JP6369527B2 - Sensor unit - Google Patents

Description

  The present invention relates to a sensor unit in which a plurality of sensors are arranged on a base.

  In general, a sensor unit (sensor package) in which a plurality of sensors, an integrated circuit, and the like are provided on a substrate is known (see, for example, Patent Document 1). As such a sensor package, for example, an angle detection sensor that detects a rotational operation of a rotating body such as an axle has been proposed (see, for example, Patent Document 2).

JP 2009-63385 A JP 2006-208255 A

  Recently, there is a strong demand for miniaturization of sensor units and improvement of detection accuracy.

  However, as dimensions are further reduced, stress due to substrate distortion due to environmental temperature changes, heat generation of integrated circuits, and the like is applied to each sensor, and as a result, the output of each sensor may be adversely affected.

  Therefore, it is desired to provide a sensor unit with excellent reliability with little reduction in detection accuracy due to thermal stress or the like.

  The sensor unit as one embodiment of the present invention includes a base including a sensor region and n (n is an integer of 2 or more) sensors. The sensor region has a substantially rectangular planar shape in which the ratio of the dimension in the second direction to the dimension in the first direction is less than n. The n sensors are arranged in a line along the second direction in the sensor region and each have a substantially rectangular planar shape.

  In the sensor unit as one embodiment of the present invention, n sensors have a substantially rectangular planar shape in which a ratio of a dimension in the second direction to a dimension in the first direction is less than n. Arranged in a row in the second direction. For this reason, as compared with the case where n sensors are installed in the sensor region in which the ratio of the dimension in the second direction to the dimension in the first direction is n or more, all of the n sensors are strained on the substrate. Is installed at a relatively small position.

  In the sensor unit as one embodiment of the present invention, each of the n sensors has a first sensor dimension along a first direction and a second sensor dimension along a second direction, It is preferable that the sensor dimension is larger than the second sensor dimension. In that case, the sensor region in which n sensors are arranged is preferable because it has a planar shape closer to a square. Further, it is preferable that n sensors are arranged at substantially equal intervals.

  In the sensor unit as one embodiment of the present invention, all the n sensors may have substantially the same planar shape and substantially the same occupied area.

  In the sensor unit as one embodiment of the present invention, it is preferable that the center position of the base body in the second direction and the center position of the sensor region in the second direction substantially coincide.

  In the sensor unit as one embodiment of the present invention, the n sensors may have substantially the same structure. For example, the n sensors may include magnetoresistive elements.

  In the sensor unit according to an embodiment of the present invention, the base has a first base dimension along the first direction and a second base substantially equal to the first base dimension along the second direction. It may have a substrate size.

  In the sensor unit as one embodiment of the present invention, the base body includes a substrate and a circuit chip stacked on the substrate, and the center position of the substrate may coincide with the center position of the circuit chip.

  According to the sensor unit as one embodiment of the present invention, the stress applied to the n sensors in accordance with the distortion of the substrate is relieved, so that the outputs of the n sensors can be stabilized. Therefore, a highly reliable sensor unit can be realized.

It is a top view showing the whole sensor unit composition as a 1st embodiment of the present invention. It is sectional drawing showing the cross-sectional structure of the sensor unit shown in FIG. It is a circuit diagram of the sensor unit shown in FIG. It is a perspective view showing the structure of the sensor shown in FIG. FIG. 2 is a characteristic diagram schematically illustrating output changes of the sensor illustrated in FIG. 1. FIG. 4 is an exploded perspective view schematically showing a main configuration of the magnetoresistive effect element shown in FIG. 3. It is a top view showing the whole structure of the sensor unit as a 1st modification of 1st Embodiment. It is a top view showing the whole structure of the sensor unit as a 2nd modification of 1st Embodiment. It is a top view showing the whole sensor unit composition as the 3rd modification of a 1st embodiment. It is a top view showing the whole structure of the sensor unit as the 2nd Embodiment of this invention. It is a top view showing the whole sensor unit composition as the 1st modification of a 2nd embodiment. It is a characteristic view showing the characteristic value of the sensor in an example of an experiment. It is a top view showing the whole structure of the sensor unit as a 1st reference example. It is a top view showing the whole structure of the sensor unit as a 2nd reference example. It is a top view showing the whole structure of the sensor unit as a 3rd reference example. It is a top view showing the whole structure of the sensor unit as a 4th reference example. It is a top view showing the whole structure of the sensor unit as a 5th reference example. It is a top view showing the whole structure of the sensor unit as a 6th reference example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The description will be given in the following order.
1. First Embodiment and Modifications An example of a sensor unit in which the center position of a base body and the center position of an IC chip coincide with each other.
2. 2nd Embodiment and its modification The example of the sensor unit which made the center position of a base | substrate differ from the center position of an IC chip.
3. Experimental Example 4 Other variations

<1. First Embodiment>
[Configuration of Sensor Unit 1A]
First, the configuration of the sensor unit 1A as the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a plan view illustrating an overall configuration example of the sensor unit 1A. FIG. 2 shows a cross section of the sensor unit 1A along the first axis J1 shown in FIG. FIG. 3 is a circuit diagram illustrating a schematic configuration of the sensor unit 1A. This sensor unit 1A is used as an angle detection sensor used for detecting the rotation angle of a rotating body, for example.

  The sensor unit 1 </ b> A includes a substrate 10, an integrated circuit (IC) chip 20 stacked on the substrate 10, and a sensor group 30 </ b> A stacked on the IC chip 20. A combination of the substrate 10 and the IC chip 20 is one specific example corresponding to the “base” of the present invention.

  The substrate 10 has a substantially rectangular planar shape including a first side 11 and a second side 12 that are substantially orthogonal to each other. Here, it is preferable that the length of the first side 11 and the length of the second side 12 are substantially equal, and the planar shape of the substrate 10 is substantially square. “Substantially” means that a deviation of a degree caused by, for example, a manufacturing error is allowed. In this specification, the direction in which the first side 11 extends is the X-axis direction, the direction in which the second side 12 extends is the Y-axis direction, and the thickness direction of the substrate 10 (with respect to the paper surface of FIG. 1). A vertical direction is defined as a Z-axis direction, and in Fig. 1, a second axis J2 passing through the center position of the substrate 10, that is, the center position of the substrate 10 in the X-axis direction and the first position passing through the center position in the Y-axis direction. 10J is attached to the intersection with the axis J1.

  The IC chip 20 has a rectangular planar shape and an occupied area smaller than that of the substrate 10. In the sensor unit 1A, the center position 20J of the IC chip 20, that is, the intersection of the center position in the X-axis direction and the center position in the Y-axis direction of the IC chip 20 substantially coincides with the center position 10J of the substrate 10. Yes. Note that the fact that the center position 20J and the center position 10J coincide with each other allows a deviation in a range of about ± 30 μm due to a manufacturing error or the like. The IC chip 20 includes an arithmetic circuit 21 (see FIG. 3).

  The sensor group 30A includes, for example, n sensors (n is an integer of 2 or more) arranged on a first axis J1 passing through the center position 10J (20J) and parallel to the X axis (in this embodiment, three sensors 31). To 33). A sensor region R30A in which the sensors 31 to 33 are arranged on the substrate 10 has a dimension X30A in the X-axis direction and a dimension Y30A in the Y-axis direction, and has an occupied area smaller than that of the IC chip 20. Here, the ratio of the dimension X30A to the dimension Y30A, that is, the aspect ratio is less than n (here, 3). The aspect ratio is preferably closer to 1, and most preferably substantially 1. Further, the first axis J1 passing through the center position 10J of the substrate 10 in the Y-axis direction and the axis J30X passing through the center position of the sensor region R30A in the Y-axis direction substantially coincide with each other.

  The planar shape of each sensor 31 to 33 is rectangular, and has a size smaller than the size of the IC chip 20. The planar shape of each sensor 31 to 33 has a dimension along the Y-axis direction larger than a dimension along the X-axis direction. In particular, all of the sensors 31 to 33 may have substantially the same planar shape and substantially the same occupied area. Each of the sensors 31 to 33 includes, for example, a magnetoresistive (MR) element having substantially the same structure. On the first axis J1, it is desirable that the distance D312 between the sensor 31 and the sensor 32 is substantially equal to the distance D323 between the sensor 32 and the sensor 33. That is, it is desirable that the n sensors are arranged at substantially equal intervals. Therefore, the sensor 31 and the sensor 33 are provided so as to be line-symmetric and point-symmetric with respect to the sensor 32 which is a center position sensor provided at the center position 10J (20J).

  Each of the sensors 31 to 33 has two sensor units that output signals having a phase difference of, for example, 90 ° with respect to a change (rotation) of the external magnetic field that is a detection target. Specifically, as shown in FIGS. 3 and 4, for example, the magnetic sensor unit 41 and the magnetic sensor unit 42 are provided. FIG. 4 is a perspective view illustrating the configuration of the sensors 31 to 33. The magnetic sensor unit 41 detects a change (rotation) of the external magnetic field H and outputs a difference signal S1 to the arithmetic circuit 21 (FIG. 3). Similarly, the magnetic sensor unit 42 detects a change (rotation) of the external magnetic field H and outputs a difference signal S2 to the arithmetic circuit 21 (FIG. 3). However, the phase of the difference signal S1 and the phase of the difference signal S2 are different from each other by 90 °. For example, as shown in FIG. 5, when the difference signal S1 represents a change in output (for example, resistance value) according to sin θ with respect to the rotation angle θ of the external magnetic field H, the difference signal S2 is output (for example, resistance) according to cos θ. Value). FIG. 5 is a characteristic diagram schematically showing a change in output with respect to the rotation angle θ of the external magnetic field H.

  As shown in FIG. 3, the magnetic sensor unit 41 includes a bridge circuit 411 in which four magnetoresistive effect (MR) elements 41 </ b> A to 41 </ b> D are bridge-connected, and a difference detector 412. . Similarly, the magnetic sensor unit 42 includes a bridge circuit 421 in which four MR elements 42 </ b> A to 42 </ b> D are bridge-connected, and a difference detector 422. In the bridge circuit 411, one ends of the MR element 41A and the MR element 41B are connected at the connection point P1, one ends of the MR element 41C and the MR element 41D are connected at the connection point P2, and the other end of the MR element 41A and the MR element are connected. The other end of 41D is connected at connection point P3, and the other end of MR element 41B and the other end of MR element 41C are connected at connection point P4. Here, the connection point P3 is connected to the power source Vcc, and the connection point P4 is grounded. The connection points P1 and P2 are connected to the input side terminals of the difference detector 412 respectively. The difference detector 412 is configured to detect a potential difference between the connection point P1 and the connection point P2 when a voltage is applied between the connection point P3 and the connection point P4 (the voltage drop generated in each of the MR elements 41A and 41D). Difference) is detected and output to the arithmetic circuit 21 as a difference signal S1.

  Similarly, in the bridge circuit 421, one ends of the MR element 42A and the MR element 42B are connected at the connection point P5, one ends of the MR element 42C and the MR element 42D are connected at the connection point P6, and the other end of the MR element 42A. And the other end of the MR element 42D are connected at a connection point P7, and the other end of the MR element 42B and the other end of the MR element 42C are connected at a connection point P8. Here, the connection point P7 is connected to the power source Vcc, and the connection point P8 is grounded. The connection points P5 and P6 are connected to the input side terminals of the difference detector 422, respectively. The difference detector 422 is configured to detect a potential difference between the connection point P5 and the connection point P6 when a voltage is applied between the connection point P7 and the connection point P8 (the voltage drop generated in each of the MR elements 42A and 42D). Difference) is detected and output to the arithmetic circuit 21 as a difference signal S2. In FIG. 3, an arrow with a symbol JSS1 schematically represents the magnetization direction of the magnetization pinned layer SS1 (described later) in each of the MR elements 41A to 41D and 42A to 42D. That is, the resistance values of the MR elements 41A and 41C change (increase or decrease) in the same direction according to the change of the external magnetic field H, and the resistance values of the MR elements 41B and 41D are both external magnetic field H. It shows that the MR elements 41A and 41C change (decrease or increase) in the opposite direction in accordance with the change of. Further, the changes in the resistance values of the MR elements 42A and 42C are 90 ° out of phase with the changes in the resistance values of the MR elements 41A to 41D in accordance with the change in the external magnetic field H. Each of the resistance values of the MR elements 42B and 42D changes in the opposite direction to the MR elements 42A and 42C according to the change of the external magnetic field H. Therefore, for example, when the external magnetic field H rotates in the direction of θ (FIG. 4), the MR elements 41A and 41C increase in resistance and the MR elements 41B and 41D decrease in resistance in a certain angle range. There is a relationship. At that time, the resistance values of the MR elements 42A and 42C change with a delay (or advance) of, for example, 90 ° with respect to the change of the resistance values of the MR elements 41A and 41C, and the resistance values of the MR elements 42B and 42D The change of the resistance values of 41B and 41D is delayed (or advanced) by 90 °.

  Each of the MR elements 41A to 41D and 42A to 42D has a spin valve structure in which a plurality of functional films including a magnetic layer are stacked as shown in FIG. 6, for example. Specifically, a magnetization free layer having a magnetization pinned layer SS1 having a magnetization JSS1 pinned in a certain direction, an intermediate layer SS2 not expressing a specific magnetization direction, and a magnetization JSS3 changing according to the magnetic flux density of the external magnetic field H The layer SS3 is sequentially laminated in the Z-axis direction. The magnetization pinned layer SS1, the intermediate layer SS2, and the magnetization free layer SS3 are all thin films extending in the XY plane. Therefore, the direction of the magnetization JSS3 of the magnetization free layer SS3 can be rotated in the XY plane. FIG. 6 shows a load state in which the external magnetic field H is applied in the direction of the magnetization JSS3. Further, the magnetization pinned layer SS1 in the MR elements 41A and 41C has a magnetization JSS1 pinned in the + X direction, for example, and the magnetization pinned layer SS1 in the MR elements 41B and 41D has a magnetization JSS1 pinned in the −X direction. . Note that each of the magnetization pinned layer SS1, the intermediate layer SS2, and the magnetization free layer SS3 may have a single-layer structure or a multilayer structure including a plurality of layers. Further, the magnetization pinned layer SS1, the intermediate layer SS2, and the magnetization free layer SS3 may be laminated in the reverse order.

  The magnetization pinned layer SS1 is made of a ferromagnetic material such as cobalt (Co), a cobalt iron alloy (CoFe), or a cobalt iron boron alloy (CoFeB). An antiferromagnetic layer (not shown) may be provided on the opposite side of the intermediate layer SS2 so as to be adjacent to the magnetization pinned layer SS1. Such an antiferromagnetic layer is composed of an antiferromagnetic material such as a platinum manganese alloy (PtMn) or an iridium manganese alloy (IrMn). For example, in the magnetic sensor unit 41, the antiferromagnetic layer is in a state where the spin magnetic moment in the + X direction and the spin magnetic moment in the -X direction completely cancel each other, and the direction of the magnetization JSS1 of the adjacent magnetization pinned layer SS1 Is fixed in the + X direction.

  When the spin valve structure functions as a magnetic tunnel junction (MTJ: Magnetic Tunnel Junction) film, the intermediate layer SS2 is a nonmagnetic tunnel barrier layer made of, for example, magnesium oxide (MgO), and is a tunnel based on quantum mechanics. It is thin enough to allow current to pass through. The tunnel barrier layer made of MgO is obtained, for example, by sputtering using a target made of MgO, oxidation treatment of a magnesium (Mg) thin film, or reactive sputtering treatment of sputtering magnesium in an oxygen atmosphere. . Further, in addition to MgO, the intermediate layer SS2 can be configured using oxides or nitrides of aluminum (Al), tantalum (Ta), and hafnium (Hf). The intermediate layer SS2 may be made of, for example, a platinum group element such as ruthenium (Ru) or gold (Au) or a nonmagnetic metal such as copper (Cu). In that case, the spin valve structure functions as a giant magnetoresistive (GMR) film.

  The magnetization free layer SS3 is a soft ferromagnetic layer and is made of, for example, a cobalt iron alloy (CoFe), a nickel iron alloy (NiFe), a cobalt iron boron alloy (CoFeB), or the like.

  The MR elements 41A to 41D constituting the bridge circuit 411 are supplied with the current I1 or the current I2 obtained by dividing the current I10 from the power supply Vcc at the connection point P3. Signals e1 and e2 extracted from the connection points P1 and P2 of the bridge circuit 411 flow into the difference detector 412, respectively. Here, for example, the signal e1 represents an output change that changes according to Acos (+ γ) + B (A and B are constants) when the angle between the magnetization JSS1 and the magnetization JSS3 is γ, and the signal e2 is Acos (γ− 180 °) represents an output change that changes according to + B.

  On the other hand, the MR elements 42A to 42D constituting the bridge circuit 421 are supplied with the current I3 or the current I4 obtained by dividing the current I10 from the power supply Vcc at the connection point P7. Signals e3 and e4 extracted from connection points P5 and P6 of the bridge circuit 421 flow into the difference detector 422, respectively. Here, the signal e3 represents an output change that varies according to Asin (+ γ) + B, and the signal e4 represents an output change that varies according to Asin (γ−180 °) + B. Further, the difference signal S 1 from the difference detector 412 and the difference signal S 2 from the difference detector 422 flow into the arithmetic circuit 21. The arithmetic circuit 21 calculates an angle corresponding to tan γ. Here, since γ corresponds to the rotation angle θ of the external magnetic field H with respect to the sensor group 30, the rotation angle θ is obtained.

[Operation and Action of Sensor Unit 1A]
In the sensor unit 1A of the present embodiment, for example, the magnitude of the rotation angle θ of the external magnetic field H in the XY plane can be detected by the sensor group 30A.

  In this sensor unit 1A, when the external magnetic field H rotates with respect to the sensor group 30A, the change in the magnetic field component in the X-axis direction and the change in the magnetic field component in the Y-axis direction that affect the sensor group 30A are both magnetic sensor units 41 and 42. MR elements 41A to 41D and 42A to 42D. At that time, as outputs from the bridge circuits 411 and 421, for example, differential signals S1 and S2 indicating changes shown in FIG. After that, the arithmetic circuit 21 can determine the rotation angle θ of the external magnetic field H based on the calculation formula Arctan (α sin θ / β cos θ).

[Effect of sensor unit 1A]
In this sensor unit 1A, the detection characteristics with respect to the external magnetic field H in the sensors 31 to 33 constituting the sensor group 30A are improved.

  Specifically, in each of the sensors 31 to 33, even when a temperature change occurs, a decrease in orthogonality is suppressed. The term “orthogonality” as used herein refers to, for example, the amount of deviation from the phase setting value (for example, 90 °) of the output (difference signal S2) from the magnetic sensor unit 42 with respect to the phase of the output (difference signal S1) from the magnetic sensor unit 41 Means. The amount of deviation is preferably closer to zero.

  In the sensor unit 1A of the present embodiment, the decrease in the orthogonality of the sensors 31 to 33 is suppressed because the sensors 31 to 33 are all installed at positions where the distortion of the substrate 10 caused by the temperature change is relatively small. It is thought that it is because. That is, the plurality of sensors 31 to 33 are arranged on the first axis J1 of the substrate 10 having a substantially rectangular planar shape, substantially parallel to the first side 11 and passing through the center position 10J. Therefore, it is considered that the substrate 10 is hardly affected by the distortion of the substrate 10. Note that the cause of the temperature change includes the heat generation of the IC chip 20 in addition to the change in the ambient environment temperature.

  In particular, in the sensor unit 1A of the present embodiment, since the plurality of sensors 31 to 33 are arranged in a direction (here, the X-axis direction) that coincides with the arrangement direction of the plurality of leads 40, each of the sensors 31 to 33 is arranged. Can relieve stress on This is because the distance in the Y-axis direction between the connection points of the plurality of leads 40 and the substrate 10 and the sensors 31 to 33 can be made substantially constant. For this reason, it is possible to avoid a decrease in the orthogonality of the sensors 31 to 33.

  In the sensor unit 1A of the present embodiment, n sensors (sensors 31 to 33) on the substrate 10 are arranged in the sensor region R30A in which the ratio of the dimension X30A to the dimension Y30A is less than n. . That is, each planar shape of the sensors 31 to 33 is a rectangle whose longitudinal direction is a direction orthogonal to the arrangement direction of the sensors 31 to 33 (here, the Y-axis direction). For this reason, the aspect ratio of the sensor region R30A can be made closer to 1, for example, compared to the case where the planar shape of each of the sensors 31 to 33 is a square. Accordingly, the amplitude ratio of each of the sensors 31 to 33 can be improved as compared with the case where n sensors are installed in the sensor region having an aspect ratio of n or more. The amplitude ratio here refers to, for example, the ratio (S2 / S1) of the amplitude of the output (difference signal S2) from the magnetic sensor unit 42 to the amplitude of the output (difference signal S1) from the magnetic sensor unit 41. The amplitude ratio S2 / S1 is preferably as close to 1, and is most preferably substantially 1.

[First Modification of First Embodiment (Modification 1-1)]
FIG. 7 is a plan view illustrating an overall configuration example of a sensor unit 1B as a first modification example (modification example 1-1) in the present embodiment. In the sensor unit 1A as the first embodiment, the case where n = 3, that is, the case where the sensor group 30A includes the three sensors 31 to 33 has been described. On the other hand, the sensor unit 1B of the present modification has a sensor group 50B corresponding to n = 4, that is, the four sensors 51 to 54, instead of the sensor group 30A. Here, the four sensors 51 to 54 are arranged on the first axis J1 and arranged in the sensor region R50B in which the ratio of the dimension X50B to the dimension Y50B is less than 4. By doing in this way, also in this modification, the improvement of the amplitude ratio in the sensors 51-54 is realizable. Note that the first axis J1 passing through the center position 10J of the substrate 10 and the axis J50X passing through the center position of the sensor region R50B in the Y-axis direction substantially coincide with each other.

[Second Modification of First Embodiment (Modification 1-2)]
FIG. 8 is a plan view illustrating an overall configuration example of a sensor unit 1C as a second modification example (modification example 1-2) in the present embodiment. In the sensor unit 1A as the first embodiment, the plurality of sensors 31 to 33 are arranged on the first axis J1 substantially parallel to the arrangement direction (X-axis direction) of the plurality of leads 40. . On the other hand, in the present modification, the plurality of sensors 34, 32,... Are arranged on the second axis J2 that is substantially orthogonal to the arrangement direction (X-axis direction) of the plurality of leads 40 and passes through the center position 10J (20J). 35 were arranged in order. That is, the second axis J2 substantially coincides with the axis J30Y passing through the center position of the sensor region R30C in the X-axis direction. The sensors 34, 32, and 35 constitute a sensor group 30C. Here, the sensor 34 and the sensor 35 may be arranged so as to have line symmetry and point symmetry with respect to the sensor 32. That is, it is desirable that the distance D342 between the sensor 34 and the sensor 32 and the distance D325 between the sensor 32 and the sensor 35 are substantially equal. The sensor group 30C formed by the sensors 34, 32, and 35 occupies a sensor region R30C in which the ratio of the dimension Y30C in the longitudinal direction to the dimension X30C in the lateral direction is less than 3. Even when the sensors 34, 32, and 35 are arranged in this manner, the amplitude ratio of the sensors 34, 32, and 35 can be improved.

[Third Modification of First Embodiment (Modification 1-3)]
FIG. 9 is a plan view illustrating an overall configuration example of a sensor unit 1D as a third modification example (modification example 1-3) in the present embodiment. In the sensor unit 1C as the second modification of the first embodiment, the case where n = 3, that is, the case where the sensor group 30C includes the three sensors 31 to 33 has been described. On the other hand, the sensor unit 1D of this modification has a sensor group 50D corresponding to n = 4, that is, composed of four sensors 55 to 58, instead of the sensor group 30C. Here, the four sensors 55 to 58 are arranged in the sensor region R50D in which the ratio of the dimension Y50D to the dimension X50D is less than 4. By doing in this way, also in this modification, the improvement of the amplitude ratio in the sensors 55-58 can be aimed at. Note that an axis J50Y passing through the center position of the sensor region R50D in the X-axis direction substantially coincides with the second axis J2.

<2. Second Embodiment>
[Configuration of Sensor Unit 2A]
FIG. 10 is a plan view illustrating an example of the overall configuration of a sensor unit 2A as a second embodiment of the present invention. In the sensor units 1A to 1D of the first embodiment, the first axis J1 or the second axis J2 passing through the center position 10J of the substrate 10 and the axes J30X, J50X passing through the centers of the sensor regions R30A, R50B or The axes J30Y and J50Y passing through the centers of the sensor regions R30C and R50D are substantially matched. On the other hand, in the sensor unit 2A of the present embodiment, the sensor group 30E having the sensors 31 to 33 arranged on the axis J30X that is parallel to the first axis J1 but at a position different from the first axis J1. I prepared.

  In the sensor unit 2A of the present embodiment, the three sensors 31 to 33 in the sensor group 30E are arranged in the sensor region R30E in which the ratio of the dimension X30E to the dimension Y30E is less than 3. For this reason, also in the sensor unit 2A, the aspect ratio of the sensor region R30E can be made closer to 1, for example, compared to the case where the planar shape of each of the sensors 31 to 33 is a square. Accordingly, the amplitude ratio in each of the sensors 31 to 33 can be improved.

[Modification of Second Embodiment (Modification 2-1)]
FIG. 11 is a plan view illustrating an overall configuration example of a sensor unit 2B as a first modification example (modification example 2-1) in the present embodiment. This modification includes a sensor group 30F having sensors 34, 32, and 35 arranged in order on an axis J30Y that is parallel to the second axis J2 but at a position different from the second axis J2. Except for this point, the rest has the same configuration as the sensor unit 2A. That is, in the sensor unit 2B, the three sensors 34, 32, and 35 in the sensor group 30F are arranged in the sensor region R30F in which the ratio of the dimension X30F to the dimension Y30F is less than 3. Even when the sensors 34, 32, and 35 are arranged in this manner, an improvement in the amplitude ratio of the sensors 34, 32, and 35 can be realized.

<3. Experimental example>
Samples of each of the sensor units 1A to 1D, 2A, and 2B mentioned as the first and second embodiments and the modifications thereof were produced, and the amplitude ratio (%) and orthogonality (deg) in each were measured. . Here, the experimental example 1A corresponds to the sensor unit 1A of FIG. 1, the experimental example 1B corresponds to the sensor unit 1B of FIG. 7, the experimental example 1C corresponds to the sensor unit 1C of FIG. 9 corresponds to the sensor unit 1A of FIG. 10, the experimental example 2A corresponds to the sensor unit 2A of FIG. 10, and the experimental example 2B corresponds to the sensor unit 2B of FIG. In these experimental examples 1A to 1D, 2A, and 2B, the planar shape of the substrate 10 was a square of 5.0 mm square, and the planar shape of the IC chip was a square of 3.5 mm square. In Experimental Examples 1A, 1C, 2A, and 2B, the sensor regions R30A, R30C, R30E, and R30F are all rectangular 1.6 mm × 0.6 mm, and the planar shapes of the sensors 31 to 35 are all 0.4 mm ×. The rectangle was 0.6 mm. In Experimental Examples 1B and 1D, the sensor regions R50B and R50D are both rectangular with a size of 2.2 mm × 0.6 mm, and the planar shapes of the sensors 51 to 58 are both rectangular with a size of 0.4 mm × 0.6 mm.

  Experimental example 3A corresponds to the sensor unit 3A as the first reference example shown in FIG. The sensor unit 3A has the same configuration as the sensor unit 1A (FIG. 1) except that the sensor unit 3A includes a sensor group 130A having sensors 131 to 133 instead of the sensor group 30A. Similarly, Experimental Example 3B corresponds to the sensor unit 3B as the second reference example shown in FIG. The sensor unit 3B has the same configuration as the sensor unit 1B (FIG. 7) except that the sensor unit 3B includes a sensor group 150B having sensors 151 to 154 instead of the sensor group 50B. Experimental example 3C corresponds to sensor unit 3C as the third reference example shown in FIG. The sensor unit 3C has the same configuration as the sensor unit 1C (FIG. 8) except that a sensor group 130C having sensors 132, 134, and 135 is provided instead of the sensor group 30C. Experimental example 3D corresponds to sensor unit 3D as the fourth reference example shown in FIG. The sensor unit 3D has the same configuration as the sensor unit 1D (FIG. 9) except that the sensor unit 3D includes a sensor group 150D having sensors 155 to 158 instead of the sensor group 50D. Experimental example 4A corresponds to sensor unit 4A as the fifth reference example shown in FIG. The sensor unit 4A has the same configuration as the sensor unit 2A (FIG. 10) except that the sensor unit 4A includes a sensor group 130E having sensors 131 to 133 instead of the sensor group 30E. Experimental example 4B corresponds to sensor unit 4B as the sixth reference example shown in FIG. The sensor unit 4B has the same configuration as the sensor unit 2B (FIG. 11) except that the sensor unit 4B includes a sensor group 130F having sensors 132, 134, and 135 instead of the sensor group 30F. In Experimental Examples 3A, 3C, 4A, and 4B, the sensor regions R130A, R130C, R130E, and R130F are all rectangular 1.6 mm × 0.4 mm, and the planar shapes of the sensors 131 to 135 are all 0.4 mm ×. The square was 0.4 mm. In Experimental Examples 3B and 3D, the sensor regions R150B and R150D are both rectangular with a size of 2.2 mm × 0.4 mm, and the planar shapes of the sensors 151 to 158 are all squares with a size of 0.4 mm × 0.4 mm.

  FIG. 12 shows the orthogonality and the difference between the amplitude ratio after heating the substrate and the amplitude ratio before heating the substrate (hereinafter simply referred to as the difference in amplitude ratio) for each sample. The amplitude ratio after heating the substrate here refers to the amplitude ratio measured immediately after holding the substrate 10 at 120 ° C. for 24 hours. The amplitude ratio before heating the substrate is the amplitude ratio measured at room temperature (23 ° C.). The difference in amplitude ratio is preferably closer to 0, and most preferably substantially 0. In FIG. 12, the horizontal axis indicates orthogonality [deg], and the vertical axis indicates amplitude ratio difference [%]. In FIG. 12, symbols PL1A to PL1D, PL2A, PL2B, PL3A to PL3D, PL4A, and PL4B are attached to plots corresponding to Experimental Examples 1A to 1D, 2A, 2B, 3A to 3D, 4A, and 4B, respectively. . In FIG. 12, the experimental example 1A (FIG. 1) is the sensor 33, the experimental example 1B (FIG. 7) is the sensor 54, the experimental example 1C (FIG. 8) is the sensor 35, and the experimental example 1D (FIG. 9) is In the sensor 58, the experimental example 2A (FIG. 10) shows data corresponding to the sensor 33, and the experimental example 2B (FIG. 11) shows data corresponding to the sensor 35, respectively. Further, in FIG. 12, Experimental Example 3A (FIG. 13) is the sensor 133, Experimental Example 3B (FIG. 14) is the sensor 154, Experimental Example 3C (FIG. 15) is the sensor 135, and Experimental Example 3D (FIG. 16) is In the sensor 158, the experimental example 4A (FIG. 17) shows data corresponding to the sensor 133, and the experimental example 4B (FIG. 18) shows data corresponding to the sensor 135.

  As shown in FIG. 12, in Experimental Examples 1A to 1D, 2A, and 2B (plots PL1A to PL1D, PL2A, and PL2B) of the present invention, Experimental Examples 3A to 3D, 4A, and 4B (Plots PL3A to PL3D as reference examples) , PL4A, PL4B), an improvement in the amplitude ratio was observed.

<4. Other variations>
While the present invention has been described with reference to some embodiments and modifications, the present invention is not limited to these embodiments and the like, and various modifications are possible. For example, in the above-described embodiment, the example in which three or four sensors are arranged in the X-axis direction or the Y-axis direction has been described. However, in the present invention, the number of sensors is not limited to this. Any number of two or more can be selected. Moreover, the shape and dimension of each sensor mounted on one sensor unit are not limited to the same case.

  Moreover, in the said embodiment etc., although the sensor unit used as an angle detection sensor used for the detection of the rotation angle of a rotary body was demonstrated, the use of the sensor unit of this invention is not limited to it. For example, the present invention can be applied to an electronic compass that detects geomagnetism. The sensor may include a detection element other than the magnetoresistive effect element, such as a Hall element.

  The present invention is particularly useful when a magnetic tunnel junction element (TMR element) having an MTJ film is employed as the magnetoresistive element, rather than when a GMR element having a GMR film is employed. This is because the TMR element is generally more sensitive than the GMR element, and thus is easily affected by the stress applied to the sensor (an increase in error is likely to occur).

  1A to 1D, 2A, 2B ... sensor unit, 10 ... substrate, 10J ... center position, 11 ... first side, 12 ... second side, 20 ... IC chip, 20J ... center position, 21 ... arithmetic circuit, 30 ... Sensor group, 31-33, 51-58 ... Sensor, 41, 42 ... Magnetic sensor unit, 411, 421 ... Bridge circuit, 412, 422 ... Difference detector, 41A-41D, 42A-42D ... MR element, 40 ... Lead, J1 ... first axis, J2 ... second axis.

Claims (12)

A substrate,
A ratio of the second dimension along the second direction to the first dimension along the first direction that is stacked on the substrate is less than n (n is an integer greater than or equal to 2) and is substantially rectangular. A circuit chip including a sensor region having a planar shape;
A sensor unit comprising: n sensors arranged in a line along the second direction in the sensor region and each having a substantially rectangular planar shape. The sensor unit according to claim 1, wherein a ratio of the second dimension to the first dimension is substantially 1. A plurality of leads each having one end provided on the substrate and arranged in the first direction or the second direction, or arranged in both the first direction and the second direction; The sensor unit according to claim 1 or 2. The sensor unit according to claim 3, wherein the plurality of leads are arranged along the first direction. Each of the n sensors has a first sensor dimension along the first direction and a second sensor dimension along the second direction;
The sensor unit according to any one of claims 1 to 4, wherein the first sensor dimension is larger than the second sensor dimension. The sensor unit according to any one of claims 1 to 5, wherein the n sensors are arranged at substantially equal intervals. The sensor unit according to claim 1, wherein all of the n sensors have substantially the same planar shape and substantially the same occupied area. The sensor according to claim 1, wherein a center position of the substrate in the second direction substantially coincides with a center position of the sensor region in the second direction. unit. The sensor unit according to any one of claims 1 to 8, wherein all the n sensors have substantially the same structure. The sensor unit according to claim 1, wherein the n sensors include a magnetoresistive effect element. The substrate, according to claim 1 having a first substrate dimensions along said first direction, along said second direction, and said first substrate dimensions substantially equal to the second substrate dimensions The sensor unit according to claim 10. The sensor unit of the center position before Symbol substrate according to any one of claims 1 to 11, which coincides with the center position of the circuit chip.

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