JP2004077374A - Arranging structure of magnetic sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an arranging structure for a magnetic sensor capable of enhancing the sensing accuracy when the direction of a magnetic flux parallel with two magnetism sensing surfaces is sensed. <P>SOLUTION: The invention includes a first IC chip 12 equipped with a first magnetic sensor 14 having one magnetism sensing surface 14a and a second IC chip 13 equipped with a second magnetic sensor 15 having another magnetism sensing surface 15a. The first magnetic sensor 14 is connected fast to the second magnetic sensor 15 using a bump 16 in such a way that the magnetism sensing surfaces 14a and 15a are positioned confronting. The two sensors 14 and 15 are arranged so that the output values in accordance with the direction of the magnetic flux to be sensed are in the contrary characteristics or in the same characteristics. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an arrangement structure of a magnetic sensor that detects a direction of a magnetic flux.
[0002]
[Prior art]
Conventionally, as shown in FIGS. 8 and 9, an arrangement structure of a first magnetic detection sensor 101 for signal detection and a second magnetic detection sensor 102 for abnormality determination is known.
[0003]
The two magnetic detection sensors 101 and 102 are formed in a size of several millimeters square and have magnetic detection surfaces 101a and 102a, respectively. The first magnetic detection sensor 101 and the second magnetic detection sensor 102 are arranged so as to be adjacent to each other on a planar mounting surface f of the IC chip 104. A structure 103 is composed of the two magnetic detection sensors 101 and 102 and the IC chip 104.
[0004]
Further, the first magnetic detection sensor 101 and the second magnetic detection sensor 102 are arranged such that output values corresponding to the directions of magnetic fluxes detected on the magnetic detection surfaces 101a and 102a have opposite characteristics. . Then, as shown in FIG. 10, the magnetic detection surfaces 101a and 102a of the two magnetic detection sensors 101 and 102 receive the magnetic flux 106 of the magnet 105 (magnetic flux parallel to the mounting surface f) and output respective output values.
[0005]
Since the output value of the first magnetic detection sensor 101 and the output value of the second magnetic detection sensor 102 have opposite characteristics, when the two magnetic detection sensors 101 and 102 function normally, Are always constant at a predetermined value. When the total value is constant, the two magnetic detection sensors 101 and 102 are assumed to be functioning normally, and the output value of the first magnetic detection sensor 101 is appropriately used.
[0006]
If the total value does not become constant, it can be determined that at least one of the first magnetic detection sensor 101 and the second magnetic detection sensor 102 has failed, and in that case, the structure 103 has failed. .
[0007]
[Problems to be solved by the invention]
However, the two magnetic detection sensors 101 and 102 are arranged on the mounting surface f of the IC chip 104 so as to be adjacent to each other.
[0008]
For this reason, when trying to detect the magnetic flux 106 parallel to the mounting surface f on the magnetic detection surfaces 101a and 102a of the two magnetic detection sensors 101 and 102, the magnetic flux detected due to a delicate difference between the two magnetic detection sensors 101 and 102 is detected. , And the density of the magnetic flux were different, so that accurate detection results could not be obtained.
[0009]
The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an arrangement structure of a magnetic sensor capable of increasing detection accuracy when detecting a direction of a magnetic flux parallel to both magnetic detection surfaces. Is to do.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, an invention according to claim 1 includes a first magnetic detection sensor having a first magnetic detection surface whose output values according to the direction of a magnetic flux to be detected have opposite characteristics or have the same characteristics. A second magnetic detection sensor having a second magnetic detection surface, wherein the first magnetic detection sensor and the second magnetic detection sensor are arranged so that the first magnetic detection surface and the second magnetic detection surface face each other. The point is that they are arranged.
[0011]
According to a second aspect of the present invention, in the arrangement structure of the magnetic sensor according to the first aspect, the first magnetic detection sensor and the second magnetic detection surface are arranged so that the first magnetic detection surface and the second magnetic detection surface are parallel to each other. The gist is that a second magnetic detection sensor is arranged.
[0012]
According to a third aspect of the invention, in the arrangement structure of the magnetic sensor according to the first or second aspect, the first magnetic detection sensor is provided on a first chip, and the second magnetic detection sensor is provided on a second chip. The gist is that the second chip is flip-chip mounted on the first chip such that the first magnetic detection sensor and the second magnetic detection sensor face each other.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS.
As shown in FIG. 1, a structure 11 of the present embodiment includes a first IC chip 12 as a first chip, a second IC chip 13 as a second chip, a first magnetic detection sensor 14 for signal detection, The second magnetic detection sensor 15 and a plurality of bumps 16 connecting the two IC chips 12 and 13 are provided.
[0014]
The two magnetic detection sensors 14 and 15 are formed in a size of several mm square.
As shown in FIGS. 1 and 2, a first magnetic detection sensor 14 is disposed on a planar mounting surface 12a (upper surface in FIG. 1) which is one side surface of the first IC chip 12.
[0015]
As shown in FIG. 4, the first magnetic detection sensor 14 has a circuit configuration in which four magnetoresistive elements R1, R2, R3, and R4 made of a ferromagnetic material such as Ni—Co are connected to a full bridge. .
[0016]
As shown in FIG. 3A, in the first magnetic detection sensor 14, one of the magnetoresistive elements R2 and R3 and the other of the magnetoresistive elements R1 and R4 have an inclination of 45 ° with respect to the reference line S1. Each is arranged.
[0017]
That is, the magnetoresistance elements R2 and R3 are arranged in the same arrangement direction, and the magnetoresistance elements R1 and R4 are arranged in an arrangement direction orthogonal to the arrangement direction of the magnetoresistance elements R2 and R3.
[0018]
In FIGS. 2 and 3A, m and n indicate the direction in which the magnetoresistive elements R1 and R4 and the magnetoresistive elements R2 and R3 are directed, and indicate the central axis of each of the magnetoresistive elements R1 to R4.
[0019]
Each of the magnetoresistive elements R1 to R4 is formed in a zigzag shape, that is, in a polygonal line shape, and the zigzag shape is arranged to be orthogonal to the arrangement direction. That is, as shown in FIG. 3B, this zigzag shape is formed by a plurality of straight portions 17 arranged in parallel with each other and a connecting portion 18 connecting between adjacent ends of the straight portion 17. ing. The linear portions 17 of the magnetoresistive elements R1 and R4 are arranged orthogonal to the m, and the linear portions 17 of the magnetoresistive elements R2 and R3 are arranged orthogonal to the n.
[0020]
As shown in FIG. 4, the first magnetic detection sensor 14 has four terminals T1 to T4. The terminal T1 is connected between the magnetoresistive elements R1 and R3, and the terminal T2 is connected between the magnetoresistive elements R2 and R4. The terminal T3 is connected between the magnetoresistive elements R1 and R2, and the terminal T4 is connected between the magnetoresistive elements R3 and R4.
[0021]
The operational amplifier 20 is formed on the mounting surface 12a of the first IC chip 12 (see FIG. 4). The inverting input terminal of the operational amplifier 20 is connected to the terminal T3, and the non-inverting input terminal is connected to the terminal T4. The terminals T1 and T2 of the first magnetic detection sensor 14 and the output terminal O1 of the operational amplifier 20 are respectively connected to conductors (not shown) formed on the mounting surface 12a.
[0022]
Then, power is applied to the terminal T1 via the conductor, and the terminal T2 is grounded via the conductor. The output terminal O1 outputs an output voltage ΔV1 via the conductor. When the first magnetic detection sensor 14 detects magnetic fluxes in different directions, the output voltage ΔV1 (see FIG. 7) output from the operational amplifier 20 becomes analog.
[0023]
On the other hand, a second magnetic detection sensor 15 having the same configuration as the first magnetic detection sensor 14 is disposed on a planar mounting surface 13a (a lower surface in FIG. 1) which is one side surface of the second IC chip 13, An operational amplifier 21 having the same configuration as the operational amplifier 20 is formed on the mounting surface 13a (see FIG. 4).
[0024]
The connection relationship between the second magnetic detection sensor 15 and the operational amplifier 21 is the same as the connection relationship between the first magnetic detection sensor 14 and the operational amplifier 20. Therefore, the magnetoresistive elements R5 to R8 and the terminals T5 to T8 in the second magnetic detection sensor 15 are replaced with the magnetoresistive elements R1 to R4 and the terminals T1 to T4 in the first magnetic detection sensor 14, respectively. Is omitted. The operational amplifier 21 has an output terminal O2. That is, the inverting input terminal of the operational amplifier 21 is connected to the terminal T7, and the non-inverting input terminal is connected to the terminal T8.
[0025]
Further, as shown in FIGS. 2 and 3A, in the second magnetic detection sensor 15, one of the magnetoresistance elements R6 and R7 and the other of the magnetoresistance elements R5 and R8 are arranged with respect to a reference line S2. They are arranged at an inclination of 45 °.
[0026]
2 and 3 (a), m 'and n' indicate the arrangement directions of the magnetoresistive elements R6 and R7 and the magnetoresistive elements R5 and R8, respectively, and indicate the central axes of the magnetoresistive elements R5 to R8. ing.
[0027]
The two IC chips 12 and 13 are connected and fixed by a plurality of bumps 16 with the mounting surface 12a and the mounting surface 13a facing each other.
The terminals T5 and T6 of the second magnetic detection sensor 15 and the output terminal O2 of the operational amplifier 21 are connected to conductors (not shown) formed on the mounting surface 12a via the bumps 16 facing the terminals T5 and T6. I have. Power is applied to the terminal T5 through the bump 16 and the conductor, and the terminal T6 is grounded through the bump 16 and the conductor. The output terminal O2 is configured to output an output voltage ΔV2 via the bump 16 and the conductor. When the second magnetic detection sensor 15 detects magnetic fluxes in different directions, the output voltage ΔV2 (see FIG. 7) output from the operational amplifier 21 becomes analog.
[0028]
The magnetic detection surface 14a of the first magnetic detection sensor 14 and the magnetic detection surface 15a of the second magnetic detection sensor 15 are arranged parallel to each other. Since the first IC chip 12 and the second IC chip 13 are connected and fixed by a plurality of bumps 16, the distance between the two magnetic detection surfaces 14a and 15a is 500 μm.
[0029]
When viewed in a plan view as shown in FIG. 3A, the central axes m and n arranged on the detection surface 14a are respectively orthogonal to the central axes n 'and m' arranged on the detection surface 15a. Magnetoresistive elements R1 to R4, R5 to R8 are arranged facing each other.
[0030]
That is, as shown in FIG. 7, the output voltages ΔV1 and ΔV2 are sinusoidal waves having a period of 180 °, and the first magnetic detection sensor 14 and the second magnetic detection sensor 15 are arranged so that their phases are shifted from each other by 180 °. ing. That is, the first magnetic detection sensor 14 and the second magnetic detection sensor 15 are arranged such that, when detecting magnetic fluxes in the same direction, the output values corresponding to the directions of the magnetic fluxes are opposite to each other.
[0031]
Hereinafter, the “magnetic flux Z” in this embodiment refers to a magnetic flux Z that is parallel to the mounting surface 12a.
Since the output value of the first magnetic detection sensor 14 and the output value of the second magnetic detection sensor 15 have opposite characteristics, when both the magnetic detection sensors 14 and 15 are functioning normally, , The sum of which is always constant at a predetermined value. When the total value is constant, the two magnetic detection sensors 14 and 15 are assumed to be functioning normally, and the output value of the first magnetic detection sensor 14 is used as appropriate.
[0032]
The magnetic detection surface 14a corresponds to a first magnetic detection surface, and the magnetic detection surface 15a corresponds to a second magnetic detection surface.
Next, the characteristic operation of the present embodiment will be described.
[0033]
FIG. 6 (a) shows the magnetic flux Z on the same plane as the magnetic detection surface 14a, and FIG. 6 (b) shows the magnetic flux Z on the same plane as the magnetic detection surface 15a. Things.
[0034]
That is, in the positional relationship between the structure 11 and the magnet M shown in FIG. 5, the magnetic flux Z detected by the magnetic detection surface 14a is the magnetic flux Z in the magnetic detection surface 14a indicated by a two-dot chain line in FIG. The magnetic flux Z detected by the magnetic detection surface 15a is the magnetic flux Z in the magnetic detection surface 15a indicated by a two-dot chain line in FIG.
[0035]
Further, in the positional relationship between the conventional structure 103 and the magnet 105 shown in FIG. 10, the magnetic flux 106 detected by the magnetic detection surface 101a of the first magnetic detection sensor 101 is a magnetic flux indicated by a two-dot chain line in FIG. It corresponds to the magnetic flux Z in the detection surface 14a. In the positional relationship between the structure 103 and the magnet 105 according to the related art, the magnetic flux 106 detected by the magnetic detection surface 102a of the second magnetic detection sensor 102 is the magnetic detection surface 102a indicated by a two-dot chain line in FIG. Corresponds to the magnetic flux Z within
[0036]
Accordingly, as shown in FIGS. 6A and 6B, in the structure 11 of the present embodiment, the magnetic flux Z in the two-dot chain line frame of the magnetic detection surface 14a and the two points of the magnetic detection surface 15a There is almost no difference in the direction from the magnetic flux Z in the chain line frame.
[0037]
However, the difference in the direction between the magnetic flux Z in the two-dot chain line frame of the magnetic detection surface 101a and the magnetic flux Z in the two-dot chain line frame of the magnetic detection surface 102a in the conventional structure 103 is smaller than that in the case of the structure 11. It is getting bigger.
[0038]
This is because the difference between the positions of the two magnetic detection surfaces 14a and 15a in the structure 11 of the present embodiment is 500 μm, whereas the difference in the position between the two magnetic detection surfaces 101a and 102a in the structure 103 of the related art is the fourth. This is because it is equal to the length of one side of one magnetic detection sensor 101, that is, several millimeters.
[0039]
That is, in the structure 11 of the present embodiment, the positional deviation between the two magnetic detection surfaces 14a and 15a is set to be one tenth or less of the positional deviation between the two magnetic detection surfaces 101a and 102a in the conventional structure 103. As a result, as compared to the structure 103, the structure 11 has a higher detection accuracy due to the positional shift.
[0040]
Therefore, according to the present embodiment, the following effects can be obtained.
(1) In the present embodiment, the first magnetic detection sensor 14 having the magnetic detection surface 14a and the second magnetic detection sensor having the magnetic detection surface 15a whose output values according to the direction of the magnetic flux Z to be detected have characteristics opposite to each other. 15 was provided. And the 1st magnetic detection sensor 14 and the 2nd magnetic detection sensor 15 were arrange | positioned so that the magnetic detection surface 14a and the magnetic detection surface 15a may face.
[0041]
Therefore, since the two magnetic detection surfaces 14a and 15a of the two magnetic detection sensors 14 and 15 are arranged so as to face each other, when the two magnetic detection surfaces 14a and 15a are arranged so as to be adjacent to each other on a plane, that is, in the conventional art. As compared with the two magnetic detection surfaces 101a and 102a, the displacement between the two magnetic detection surfaces 14a and 15a can be set smaller. Therefore, the two magnetic detection sensors 14 and 15 can increase the detection accuracy when detecting the direction of the magnetic flux Z parallel to the two magnetic detection surfaces 14a and 15a. Further, since the two magnetic detection sensors 14 and 15 are arranged to face each other, a space on the mounting surface 12a is not taken up as compared with the case where the two magnetic detection sensors 14 and 15 are arranged side by side. For this reason, the arrangement space of the two magnetic detection sensors 14 and 15 in the plan view of the structure 11 can be reduced, and as a result, the structure 11 can be downsized.
[0042]
(2) In the present embodiment, the first magnetic detection sensor 14 and the second magnetic detection sensor 15 are arranged so that the magnetic detection surface 14a and the magnetic detection surface 15a are parallel. Therefore, the two magnetic detection surfaces 14a and 15a can be arranged close to each other so as not to be displaced as much as possible, and the detection accuracy can be further improved.
[0043]
(3) In the present embodiment, the first magnetic detection sensor 14 is disposed on the first IC chip 12, the second magnetic detection sensor 15 is disposed on the second IC chip 13, and the two magnetic detection sensors 14, 15 are opposed to each other. Then, the second IC chip 13 was flip-chip mounted on the first IC chip 12. Therefore, the distance between the first magnetic detection sensor 14 and the second magnetic detection sensor 15 can be set based on the height of the bump 16 formed by flip chip mounting.
[0044]
(4) In the present embodiment, the first magnetic detection sensor 14 and the second magnetic detection sensor 15 are arranged such that the phases of their output values are shifted from each other by 180 °. Therefore, while the sum of the output values of the two magnetic detection sensors 14 and 15 is constant at a predetermined value, both the magnetic detection sensors 14 and 15 are assumed to be functioning normally and the first magnetic The output value of the detection sensor 14 can be appropriately used.
(Other embodiments)
The above embodiment may be embodied by being changed to another embodiment as described below.
[0045]
-In the said embodiment, the 1st magnetic detection sensor 14 and the 2nd magnetic detection sensor 15 were arrange | positioned so that the phase of the output value might be mutually shifted by 180 degrees. Not limited to this, the first magnetic detection sensor 14 and the second magnetic detection sensor 15 are arranged so that the phases of the output values coincide with each other, the terminal T3 is connected to the non-inverting input terminal of the operational amplifier 20, and the terminal T4 is connected. It may be connected to the inverting input terminal of the operational amplifier 20. That is, when viewed in a plan view in FIG. 3A, the magnetic axes are arranged such that the central axes m and n arranged on the detection surface 14a coincide with the central axes n 'and m' arranged on the detection surface 15a. The resistance elements R1 to R4 and R5 to R8 may be arranged to face each other. In this case, as a result, the output voltages ΔV1 and ΔV2 output from the operational amplifiers 20 and 21 have opposite characteristics. In this case, the operational amplifier 20 corresponds to an inverting amplifier circuit. Further, instead of changing the connection relationship between the non-inverting input terminal and the inverting input terminal of the operational amplifier 20 at the terminals T3 and T4, the non-inverting input terminal of the operational amplifier 21 at the terminals T7 and T8 of the second magnetic detection sensor 15 is inverted. The connection relationship with the input terminal may be changed. In this case, the operational amplifier 21 corresponds to an inverting amplifier circuit.
[0046]
In the embodiment, the first IC chip 12 and the second IC chip 13 are connected and fixed by the bumps 16. Instead, the first IC chip 12 and the second IC chip 13 may be connected and fixed by solder balls.
[0047]
In the above embodiment, the first IC chip 12 and the second IC chip 13 are flip-chip mounted, so that the two magnetic detection surfaces 14a and 15a of the two magnetic detection sensors 14 and 15 are arranged so as to face each other. . However, the present invention is not limited to this, and any structure may be used for fixing the first IC chip 12 and the second IC chip 13 as long as the two magnetic detection surfaces 14a and 15a are arranged so as to face each other.
[0048]
-In the said embodiment, the 1st and 2nd magnetic detection sensors 14 and 15 were comprised by the magnetic resistance element R1-R4, R5-R8. However, the present invention is not limited thereto, and the first and second magnetic detection sensors 14 and 15 may be configured by a Hall element or a giant magnetoresistive element (GMR).
[0049]
Next, technical ideas that can be grasped from the above embodiment and other embodiments will be additionally described below.
(1) The first magnetic detection sensor and the second magnetic detection sensor are arranged such that the phases of their output values are shifted from each other by 180 °. Arrangement structure of the magnetic sensor described in the paragraph.
[0050]
(B) an inverting amplifier circuit in which the first magnetic detection sensor and the second magnetic detection sensor are arranged so that their output values have the same phase, and the phase of one of the output values is in the opposite phase; The arrangement structure of a magnetic sensor according to any one of claims 1 to 3, wherein:
[0051]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to increase the detection accuracy when detecting the direction of a magnetic flux parallel to both magnetic detection surfaces.
[Brief description of the drawings]
FIG. 1 is a front view of a structure according to an embodiment.
FIG. 2 is a perspective view showing a first IC chip and a second IC chip according to the embodiment.
FIG. 3A is an explanatory diagram showing a positional relationship between a first magnetic detection sensor and a second magnetic detection sensor as viewed from the direction of arrows AA in FIG. 1; (B) is a plan view showing a magnetoresistive element.
FIG. 4 is a circuit diagram showing a connection relationship between a first magnetic detection sensor and an operational amplifier according to the embodiment.
FIG. 5 is an explanatory diagram showing a positional relationship between a magnetic flux of a magnet and a structure according to the embodiment.
FIG. 6A is an explanatory diagram showing a magnetic flux on the same plane as a magnetic detection surface of a first magnetic detection sensor. (B) is an explanatory view showing the magnetic flux on the same plane as the magnetic detection surface of the second magnetic detection sensor.
FIG. 7 is a characteristic diagram showing a relationship between an output voltage on a first magnetic detection sensor side and an output voltage on a second magnetic detection sensor side in the embodiment.
FIG. 8 is a plan view showing a structure according to a conventional technique.
FIG. 9 is a front view showing a structure according to the related art.
FIG. 10 is an explanatory diagram showing a relationship between a magnetic flux of a magnet and a structure according to a conventional technique.
[Explanation of symbols]
12 a first IC chip as a first chip,
13: a second IC chip as a second chip,
14: a first magnetic detection sensor; 14a: a magnetic detection surface as a first magnetic detection surface;
15: a second magnetic detection sensor, 15a: a magnetic detection surface as a second magnetic detection surface,
Z: magnetic flux.

Claims (3)

A first magnetic detection sensor having a first magnetic detection surface and a second magnetic detection sensor having a second magnetic detection surface, wherein output values according to the direction of the magnetic flux to be detected have opposite or same characteristics.
An arrangement structure of a magnetic sensor, wherein the first magnetic detection sensor and the second magnetic detection sensor are arranged so that the first magnetic detection surface and the second magnetic detection surface face each other. The magnetic sensor according to claim 1, wherein the first magnetic detection sensor and the second magnetic detection sensor are arranged such that the first magnetic detection surface and the second magnetic detection surface are parallel. Arrangement structure. The first magnetic detection sensor is provided on a first chip, the second magnetic detection sensor is provided on a second chip, and the second magnetic detection sensor is provided so that the first magnetic detection sensor and the second magnetic detection sensor face each other. The arrangement structure of a magnetic sensor according to claim 1, wherein a chip is flip-chip mounted on the first chip.

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