JP6021239B2 - 3D magnetic field detection element and 3D magnetic field detection device - Google Patents

Description

The present invention realizes the basic functions of high sensitivity, low noise, wide measurement range, etc. of the azimuth sensor by realizing the functions of the three magnetic detection elements of the X, Y, and Z axes used in the azimuth sensor on one substrate. The present invention relates to a technology that makes it possible to reduce the height and size of a three-dimensional magnetic field detection element while maintaining performance , and to enable a three-dimensional magnetic field detection device .

The azimuth sensor measures the geomagnetic vector by combining three magnetic sensor elements of the X axis, Y axis and Z axis and an integrated circuit, and calculates the azimuth from the measured value. It is widely used as a three-dimensional azimuth meter in combination with an accelerometer and vibration gyro sensor in smart phones, tablets, remote controls for Internet TV, motion games, motion capture, etc.
In recent years, there has been a strong demand for downsizing and thinning of these apparatuses together with higher sensitivity, lower noise, and wider measurement range. In particular, along with the thinning of smart phones, the orientation sensor height has been reduced from 40 mm to 40 mm or more, from 1.0 mm to 0.6 mm, and the size has been reduced from conventional 2.0 mm square to 1.5 mm square by 50% or more. Miniaturization is required. In addition, with respect to noise, a 10-fold increase in performance from the conventional 10 mG or less to 1 mG or less is required.

In the azimuth sensor, a Hall element, MR element, MI (abbreviation of Magne-Impedance) element, or the like is used as a magnetic field detection element. Usually, in order to measure the strength of the magnetic field vector components Hx, Hy, and Hz in the X-axis direction , the Y-axis direction , and the Z-axis direction, three elements of the X-axis element, the Y-axis element, and the Z-axis element are used. Measure. In the case of a Hall element, since a magnetic field is detected in a direction perpendicular to the element surface, it is necessary to place the Z-axis element on the surface and assemble the X-axis element and the Y-axis element upright on the sensor substrate. On the other hand, since the MR element, MI element, etc. detect a magnetic field parallel to the element surface, the X-axis element and the Y-axis element are arranged on the surface, and the Z-axis element is mounted upright on the sensor substrate (Z-axis direction). There is a need. As long as three elements are used, there is a problem that the height of the sensor increases.

  To solve this problem, Asahi Kasei Co., Ltd. uses Hall elements to place four Z-axis elements on a single substrate,Not useIn addition, the company succeeded in developing a three-dimensional magnetic field detection element and produced and sold it as an orientation sensor (part number AKM8974). The three-dimensional magnetic field detection element has a structure in which a pair of ZX1 elements and ZX2 elements and a pair of ZY1 elements and ZY2 elements are arranged in a cross shape on the substrate in the X-axis direction and the Y-axis direction, respectively, with a magnetic material at the center. A permalloy thin disk is placed. This device detects a three-dimensional magnetic field vector. First, the magnetic field in the Z-axis direction is detected by adding the four outputs of the ZX1, ZX2, ZY1, and ZY2 elements. Each of these magnetic fields generates a direction change component in the Z-axis direction by a permalloy disk, the magnetic field in the X-axis direction is the difference between the outputs of the ZX1 element and the ZX2 element, and the magnetic field in the Y-axis direction is the output of the ZY1 element and the ZY2 element. It is detected by the difference. Since there is no element to stand on the sensor board surface, the height can be reduced and the size can be reduced.it can. A magnetic field detection element that can detect a magnetic field perpendicular to the element surface, such as a Hall element, easily thins the device. Yes, butThis type of magnetic field detecting element such as a hall sensor has a drawback that noise is too large for the requirement of about 10 mG and 1 mG or less, and has been a big problem in use.

On the other hand, the MI element can be improved to a noise of 1 mG or less, but when the Z-axis element is assembled on the substrate surface, the height of the MI element and the detection sensitivity are contradictory, so the height should be reduced. Was difficult. Since, MI elements, those in the magnetic sensitive member of amorphous wire, such as wound detection coil by flowing a high-frequency pulse current such as the magnetic sensitive member, for detecting a detection coil voltage proportional to the external magnetic field generated at that time Is. This is because the detection sensitivity of the MI element is proportional to the length of the MI field and the number of turns of the coil, and therefore depends on the length of the detection magnetic field.

Japanese Patent No. 4626728

On the other hand, Patent Document 1 describes an integrated MI sensor device having an X-axis element function and a Z-axis element function arranged on a single substrate. A pair of X1-axis elements, X2-axis elements, Y1-axis elements, and Y2-axis elements are arranged in a cross shape on the substrate surface in the X-axis direction and Y-axis direction, respectively, and a permalloy mandrel is arranged below the center point. This device detects a three-dimensional magnetic field vector. First, the magnetic field in the X-axis direction is detected by adding the outputs of the X1-axis element and the X2-axis element, and the magnetic field in the Y-axis direction is output from the Y1-axis element and the Y2-axis element. Further, the magnetic field in the Z-axis direction is generated by a permalloy mandrel in the plane direction by the permalloy mandrel, and the difference between the output of the X1-axis element and the X2-axis element and the Y1-axis element And the difference between the outputs of the Y2 axis elements are detected.
However, the force that changes the Z-axis direction magnetic field in the plane direction by the permalloy mandrel is extremely weak. Therefore, a long and large-diameter permalloy is required, and the thickness of the apparatus is 0.5 mm or more, which is not practical.

  As described above, an integrated device has been invented in which the X-axis element and the Y-axis element and the soft magnetic material are arranged on one substrate to realize the Z-axis element function. However, the MI element type is required to be further improved in terms of thickness.

In view of the technical background as described above, the present invention forms a plurality of X-axis and Y-axis MI elements on one substrate to realize the function of the Z-axis element, and with small noise, It is an object of the present invention to provide a magnetic field detection device that can be made much thinner than before. The present invention is not limited to the MI element, and can be provided for a type of magnetic field detection element that detects a magnetic field parallel to the magnetic field detection element arrangement surface using a magnetic material as a magnetic sensitive body.

The present inventor provided a soft magnetic body at one upper portion and a soft magnetic body at the other lower portion at both ends of the MI element, and formed a crank-like magnetic circuit by using these two soft magnetic bodies and the element. It was devised to effectively detect the magnetic field in the Z-axis direction if formed .
The first invention uses a magnetic field detection element of a type that detects a magnetic field in a direction parallel to the magnetic field detection element arrangement surface of the substrate, and has four magnetic field detection elements on the substrate surface in the first axial direction with the origin as the center. along two, the second axial direction two arranged along a further upper soft magnetic body origin opposite ends of the lower substrate and the four elements of the origin intersects the first axis By having a magnetic field detection unit that forms a magnetic circuit between the magnetic field detection element and the soft magnetic material by the arrangement structure, the strength of the magnetic field in the X-axis, Y-axis, and Z-axis directions can be determined from the outputs of the four magnetic field detection elements. is a three-dimensional magnetic field detection element according to feature to effectively detected.
Here, preferably, the height of the upper soft magnetic body is about 0.05 mm to 0.2 mm, the gap with the MI element is 0.02 mm or less, and the same lower soft magnetic body has the same size and positional relationship. The three parts are arranged in a crank shape.
The vertical arrangement of the soft magnetic material is relative to the vertical direction, and the soft magnetic material is arranged at the upper part of the substrate at the origin and the lower part of the end opposite to the origin of the four magnetic field detection elements. It is also possible.

Describing the function of the crank-shaped magnetic circuit, the magnetic field in the Z-axis direction flows from the soft magnetic body at one end of the element through the magnetic wire in the element to the other soft magnetic body. The magnetic field in the Z-axis direction is changed to a magnetic field that flows radially in the in-plane directions of the X-axis and the Y-axis. At this time, a strong magnetic field proportional to the magnetic field in the Z-axis direction flows through the amorphous wire on the substrate surface. Thus, even with a small soft magnetic material at each end, a large output can be obtained. Therefore, if this magnetic circuit is utilized, the height of the element can be reduced from the 0.5 mm level of Patent Document 1 to about 0.10 mm to 0.30 mm.

The three-dimensional magnetic field detection element of the present invention uses a magnetic field detection element of a type that detects a magnetic field in a direction parallel to the magnetic field detection element placement surface, and has four magnetic field detection elements on the substrate plane and the X axis centered on the origin. Two in the direction and two in the Y-axis direction, and furthermore, a soft magnetic member is arranged at the lower part of the origin and the upper part of the end opposite to the origin of the four elements to form four crank-shaped magnetic circuits It is a thing. Here, the X1-axis element and the X2-axis element form a crank-shaped magnetic circuit in an antisymmetric manner, and their outputs are in proportion to the strength of the magnetic field in the Z-axis direction and the absolute values of both are the same. The sign is opposite. Therefore, if the difference between both outputs is taken, the difference is proportional to the strength of the magnetic field in the Z-axis direction. Similarly, the Y1-axis element and the Y2-axis element form an asymmetric crank-shaped magnetic circuit, and if the difference between the outputs is taken, it is proportional to the strength of the Z-axis magnetic field. By summing the difference between the X-axis output and the Y-axis output, the strength of the magnetic field in the Z-axis direction can be calculated.

Further, the outputs of the X1-axis element and the X2-axis element are values whose magnitude is proportional to the strength of the magnetic field in the X-axis direction, and the signs thereof are the same. The strength of the magnetic field in the X-axis direction can be obtained from the sum of both outputs. Similarly, the strength of the magnetic field in the Y-axis direction can be obtained from the sum of the outputs of the Y1-axis element and the Y2-axis element.
As described above, the three-dimensional magnetic field detection element of the present invention uses a magnetic field detection element of a type that detects a magnetic field in a direction parallel to the magnetic detection element arrangement surface of the substrate, and has the first on the substrate as the center. a pair of the magnetic field detection element on the axis direction, the second axis direction intersecting the first axis direction becomes a pair of the magnetic field detecting element, and, contrary to the origin of the origin and the magnetic field detecting element And a magnetic circuit formed by the magnetic field detection element and the soft magnetic body on both sides of the magnetic field detection element is antisymmetric about the origin. it is characterized in that a specific class link shape.

Therefore, to place the two X-axis element and two Y-axis elements on a substrate, by placing a small soft magnet in the vertical position of the end portion, characterized in that to form a magnetic circuit between the two 3D magnetic field detecting element of the present invention, the height of the device in consideration of the thickness of the substrate material can be reduced to 0.1 to 0.3 mm.

The above-described three-dimensional magnetic field detecting element is desirably used by being joined to an integrated circuit chip of the same size by using a solder pad for an electrode by the CSP (chip size package) method. The integrated circuit of the MI sensor is formed of a pulse oscillation circuit, a signal processing circuit, and an electronic circuit including the arithmetic means. An example of the signal processing circuit includes a buffer circuit, a sample timing adjustment circuit, an electronic switch, a hold circuit, and an amplifier circuit. In the present invention, various combinations are possible for the combination of the device of the present invention and the wiring of the signal processing circuit and the integrated circuit chip. The device of the present invention is not limited to the combination.

The electronic circuit that drives the three-dimensional magnetic field detection device performs a predetermined calculation after a pulse current is simultaneously supplied from the pulse circuit to the four elements, and the coil voltage is simultaneously detected by the four signal processing circuits. It is desirable to determine the strength of the magnetic field in the X-axis, Y-axis, and Z-axis directions. In addition, the electronic switch switches the measurement of the X-axis element and the measurement of the Y-axis element instantaneously, for example, in 1 microsecond, and measures using one pulse oscillation circuit and two detection circuits, and saves the measured value as data Then, a predetermined calculation may be performed. Obviously, the present invention is not limited by the combination with the integrated circuit.
The total thickness of the azimuth sensor, which is a magnetic field detection device in which the element of the present invention is combined with the silicon substrate of the signal processing circuit and the integrated circuit, can be made extremely thin as 0.3 to 0.6 mm. Here, illustration of the silicon substrate is omitted.

Explaining the compatibility between high sensitivity and an appropriate measurement range, the output of the MI element takes a peak value at a certain magnetic field strength, and the measurement range is restricted between the peaks. The measurement range can be expanded by reducing the length of the MI element and increasing the demagnetizing field of the wire. In this way, it is a general method to adjust the length of the MI element to adjust the measurement range that is in a contradictory relationship with the sensitivity to a predetermined range. Also in the present invention, this general method can be applied to magnetic field measurement in the X-axis direction and the Y-axis direction. Further, in the magnetic field measurement in the Z-axis direction, the shorter the MI element length, the more the magnetic circuit having a lower magnetic resistance can be formed, so that the sensitivity is improved, and it means that both can be realized with a smaller soft magnetic material. In other words, in the present invention, compatibility between sensitivity and measurement range is not impaired.

In order to increase the sensitivity of the device of the present invention, for example, when considering a square substrate of a three-dimensional magnetic field detection element, when each side is vertically and horizontally, it is on a diagonal line forming 45 degrees with each side. It is desirable to arrange the MI element along the X axis and the Y axis. Thereby, the length of the MI element can be increased with respect to the substrate of the same size. That is, the length of the magnetic sensitive body (amorphous wire or the like) and the number of turns of the detection coil can be increased, and the output voltage can be improved.

Further enhancement of sensitivity can be realized by arranging a plurality of three-dimensional magnetic field detection elements (magnetic field detection units) according to the first invention of the present invention on the same substrate.
That is, the second invention is a three-dimensional magnetic field detection element characterized in that a plurality of magnetic field detection units described in the first invention are arranged on the same substrate plane.
Realized by combining a plurality of units on the substrate with the magnetic field detection unit comprising the four magnetic detection elements of the first invention as a basic unit and combining them with an integrated circuit having a drive circuit and a detection circuit as many as the corresponding units. it can. Regarding the drive circuit, the number of wire electrodes of the elements in the X-axis direction and the Y-axis direction can be electrically connected in series and the excitation pulse current can be made to flow to one. Also for the detection circuit, the number of signal processing circuits can be reduced by connecting the output electrodes of a plurality of pickup coils corresponding to the X1-axis element, X2-axis element, Y1-axis element, and Y2-axis element in series. The same four can remain.
Furthermore, a third invention is a three-dimensional magnetic field detection element device in which the three-dimensional magnetic field detection element described in the first invention and an integrated circuit chip are joined. By bonding in this way, the element can be thinned in the direction of the substrate.

3 is a plan view of a three-dimensional magnetic field detection element according to Embodiment 1. FIG. It is sectional drawing cut | disconnected by AA shown in the top view. 1 is a plan view showing a basic structure of an MI element according to Example 1. FIG. 1 is a crank-shaped magnetic circuit according to a first embodiment. 1 is an electronic circuit diagram of an element according to Example 1. FIG. 3 is an electronic circuit diagram of a three-dimensional element according to Example 1. FIG. 6 is a plan view of a three-dimensional magnetic field detection element according to Embodiment 2. FIG. 6 is a plan view of a three-dimensional magnetic field detection element (device) according to Embodiment 3. FIG.

The present invention will be described in more detail with reference to embodiments of the invention.
The three-dimensional magnetic field detection apparatus of the present invention is an apparatus that detects magnetism using a magnetic impedance element (MI element). As described above, the MI element includes a magnetic sensitive body that can cause an impedance change and a magnetic flux amount change in response to a time such as a magnetic field (magnetic field), and a detection unit that detects the amount of change of the magnetic sensitive body. The material and form of the magnetosensitive material are not limited. Further, the detection means may be one that directly detects the impedance of the magnetic body, or may be a pickup coil (detection coil) that is wound around the magnetic body and outputs an electromotive force according to a change in the amount of magnetic flux. The magnetic sensitive body is usually made of a soft magnetic material such as an amorphous wire, and is made of a wire or a thin film having a corresponding length. The magnetosensitive body is particularly preferably a zero magnetostrictive amorphous wire in terms of strength and cost.

The soft magnetic material forms an X1-axis element, an X2-axis element, a Y1-axis element, a Y2-axis element and four crank-shaped magnetic circuits arranged on the substrate, and applies a magnetic field in the Z-axis direction to the X-axis on the substrate. The direction is changed to the Y-axis direction, and the strength of the magnetic field in the Z-axis direction can be detected. However, as long as the magnetic circuit can be formed using such a soft magnetic material, the material and form of the soft magnetic material are not limited. The higher the magnetic permeability of the soft magnetic material, the larger the magnetic field collecting effect, which is preferable. The soft magnetic material has a shape that can be effectively magnetized by a magnetic field in the Z-axis direction by reducing the demagnetizing factor. Preferably there is.

The arrangement position of the soft magnetic material is preferably arranged at a position where the magnetic circuit is easily formed effectively. For example, the magnetic circuit resistance is reduced by bringing the magnetic pole surface of the soft magnetic material and the end of the amorphous wire as close as possible. The size of the soft magnetic material expressed by the cross-sectional area and the thickness has a relative relationship with the length and diameter of the element, and it is preferable that the thickness of the soft magnetic material is increased as the element becomes longer.

As long as the gist of the present invention is met, it is desirable that the X-axis element and the Y-axis element or the soft magnetic material are arranged at right angles to each other. Processing can be performed by performing an appropriate correction calculation in accordance with this.

It is desirable that the X-axis direction and the Y-axis direction match the vertical and horizontal directions of the element substrate shape, but if they do not match, measure the deviation angle and apply a correction calculation. Can do.

Of course, it is desirable that the MI elements arranged symmetrically or the soft magnetic materials forming the magnetic circuit have substantially the same sensitivity characteristics, detection characteristics, magnetic collection characteristics, and the like. If the characteristics are different, the measured values of each element can be processed by being sent to the electronic circuit and the arithmetic processing unit to be corrected and made identical.

  In any case, the correction coefficient or the correction term in the arithmetic expression can be simplified by skillfully using the symmetry between the pair of MI elements in the X direction or the pair of MI elements in the Y direction and the soft magnetic material. Then, highly accurate magnetic field detection becomes easy and preferable.

The present invention reduces the size of a magnetic field detection device that detects a magnetic field of three axes by forming a magnetic circuit with an X-axis element, a Y-axis element, and a soft magnetic material in which a magnetic field in the Z-axis direction is placed on a substrate. It is characterized in that it can be made thinner. The composite element of the present invention and the integrated circuit can be bonded using wire bonding, but extra area and height are required for wire bonding. Therefore, it is desirable to laminate the magnetic field detection element and the integrated circuit and to electrically bond them by pad bonding in order to further reduce the overall size or thickness.

Further, the layers to be integrated are not limited to the magnetic field detection element and the integrated circuit chip layer. The three-dimensional magnetic field detection apparatus of the present invention can be assembled and used as a composite sensor by being laminated with an acceleration sensor, a temperature sensor, or the like.

The present invention will be described in detail based on the following examples with reference to the drawings.
[Example 1]
A three-dimensional magnetic field detection element 1 according to Example 1 is shown in FIG. FIG. 1 is a plan view of the three-dimensional magnetic field detection element 1, and FIG. 2 is a cross-sectional view taken along the line AA shown in FIG. Figure 3 is a plan view showing a basic structure of the MI element.

The three-dimensional magnetic field detection element 1 includes four MI elements 2 that can detect a minute magnetic field such as geomagnetism,
That is, the X1 axis element 2X1, the X2 axis element 2X2, the Y1 axis element 2Y1 and the Y2 axis element 2Y2, the substrate 11 arranged in these MI elements, and the lower side of the common origin position of the four elements are formed on the substrate 11 It comprises a three-layer structure of a rod-shaped soft magnetic body 31 disposed in the formed hole, a bar-shaped soft magnetic body 32 disposed on the upper end of the four-element substrate 11 in the outer edge direction, and electrodes. Electrode is made up of four of the electrodes pads 24 connected with the wire terminal 23 which is connected to the element wires, four detection coils of the detection coil terminal 25 and the connected electrode pads 26.. An integrated circuit silicon substrate (not shown) disposed at the upper position can be connected to the electrodes by installing solder pads for bonding.

The soft magnetic material 31 installed at the origin position of the substrate 11 is provided with a cylindrical hole having a diameter of 100 μm and a depth of 200 μm with the Z axis as the axis at the origin position of the substrate 11, and 45 at% Ni− A permalloy alloy having an Fe composition is embedded. The soft magnetic material 32 installed on the upper surface of the substrate upper surface 11 is a permalloy alloy formed by a button-like 45 at% Ni—Fe plating method having a diameter of 50 μm and a thickness of 50 μm at the end of the amorphous 21. As the soft magnetic material 3, known soft magnetic materials such as pure Ni, pure iron, permalloy alloys of other compositions, sendust, and permendur can be used.

The structure of the MI element 2 will be described with reference to FIG.
The four elements have the same structure. In the structure, an amorphous wire 21 having a diameter of 10 μm and a length of 400 μm is arranged at the center, and a detection coil 22 having an inner diameter of 30 μm, a coil pitch of 5 μm , and a winding number of 30 is provided. Further, wire terminals 23 and detection coil terminals 25 , which are electrode terminals, are attached to both ends of the wire 21 and the coil 22, respectively. An electrode pad 24 from the wire terminal 23 and an electrode pad 26 from the detection coil terminal 25 are used to correspond to an integrated circuit terminal (not shown). Each terminal of each MI element 2 and each terminal of the silicon substrate of the integrated circuit are electrically joined by electrode pads.

  Four elements of the X1 axis element 2X1, X2 axis 2X1, Y1 axis element 2Y1, and Y2 axis element 2Y2 arranged on the substrate of the first embodiment, the soft magnetic body at the origin position, and the four wire end portions 32 The soft magnetic material forms four crank-shaped magnetic circuits, and makes it possible to effectively detect the strength of the magnetic field in the Z-axis direction.

The function of the crank-shaped magnetic circuit will be described in detail with reference to FIG. 4 (AA sectional view of FIG. 1). The magnetic field Hz in the Z-axis direction magnetizes the soft magnetic material at both ends of the MI element. When the magnetic pole on the lower surface of the soft magnetic body 32 on the upper side of the end of the MI element is an N pole, the magnetic pole on the upper surface of the soft magnetic body 31 at the origin position is an S pole, and the amorphous MI element between them A crank-shaped magnetic circuit is formed through the wire 21. At this time, a strong magnetic field proportional to the magnetic field in the Z-axis direction flows through the amorphous wire. Since a large output can be obtained effectively by this magnetic circuit formation, the height of the soft magnetic material at the end can be reduced to 0.05 mm. As a result, together with the thickness 0.05mm the MI element, the overall height of the three-dimensional magnetic field sensor could be 0.30 mm.

The outputs of the four MI elements are individually measured. If the measured values of the X1 axis element, the X2 axis element, the Y1 axis element, and the Y2 axis element are Hx1, Hx2, Hy1, and Hy2, a calculation process is performed. The magnetic field strengths Hx, Hy, and Hz in the direction , the Y-axis direction, and the Z-axis direction are calculated.

As described above, the X1-axis element and the X2-axis element form a crank-shaped magnetic circuit in an antisymmetric manner, and the output of both elements is proportional to the magnitude of the magnetic field in the Z-axis direction. Is the opposite. Therefore, if the difference between both outputs is taken, the difference is proportional to the strength of the magnetic field in the Z-axis direction. Similarly, the Y1-axis element and the Y2-axis element form a crank-like magnetic circuit antisymmetrically with respect to the magnetic field component in the Z-axis direction, and if the difference between the outputs is taken, it is proportional to the strength of the Z-axis element. . By summing the difference between the X-axis output and the Y-axis output, the strength of the magnetic field in the Z-axis direction can be calculated.

In addition, the outputs of the X1-axis element and the X2-axis element are symmetrical with respect to the magnetic field component in the X-axis direction. The magnitude is proportional to the strength of the magnetic field in the X-axis direction, and the sign is the same sign. The The strength of the magnetic field in the X-axis direction can be obtained from the sum of both outputs.
Similarly, the strength of the magnetic field in the Y-axis direction is obtained from the sum of the outputs of the Y1-axis element and the Y2-axis element. Can do.

An electronic circuit for driving the three-dimensional magnetic field detection element 1 used in this embodiment will be described with reference to FIGS. Light up.
First, the basic operation of the electronic circuit 8 of the MI sensor will be described with reference to FIG. The electronic circuit 8 is A pulse oscillation circuit 81 and a signal processing circuit 82 are included. Signal processing circuit 82 Includes a buffer circuit 83, a detection timing adjustment circuit 84, an electronic switch 85, and a sample. It comprises a hold circuit 86 and an amplifier 87. 50 generated by the pulse oscillation circuit 81 A high-frequency pulse current corresponding to 0 MHz is supplied to the amorphous wire 21 of the MI element 2. Then, the magnetic field generated in the wire circumferential direction of the amorphous wire 21 by the pulse current and An external magnetic field acts, and a voltage corresponding to the external magnetic field is generated in the detection coil 22. In addition The pulse frequency here has a period that is four times the “falling” time Δt of the pulse current. The reciprocal was defined as the pulse frequency for convenience.

The output voltage of the detection coil 22 is input to the buffer circuit. The output voltage of the buffer circuit is supplied to the sample hold circuit 86 by the detection timing adjustment circuit 84 by switching the electronic switch 85 for a short time (on-off) at a predetermined timing from the fall of the pulse current. At this time, the voltage generated in the detection coil 22 is held as a capacitor voltage of the sample hold circuit 86, and this sampling voltage is amplified by an amplifier and output.

Next, the function of the electronic circuit of this embodiment having four elements will be described with reference to FIG. This circuit is one pulse oscillation circuit (pulse generator) 81, a signal processing circuit 82 is provided with four to measure the output of each element at the same time. Outputs from the four MI elements are sequentially converted into digital data by the AD converter 882 using the changeover switch 881, and then transferred to the arithmetic circuit 883 for appropriate arithmetic processing. Therefore, it is converted into the strength of a three-dimensional magnetic field vector . Thereafter, the data is transferred via a data communication circuit to a central processing unit that controls a system such as a smart phone.

[Example 2]
  A plan view of a three-dimensional magnetic field detection element 12 in which the arrangement of the MI element 2 is changed from the three-dimensional magnetic field detection element 1 (FIG. 1) is shown in FIG. For the sake of convenience, the same members as those of the above-described three-dimensional magnetic field detection element are denoted by the same reference numerals (Less than,The same). In the three-dimensional magnetic field detection element 12, a square shape On boardIn addition, the MI element 2 is arranged on a diagonal line forming 45 degrees with each side. In this way, the MI element 2 is
When arranged, the length of the MI element can be increased with respect to the substrate of the same size. That is, the length of the magnetic sensitive body (amorphous wire or the like) and the number of turns of the detection coil can be increased, and the output voltage can be improved.

[Example 3]
The third embodiment is a three-dimensional magnetic field detection element 13 in which the three-dimensional magnetic field detection element 1 shown in the first embodiment is used as a magnetic detection unit and four of them are combined in a square shape. The plan view is shown in FIG.
The element size is 1.4 mm square, the height is 0.3 mm, and the height as the three-dimensional magnetic field detection device 14 combined with the 1.4 mm square integrated circuit chip (not shown) is 0.5 mm. The electrode on the device side and the electrode on the integrated circuit chip side were joined with a solder pad. The output of the element of Example 2 is four times that of Example 1.

The electronic circuit is composed of a digital circuit such as one pulse oscillation circuit, four detection timing adjustment circuits, an AD converter, an arithmetic circuit, and a communication circuit. The amorphous wires 21 of the 16 elements are electrically joined and excited in synchronization with a pulse supplied from one pulse oscillation circuit. Detection coils X1-axis elements, X2 axis element, Y1 axis elements, is divided into four types of Y2 axis element, four X1-axis elements connected in series, the output to the X1 axis element dedicated detection circuit To detect. Similarly, the X2-axis element, the Y1-axis element, and the Y2-axis element are also detected by a dedicated detection circuit, which is sequentially converted into a digital signal via an AD converter, and an arithmetic circuit according to a predetermined calculation formula, Direction , Y-axis direction, and Z-axis direction magnetic field strength.

[Example 4]
In Example 4, the three-dimensional magnetic field detection element of the present invention and an integrated circuit chip, an acceleration sensor element, a vibration gyro element, and a pressure sensor element are integrally joined. Each element is bonded to the corresponding electrode with a scan Ruhoru and electrode pads through the respective elements. The device of the present invention enables the production of such a thin and small composite sensor.

  The three-dimensional magnetic field detection element of the present invention is necessary for a three-dimensional azimuth meter that requires three-dimensional geomagnetic measurement, such as an electronic compass and a magnetic gyroscope. In particular, the three-dimensional magnetic field detection device of the present invention is a mobile phone. It is suitable for a device that requires downsizing and thinning in a direction perpendicular to the substrate to be placed (so-called Z-axis direction), such as a portable terminal.

1: Three-dimensional magnetic field detection element of Example 1
12: Three-dimensional magnetic field detection element of Example 2
13: Three-dimensional magnetic field detection element of Example 3
2: MI element (four elements of 2X1, 2X2, 2Y1, 2Y2)
3: Soft magnetic material
31: AmorphousOneAt the edge of the substrate center, amorphous wireotherBoard edge at the edge
4: 3D magnetic field detectionelementHeight of
5: Resin for MI element insulation protection
6: Crank-shaped magnetic circuit
21: Amorphous wire, 22: Detection coil, 23:Wire terminal24: Electrode pad, 25:Coil terminal, 26: electrode pad
8: Electronic circuit
81: Pulse transmitter, 82: Signal processing circuit, 83: Buffer circuit, 84: Detection timing AdjustmentCircuit 85: Electronic switch 86: Sample hold circuit 87: Amplifier
88: Digital circuit
881: changeover switch, 882: AD converter, 883: arithmetic circuit, 884: data communication circuit
 

Claims (4)

Using a type of magnetic field detection element that detects a magnetic field parallel to the magnetic field detection element placement surface of the board ,
Two magnetic field detecting elements on the substrate plane are arranged in the first axis direction with the origin of the substrate as the center. Two, arranged in the second axis direction intersecting the first axis,
Further, in the substrate below the origin and in front of the four magnetic field detecting elements on the opposite side of the origin. By placing a soft magnetic material on the top of the end of the magnetic field detection element,
A magnetic field detection unit for forming a magnetic circuit composed of the soft magnetic material and the magnetic field detection element; A three-dimensional magnetic field detecting element. A three-dimensional magnetic field detection element comprising a plurality of magnetic field detection units according to claim 1 arranged on the same substrate plane. Using a magnetic field detection element of the type that detects the magnetic field on the magnetic field detection element placement surface of the board,
A pair of the magnetic field detection elements are provided in the first axial direction around the origin on the substrate, and the first axial direction A pair of the magnetic field detection elements in the intersecting second axis direction,
And at the end of the magnetic field detection element on the opposite side of the origin and the origin of the magnetic field detection element. Each has a soft magnetic material,
Magnetic circuit formed by the magnetic field detection element and the soft magnetic material on both sides of the magnetic field detection element Has a crank shape that is antisymmetric about the origin. . A three-dimensional magnetic field detection measure comprising the integrated circuit chip and the three-dimensional magnetic field detection element according to any one of claims 1 to 3.

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