JP-7854901-B2 - Magnetic sensor device

Inventors

• 太田 憲和
• 望月 慎一郎
• 渡部 司也
• 平林 啓

Assignees

• ＴＤＫ株式会社

Dates

Publication Date

20260507

Application Date

20220902

Priority Date

20210921

Claims (14)

1. A first detection circuit is configured to detect a unidirectional component of the target magnetic field, which is the magnetic field to be detected, and generate a first detection signal. A second detection circuit is configured to detect a component of the target magnetic field in another direction and generate a second detection signal. A third detection circuit, Equipped with a processor, The aforementioned processor, A first generation process that generates a first initial detection value using the first detection signal, A second generation process that generates a second initial detection value using the second detection signal, A first correction process updates the first initial detection value by correcting it using a second correction value generated from the latest second initial detection value, A second correction process updates the second initial detection value by correcting it using a first correction value generated from the latest first initial detection value, A determination process that determines the latest first initial detection value as a first detection value having a corresponding relationship with the component of the target magnetic field parallel to the first reference direction, and determines the latest second initial detection value as a second detection value having a corresponding relationship with the component of the target magnetic field parallel to the second reference direction, It is configured to perform, The processor performs the first correction process and the second correction process alternately, and then performs the determination process . The direction of the component of the target magnetic field detected by the first detection circuit is parallel to the reference plane. The direction of the component of the target magnetic field detected by the second detection circuit is inclined with respect to the reference plane. The third detection circuit is configured to generate a third detection signal by detecting a component of the target magnetic field that is tilted with respect to the reference plane and in a direction different from the direction of the component of the target magnetic field detected by the second detection circuit, The second generation process is a process that generates the second initial detection value and the third initial detection value using the second detection signal and the third detection signal. The second correction process is a process that corrects the second initial detection value and the third initial detection value using the first correction value and updates the second initial detection value and the third initial detection value. The magnetic sensor device is characterized in that the determination process further determines the latest third initial detection value as a third detection value having a correspondence with the component of the target magnetic field perpendicular to the reference plane .
2. The magnetic sensor device according to claim 1, characterized in that the processor performs the first correction process and the second correction process twice each.
3. The magnetic sensor device according to claim 1, characterized in that the processor performs the first second correction process before performing the first first correction process.
4. The first correction value is a value calculated by a calculation that includes multiplying the latest first initial detection value by a first correction coefficient. The magnetic sensor device according to any one of claims 1 to 3, characterized in that the second correction value is a value calculated by a calculation that includes multiplying the latest second initial detection value by a second correction coefficient.
5. Each of the first detection circuit and the second detection circuit is, A first magnetoresistive element and a second magnetoresistive element are connected in series in a first path, which is a path electrically connecting a first node and a second node. The system includes a third magnetoresistive element and a fourth magnetoresistive element connected in series in a second path, which is another path electrically connecting the first node and the second node. The first magnetoresistive element and the fourth magnetoresistive element are connected to the first node. The second magnetoresistive element and the third magnetoresistive element are connected to the second node. Each of the first to fourth magnetoresistive elements includes a magnetization-fixed layer having a first magnetization with a fixed direction, a free layer having a second magnetization whose direction can change according to the target magnetic field, and a gap layer disposed between the magnetization-fixed layer and the free layer. The direction of the first principal component of magnetization in the first magnetoresistive element and the direction of the first principal component of magnetization in the third magnetoresistive element are the same. The direction of the first principal component of magnetization in the second magnetoresistive element and the direction of the first principal component of magnetization in the fourth magnetoresistive element are the same. The direction of the first main component of magnetization in the second magnetoresistive element is opposite to the direction of the first main component of magnetization in the first magnetoresistive element. The direction of the first main component of magnetization in the fourth magnetoresistive element is opposite to the direction of the first main component of magnetization in the third magnetoresistive element. The magnetic sensor device according to claim 1, characterized in that the direction of the second principal component of magnetization in each of the two magnetoresistive elements among the first to fourth magnetoresistive elements is opposite to the direction of the second principal component of magnetization in each of the other two magnetoresistive elements among the first to fourth magnetoresistive elements when the target magnetic field is not applied to the first and second detection circuits.
6. The magnetic sensor device according to claim 5, characterized in that the gap layer is a tunnel barrier layer.
7. The magnetic sensor device according to claim 1, characterized in that neither the first detection circuit nor the second detection circuit is provided with a shield.
8. The magnetic sensor device according to claim 1, characterized in that both the first reference direction and the second reference direction are parallel to the reference plane and orthogonal to each other.
9. The second generation process includes a first process for generating a first value using the second detection signal, a second process for generating a second value using the third detection signal, and a third process for generating a second initial detection value and a third initial detection value using the first value and the second value. The second correction process substantially includes the third process, The magnetic sensor device according to claim 1, characterized in that the processor executes the first processing and the second processing, and then executes the first second correction processing and the first first correction processing in this order.
10. The second generation process includes a first process for generating a first value using the second detection signal, a second process for generating a second value using the third detection signal, and a third process for generating a second initial detection value and a third initial detection value using the first value and the second value. The magnetic sensor device according to claim 1, characterized in that the second correction process includes a fourth process of correcting the first value and the second value using the first correction value to update the first value and the second value; a fifth process of generating the second initial detection value and the third initial detection value using the latest first value and the latest second value; and a sixth process of updating the second initial detection value and the third initial detection value using the second initial detection value and the third initial detection value generated by the fifth process.
11. Each of the first to third detection circuits is: A first magnetoresistive element and a second magnetoresistive element are connected in series in a first path, which is a path electrically connecting a first node and a second node. The system includes a third magnetoresistive element and a fourth magnetoresistive element connected in series in a second path, which is another path electrically connecting the first node and the second node. The first magnetoresistive element and the fourth magnetoresistive element are connected to the first node. The second magnetoresistive element and the third magnetoresistive element are connected to the second node. Each of the first to fourth magnetoresistive elements includes a magnetization-fixed layer having a first magnetization with a fixed direction, a free layer having a second magnetization whose direction can change according to the target magnetic field, and a gap layer disposed between the magnetization-fixed layer and the free layer. The direction of the first principal component of magnetization in the first magnetoresistive element and the direction of the first principal component of magnetization in the third magnetoresistive element are the same. The direction of the first principal component of magnetization in the second magnetoresistive element and the direction of the first principal component of magnetization in the fourth magnetoresistive element are the same. The direction of the first main component of magnetization in the second magnetoresistive element is opposite to the direction of the first main component of magnetization in the first magnetoresistive element. The direction of the first main component of magnetization in the fourth magnetoresistive element is opposite to the direction of the first main component of magnetization in the third magnetoresistive element. The magnetic sensor device according to any one of claims 1, 9, or 10, characterized in that the direction of the second principal component of magnetization in each of the two magnetoresistive elements among the first to fourth magnetoresistive elements is opposite to the direction of the second principal component of magnetization in each of the other two magnetoresistive elements among the first to fourth magnetoresistive elements when the target magnetic field is not applied to the first to third detection circuit.
12. The magnetic sensor device according to claim 11 , characterized in that the gap layer is a tunnel barrier layer.
13. The magnetic sensor device according to any one of claims 1, 9, or 10, characterized in that each of the first to third detection circuits is not provided with a shield.
14. Furthermore, the magnetic sensor device according to any one of claims 1, 9, or 10 is characterized by comprising a first chip including the first detection circuit and a second chip including the second detection circuit and the third detection circuit.

Description

This invention relates to a magnetic sensor device configured to detect multiple magnetic fields in multiple directions that are distinct from each other. In recent years, magnetic sensors using magnetoresistive elements have been utilized in various applications. In systems including magnetic sensors, it is sometimes necessary to detect a magnetic field containing a component perpendicular to the substrate surface using a magnetoresistive element provided on the substrate. In this case, a magnetic field containing a component perpendicular to the substrate surface can be detected by providing a soft magnetic material that converts a magnetic field perpendicular to the substrate surface into a magnetic field parallel to the substrate surface, or by arranging the magnetoresistive element on an inclined surface formed on the substrate. Patent Document 1 discloses a magnetic sensor in which X-axis, Y-axis, and Z-axis sensors are provided on a substrate. The magnetoresistive element constituting the Z-axis sensor is provided on the slanted surface of a protrusion formed in the substrate's underlying film. Japanese Patent Publication No. 2006-261401 This is a perspective view showing a magnetic sensor device according to the first embodiment of the present invention.This is a plan view showing a magnetic sensor device according to the first embodiment of the present invention.This is a functional block diagram showing the configuration of a magnetic sensor device according to the first embodiment of the present invention.This is a circuit diagram showing the circuit configuration of the first detection circuit in the first embodiment of the present invention.This is a circuit diagram showing the circuit configuration of the second detection circuit in the first embodiment of the present invention.This is a circuit diagram showing the circuit configuration of the third detection circuit in the first embodiment of the present invention.This is a plan view showing a part of the first chip in the first embodiment of the present invention.This is a cross-sectional view showing a part of the first chip in the first embodiment of the present invention.This is a plan view showing a part of the second chip in the first embodiment of the present invention.This is a cross-sectional view showing a part of the second chip in the first embodiment of the present invention.This is a side view showing a magnetoresistive element in the first embodiment of the present invention.This is a functional block diagram showing the configuration of the processor in the first embodiment of the present invention.This is a circuit diagram showing the circuit configuration of the first detection circuit in the second embodiment of the present invention.This is a circuit diagram showing the circuit configuration of the second detection circuit in the second embodiment of the present invention.This is a circuit diagram showing the circuit configuration of the third detection circuit in the second embodiment of the present invention.This is a functional block diagram showing the configuration of a magnetic sensor device according to a third embodiment of the present invention.This is a circuit diagram showing the circuit configuration of the first detection circuit in the third embodiment of the present invention.This is a circuit diagram showing the circuit configuration of the second detection circuit in the third embodiment of the present invention.This is a circuit diagram showing the circuit configuration of the third detection circuit in the third embodiment of the present invention.This is a perspective view showing a plurality of magnetoresistive elements and a plurality of yokes in a third embodiment of the present invention.This is a side view showing a plurality of magnetoresistive elements and a plurality of yokes in a third embodiment of the present invention.This is a functional block diagram showing the configuration of the processor in the third embodiment of the present invention. [First Embodiment] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, the configuration of a magnetic sensor device according to the first embodiment of the present invention will be described with reference to Figures 1 to 3. Figure 1 is a perspective view showing the magnetic sensor device 100. Figure 2 is a plan view showing the magnetic sensor device 100. Figure 3 is a functional block diagram showing the configuration of the magnetic sensor device 100. The magnetic sensor device 100 includes a magnetic sensor 1. The magnetic sensor device 100 comprises a first chip 2, a second chip 3, and a support 4 that supports the first and second chips 2 and 3. The magnetic sensor 1 is composed of the first chip 2 and the second chip 3. The first chip 2, the second chip 3, and the support 4 all have a rectangular parallelepiped shape. The support 4 has a reference plane 4a which is the upper su