70 and the detection coil 71 form a magnetic impedance type magnetic sensing element.

As illustrated by the present embodiment, the magnetic sensory element used in the present invention may be a magnetic impedance type magnetic sensory element.

FIG. 18 is a schematic perspective view showing the configuration of the magnetic sensor 10H according to the eighth embodiment of the present invention.

The magnetic sensor 10H shown in FIG. 18 is different from the magnetic sensor 10E shown in FIG. 15 in that the sensor substrate 80 is provided instead of the sensor substrate 30. Since the other configurations are the same as those of the magnetic sensor 10E according to the fifth embodiment shown in FIG. 15, the same elements are designated by the same reference numerals, and redundant description will be omitted.

FIG. 19 is a substantially exploded perspective view for explaining the structure of the main part of the sensor substrate 80.

As shown in FIG. 19, the sensor substrate 80 includes an insulating layer 81 to 83, a magnetic body 84 formed on the surface of the insulating layer 82, and an exciting coil 85 and a detection coil 86 wound around the magnetic body 84. And. The exciting coil 85 includes a conductor pattern 85a formed on the surface of the insulating layer 81 and a conductor pattern 85b formed on the surface of the insulating layer 83, and passes through the overlapping ends of each other in a plan view (when viewed from the y direction). By connecting with a hole conductor 85c, it is wound around the magnetic body 84. Similarly, the detection coil 86 includes a conductor pattern 86a formed on the surface of the insulating layer 81 and a conductor pattern 86b formed on the surface of the insulating layer 83, and ends overlapping each other in a plan view (when viewed from the y direction). By connecting them to each other with a through-hole conductor 86c, they are wound around the magnetic body 84. As the magnetic material 84, a thin film or foil of a high magnetic permeability magnetic material such as an amorphous magnetic material can be used. In this case, the magnetic body 84, the exciting coil 85, and the detection coil 86 form a fluxgate type magnetic sensing element.

As illustrated by the present embodiment, the magnetic sensing element used in the present invention may be a type of magnetic sensing element in which a coil conductor is wound around a magnetic material formed on a substrate.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the present invention, and these are also the present invention. It goes without saying that it is included in the range.

1 to 4 Measurement area 10A to 10H Magnetic sensor 20 Circuit board 21 Mounting surface 22 Mounting area 30 Sensor board 31 Element forming surface 32 Central area 40 Magnetic body 41 First magnetic body 42 Second magnetic body 43 Third magnetic body 44 Fourth magnetic material 45 Fifth magnetic material 51-53 Magnetic material layer 60, 70, 84 Magnetic material 61, 85 Excitation coil 62, 71, 86 Detection coil 80 Sensor substrate 81-83 Insulation layer C Central axis E11- E14 Terminal electrodes E21 to E24 Land pattern L1, L2 Length R1 to R6 Magnetic sensor S Solder S1, S2 Cross-sectional area φ magnetic flux

Claims (12)

A magnetic element and a magnetic material that collects magnetic flux in the magnetic element are provided.
The magnetic material includes a first magnetic material and a second magnetic material located between the magnetic sensitive element and the first magnetic material.
The cross-sectional areas of the first and second magnetic materials in the cross section perpendicular to the magnetic collection direction are S1 and S2, respectively, and the lengths of the first and second magnetic materials in the magnetic collection direction are L1 and S, respectively. When set to L2
S1> S2 and L1 / L2 ≦ 2
Meet the,
The magnetic sensitive element includes a plurality of magnetic sensitive elements to be bridge-connected.
A magnetic sensor characterized in that the plurality of magnetic sensitive elements are formed on an element forming surface of a sensor substrate, and the element forming surface of the sensor substrate is covered with a magnetic material layer . A magnetic element and a magnetic material that collects magnetic flux in the magnetic element are provided.
The magnetic material includes a first magnetic material and a second magnetic material located between the magnetic sensitive element and the first magnetic material.
The cross-sectional areas of the first and second magnetic materials in the cross section perpendicular to the magnetic collection direction are S1 and S2, respectively, and the lengths of the first and second magnetic materials in the magnetic collection direction are L1 and S, respectively. When set to L2
S1> S2 and L1 / L2 ≦ 2
Meet the,
The sensitivity direction of the magnetic sensing element is substantially parallel to the magnetic collection direction.
The magnetic sensor is a magnetic sensor including a plurality of magnetic sensing elements whose sensitivity directions differ from each other by 180 ° . A magnetic element and a magnetic material that collects magnetic flux in the magnetic element are provided.
The magnetic material includes a first magnetic material and a second magnetic material located between the magnetic sensitive element and the first magnetic material.
The cross-sectional areas of the first and second magnetic materials in the cross section perpendicular to the magnetic collection direction are S1 and S2, respectively, and the lengths of the first and second magnetic materials in the magnetic collection direction are L1 and S, respectively. When set to L2
S1> S2 and L1 / L2 ≦ 2
Meet the,
The sensitivity direction of the magnetic sensing element is substantially perpendicular to the magnetic collecting direction, and the second magnetic material is arranged so as to be offset from the magnetic collecting direction when viewed from the magnetic collecting direction. A characteristic magnetic sensor. The magnetic sensor according to claim 3 , wherein the second magnetic material does not overlap with the magnetic sensing element when viewed from the magnetic collection direction. The magnetic material further contains a third magnetic material, and the magnetic material further contains a third magnetic material.
The magnetic sensor according to claim 3 or 4 , wherein the magnetic sensing element is located between the second magnetic body and the third magnetic body when viewed from the magnetic collection direction. A magnetic element and a magnetic material that collects magnetic flux in the magnetic element are provided.
The magnetic material includes a first magnetic material and a second magnetic material located between the magnetic sensitive element and the first magnetic material.
The cross-sectional areas of the first and second magnetic materials in the cross section perpendicular to the magnetic collection direction are S1 and S2, respectively, and the lengths of the first and second magnetic materials in the magnetic collection direction are L1 and S, respectively. When set to L2
S1> S2 and L1 / L2 ≦ 2
Meet the,
The magnetic material further includes a fourth magnetic material and a fifth magnetic material located between the magnetic sensitive element and the fourth magnetic material.
The magnetic sensitive element is located between the first and second magnetic materials and the fourth and fifth magnetic materials.
The cross-sectional areas of the fourth and fifth magnetic materials in the cross section perpendicular to the magnetic collection direction are S4 and S5, respectively, and the lengths of the fourth and fifth magnetic materials in the magnetic collection direction are L4, respectively. And L5
S4> S5, and
L4 / L5 ≦ 2
A magnetic sensor characterized by satisfying. Has the said first magnetic body fourth magnetic body substantially same shape, claim 6 wherein the second magnetic member and the fifth magnetic member is characterized by having substantially the same shape as each other The magnetic sensor described in. A magnetic element and a magnetic material that collects magnetic flux in the magnetic element are provided.
The magnetic material includes a first magnetic material and a second magnetic material located between the magnetic sensitive element and the first magnetic material.
The cross-sectional areas of the first and second magnetic materials in the cross section perpendicular to the magnetic collection direction are S1 and S2, respectively, and the lengths of the first and second magnetic materials in the magnetic collection direction are L1 and S, respectively. When set to L2
S1> S2 and L1 / L2 ≦ 2
Meet the,
A sensor substrate having an element forming surface on which the magnetic sensitive element is formed,
A circuit board having a mounting surface on which the sensor board and the second magnetic material are mounted is further provided.
The sensor board is a magnetic sensor mounted on the circuit board so that the element forming surface is substantially orthogonal to the mounting surface of the circuit board . The magnetic sensor according to any one of claims 1 to 8, wherein the centers of the first and second magnetic materials in the cross section are substantially on the same axis as each other. Sensitivity direction of the magnetic sensing element is a magnetic sensor according to claim 1, wherein said magnetic flux collecting direction and are substantially parallel. The magnetic sensor according to any one of claims 1 to 10 , wherein the magnetic sensing element is a magnetoresistive element. The magnetic sensor according to claim 11 , wherein the magnetoresistive element constituting the magnetic sensing element is a spin valve type GMR element.

Images