JP2005227297A - Magneto-impedance sensor element with electromagnet coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain a wide range with a high sensitivity, a thin miniaturization, a small volume, a low consumption of an electric power. <P>SOLUTION: A magnetic sensing body 2 sensing a magnetic field on an electrode wiring board 1 and an electromagnet coil 3 below 200 μm inner diameter which intervenes only an insulator around the magnetic sensing body under the condition which no fixing board of the magnetic sensing body 2 exists between the magnetic sensing body 2 and the electromagnet coil 3 are located. The terminals of the magnetic sensing body 2 and the coil 3 are connected to each of the electrodes 51, 52 on the board 1. A high frequency or pulse current is passed to the magnetic sensing body 2, the magneto-impedance sensor element with the electromagnetic coil outputs a voltage corresponding to an intensity of an external magnetic field generated in the electromagnet coil 3 at that time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to miniaturization and high sensitivity of a magneto-impedance sensor element (hereinafter referred to as MI element) using an electromagnetic coil used as a magnetic sensor, and to a wide range enabling application in the automobile field, for example.

FIG. 13 shows the structure of a conventional MI element.
JP 2000-81471 A JP 2001-296127 A

  In the MI element, a magnetosensitive body made of an amorphous wire is fixed on the electrode substrate at the center, and an electromagnetic coil is wound around the electrode substrate. The electromagnetic coil had a diameter of about 1 mm to 5 mm. The size of the MI element is generally 3 mm in width, 2 mm in height, and 4 mm in length.

  The conventional MI element can achieve high sensitivity, miniaturization, and low power consumption to some extent when applied as a magnetic sensor, but there is a problem that miniaturization of a high-performance magnetic sensor is not always sufficient.

  Currently, in this field, further miniaturization is required for a high-performance magnetic sensor (hereinafter referred to as MI sensor) using this MI element. However, since the conventional MI element has a structure in which the electromagnetic coil winds the electrode substrate from the outside, the size has to be large. Therefore, further miniaturization of the MI element has been demanded.

  Therefore, as a result of diligent investigations on the miniaturization of the MI element, the present inventor has disposed on the electrode wiring board a member made of an insulator in which a magnetic body for detecting a magnetic field is inserted and an electromagnetic coil is disposed on the surface. The magnetosensitive body and the coil terminals are connected to respective electrodes on the substrate, a high frequency or pulse current is passed through the magnetosensitive body, and a voltage corresponding to the strength of the external magnetic field generated in the electromagnetic coil at that time is output. As a result of further research and development focusing on the technical idea of the present invention, the present invention has been achieved to achieve the objectives of miniaturization, thinning, small volume, low power consumption, high sensitivity and wide range. is there.

The magneto-impedance sensor element with an electromagnetic coil of the present invention (first invention according to claim 1) is:
A magnetic material for detecting a magnetic field is inserted, and a member made of an insulator having an electromagnetic coil disposed on the surface is disposed on the electrode wiring board,
The magnetosensitive body and coil terminals are connected to respective electrodes on the substrate,
A high frequency or pulse current is passed through the magnetic sensitive body, and a voltage corresponding to the strength of the external magnetic field generated in the electromagnetic coil is output.

The magneto-impedance sensor element with an electromagnetic coil of the present invention (the second invention according to claim 2),
In the first invention,
The magnetic sensitive body is made of an amorphous conductive magnetic wire.

The magneto-impedance sensor element with an electromagnetic coil of the present invention (the third invention according to claim 3),
In the second invention,
The electromagnetic coil has a winding inner diameter of 200 μm or less.

The magneto-impedance sensor element with an electromagnetic coil of the present invention (the fourth invention according to claim 4),
In the third invention,
The electromagnetic coil has a winding interval per turn of 100 μm / turn or less.

The magneto-impedance sensor element with an electromagnetic coil of the present invention (the fifth invention according to claim 5),
In the second invention,
The magnetic sensitive body is set to a length of 3 mm or less.

The magneto-impedance sensor element with an electromagnetic coil of the present invention (the sixth invention according to claim 6),
In the second invention,
In the magnetic sensitive body, the aspect ratio of the ratio of the length to the wire diameter is set to 10 to 100.

The magneto-impedance sensor element with an electromagnetic coil according to the present invention (seventh invention according to claim 7) is:
In the second invention,
The inner diameter of the coil of the electromagnetic coil is set to 1.005 to 10 times the wire diameter of the magnetic sensitive body.

The magneto-impedance sensor element with an electromagnetic coil of the present invention (the eighth invention according to claim 8),
In the second invention,
The electromagnetic coil has a winding inner diameter of 100 μm or less.

A magneto-impedance sensor element with an electromagnetic coil according to the present invention (the ninth invention according to claim 9),
In the third invention,
The electromagnetic coil has a winding interval per turn of 50 μm / wind or less.

  The magneto-impedance sensor element with an electromagnetic coil according to the first aspect of the present invention having the above-described configuration is obtained when a high frequency or pulse current is applied to a magnetosensitive member inserted in a member made of an insulator disposed on an electrode wiring board. Since the voltage corresponding to the strength of the external magnetic field generated in the electromagnetic coil disposed on the surface of the member made of the insulator is output, it is possible to reduce the size and thickness and reduce the power consumption.

  The magneto-impedance sensor element with an electromagnetic coil according to the second invention configured as described above has the effect of achieving high sensitivity because the magnetic sensitive body is made of an amorphous conductive magnetic wire in the first invention. Play.

  The magneto-impedance sensor element with an electromagnetic coil according to the third aspect of the present invention having the configuration described above has the effect of realizing a reduction in size and thickness since the electromagnetic coil has a winding inner diameter of 200 μm or less in the second aspect.

  The magneto-impedance sensor element with an electromagnetic coil according to the fourth aspect of the present invention having the above-described structure is the above-described electromagnetic coil having a high density because the electromagnetic coil has a winding interval of 100 μm / turn or less per turn in the third aspect. In order to realize the coil, there is an effect of realizing high sensitivity.

  The magneto-impedance sensor element with an electromagnetic coil according to the fifth aspect of the present invention constructed as described above has the effect of realizing downsizing since the magnetic sensitive element is set to a length of 3 mm or less in the second aspect. Play.

  In the magneto-impedance sensor element with an electromagnetic coil of the sixth invention configured as described above, in the second invention, the magnetosensitive body has an aspect ratio of the ratio of the length to the wire diameter set to 10 to 150. The measurement magnetic field range that can be measured while maintaining linearity is widened, and for example, an effect of realizing a wide range that can be applied in the automobile field is achieved.

  A magneto-impedance sensor element with an electromagnetic coil according to a seventh aspect of the present invention having the above-described configuration is characterized in that, in the sixth aspect, the inner diameter of the electromagnetic coil is set to 1.005 to 10 times the wire diameter of the magnetic sensitive body. Therefore, there is an effect of realizing high sensitivity.

  The magneto-impedance sensor element with an electromagnetic coil of the eighth invention configured as described above has the effect of realizing a reduction in size and thickness because the electromagnetic coil has a winding inner diameter of 100 μm or less in the second invention.

  The magneto-impedance sensor element with an electromagnetic coil according to the ninth aspect of the present invention having the above-described configuration is the electromagnetic coil having a high density according to the third aspect, because the electromagnetic coil has a winding interval per turn of 50 μm / turn or less. In order to realize the coil, there is an effect of realizing high sensitivity.

  The best mode for carrying out the present invention will be specifically described below with reference to the drawings based on the embodiments and examples.

First embodiment

  As shown in FIGS. 1 and 2, the magneto-impedance sensor element with an electromagnetic coil according to the first embodiment includes a magnetosensitive body 2 for detecting a magnetic field on the electrode wiring board 1 in the MI element, An electromagnetic coil 3 having an inner diameter of 200 μm or less is disposed around the magnetic sensing element with only an insulator in the state where there is no substrate for fixing the magnetic sensing element 2 between the electromagnetic coils 3, and terminals of the magnetic sensing element 2 and the coil 3. Are connected to the respective electrodes 51 and 52 on the substrate 1, a high frequency or pulse current is passed through the magnetosensitive body 2, and a voltage corresponding to the intensity of the external magnetic field generated in the electromagnetic coil 3 at that time is output. .

  In the present MI element, since the electromagnetic coil 3 is installed around the magnetic sensitive body 2 via only an insulator, the inner diameter thereof can be set to 200 μm or less, and the miniaturization of the MI element can be achieved as a whole.

  Further, in this embodiment, in the MI element, the magnetosensitive body 2 is a conductive magnetic wire having a diameter of 1 to 150 μm, the electrode wiring board 1 has a groove 11 having a depth of 5 to 200 μm, In the electromagnetic coil 3, one side 31 of the electromagnetic coil is disposed along the groove surface 111, the remaining one side 32 of the electromagnetic coil disposed on the lower surface of the upper substrate 12 is disposed on the upper surface of the groove, A two-layer structure is formed with the remaining one side 32 of the coil on the upper surface of the groove.

  The magnetic sensitive body 2 can have a coil diameter of 200 μm or less by employing a conductive magnetic wire having a diameter of 1 to 150 μm.

  Furthermore, when a magnetic wire is used for the magnetic sensitive body 2, since the magnetic wire has excellent magnetic sensing performance, the output voltage per winding of the electromagnetic coil increases, and therefore the number of windings can be reduced. The length can be shortened.

  Further, by adopting a groove structure in which the groove 11 is formed in the electrode wiring board 1, further miniaturization can be achieved as compared with the case where the electromagnetic coil 3 is arranged on the electrode wiring board 1, and the outside of the electromagnetic coil 3 The mechanical contact can also be prevented and a mechanically stable MI element can be realized.

  Furthermore, in this embodiment, in the MI element, the conductive magnetic wire is made of amorphous.

  If the material of the magnetic wire is specified as amorphous, since the amorphous has excellent magnetic sensing performance, the output voltage per winding of the electromagnetic coil increases, and the number of windings can be reduced, so the length of the MI element is shortened. be able to.

  In the present embodiment, in the MI element, the winding interval per unit length of the electromagnetic coil 3 is set to 100 μm / wind or less.

  The output voltage increases by decreasing the winding interval per turn (per unit length) of the electromagnetic coil 3 and increasing the number of windings per turn (per unit length). Practically, it is preferably 100 μm / wind or less. If the same output voltage is sufficient, the length of the MI element can be shortened.

  Furthermore, this embodiment is an MI element characterized in that in the MI element, the size of the electrode wiring board 1 is 20 μm to 1 mm in width, 20 μm to 1 mm in thickness, and 200 μm to 4 mm in length. is there.

  Since the width and height of the circle-equivalent diameter of the electromagnetic coil 3 is 200 μm at the maximum, the electrode wiring board 1 can be made the above-mentioned size, and the entire element can be significantly reduced in size and thickness and reduced in volume. it can.

Second embodiment

  The magneto-impedance sensor element with an electromagnetic coil according to the second embodiment will be described below.

  In general, a high-sensitivity magnetic sensor has a very high sensitivity because a change in detection output is large with respect to a change in detection input, but conversely, a detection range is narrow because it reaches the full scale up to the saturation magnetic field immediately. In order to widen the range, there is a method of using a demagnetizing field by reducing the aspect ratio, which is the ratio of the length to the diameter of the magnetosensitive element.

  However, the conventional high-sensitivity magnetic sensor (MI, FG sensor) having the structure shown in FIG. 13 has limitations in miniaturization, and it is difficult to miniaturize to the extent that a wide range is realized. There is a problem that sensitivity is extremely lowered when the length is shortened.

  Therefore, the aspect ratio, which is the ratio of the length to the diameter of the amorphous wire in the second embodiment, is extremely reduced to achieve a wide range, and a micro-high density coil is wound around the amorphous wire, Since the sensitivity is improved and the coil shape is small and the inductance L is extremely small, the vibration induced in the coil is high, but the magnetic field signal is detected without impairing the sensitivity by using an analog switch.

  That is, from the viewpoint of widening the range, if the length of the amorphous wire is set to 100 μm to 10000 μm and the aspect ratio is set to 10 to 150 with respect to the diameter φ10 μm to 100 μm, the detection range is 1.5 to 1.5 If it becomes 20 times and is set to 10 to 100, the detection range becomes 3 to 20 times the conventional range. Preferably, when the aspect ratio is set to 10 to 50, the detection range is 5 to 20 times the conventional range.

  From the viewpoint of increasing sensitivity, it is preferable to set the diameter of the electromagnetic coil to 10.05 μm to 1000 μm and 1.005 to 10 times the diameter φ10 μm to 100 μm of the amorphous wire.

  As a detection method, a magnetic field signal can be detected without losing sensitivity by using an analog switch.

  Embodiments of the present invention will be described below with reference to the drawings.

First embodiment

  A magneto-impedance sensor element with an electromagnetic coil according to the first embodiment will be described below with reference to FIGS.

  The substrate 1 has a width of 0.5 mm, a height of 0.5 mm, and a length of 1.5 mm. The magnetic sensitive body is an amorphous wire 2 having a diameter of 30 μm or 20 μm using a CoFeSiB alloy. The groove 11 on the substrate has a depth of 50 μm, a width of 70 μm, and a length of 1.5 mm. The electromagnetic coil 3 is formed by a two-layer structure of one side 31 of the coil formed on the groove surface 111 and the remaining one side coil 32 formed on the groove upper surface 112 (the upper surface 41 of the resin 4). )

  One side 31 of the coil formed on the groove surface 111 includes the entire surface of the groove surface 111 of the groove 11 formed in the longitudinal direction of the electrode wiring board 1 and the upper surface of the electrode wiring board 1 as shown in FIGS. A conductive magnetic metal thin film constituting a coil is formed by vapor deposition in the vicinity of the groove 11 and the conductive metal thin film portion constituting the gap is selectively etched so that the formed metal thin film remains spirally. It is formed by removing by.

  That is, a coil portion 311 extends perpendicularly in the vertical direction on the groove side surface 113 of the groove 11, and is continuous with the adjacent vertical coil portion on the groove bottom surface 110 of the groove 11 with respect to the width direction. The coil portion 312 is formed to be inclined.

  The remaining coil 32 formed on the groove upper surface 112 (the upper surface 41 of the resin 4) is opposed to the groove 11 formed in the longitudinal direction of the electrode wiring board 1 on the groove upper surface 112 (the upper surface 41 of the resin 4). A conductive magnetic metal thin film constituting a coil is formed by vapor deposition over a wider range in the width direction of the portion to be formed, and the formed conductive magnetic metal thin film is longer than the length of the groove 11 in the width direction at a constant pitch. It is formed by removing the magnetic metal thin film portion by a selective etching method so as to form a gap portion having a constant pitch so as to remain in a strip shape in the width direction. A protective film may be formed on the upper surface of the coil as necessary.

  The inner diameter of the coil of the electromagnetic coil 3 is equivalent to a circle (the diameter of a circle having the same area as the groove cross-sectional area formed by the height and width) is 66 μm. The winding interval per turn (per unit length) of the electromagnetic coil 3 is 50 μm / turn.

  An insulating resin 4 is disposed between the amorphous wire 2 and the electromagnetic coil 3 to keep the conductive magnetic amorphous wire and the electromagnetic coil insulated. A total of four electrodes 5, an electromagnetic coil terminal 51 and a magnetosensitive terminal 52, are baked on the upper surface of the substrate. Both ends of the preceding amorphous wire 2 and both ends of the electromagnetic coil 3 are connected to the electrode 5. The MI element 10 of the present invention has the above-described configuration. Incidentally, the size of this MI element is the same as the size of the electrode wiring board.

  Next, the characteristics of the MI element 10 were evaluated using the MI sensor shown in FIG. The electronic circuit of the MI sensor used for the evaluation includes a signal generator 6, the MI element 10, and a signal processing device 7. The signal is a pulse signal having a strength of 170 mA corresponding to 200 MHz, and the signal interval is 1 μsec. The pulse signal is input to the amorphous wire 2, and a voltage proportional to the external magnetic field is generated in the electromagnetic coil 3 during the input time.

  The signal processing circuit 7 takes out the voltage generated in the electromagnetic coil 3 through the synchronous detection 71 that opens and closes in conjunction with the input of the pulse signal, and amplifies the voltage to a predetermined voltage by the amplifier 72.

The sensor output from the circuit is shown in FIG.
The horizontal axis in FIG. 7 is the magnitude of the external magnetic field, and the vertical axis is the sensor output voltage. The sensor output exhibits excellent linearity between ± 10G. Furthermore, the sensitivity was 20 mV / G. This is a level that can be sufficiently used as a high-sensitivity magnetic sensor.

  On the other hand, the dimensions of the conventional MI element 9 shown in FIG. 13 as a comparative example are as follows. The substrate 91 for fixing the amorphous wire has a width of 0.7 mm, a height of 0.5 mm, and a length of 3.5 mm. The magnetic sensitive body is an amorphous wire 92 having a diameter of 30 μm using a CoFeSiB alloy. Between the amorphous wire 92 and the electromagnetic coil 93, the conductive magnetic amorphous wire and the electromagnetic coil are insulated and held by a winding frame 94 having an insulating property.

The core part formed by the resin mold of the winding frame 94 has a width of 1 mm, a height of 1 mm, and a length of 3 mm. At this time, the inner diameter of the electromagnetic coil 93 is 1.5 mm. A total of four electrodes 95, that is, an electromagnetic coil terminal and a magnetic sensitive body terminal, are arranged on the winding frame 94. Both ends of the amorphous wire 92 and both ends of the electromagnetic coil 93 are connected to the electrode 95. The conventional MI element 9 has the configuration as described above. The dimensions of the MI element 9 in this case are a width of 3 mm, a height of 2 mm, and a length of 4 mm. Conventional MI elements are large as described above and cannot be applied to sensors with limited installation space.
On the other hand, since the first embodiment is very small and thin, it can be applied to ultra-small magnetic sensors for small electronic devices such as sensors for mobile phones and sensors for wristwatches.

  In the first embodiment, a conductive magnetic metal thin film constituting a coil is formed by vapor deposition on the groove surface 111 of the groove 11 formed in the longitudinal direction of the electrode wiring substrate 1 and the lower surface 112 of the upper substrate 12 and formed. The conductive metal thin film portion constituting the gap is removed by a selective etching method so that the metal thin film thus formed remains in a spiral shape, so that an electromagnetic coil is formed. The effect of making it possible.

  As a result of using the MI element 10 of the first embodiment, as shown in FIGS. 3 to 5, compared with the conventional MI sensor using the MI element, the digit is about 1/50 (1/48). Despite the difference in size, excellent linearity was obtained in a magnetic field region of ± 10 G.

  For comparison, a conventional bobbin type sensor (wire length 2.5 mm, coil length 2 mm, 40 turns) as a comparative example shown in FIG. 13 and the sensor of the first embodiment (wire diameter φ20 μm and FIG. 8 shows a result of comparison with respect to a range at a length of 1.5 mm, a coil length of 1 mm, and 18 turns. The horizontal axis in FIG. 8 is the external magnetic field, and the vertical axis is the output voltage.

  As apparent from FIG. 8, the ranges of the conventional bobbin type sensor and the sensor of the first embodiment described above are substantially equal to ± 3 G, and the sensor of the first embodiment described above compared to the conventional bobbin type sensor. The output voltage is slightly more than 80%, and the output voltage drop is low for the small and thin size, but there is a large difference in the number of turns, so the voltage per turn is 28 mV / turn for the bobbin tamp. Thus, the sensor of the first embodiment is 53 mV / turn, which is about twice that of the bobbin tamp, and is suitable for downsizing.

Second embodiment

  The magneto-impedance sensor element with an electromagnetic coil of the second embodiment realizes a wide range that can be applied in, for example, the automobile field, and will be described below with reference to FIGS.

  The substrate 1 has a length of 0.67 mm, and the magnetic sensitive body 2 is an amorphous wire 2 having a diameter of 30 μm using a CoFeSiB alloy. The electromagnetic coil 3 is formed by a two-layer structure of one side 31 of the coil formed on the groove surface 111 and the remaining one side coil 32 formed on the groove upper surface 112 (the upper surface 41 of the resin 4). The total length of the element is 0.67 mm.

In the second embodiment, the diameter of the amorphous wire as the magnetic sensitive body 2 is set to φ30 μm, and the inner diameter of the electromagnetic coil 3 is set to φ80 μm.
The longitudinal width of the groove 11 of the coil part 311 and the coil part 312 shown in FIGS. 3 and 5 and Table 1 is set to 50 μm, 10 μm, 25 μm, etc., and the same width of the gap part is 25 μm, respectively. It is set to 5 μm, 25 μm, and the like.

  The ratio of the diameter of the amorphous wire to the inner diameter of the coil 3 of the electromagnetic coil 3 is set in a range of 1.005 to 10, and the diameter of the amorphous wire is set in a range of φ10 μm to 100 μm, so the diameter of the amorphous wire is φ10 μm. In this case, the inner diameter of the electromagnetic coil 3 is set within a range of 10.05 μm to 100 μm, and when the diameter of the amorphous wire is 100 μm, the inner diameter of the electromagnetic coil 3 is set within a range of 100.5 μm to 1000 μm. .

  When the diameter of the amorphous wire is φ10 μm, the inner diameter of the electromagnetic coil 3 is 11 μm to 70 μm (1.1 to 7 times), and when the diameter of the amorphous wire is φ100 μm, the inner diameter of the electromagnetic coil 3 is 200 μm or less. 300 μm (2 to 3 times).

  If the length of the amorphous wire is set to 100 μm to 10000 μm and the aspect ratio is set to 10 to 100 with respect to the diameter of the amorphous wire of φ100 μm, the detection range becomes 3 to 20 times the conventional range, so a wide range is required. Application in the automotive field.

  Also, four types of amorphous wire lengths of 0.6 mm, 0.7 mm, 0.9 mm, and 1.5 mm are prepared as the magnetic sensitive body 2, and the amorphous wire has a higher drive voltage than the first embodiment shown in FIG. 7. FIG. 9 shows the result of comparison for each range when driven by. The horizontal axis in FIG. 9 is the external magnetic field, and the vertical axis is the output voltage.

  As can be seen from FIG. 9, the range of 0.6 mm with the shortest amorphous wire length is ± 45 G, and the range is the widest. The range becomes narrower as the amorphous wire length increases, and the range becomes 1.5 mm. Compared to 9 times the area.

  Furthermore, when the wire diameter is set to φ30 μm for the four types of the amorphous wire as the prepared magnetic sensitive body 2 of 0.6 mm, 0.7 mm, 0.9 mm, and 1.5 mm, the saturation magnetic field determines the measurable range. For (G), the measurement results are shown in FIG. 10, with the horizontal axis representing the total wire length, that is, the aspect ratio, and the vertical axis representing the measurable range (saturation magnetic field (G)). As is apparent from FIG. 10, the saturation magnetic field (G) is linearly related to the total length of the wire, that is, the aspect ratio, for four types of amorphous wire lengths of 0.6 mm, 0.7 mm, 0.9 mm, and 1.5 mm. Is shown.

In addition, a wide range of ± 40 G is realized when the length of the amorphous wire closest to 0.67 mm, which is the total length of the target element when the diameter of the amorphous wire is 20 μm and the inner diameter of the electromagnetic coil 3 is φ80 μm, is 0.7 mm.
The above-mentioned range was also confirmed for the amorphous wire having a length of 0.4 mm, but a wider range than the above-described 0.6 mm is the measurable range.

  The magneto-impedance sensor element with an electromagnetic coil of the second embodiment can widen the detection range without impairing the sensor sensitivity. Since the element shape is small as described above, the spatial resolution is improved and Since the total length (L) is small, there is an advantage that the frequency response is improved.

  The above-described embodiments have been illustrated for the purpose of explanation, and the present invention is not limited thereto. Those skilled in the art will recognize from the claims, the detailed description of the invention, and the description of the drawings. Modifications and additions can be made without departing from the technical idea of the present invention.

  In the first embodiment described above, as an example, at the groove bottom surface 110 of the groove 11, the coil portion 312 extends and is inclined with respect to the width direction so as to be continuous with the adjacent vertical coil portion, The example in which the coil 32 on one side is formed on the lower surface 112 of the upper substrate 12 in the width direction of the electrode wiring substrate 1 perpendicular to the groove 11 formed in the longitudinal direction of the electrode wiring substrate 1 has been described. However, the present invention is not limited to these examples. As shown in FIG. 11A, the coil portion 312 is inclined and extended, and the coil 32 on one side is also inclined and formed. As shown in B), the coil portion 312 is formed in the width direction perpendicular to the groove 11 formed in the longitudinal direction of the electrode wiring board 1 and the coil 32 on one side is inclined and formed. You It can be.

  In the first embodiment described above, the groove structure in which the rectangular groove 11 is formed in the electrode wiring substrate 1 as shown in FIG. 2 is described as an example. However, the present invention is not limited thereto. Instead, as shown in FIGS. 12A to 12C, when the electrode wiring board 1 is removed by etching to form the groove 11, the U-shape when etched obliquely from above is etched from above. Embodiments in which the inverted trapezoidal or V-shaped, trapezoidal or inverted V-shaped grooves are formed may be employed.

  Further, in the first embodiment described above, the example in which the coil is disposed on the inner wall surface of the groove 11 formed in the electrode wiring board 1 has been described as an example. However, the present invention is not limited thereto. As long as it forms a spiral electromagnetic coil by depositing a conductive magnetic metal thin film on the surface of the member and then removing it by selective etching, for example, from a circular, rectangular or polygonal cross-sectional insulating material Forming a conductive magnetic metal thin film on the entire outer wall of the linear member by vapor deposition, and rotating the linear member at a constant speed to form a gap with a constant pitch while rotating the linear member. It is possible to adopt an embodiment in which a spiral electromagnetic coil is formed by removing the wire in a spiral shape using a selective etching technique, and then cut into a predetermined length and an amorphous wire is inserted. Come.

  The magneto-impedance sensor element with an electromagnetic coil according to the present invention is extremely small and highly sensitive, so that it can be applied to an ultra-small magnetic sensor for a small electronic device such as a sensor for a mobile phone or a sensor for a wristwatch. In addition, in order to realize a compact and wide range, it can be applied in the automobile field.

It is a front view which shows MI element of 1st Embodiment and 1st Example of this invention. It is sectional drawing which follows the AA 'line | wire of FIG. 1 which shows the MI element of this 1st Embodiment and 1st Example. It is a fragmentary perspective view which shows the arrangement | positioning form of the coil in a groove | channel in this 1st Embodiment and 1st Example. It is a fragmentary top view which shows the arrangement | positioning form of the coil in a groove | channel in this 1st Embodiment and 1st Example. It is a fragmentary top view which shows the arrangement | positioning form of the coil in a groove | channel in this 1st Embodiment and 1st Example. It is a block circuit diagram which shows the electronic circuit of MI sensor in this 1st Embodiment and 1st Example. It is a diagram which shows the characteristic of the sensor output voltage versus the external magnetic field in the MI sensor using the MI element in the first embodiment and the first example. It is a diagram which shows the relationship between the external magnetic field and output voltage in the sensor of this 1st Example, and the conventional bobbin type sensor. It is a diagram which shows the relationship between an external magnetic field and an output voltage, in order to compare the range of the amorphous wire of various lengths as a magnetic sensitive body in the MI element of 2nd Example of this invention. It is a diagram which shows the relationship between the saturation magnetic field (G) and the wire full length, ie, aspect ratio, in the amorphous wire of various length as a magnetic sensitive body in the MI element of the 2nd Example. It is each partial top view which shows the arrangement | positioning form of the coil in the groove | channel in the other embodiment and Example of this invention. It is a fragmentary sectional view which shows the example of the groove shape in other embodiment and Example of this invention. It is a front view which shows the MI element of a comparative example and a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrode wiring board 2 Magnetosensitive body 3 Electromagnetic coil 51, 52 Electrode

Claims (9)

A magnetic material for detecting a magnetic field is inserted, and a member made of an insulator having an electromagnetic coil disposed on the surface is disposed on the electrode wiring board,
The magnetosensitive body and coil terminals are connected to respective electrodes on the substrate,
A magneto-impedance sensor element with an electromagnetic coil, wherein a high frequency or pulse current is passed through the magnetic sensitive body and a voltage corresponding to the strength of an external magnetic field generated in the electromagnetic coil is output at that time. In claim 1,
A magneto-impedance sensor element with an electromagnetic coil, wherein the magnetic sensitive body is made of an amorphous conductive magnetic wire. In claim 2,
The magneto-impedance sensor element with an electromagnetic coil, wherein the electromagnetic coil has a winding inner diameter of 200 μm or less. In claim 3,
The electromagnetic impedance sensor element with an electromagnetic coil, wherein the electromagnetic coil has a winding interval per turn of 100 μm / winding or less. In claim 2,
The magneto-impedance sensor element with an electromagnetic coil, wherein the magnetic sensitive body is set to a length of 3 mm or less. In claim 2,
A magneto-impedance sensor element with an electromagnetic coil, wherein the magnetosensitive body has an aspect ratio of a ratio of a length to a wire diameter of 10 to 100. In claim 2,
A magneto-impedance sensor element with an electromagnetic coil, wherein the inner diameter of the coil of the electromagnetic coil is set to 1.005 to 10 times the wire diameter of the magnetic sensitive body. In claim 2,
The electromagnetic impedance sensor element with an electromagnetic coil, wherein the electromagnetic coil has a winding inner diameter of 100 μm or less. In claim 3,
The electromagnetic impedance sensor element with an electromagnetic coil, wherein the electromagnetic coil has a winding interval per turn of 50 μm / winding or less.

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