Magnetic sensors and current sensors

Abstract

The present invention provides a magnetic sensor and a current sensor. The in-phase voltage generated by the magnetic field distribution is suppressed. The magnetic sensor has a first magnetoelectric conversion unit, which includes a magnetoresistive edge Ra, a magnetoresistive edge Rb, a magnetoresistive edge Rc and a magnetoresistive edge Rd formed by connecting a plurality of magnetoresistive elements in series, respectively. The magnetoresistive edges Ra and Rd have the same magnetic sensitivity directions, the magnetoresistive edges Rb and Rc have the same magnetic sensitivity directions and are opposite to the magnetoresistive edges Ra and Rd. The magnetoresistive edges Ra and Rb are connected in series, the magnetoresistive edges Rc and Rd are connected in series and connected in parallel with the magnetoresistive edges Ra and Rb to form a Wheatstone bridge circuit. At least a portion of the first magnetoelectric conversion unit is arranged on an arm included in a conductor, and the width of the first magnetoelectric conversion unit is less than 0.3 times the width of the arm. Thus, the in-phase voltage included in the output voltage can be suppressed.

Description

Technical Field

[0001] The invention relates to a magnetic sensor and a current sensor. Background Art

[0002] A magnetic sensor is known that has a Wheatstone bridge circuit composed of four magnetoresistive edges each including a magnetoresistive element (TMR), and detects magnetic field strength by inputting a driving voltage from a pair of power supply nodes and obtaining a differential voltage from a pair of output nodes (see patent documents 1 and 2). In a magnetic sensor with such a structure, multiple TMRs are connected in series to form each magnetoresistive edge, thereby improving the DC withstand voltage and ESD withstand voltage of the magnetic sensor. However, the chip area (equal to the area of ​​the magnetic sensitive part) becomes wider, that is, the closed loop formed by the four magnetoresistive edges becomes larger, and the induced electromotive force is generated due to more magnetic flux passing through the inside of the closed loop, which not only brings di / dt noise, but also generates an in-phase signal due to the magnetic field distribution on the magnetic sensitive part, which may bring differential amplification noise.

[0003] Patent Document 1: International Publication No. 2015 / 107949

[0004] Patent Document 2: U.S. Patent Application Publication No. 2020 / 0018780 Summary of the invention

[0005] Summary of the Invention

[0006] Solutions to Solve Problems

[0007] In a first embodiment of the present invention, a magnetic sensor is provided, comprising a first magnetoelectric conversion unit, wherein the first magnetoelectric conversion unit includes a first magnetoresistance edge, a second magnetoresistance edge, a third magnetoresistance edge and a fourth magnetoresistance edge formed by connecting a plurality of magnetoresistance elements in series, respectively, the magnetically sensitive directions of the first magnetoresistance edge and the fourth magnetoresistance edge are the same as each other, the magnetically sensitive directions of the second magnetoresistance edge and the third magnetoresistance edge are the same as each other and are opposite to the magnetically sensitive directions of the first magnetoresistance edge and the fourth magnetoresistance edge, the first magnetoresistance edge and the second magnetoresistance edge are connected in series, the third magnetoresistance edge and the fourth magnetoresistance edge are connected in series and are opposite to each other. The first magnetoresistance edge and the second magnetoresistance edge are connected in parallel to form a Wheatstone bridge circuit, and at least a portion of the first magnetoelectric converter is arranged on the first arm included in the conductor, and at least a portion of the multiple magnetoresistance elements forming the first magnetoresistance edge to the fourth magnetoresistance edge are respectively formed in a unit area where the magnetoresistance elements are adjacently arranged along the width direction. The separation distance between the center of gravity of the unit area of ​​the magnetoresistance edge located at the one side closest to the width direction of the first arm and the center of gravity of the unit area of ​​the magnetoresistance edge located at the other side closest to the width direction of the first arm, that is, the width of the first magnetoelectric converter is less than 0.3 times the width of the first arm.

[0008] According to a second aspect of the present invention, there is provided a current sensor including a conductor through which a current to be measured flows and the magnetic sensor according to the first aspect.

[0009] It should be noted that the above summary of the invention does not list all the features of the present invention, and sub-combinations of these feature groups also constitute inventions. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1A The internal structure of the current sensor according to this embodiment is shown in a plan view.

[0011] Figure 1B The internal structure of the current sensor according to this embodiment is shown in a side view.

[0012] Figure 2 The circuit structure of the magnetic sensor (magnetoelectric converter) is shown.

[0013] Figure 3 The structure of the magnetoresistive element is shown in a side view.

[0014] Figure 4A An example of the configuration of a magnetic sensor that detects a horizontal magnetic field is shown.

[0015] Figure 4B Show Figure 4A The circuit structure of the first magnetoelectric converter and the magnetic field sensing direction of the magnetoresistive element.

[0016] Figure 4C Show Figure 4A The circuit structure of the second magnetoelectric converter and the magnetic field sensing direction of the magnetoresistive element.

[0017] Figure 5A An example of the configuration of a magnetic sensor that detects a perpendicular magnetic field is shown.

[0018] Figure 5B Show Figure 5A The circuit structure of the first magnetoelectric converter and the magnetic field sensing direction of the magnetoresistive element.

[0019] Figure 5C Show Figure 5A The circuit structure of the second magnetoelectric converter and the magnetic field sensing direction of the magnetoresistive element.

[0020] Fig. 6A The generation principle of di / dt noise associated with induced electromotive force is shown.

[0021] Figure 6B The principle of suppressing di / dt noise by twisting the wiring is shown.

[0022] Fig. 7A A planar arrangement of a plurality of magnetoresistive elements is shown.

[0023] Figure 7B The three-dimensional arrangement of multiple magnetoresistive elements is shown.

[0024] Fig. 8A The arrangement of the unit regions of the first magnetoelectric converter is shown.

[0025] Figure 8B The arrangement of the unit regions of the second magnetoelectric converter is shown.

[0026] Fig. 9 The magnetic field strength relative to the position on the conductor and the common-phase voltage output from the magneto-electric converter are shown.

[0027] Fig.10 The in-phase voltage output from the magneto-electric converter relative to the ratio of the width of the magneto-electric converter to the width of the conductor is shown.

[0028] Fig.11A The following diagram shows a state of a lead frame forming step in the manufacturing process of the current sensor.

[0029] Fig. 11B The following diagram shows the state of the chip mounting process in the manufacturing flow of the current sensor.

[0030] Fig. 11C FIG. 1 shows a state of a wire bonding process in a manufacturing flow of a current sensor.

[0031] Fig.11D The following diagram shows the state of the molding process in the manufacturing flow of the current sensor.

[0032] Fig. 12A The internal structure of a current sensor according to a modified example is shown in a plan view.

[0033] Fig. 12B The internal structure of a current sensor according to a modified example is shown in a side view.

[0034] Fig.13A The following shows a state of a lead frame forming step in the manufacturing flow of a current sensor according to a modified example.

[0035] Fig. 13B The following shows a state of a magnetic sensor installation step in a manufacturing flow of a current sensor according to a modified example.

[0036] Fig. 13C The following shows a state of a wire bonding process in a manufacturing flow of a current sensor according to a modified example.

[0037] Fig.13D The following shows a state of a molding process in a manufacturing flow of a current sensor according to a modified example.

[0038] Description of symbols

[0039] 9…package, 10…base, 11…main body, 12, 14…protrusion, 15, 16, 17…device terminal, 15a, 16a…terminal portion, 17…device terminal, 17a…terminal portion, 18…insulating member, 24…conductor, 24a, 24e…terminal portion, 24b, 24d…main body portion, 24c…curved portion, 24c1, 24c2…arm, 24c3…connecting portion, 24e…current terminal, 44…signal processing device, 50…magnetic sensor, 50a…first magnetoelectric conversion portion, 50b…second magnetoelectric conversion portion, 51 (51a to 51h)…magnetoresistive element, 51o…fixed layer, 51 p…tunnel layer, 51q…free layer, 51r…cap layer, 51s…electrode rod, 52, 53…electrode sheet, 60…magnetic sensor, 61…substrate, 62…magnetoelectric conversion unit, 63…signal processing device, 100, 110…current sensor, E…unit area (planar area, three-dimensional area), Ea1~Ea4, Eb1~Eb4, Ec1~Ec4, Ed1~Ee4, Ef1~Ef4, Eg1~Eg4, Eh1~Eh4…unit area, GND…ground terminal, Np1, Np2…output terminals, Ra~Rh…magnetoresistance edge, VDD…power supply terminal. DETAILED DESCRIPTION

[0040] The present invention will be described below by way of the embodiments of the invention, but the following embodiments do not limit the invention of the claims. Furthermore, not all combinations of features described in the embodiments are essential to the solution provided by the invention.

[0041] Figure 1A and Figure 1B The internal structure of the current sensor 100 of this embodiment is shown through the package 9 in a top view and a side view. Figure 1B Show about Figure 1A The cross-sectional structure of the current sensor 100 on the reference line BB. Figure 1A Set the vertical direction in the vertical direction. Figure 1A and Figure 1B Set the left and right directions in the horizontal direction to horizontal. Figure 1B The vertical direction in the figure is the height direction. The current sensor 100 is a sensor that measures the current by detecting the magnetic field generated around the conductor 24 due to the flow of the measured current to the conductor 24 using the magnetic sensor 50, and is particularly capable of suppressing di / dt noise caused by induced electromotive force and / or differential amplifier noise associated with the expansion of the magnetic field distribution. The current sensor 100 includes a package 9, a base 10, a plurality of device terminals 17, a conductor 24, a magnetic sensor 50, and a signal processing device 44.

[0042] The package 9 is a member that seals and protects the components of the current sensor 100, except for two device terminals 15 and 16, a plurality of device terminals 17, and each terminal portion of the conductor 24, which are included in the base 10 described later. The package 9 is molded into a flat rectangular parallelepiped by using a sealing resin having excellent insulating properties such as epoxy resin.

[0043] The base 10 is a plate-shaped member that supports the signal processing device 44. The base 10 is formed into a plate shape using, for example, a metal with high thermal conductivity in order to dissipate heat generated by the signal processing device 44. The base 10 includes a main body 11, protrusions 12, 14, and device terminals 15, 16.

[0044] The main body 11 is a portion that supports the signal processing device 44. As an example, the main body 11 has a substantially rectangular shape having a size sufficient to support the signal processing device 44 in a plan view.

[0045] The protrusions 12 and 14 extend from one side (i.e., Figure 1A The right side of Figure 1A The upper end) and the other end (i.e. Figure 1A When the magnetic sensor 50 is arranged around the conductor 24, an insulating member can be fixed between the protrusions 12 and 14, and the magnetic sensor 50 can be arranged on the insulating member.

[0046] The device terminals 15 and 16 are used to output the detection result of the measured current output from the signal processing device 44 to an external device. The device terminals 15 and 16 are connected from the other side (i.e., Figure 1A The left side of Figure 1A The upper end) and the other end (i.e. Figure 1A The device terminals 15 and 16 are bent downward at their ends by a bending process, and then the front ends are bent horizontally, thereby forming terminal portions 15a and 16a at their ends, respectively.

[0047] The base body 10 is sealed in the package 9 so that terminal portions 15 a and 16 a of the device terminals 15 and 16 protrude from the side surfaces of the package 9 .

[0048] The plurality of device terminals 17 are secondary conductors for outputting the detection result of the measured current output from the signal processing device 44 to an external device together with the device terminals 15 and 16. In addition, the plurality of device terminals 17 are used together with the device terminals 15 and 16 to provide power or operation parameters to the signal processing device 44. In the present embodiment, as an example, three device terminals 17 are arranged at equal intervals between the device terminals 15 and 16 of the substrate 10 with their lengths oriented horizontally. The device terminals 17 are formed into a rectangular plate shape using metal, and their ends are bent downward by bending processing like the device terminals 15 and 16, and the front ends are bent horizontally, thereby forming terminal portions 17a at their ends.

[0049] The conductor 24 is a primary conductor that forms a current path for the measured current to flow. In the present embodiment, the conductor 24 has a portion extending from one side on the right side of the package 9 (ie, Figure 1A The current terminal 24a provided on the upper side of the package body 9 passes through the interior of the package body 9 and returns to the right side, and reaches the other side on the right side (ie, Figure 1A The conductor 24 is formed of a metal. The conductor 24 includes current terminals (also referred to as terminal portions) 24a and 24e, main body portions 24b and 24d, and a bent portion 24c.

[0050] The terminal portions 24a and 24e protrude from the right side of the package 9, and their ends are bent downward by a bending process, and the front ends are bent horizontally, thereby forming terminals for inputting current.

[0051] The main body 24b, 24d is a part connecting the terminal 24a, 24e to the bent part 24c. The main body 24b, 24d is formed in a rectangular shape as an example, and the two main body 24b, 24d are connected separately on the right side and the two arms 24c1, 24c2 of the bent part 24c are connected on the left side.

[0052] The curved portion 24c has two arms 24c1 and 24c2 and a connecting portion 24c3 connecting the two arms 24c1 and 24c2. The two arms 24c1 and 24c2 extend toward the same side relative to the connecting portion 24c3. Here, the direction in which the width of the arm 24c1 is extended is also referred to as the width direction (equal to Figure 1A The direction in which the arm 24c1 extends relative to the connecting portion 24c3 is also referred to as the extension direction (equal to the longitudinal direction in FIG. Figure 1AThe two arms 24c1 and 24c2 have a smaller longitudinal width than the main body 24b and 24d. The bending portion 24c bends the connecting portion 24c3 into a roughly circular arc shape, and separates the two arms 24c1 and 24c2 from each other in the width direction and extends in the transverse direction from both ends. It should be noted that the bending portion 24c can be bent into a U-shape. In the bending portion 24c, the measured current is input to one of the two arms 24c1 and 24c2, and the measured current is output from the other arm via the connecting portion 24c3.

[0053] The conductor 24 is sealed in the package 9 with the bent portion 24 c disposed between the protruding portions 12 and 14 of the base 10 and the front ends of the terminal portions 24 a and 24 e protruding from the right side of the package 9 .

[0054] The magnetic sensor 50 is a sensor that detects a magnetic field generated by a measured current flowing through the conductor 24. As an example, the magnetic sensor 50 includes two magnetoelectric converters, namely, a first magnetoelectric converter 50a and a second magnetoelectric converter 50b, each configured to detect a longitudinal magnetic field (an example of a horizontal magnetic field) generated around the conductor 24. The first magnetoelectric converter 50a and the second magnetoelectric converter 50b are respectively arranged on the arms 24c1 and 24c2 of the curved portion 24c of the conductor 24 and are connected in parallel. It should be noted that the magnetic sensor 50 may include only one of the first magnetoelectric converter 50a and the second magnetoelectric converter 50b.

[0055] Figure 2 The circuit structure of the first magnetoelectric conversion unit 50a of the magnetic sensor 50 is shown. The first magnetoelectric conversion unit 50a has four magnetoresistive edges Ra to Rd. Here, the four magnetoresistive edges Ra to Rd form a Wheatstone bridge circuit. That is, the magnetoresistive edge Ra and the magnetoresistive edge Rb are connected in series to form an output terminal Np1 between them, the magnetoresistive edge Rc and the magnetoresistive edge Rd are connected in series to form an output terminal Np2 between them, the magnetoresistive edge Ra and the magnetoresistive edge Rb are connected in parallel with the magnetoresistive edge Rc and the magnetoresistive edge Rd to form a power supply terminal VDD between the magnetoresistive edge Ra and the magnetoresistive edge Rc, and a ground terminal GND is formed between the magnetoresistive edge Rb and the magnetoresistive edge Rd.

[0056] It should be noted that in the current sensor 100 of the present embodiment, the magnetic field sensing direction (ie, magnetic sensitive direction) from the magnetic resistance side Ra to the magnetic resistance side Rd and the width direction ( Figure 1A The magnetic field sensing directions of the magnetic resistance edge Ra and the magnetic resistance edge Rd are the same, and in this example, they are set to Figure 1A The magnetic field sensing directions of the magnetic resistance edge Rb and the magnetic resistance edge Rc are the same, and in this example, they are set to Figure 1AThe magnetic field sensing direction of the magnetic resistance edge Ra and the magnetic resistance edge Rd is the opposite direction of the magnetic field sensing direction of the magnetic resistance edge Rb and the magnetic resistance edge Rc.

[0057] The four magnetoresistive sides Ra to Rd are formed by, for example, connecting a plurality of magnetoresistive elements 51 (51a to 51d) in series. It should be noted that, as the magnetoresistive element, for example, a tunnel magnetoresistive element or a giant magnetoresistive element can be used.

[0058] Figure 3 The structure of the magnetoresistive element 51 (51a to 51d) is shown in a side view. The magnetoresistive element 51 is an element whose magnetic resistance value changes due to the application of a magnetic field, and has a fixed layer 51o, a tunnel layer 51p, a free layer 51q and a cap layer 51r. The fixed layer 51o is a magnetic film whose magnetization direction is fixed. The fixed layer 51o is excited in a manner such that its magnetization is oriented in a one-axis direction within a plane (also called a magnetic sensitive surface) in which the magnetic film extends or in a perpendicular direction perpendicular to the magnetic sensitive surface. The magnetization direction of the fixed layer 51o determines the magnetic field sensing direction of the magnetoresistive element 51. The tunnel layer 51p is, for example, a non-magnetic insulating film with a thickness of several nanometers. The free layer 51q is a magnetic film whose magnetization direction is changed by an external magnetic field. It should be noted that the material of the magnetic film is an alloy containing at least one of Co, Fe, B, Ni, and Si, for example. More specifically, cobalt iron (CoFe), cobalt iron boron (CoFeB), and nickel iron (NiFe) can be used. The fixed layer 51o, the tunnel layer 51p and the free layer 51q are stacked to form a stack. Here, electrons pass through the tunnel layer 51p to move from the fixed layer 51o to the free layer 51q or from the free layer 51q to the fixed layer 51o, so that the current flows in the element along the stacking direction. The cap layer 51r is a component that covers the stack from above, and is an alloy containing at least one of Ta, Ru, Pt, Mn, Ir, Mg, Cu, Fe, Ni, Cr, Fe, Co, and Al, and more specifically, platinum manganese (PtMn) and iridium manganese (IrMn) can be used. It should be noted that the magnetoresistive element 51 is surrounded by an insulator (not shown), such as silicon dioxide (SiO2), silicon nitride (SiN), etc.

[0059] When an external magnetic field is applied to the magnetoresistive element 51, due to the magnetoresistive effect (MR effect), the direction of magnetization of the free layer 51q changes according to the direction and strength of the magnetic field, that is, the direction of magnetization of the free layer 51q changes relative to the direction of magnetization of the fixed layer 51o, thereby changing the magnetoresistance value between the fixed layer 51o and the free layer 51q. In particular, when the direction of magnetization of the free layer 51q is the same as the direction of magnetization of the fixed layer 51o (the magnetizations of the two layers are parallel), the magnetoresistance value becomes small, and when they are opposite (the magnetizations of the two layers are antiparallel), the magnetoresistance value becomes large.

[0060] It should be noted that by connecting a plurality of magnetoresistive elements 51 in series, the DC withstand voltage can be improved. Here, the electrode sheet 52 is connected to the cap layer 51r via the electrode rod 51s, and the electrode sheet 53 is connected to the lower surface of the fixed layer 51o, so that the magnetoresistive element 51 can be connected to other magnetoresistive elements 51 via these electrode sheets 52 and 53. That is, a plurality of magnetoresistive elements 51 can be arranged in a plane. Moreover, by connecting the cap layer 51r of the magnetoresistive element 51 to the fixed layer 51o of other magnetoresistive elements 51 via the electrode rod 51s, a plurality of magnetoresistive elements 51 can be arranged in three dimensions.

[0061] The first magnetoelectric converter 50a is configured with at least a portion (for example, any one of the multiple unit areas Ea1 to Ea4, Eb1 to Eb4, Ec1 to Ec4, and Ed1 to Ed4 included in the magnetoresistive edges Ra to Rd described later) on the arm 24c1. When the measured current flows to the conductor 24 and a magnetic field is generated around the conductor 24, a longitudinal magnetic field is applied to the magnetoresistive edges Ra to Rd (the magnetoresistive elements 51a to 51d included) of the first magnetoelectric converter 50a configured on the arm 24c1 of the conductor 24, and the respective magnetoresistive values ​​change. For example, the magnetoresistive values ​​of the magnetoresistive edges Ra and Rd increase (or decrease), and the magnetoresistive values ​​of the magnetoresistive edges Rb and Rc decrease (or increase), thereby destroying the magnetoresistive balance of the magnetoresistive edges Ra to Rd. Here, a driving voltage is input to the power supply terminal VDD relative to the ground terminal GND, and the magnetic field strength can be detected by detecting the differential voltage output between the output terminals Np1 and Np2.

[0062] The second magnetoelectric converter 50b is configured similarly to the first magnetoelectric converter 50a. The first magnetoelectric converter 50a includes four magnetoresistance edges Re to Rh (see Figure 4C ). Here, the four magnetic resistance sides Re to Rh form a Wheatstone bridge circuit. That is, the magnetic resistance side Re and the magnetic resistance side Rf are connected in series to form an output terminal Np1 between them, the magnetic resistance side Rg and the magnetic resistance side Rh are connected in series to form an output terminal Np2 between them, and the magnetic resistance side Re and the magnetic resistance side Rf are connected in parallel with the magnetic resistance side Rg and the magnetic resistance side Rh to form a power supply terminal VDD between the magnetic resistance side Re and the magnetic resistance side Rg and form a ground terminal GND between the magnetic resistance side Rf and the magnetic resistance side Rh.

[0063] The magnetic field sensing direction (i.e., magnetic sensitive direction) from the magnetic resistance edge Re to the magnetic resistance edge Rh and the width direction ( Figure 1A The magnetic field sensing directions of the magnetoresistive edge Re and the magnetoresistive edge Rh are the same, and in this example, they are set to Figure 1A The magnetic field sensing directions of the magnetic resistance edge Rf and the magnetic resistance edge Rg are the same, and in this example, they are set to Figure 1AThe magnetic field sensing direction of the magnetoresistive edge Re and the magnetoresistive edge Rh is the opposite direction of the magnetic field sensing direction of the magnetoresistive edge Rf and the magnetoresistive edge Rg.

[0064] The four magnetoresistive edges Re to Rh are formed by, for example, connecting a plurality of magnetoresistive elements 51 ( 51 e to 51 h ) in series. It should be noted that, as the magnetoresistive element, for example, a tunnel magnetoresistive element or a giant magnetoresistive element can be used.

[0065] The second magnetoelectric converter 50b is configured with at least a portion (for example, any one of the multiple unit areas Ea1 to Ea4, Eb1 to Eb4, Ec1 to Ec4, Ed1 to Ed4 included in the magneto-resistance edges Re to Rh described later) on the arm 24c2. When the measured current flows to the conductor 24 and a magnetic field is generated around the conductor 24, a longitudinal magnetic field is applied to the magneto-resistance edges Re to Rh (the magneto-resistance elements 51e to 51h included) of the second magnetoelectric converter 50b configured on the arm 24c2 of the conductor 24, and the respective magneto-resistance values ​​change. For example, the magneto-resistance values ​​of the magneto-resistance edges Re and Rh increase (or decrease), and the magneto-resistance values ​​of the magneto-resistance edges Rf and Rg decrease (or increase), thereby destroying the magneto-resistance balance of the magneto-resistance edges Re to Rh. Here, a driving voltage is input to the power supply terminal VDD relative to the ground terminal GND, and the magnetic field strength can be detected by detecting the differential voltage output between the output terminals Np1 and Np2.

[0066] It should be noted that, in the magnetic sensor 50, the second magnetoelectric converter 50b can be connected in parallel to the first magnetoelectric converter 50a. That is, the ground terminals GND of the first magnetoelectric converter 50a and the second magnetoelectric converter 50b can be connected, and the power supply terminals VDD of the first magnetoelectric converter 50a and the second magnetoelectric converter 50b can be connected. Moreover, the first magnetoelectric converter 50a and the second magnetoelectric converter 50b can be constructed independently of each other. The structures of the first magnetoelectric converter 50a and the second magnetoelectric converter 50b of the magnetic sensor 50 will be further described later.

[0067] The first magnetoelectric converter 50 a and the second magnetoelectric converter 50 b of the magnetic sensor 50 are connected to the signal processing device 44 by wire bonding, and output a voltage corresponding to the detected magnetic field intensity to the signal processing device 44 as an output signal.

[0068] The signal processing device 44 processes the output signal of the magnetic sensor 50 and calculates the amount of the measured current flowing through the conductor 24. The signal processing device 44 may have a built-in memory, a sensitivity correction circuit, an offset correction circuit for correcting the offset of the output, an amplifier circuit for amplifying the output signal from the magnetic sensor 50, and a temperature correction circuit for correcting the output according to the temperature. The signal processing device 44 is supported on the main body 11 of the substrate 10 and is connected to the device terminals 15, 16 and three device terminals 17 of the substrate 10 by wire bonding. Thus, the signal processing device 44 outputs the calculation result of the amount of the measured current flowing through the conductor 24 via the device terminals 15, 16, and 17.

[0069] Figure 4A An example of the configuration of the magnetic sensor 50 (the first magnetoelectric converter 50a and the second magnetoelectric converter 50b) is shown. As mentioned above, the first magnetoelectric converter 50a and the second magnetoelectric converter 50b can be respectively configured on the two arms 24c1 and 24c2 of the conductor 24. By calculating the difference in the output signals of the first magnetoelectric converter 50a and the second magnetoelectric converter 50b, the offset caused by the interfering magnetic field can be offset. The magnetic sensor 50 configured in such a position detects a horizontal magnetic field parallel to the upper surface of the conductor 24 (in this case, Figure 1A It should be noted that one of the first magnetoelectric converter 50a and the second magnetoelectric converter 50b may be disposed on the conductor 24 (the two arms 24c1, 24c2 or the connecting portion 24c3, etc.).

[0070] Figure 4B Show Figure 4A The magnetic field sensing directions of the four magnetoresistance edges Ra to Rd (magnetoresistance elements 51a to 51d contained in each) of the first magnetoelectric converter 50a are shown in FIG. The magnetic field sensing directions of the magnetoresistance edges Ra (magnetoresistance element 51a) and the magnetoresistance edges Rd (magnetoresistance element 51d) are the same, and in this example, are set to one direction of a one-axis direction parallel to the upper surface of the conductor 24 (indicated by hollow arrows in the figure). The magnetic field sensing directions of the magnetoresistance edges Rb (magnetoresistance element 51b) and the magnetoresistance edges Rc (magnetoresistance element 51c) are the same, and in this example, are set to another direction of a one-axis direction parallel to the upper surface of the conductor 24 (indicated by black arrows in the figure). The magnetic field sensing directions of the magnetoresistance edges Ra and Rd are opposite to those of the magnetoresistance edges Rb and Rc. Thus, the horizontal magnetic field generated on the upper surface of the arm 24c1 of the conductor 24 can be detected through the first magnetoelectric converter 50a.

[0071] Figure 4C Show Figure 4AThe magnetic field sensing directions of the four magnetoresistance edges Re to Rh (magnetoresistance elements 51e to 51h contained in each) of the second magnetoelectric conversion section 50b are shown in FIG. The magnetic field sensing directions of the magnetoresistance edges Re (magnetoresistance element 51e) and the magnetoresistance edges Rh (magnetoresistance element 51h) are the same, and in this example, are set to one direction of a one-axis direction parallel to the upper surface of the conductor 24 (indicated by hollow arrows in the figure). The magnetic field sensing directions of the magnetoresistance edges Rf (magnetoresistance element 51f) and the magnetoresistance edges Rg (magnetoresistance element 51g) are the same, and in this example, are set to another direction of a one-axis direction parallel to the upper surface of the conductor 24 (indicated by black arrows in the figure). The magnetic field sensing directions of the magnetoresistance edges Re and Rh are opposite to those of the magnetoresistance edges Rf and Rg. Thus, the horizontal magnetic field generated on the upper surface of the arm 24c2 of the conductor 24 can be detected by the second magnetoelectric conversion section 50b.

[0072] Figure 5A Another example of the configuration of the magnetic sensor 50 (the first magnetoelectric converter 50a and the second magnetoelectric converter 50b) is shown. The first magnetoelectric converter 50a is configured in the spacing area surrounded by the bent portion 24c of the conductor 24. In addition, the second magnetoelectric converter 50b can also be configured near one of the two arms 24c1 and 24c2 of the conductor 24 (in this example, on the right side of the arm 24c1). In this way, the interfering magnetic field can be eliminated. The first magnetoelectric converter 50a and the second magnetoelectric converter 50b configured in such a position detect a vertical magnetic field perpendicular to the upper surface of the conductor 24 (in this example, Figure 1A The magnetic field in the height direction).

[0073] It should be noted that the first magnetoelectric converter 50a and the second magnetoelectric converter 50b are attached to the lower surfaces of the protrusions 12 and 14 of the base 10, and an insulating member 18 is provided between the protrusions 12 and 14 (see Figure 5A ), and can be arranged near the conductor 24 by being supported on the insulating member 18. It should be noted that, as an example, the insulating member 18 is formed into a film using a material with high insulation withstand voltage such as a polyimide tape.

[0074] In addition, the bent portion 24c of the conductor 24 can be raised relative to the main body 24b, 24d by providing a step in the height direction through step processing (e.g., half punching, etching, molding, stamping, etc.). As a result, the bottom surface of the bent portion 24c is higher than the upper surface of the insulating member 18 pasted on the bottom surface of the protrusions 12, 14 of the substrate 10, and the primary conductor including the conductor 24 is separated from the insulating member 18 connected to the secondary conductor including the device terminals 15, 16, 17, thereby obtaining a high insulation withstand voltage between the primary conductor and the secondary conductor in the package 9.

[0075] Figure 5B Show Figure 5A The magnetic field sensing directions of the four magnetoresistance edges Ra to Rd (the magnetoresistance elements 51a to 51d contained in each) of the first magnetoelectric conversion section 50a are shown in FIG. The magnetic field sensing directions of the magnetoresistance edge Ra (magnetoresistance element 51a) and the magnetoresistance edge Rd (magnetoresistance element 51d) are the same, and in this example, are set to the upward direction in the vertical direction perpendicular to the upper surface of the conductor 24 (indicated by the hollow arrow in the figure). The magnetic field sensing directions of the magnetoresistance edge Rb (magnetoresistance element 51b) and the magnetoresistance edge Rc (magnetoresistance element 51c) are the same, and in this example, are set to the downward direction in the vertical direction perpendicular to the upper surface of the conductor 24 (indicated by the black arrow in the figure). The magnetic field sensing directions of the magnetoresistance edges Ra and Rd are opposite to those of the magnetoresistance edges Rb and Rc. Thus, the vertical magnetic field generated in the gap area of ​​the conductor 24 can be detected by the first magnetoelectric conversion section 50a.

[0076] Figure 5C Show Figure 5A The magnetic field sensing directions of the four magnetoresistance edges Re to Rh (magnetoresistance elements 51e to 51h contained in each) of the second magnetoelectric conversion section 50b are the same. The magnetic field sensing directions of the magnetoresistance edge Re (magnetoresistance element 51e) and the magnetoresistance edge Rh (magnetoresistance element 51h) are the same, and in this example, they are set to the upward direction in the vertical direction perpendicular to the upper surface of the conductor 24 (indicated by the hollow arrow in the figure). The magnetic field sensing directions of the magnetoresistance edge Rf (magnetoresistance element 51f) and the magnetoresistance edge Rg (magnetoresistance element 51g) are the same, and in this example, they are set to the downward direction in the vertical direction perpendicular to the upper surface of the conductor 24 (indicated by the black arrow in the figure). The magnetic field sensing directions of the magnetoresistance edges Re and Rh are opposite to those of the magnetoresistance edges Rf and Rg. Thus, the second magnetoelectric conversion section 50b can detect the vertical magnetic field generated around the conductor 24.

[0077] Fig. 6A The generation principle of di / dt noise associated with induced electromotive force is shown. A magnetic field (magnetic flux density B) is applied to two wirings of the Wheatstone bridge circuit (i.e., closed loop) constituting the magnetic sensor 50 (the first magnetoelectric converter 50a and the second magnetoelectric converter 50b). When the magnetic flux passes through the space between the two wirings (φ=BS, S is the area between the wirings), an induced electromotive force (V=-dφ / dt=-SdB / dt) is generated in the two wirings in such a way that the increase and decrease of the magnetic flux density (magnetic field intensity B / μ, μ is the magnetic permeability) are offset. In the case of parallel wiring, the leftward induced electromotive force (indicated by the hollow arrow in the figure) applied to the upper wiring and the rightward induced electromotive force (indicated by the black arrow in the figure) applied to the lower wiring by each magnetic flux passing through the wiring are added, and a large induced electromotive force is generated between the two wirings. As a result, the noise associated with the induced electromotive force, the so-called di / dt noise, overlaps with the output signal of the magnetic sensor.

[0078] Figure 6B The principle of suppressing di / dt noise is shown. The two wirings constituting a closed loop are twisted to form a twisted wire, thereby forming multiple local loops of equal area in the closed loop. A magnetic field (magnetic flux density B) is applied to the two wirings, and when the magnetic flux passes through each of the multiple local loops, an induced electromotive force is generated in the wiring constituting each local loop in a manner that offsets the increase and decrease of the magnetic flux density. In the case of a twisted wire, in each local loop, an induced electromotive force to the left is applied to the wiring on the upper side (indicated by a hollow arrow in the figure), and an induced electromotive force to the right is applied to the wiring on the lower side (indicated by a black arrow in the figure). However, in each wiring of the two wirings, the direction of the induced electromotive force changes in each part constituting the local loop, thereby suppressing the induced electromotive force applied to the wiring as a whole. It should be noted that the direction of the induced electromotive force generated in each loop is also referred to as polarity. In particular, when an even number of local loops are formed, the induced electromotive force applied to the wiring as a whole offsets. By providing an even number of partial loops having equal loop areas and opposite polarities in the Wheatstone bridge circuit of the magnetic sensor 50 as described above, di / dt noise can be canceled or strongly suppressed.

[0079] Fig. 7A and Figure 7B The arrangement of the plurality of magnetoresistive elements 51 in the first magnetoelectric conversion section 50a and the second magnetoelectric conversion section 50b is shown respectively, namely, a planar arrangement and a three-dimensional arrangement. The magnetoresistive edges Ra to Rh include one or more unit regions E, and at least a portion of the plurality of magnetoresistive elements 51 forming each magnetoresistive edge is adjacent to (closely attached to) the one or more unit regions E and is arranged inside them. That is, the plurality of magnetoresistive elements 51 forming a magnetoresistive edge (for example, the magnetoresistive edge Ra) are divided into one or more groups and are arranged in the unit regions E, respectively. It should be noted that the unit region E can be a planar region or a three-dimensional region.

[0080] exist Fig. 7AIn the top view shown, 15 magnetoresistive elements 51 are arranged in a 3×5 matrix in a rectangular plane region E. Here, the magnetoresistive element 51 located in the jth column (jth from the left) of the i-th row (i-th from the top) is referred to as the (i,j) magnetoresistive element 51. The upper surfaces of the magnetoresistive elements 51 of (1,1) and (1,2), the magnetoresistive elements 51 of (1,3) and (1,4), the magnetoresistive elements 51 of (1,5) and (2,5), the magnetoresistive elements 51 of (2,4) and (2,3), the magnetoresistive elements 51 of (2,2) and (2,1), the magnetoresistive elements 51 of (3,1) and (3,2), and the magnetoresistive elements 51 of (3,3) and (3,4) are connected via electrode sheets 52. The lower surfaces of the magnetoresistive elements 51 of (1,2) and (1,3), the magnetoresistive elements 51 of (1,4) and (1,5), the magnetoresistive elements 51 of (2,5) and (2,4), the magnetoresistive elements 51 of (2,3) and (2,2), the magnetoresistive elements 51 of (2,1) and (3,1), the magnetoresistive elements 51 of (3,2) and (3,3), and the magnetoresistive elements 51 of (3,4) and (3,5) are connected by the electrode sheet 53. Thus, the 15 magnetoresistive elements 51 are connected in series by reciprocating one and a half turns in the lateral direction and are arranged adjacent to each other in the unit area E. The outermost periphery of the 15 magnetoresistive elements 51 at this time (indicated by a single-dot chain line in the figure) is also the unit area E.

[0081] exist Figure 7B In the side view shown, the composition Fig. 7A The 15 magnetoresistive elements 51 in a row shown in FIG. 1 are arranged in a 3×5 matrix in the rectangular three-dimensional region E. That is, three magnetoresistive elements 51 connected in series in the height direction via the electrode rods 51s are arranged as follows. Fig. 7A As shown in the planar arrangement, the 45 magnetoresistive elements 51 connected in series are arranged in a three-dimensional matrix of 3×5×3 in the cubic unit area E. The outermost periphery of the 45 magnetoresistive elements 51 (indicated by a dashed line in the figure) is also the unit area E.

[0082] Fig. 8A 1 and 2 show the arrangement of the unit regions Ea1 to Ea4, Eb1 to Eb4, Ec1 to Ec4, and Ed1 to Ed4 in the first magnetoelectric converter 50a. Fig. 8A The up and down directions correspond to Figure 4A The up and down direction, Fig. 8A The left and right directions correspond to Figure 4AThe four magnetic resistance edges Ra to Rd each include a plurality of (four as an example) unit regions E, and the plurality of magnetic resistance elements 51 forming each magnetic resistance edge are divided into four groups and arranged in the plurality of unit regions E. It should be noted that the unit regions Ea1 to Ea4 included in each magnetic resistance edge (for example, the magnetic resistance edge Ra) are connected by wiring, and the magnetic resistance elements 51 included in the unit regions Ea1 to Ea4 are all connected in series.

[0083] The unit regions Ea1 to Ea4, Eb1 to Eb4, Ec1 to Ec4, and Ed1 to Ed4 of the magnetic resistance side Ra to the magnetic resistance side Rd are arranged along the width direction of the arm 24c1 ( Fig. 8A Here, the magnetic resistance side Ra to the magnetic resistance side Rd are respectively included in one side and the other side ( Fig. 8A The unit areas Ea1 to Ed1 and the unit areas Ea2 to Ed2 are respectively arranged on the upper and lower sides of the arm 24c1. The unit areas Ea1 to Ed1 are arranged from left to right in the order of Eb1, Ec1, Ed1, and Ea1. The unit areas Ea2 to Ed2 are arranged from left to right in the order opposite to that of the unit areas Ea1 to Ed1, that is, in the order of Ea2, Ed2, Ec2, and Eb2. Thus, the unit areas Ea1 to Ed1 and Ea2 to Ed2 respectively included in the magnetoresistance side Ra to the magnetoresistance side Rd are arranged on the arm 24c1 to be 180 degrees rotationally symmetrical. In this way, the arrangement of the unit areas Ea1 to Ed1 and the unit areas Ea2 to Ed2 of the magnetoresistance sides Ra to Rd is reversed, and the connecting lines of the magnetoresistance elements 51 constituting the magnetoresistance sides Ra to Rd are twisted, thereby reducing the local loop formed by the connecting lines of the magnetoresistance elements 51.

[0084] It should be noted that the unit areas Ea1~Ed1 and Ea2~Ed2 of the magnetic resistance side Ra, the magnetic resistance side Rb, the magnetic resistance side Rc and the magnetic resistance side Rd can be arranged in any order as long as the unit areas Ea1~Ed1 and the unit areas Ea2~Ed2 are arranged in the opposite order to each other.

[0085] The magnetic resistance sides Ra to Rd are respectively included on one side and the other side ( Fig. 8AUnit areas Ea3 to Ed3 and unit areas Ea4 to Ed4 are respectively arranged on the upper and lower sides of the unit areas Ea1 to Ed1 and Ea2 to Ed2. It should be noted that although the unit areas Ea3 to Ed3 and the unit areas Ea4 to Ed4 are set to be arranged on the lower sides of the unit areas Ea1 to Ed1 and the unit areas Ea2 to Ed2, it is not limited to this and can also be arranged at any position such as the upper side, the left side, the right side, or an inclined position. The unit areas Ea3 to Ed3 are arranged from left to right in the order of Eb3, Ec3, Ed3, and Ea3. The unit areas Ea4 to Ed4 are arranged from left to right in the opposite order of the unit areas Ea3 to Ed3, that is, in the order of Ea4, Ed4, Ec4, and Eb4. As a result, the unit areas Ea3 to Ed3 and Ea4 to Ed4 contained in the magnetic resistance edge Ra to the magnetic resistance edge Rd are arranged on the arm 24c1 to be 180 degrees rotationally symmetrical. In this way, the arrangement of the unit areas Ea3 to Ed3 and the unit areas Ea4 to Ed4 of the magnetic resistance sides Ra to Rd is reversed and the connection lines of the magnetic resistance elements 51 constituting the magnetic resistance sides Ra to Rd are twisted, thereby reducing the local loop formed by the connection lines of the magnetic resistance elements 51. It should be noted that the arrangement of the unit areas Ea3 to Ed3 and the unit areas Ea4 to Ed4 only needs to be reversed to each other and does not need to be consistent with the arrangement of the unit areas Ea1 to Ed1 and the unit areas Ea2 to Ed2.

[0086] It should be noted that the unit areas Ea3~Ed3 and Ea4~Ed4 of the magnetic resistance side Ra, the magnetic resistance side Rb, the magnetic resistance side Rc and the magnetic resistance side Rd can be arranged in any order as long as the unit areas Ea3~Ed3 and the unit areas Ea4~Ed4 are arranged in the opposite order to each other.

[0087] Thus, by providing an even number of partial loops with equal loop areas and opposite polarities in the connection line of the magnetoresistive element 51 between the magnetoresistive side Ra and the magnetoresistive side Rd, the di / dt noise can be offset or strongly suppressed.

[0088] Figure 8B 1 and 2 show the arrangement of the unit regions Ee1 to Ee4, Ef1 to Ef4, Eg1 to Eg4, and Eh1 to Eh4 in the second magnetoelectric converter 50b. Figure 8B The up and down directions correspond to Figure 4A The up and down direction, Figure 8B The left and right directions correspond to Figure 4AThe four magnetoresistance edges Re to Rh each include a plurality of (four, for example) unit regions E, and a plurality of magnetoresistance elements 51 forming each magnetoresistance edge are divided into four groups and arranged in the unit regions E. It should be noted that the unit regions Re1 to Re4 included in each magnetoresistance edge (for example, the magnetoresistance edge Re) are connected by wiring, and the magnetoresistance elements 51 included in the unit regions Re1 to Re4 are all connected in series.

[0089] The unit regions Ee1 to Ee4, Ef1 to Ef4, Eg1 to Eg4, and Eh1 to Eh4 from the magnetic resistance side Re to the magnetic resistance side Rh are arranged along the width direction of the arm 24c2 ( Figure 8B Here, the magnetic resistance side Re to the magnetic resistance side Rh are respectively included in one side and the other side (the conducting direction of the current flowing to the conductor 24 (arm 24c2) Figure 8B The unit areas Ee1 to Eh1 and the unit areas Ee2 to Eh2 are respectively arranged on the upper and lower sides of the arm 24c2. The unit areas Ee1 to Eh1 are arranged from left to right in the order of Ef1, Eg1, Eh1, and Ee1. The unit areas Ee2 to Eh2 are arranged from left to right in the order opposite to that of the unit areas Ee1 to Eh1, that is, in the order of Ee2, Eh2, Eg2, and Ef2. Thus, the unit areas Ee1 to Eh1 and Ee2 to Eh2 respectively included in the magnetoresistance edge Re to the magnetoresistance edge Rh are arranged on the arm 24c2 to be 180 degrees rotationally symmetrical. In this way, the arrangement of the unit areas Ee1 to Eh1 and the unit areas Ee2 to Eh2 of the magnetoresistance edges Re to Rh is reversed, and the connecting lines of the magnetoresistance elements 51 constituting the magnetoresistance edges Re to Rh are twisted, thereby reducing the local loop formed by the connecting lines of the magnetoresistance elements 51.

[0090] It should be noted that the unit areas Ee1~Eh1 and Ee2~Eh2 of the magnetoresistance side Re, magnetoresistance side Rf, magnetoresistance side Rg and magnetoresistance side Rh can be arranged in any order as long as the unit areas Ee1~Eh1 and the unit areas Ee2~Eh2 are arranged in reverse order to each other.

[0091] The magnetic resistance sides Re to Rh are respectively included on one side and the other side ( Figure 8BUnit areas Ee3 to Eh3 and unit areas Ee4 to Eh4 are respectively arranged on the upper and lower sides of the arm 24c2. It should be noted that although the unit areas Ee3 to Eh3 and the unit areas Ee4 to Eh4 are set to be arranged on the lower sides of the unit areas Ee3 to Eh3 and the unit areas Ee4 to Eh4, it is not limited to this and can also be arranged at any position such as the upper side, the left side, the right side, or an inclined position. The unit areas Ee3 to Eh3 are arranged from left to right in the order of Ef3, Eg3, Eh3, and Ee3. The unit areas Ee4 to Eh4 are arranged from left to right in the opposite order of the unit areas Ee3 to Eh3, that is, in the order of Ee4, Eh4, Eg4, and Ef4. As a result, the unit areas Ee3 to Eh3 and Ee4 to Eh4 contained in the magnetic resistance side Re to the magnetic resistance side Rh are arranged on the arm 24c2 to be 180 degrees rotationally symmetrical. In this way, the arrangement of the unit areas Ee3 to Eh3 and the unit areas Ee4 to Eh4 of the magnetoresistive edges Re to Rh is reversed and the connecting lines of the magnetoresistive elements 51 constituting the magnetoresistive edges Re to Rh are twisted, thereby reducing the local loop formed by the connecting lines of the magnetoresistive elements 51. It should be noted that the arrangement of the unit areas Ee3 to Eh3 and the unit areas Ee4 to Eh4 only needs to be reversed to each other and does not need to be consistent with the arrangement of the unit areas Ee1 to Eh1 and the unit areas Ee2 to Eh2.

[0092] It should be noted that the respective unit areas Ee3~Eh3 and unit areas Ee4~Eh4 of the magnetic resistance side Re, magnetic resistance side Rf, magnetic resistance side Rg and magnetic resistance side Rh can be arranged in any order as long as the unit areas Ee3~Eh3 and unit areas Ee4~Eh4 are arranged in the opposite order to each other.

[0093] Thus, by providing an even number of local loops with equal loop areas and opposite polarities in the connection line of the magnetoresistive element 51 included in the magnetoresistive edge Re to the magnetoresistive edge Rh, the di / dt noise can be offset or the di / dt can be strongly suppressed. On the other hand, due to the intensity distribution of the magnetic field, differences in magnetic sensitivity are generated between the multiple local loops, and the same-phase voltage can be generated.

[0094] Fig. 9 The magnetic field intensity relative to the position X on the arm 24c1 of the conductor 24 and the common-phase voltage Vcm output from the first magnetoelectric converter 50a are shown. The position X on the arm 24c1 is defined with reference to the center line L of the conductor 24 (see Figure 4A At the center of the first magnetoelectric converter 50a ( Fig. 8AWhen the distance from the center line L to the center line of the spacing is X, the common-phase voltage Vcm of the first magnetoelectric converter 50a is determined as the average of the voltages output from the output terminals Np1 and Np2, respectively. As an example, the width W of the arm 24c1 is 620 μm, and the position X on the arm 24c1 is indicated by the section line. The width w of the first magnetoelectric converter 50a can be defined as the unit area of ​​the magnetic resistance edge Ra~Rd located at the sidemost in the width direction of the arm 24c1 (for example, Fig. 8A The center of gravity (also the center of the plane) of the unit area Eb1 located on the leftmost side in the first row and the unit area ( Fig. 8A The separation distance between the centers of gravity (also the centers of the plane) of the rightmost unit area Ea1 in the first row.

[0095] Here, in Fig. 8A In the diagram, the magnetoresistive elements are neatly arranged in a rectangular shape of 4×4, so the center of the first magnetoelectric conversion unit 50a is defined as the center of the rectangle. On the other hand, the magnetoresistive elements do not have to be neatly arranged in a rectangular shape. In this case, the center of the first magnetoelectric conversion unit 50a can be defined as the center of the quadrilateral with the smallest area among the following quadrilaterals in a top view, wherein the quadrilateral completely surrounds the centroids of the magnetoresistive elements constituting the first magnetoresistive side to the fourth magnetoresistive side, and has two sides parallel to the width direction and two sides perpendicular to the width direction.

[0096] When a unit current flows through the conductor 24, a magnetic field Bx parallel to the width direction is generated on the upper surface of the arm 24c1. The parallel magnetic field Bx has the following intensity distribution in the width direction (equal to the X-axis direction): it is weakest at the interval center line L, increases as it moves away from the interval center line L in the +X direction, is strongest at a position slightly closer to the origin from the center line of the arm 24c1, and decays as it moves further away from the interval center line L in the +X direction. In contrast, when the width w of the first magnetoelectric converter 50a is set to 150 μm, the common-phase voltage Vcm output from the first magnetoelectric converter 50a presents the following distribution: it presents a positive value when the center of the first magnetoelectric converter 50a is located within the gap, becomes 0 at the extreme inner side of the arm 24c1 (nearly 150 μm from the gap center line L), increases in the negative direction as it separates from the gap center line L in the +X direction, becomes extremely small at a position slightly closer to the gap center line L than the maximum position of the parallel magnetic field Bx, and increases in the positive direction as it further separates from the gap center line L in the +X direction. When the width w of the first magnetoelectric converter 50a is set to 100 μm, the common-phase voltage Vcm output from the first magnetoelectric converter 50a presents the same distribution as when the width w = 150 μm with an extremely small absolute value relative to the width w = 150 μm.

[0097] Therefore, the center of the first magnetoelectric converter 50a (magnetoresistive edge Ra to magnetoresistive edge Rd) is preferably located in the width direction at a position closer to the spacing center line L (i.e., arm 24c2) than the maximum position of the parallel magnetic field Bx generated on the arm 24c1 when the current is conducted to the conductor 24. Thus, the parallel magnetic field Bx can be reduced and the in-phase voltage Vcm can be suppressed. Moreover, the center of the first magnetoelectric converter 50a (magnetoresistive edge Ra to magnetoresistive edge Rd) is preferably located in the width direction at a position closer to the arm 24c2 than the center line of the arm 24c1. Thus, the magnetic sensor 50 can be compactly formed by including the first magnetoelectric converter 50a and the second magnetoelectric converter 50b.

[0098] Fig.10 The common-phase voltage Vcm output from the first magnetoelectric converter 50a is shown relative to the ratio of the width w of the first magnetoelectric converter 50a to the width W of the arm 24c1. It should be noted that the center of the first magnetoelectric converter 50a can be arranged at any position on the upper surface of the arm 24c1, and in particular, can be arranged on the center line of the arm 24c1 where the common-phase voltage Vcm becomes the maximum. The common-phase voltage Vcm of the first magnetoelectric converter 50a is the average of the voltages output from the output terminals Np1 and Np2 respectively when a unit current flows to the conductor 24. The common-phase voltage Vcm increases as the ratio w / W increases, and exceeds the specification limit of 0.01mV / A at about 0.3 or more. Therefore, it is preferred that the width w of the first magnetoelectric converter 50a is smaller than the width W of the arm 24c1, and in particular, if it is less than 0.3 times the width W of the arm 24c1, the common-phase voltage Vcm can be suppressed to below the specification limit. It should be noted that the width w of the first magnetoelectric converter 50a may be 0.27 times or less, preferably 0.25 times or less, more preferably 0.23 times or less, and even more preferably 0.20 times or less of the width W of the arm 24c1.

[0099] A method for manufacturing the current sensor 100 will be described below.

[0100] like Fig.11A As shown, first, a metal plate is stamped to form a pattern of a substrate 10, a plurality of device terminals 17, and a conductor 24. The pattern includes the substrate 10, a plurality of device terminals 17, and the conductor 24 by connecting the terminal portions of the substrate 10, the plurality of device terminals 17, and the conductor 24 to the inside of a rectangular frame (not shown).

[0101] Next, the pattern is stepped to provide steps on the device terminals 15 and 16, the plurality of device terminals 17, and the conductor 24 of the base 10. Thus, the inner portion of the pattern rises relative to the frame and the terminals thereof connected to the frame.

[0102] like Fig. 11BAs shown, next, a magnetic sensor 50 (a first magnetoelectric converter 50a and a second magnetoelectric converter 50b) and a signal processing device 44 are provided. Here, the first magnetoelectric converter 50a and the second magnetoelectric converter 50b are respectively arranged on the arms 24c1 and 24c2 of the conductor 24. The signal processing device 44 is arranged on the main body 11 of the substrate 10.

[0103] like Fig. 11C As shown, next, the magnetic sensor 50 (the first magnetoelectric converter 50a and the second magnetoelectric converter 50b) is connected to the signal processing device 44 by wire bonding, and the signal processing device 44 is connected to the device terminals 15, 16, and 17.

[0104] like Fig.11D As shown, the pattern is then molded while leaving the frame, the base 10 connected to the frame, the plurality of device terminals 17, and the terminal portion of the conductor 24. Thus, a package 9 is formed, in which the magnetic sensor 50, the signal processing device 44, and the inner portion of the pattern in which the magnetic sensor 50 and the signal processing device 44 are provided are sealed.

[0105] Finally, the frame exposed from the package 9 is cut from the pattern. Thus, the base 10, the plurality of device terminals 17, and the conductors 24 are separated from each other, and the current sensor 100 is completed.

[0106] Fig. 12A and Fig. 12B The internal structure of the current sensor 110 of the modified example is shown in a top view and a side view through the package 9. Fig. 12B Show Fig. 12A The cross-sectional structure of the current sensor 110 on the reference line BB. Fig. 12A Set the vertical direction in the vertical direction. Fig. 12A and Fig. 12B Set the left and right directions in the horizontal direction to horizontal. Fig. 12B The vertical direction in the figure is the height direction. The current sensor 110 is a sensor that measures the current by detecting the magnetic field generated around the conductor 24 due to the flow of the measured current therein using the magnetic sensor 60, and is particularly capable of suppressing di / dt noise caused by induced electromotive force and / or differential amplifier noise associated with the expansion of magnetic field distribution. The current sensor 110 includes a package 9, a plurality of device terminals 17, a conductor 24, and a magnetic sensor 60.

[0107] The package 9 is a member that seals and protects the components of the current sensor 110 except for the plurality of device terminals 17 and the terminal portions of the conductors 24. The package 9 can be formed using the same material as the package 9 in the current sensor 100 of the first embodiment.

[0108] The plurality of device terminals 17 are secondary conductors for outputting the detection result of the measured current output from the magnetic sensor 60 to an external device. In this example, as an example, eight device terminals 17 are arranged at equal intervals on the left side of the package 9 with their lengths oriented in the horizontal direction. The plurality of device terminals 17 are formed in the same manner as the plurality of device terminals 17 in the current sensor 100 of the first embodiment.

[0109] The conductor 24 is a primary conductor that forms a current path for the measured current to flow. The conductor 24 is formed similarly to the conductor 24 in the current sensor 100 of the first embodiment, and its terminal portions 24a and 24e are arranged on the right side of the package 9, and the two arms 24c1 and 24c2 included in the bent portion 24c are arranged in the center of the package 9.

[0110] The magnetic sensor 60 is a sensor that detects a magnetic field generated by a measured current flowing through the conductor 24. As an example, the magnetic sensor 60 detects a longitudinal magnetic field (an example of a horizontal magnetic field) generated around the conductor 24, and includes a substrate 61, two magnetoelectric converters 62, and a signal processing device 63.

[0111] The substrate 61 is a plate-shaped member that supports the two magnetoelectric converters 62. The substrate 61 is formed using, for example, silicon (Si), and a plurality of wirings (not shown) are laid on the upper surface thereof.

[0112] The two magnetoelectric converters 62 detect the magnetic field generated by the measured current flowing through the conductor 24. The two magnetoelectric converters 62 use the magnetoresistive elements 51 arranged on the substrate 61, and include four magnetoresistive edges connected in a Wheatstone bridge circuit like the first magnetoelectric converter 50a and the second magnetoelectric converter 50b described above. The two magnetoelectric converters 62 are separately arranged on the substrate 61 along the longitudinal direction (the width direction of the arms 24c1 and 24c2), and their respective power supply terminals VDD, ground terminals GND, and output terminals Np1 and Np2 are connected to the signal processing device 63 via wiring on the substrate 61.

[0113] The signal processing device 63 processes the output signals of the two magnetoelectric conversion units 62 and calculates the amount of the measured current flowing through the conductor 24. The signal processing device 63 can be configured in the same manner as the aforementioned signal processing device 44. The signal processing device 63 is formed as a single chip on the substrate 61 together with the two magnetoelectric conversion units 62, and in this example, is arranged in the center of the substrate 61 and connected to the device terminal 17 via the wiring (not shown) laid on the substrate 61 and the wire bonding. As a result, the signal processing device 63 can output the calculation result of the amount of the measured current flowing through the conductor 24 via the device terminal 17.

[0114] The magnetic sensor 60 is arranged on the curved portion 24c of the conductor 24. Thus, the two magnetoelectric converters 62 are respectively arranged on the two arms 24c1 and 24c2 of the curved portion 24c. Thus, a driving voltage can be applied to the two magnetoelectric converters 62 via the device terminal 17, and the amount of the measured current calculated by the signal processing device 63 based on the respective output voltages is output.

[0115] A method for manufacturing the current sensor 110 according to a modified example will be described below.

[0116] like Fig.13A As shown, first, a metal plate is stamped to form a pattern of multiple device terminals 17 and conductors 24. The pattern includes multiple device terminals 17 and conductors 24 by connecting the terminal portions of the multiple device terminals 17 and conductors 24 to the inside of a rectangular frame (not shown).

[0117] Next, the pattern is stepped to provide steps in the device terminals 17 and the conductors 24. Thus, the terminal portions 17a are formed in the device terminals 17, and the terminal portions 24a and 24e are formed in the conductors 24, and the inner portion of the pattern rises relative to these terminal portions.

[0118] like Fig. 13B As shown, next, the magnetic sensor 60 is provided on the bent portion 24c of the conductor 24. Here, two magneto-electric converters 62 are arranged on the arms 24c1 and 24c2 of the conductor 24, respectively.

[0119] like Fig. 13C As shown, next, the magnetic sensor 60 is connected to the plurality of device terminals 17 by wire bonding.

[0120] like Fig.13D As shown, the pattern is molded while retaining the frame and the terminal portions 17a of the plurality of device terminals 17 connected to the frame and the terminal portions 24a, 24e of the conductor 24 to form a package 9. Thus, the package 9 is formed, and the magnetic sensor 60 and the inner portion of the pattern are sealed therein.

[0121] Finally, the frame exposed from the package 9 is cut from the pattern. Thus, the plurality of device terminals 17 and the conductors 24 are separated from each other, and the current sensor 110 is completed.

[0122] It should be noted that the magnetic sensor 60 may not include the signal processing device 63, and the wiring on the substrate 61 connected to the power supply terminal VDD, the ground terminal GND and the output terminals Np1 and Np2 of the two magnetoelectric converters 62 is connected to the device terminal 17 by wire bonding. Thus, a driving voltage can be applied to the two magnetoelectric converters 62 via the device terminal 17 and their respective output voltages can be output.

[0123] The magnetic sensor 50 of the present embodiment has a first magnetoelectric conversion unit 50a, and the first magnetoelectric conversion unit 50a includes a magnetoresistive edge Ra, a magnetoresistive edge Rb, a magnetoresistive edge Rc, and a magnetoresistive edge Rd formed by connecting a plurality of magnetoresistive elements 51 in series, respectively. The magnetoresistive edges Ra and Rd have the same magnetic sensitivity directions, the magnetoresistive edges Rb and Rc have the same magnetic sensitivity directions and are opposite to the magnetoresistive edges Ra and Rd, the magnetoresistive edges Ra and Rb are connected in series, the magnetoresistive edges Rc and Rd are connected in series and are connected in parallel to the magnetoresistive edges Ra and Rb. At least a portion of the multiple magnetoresistive elements 51 forming a Wheatstone bridge circuit are arranged on the arm 24c1 included in the conductor 24, and at least a portion of the magnetoresistive elements 51 forming magnetoresistive edges Ra to Rd are arranged adjacent to each other along the width direction. In the unit area E in which at least a portion of the magnetoresistive elements 51 forming a plurality of magnetoresistive edges 51 respectively form magnetoresistive edges Ra to Rd, the separation distance between the center of gravity of the unit area E of the magnetoresistive edges Ra to Rd located at the one side in the width direction of the arm 24c1 of the conductor 24 and the center of gravity of the unit area E of the magnetoresistive edges Ra to Rd located at the other side, that is, the width w of the first magnetoelectric conversion part 50a, is less than 0.3 times the width W of the arm 24c1. The width w of the first magnetoelectric conversion portion 50a is less than 0.3 of the width of the arm 24c1 of the conductor 24, thereby reducing the imbalance of the respective magnetic susceptibility from the magnetoresistance edge Ra to the magnetoresistance edge Rd in the width direction of the arm 24c1 accompanied by the magnetic field distribution on the arm 24c1, thereby suppressing the in-phase voltage Vcm contained in the output voltage output from the connection point of the magnetoresistance edge Ra and the magnetoresistance edge Rb and the connection point of the magnetoresistance edge Rc and the magnetoresistance edge Rd.

[0124] The current sensor 100 of the present embodiment includes the conductor 24 through which the measured current flows and the magnetic sensor 50. This can suppress di / dt noise caused by the induced electromotive force and / or differential amplification noise associated with the spread of magnetic field distribution.

[0125] It should be noted that the conductor 24 in which the measured current flows includes an arm 24c1, an arm 24c2 separated from the arm 24c1 in the width direction, and a connecting portion 24c3 connecting the arm 24c1 and the arm 24c2, and the arm 24c1 and the arm 24c2 extend to the same side relative to the connecting portion 24c3. Here, the distance from the surface of the conductor 24 having the magnetoelectric conversion portion 50a to the magnetic sensitive surface of the magnetoresistive element 51 (that is, the height of the magnetic sensitive surface of the magnetoresistive element 51 from the surface of the conductor 24) can be greater than 0.16 mm and can be less than 3.5 mm. As a result, the di / dt noise caused by the induced electromotive force and / or the differential amplification noise associated with the expansion of the magnetic field distribution can be suppressed, and the sensitivity of the magnetoresistive element can be balanced.

[0126] The present invention has been described above using the embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is self-evident to those skilled in the art that various changes or improvements can be made to the above embodiments. According to the description of the claims, the technical scope of the present invention is also included in the form of such changes or improvements.

[0127] It should be noted that the execution order of each process such as actions, sequences, steps and stages in the apparatus, system, program and method shown in the claims, the specification and the drawings can be implemented in any order unless it is specifically stated as "before", "before", etc., and the output of the preceding process is not used in the subsequent process. Even if the action flow in the claims, the specification and the drawings is described using "first", "next", etc. for the sake of simplicity, it is not necessary to implement it in this order.

Claims

1. A magnetic sensor, wherein: The magnetic sensor includes a first magnetoelectric conversion unit, the first magnetoelectric conversion unit includes a first magnetoresistance side, a second magnetoresistance side, a third magnetoresistance side and a fourth magnetoresistance side formed by connecting a plurality of magnetoresistance elements in series, the first magnetoresistance side and the fourth magnetoresistance side have the same magnetic sensitivity directions, the second magnetoresistance side and the third magnetoresistance side have the same magnetic sensitivity directions and are opposite to the magnetic sensitivity directions of the first magnetoresistance side and the fourth magnetoresistance side, the first magnetoresistance side and the second magnetoresistance side are connected in series, the third magnetoresistance side and the fourth magnetoresistance side are connected in series and in parallel with the first magnetoresistance side and the second magnetoresistance side to form a Wheatstone bridge circuit, and at least a portion of the first magnetoelectric conversion unit is arranged on a first arm included in a conductor, In a unit area where at least a portion of the multiple magnetoresistive elements that respectively form the first to fourth magnetoresistive edges are adjacently arranged along the width direction, a separation distance between the center of gravity of the unit area of ​​the magnetoresistive edge located at the one side closest to the width direction of the first arm and the center of gravity of the unit area of ​​the magnetoresistive edge located at the other side closest to the width direction of the first arm, that is, the width of the first magnetoelectric conversion portion, is less than 0.3 times the width of the first arm.

2. The magnetic sensor according to claim 1, wherein: The conductor further includes a second arm separated from the first arm in the width direction, and a current is input to one of the first arm and the second arm and the current is output from the other arm. The first magneto-electric conversion portion including the first to fourth magneto-resistance sides is located closer to the second arm side than the center line of the first arm in the width direction.

3. The magnetic sensor according to claim 1, wherein: The conductor further includes a second arm separated from the first arm in the width direction, and a current is input to one of the first arm and the second arm and the current is output from the other arm. The center of the first magneto-electric converter including the first to fourth magneto-resistance sides is located closer to the second arm in the width direction than a maximum position of a magnetic field generated in the first arm when the current is conducted through the conductor.

4. The magnetic sensor according to claim 1, wherein: The respective unit regions of the first magnetic resistance side to the fourth magnetic resistance side are arranged along the width direction.

5. The magnetic sensor according to claim 4, wherein: The first to fourth magnetic resistance sides respectively include a first unit region and a second unit region respectively arranged on one side and the other side of a conduction direction of a current flowing to the conductor, The first unit regions from the first magnetic resistance side to the fourth magnetic resistance side are arranged along the width direction. The second unit regions of each of the first to fourth magnetic resistance sides are arranged in an order opposite to that of the first unit regions along the width direction.

6. The magnetic sensor according to claim 5, wherein: The first magnetic resistance side to the fourth magnetic resistance side further include a third unit area and a fourth unit area respectively arranged on one side and the other side of the conducting direction of the current, The third unit regions from the first magnetic resistance side to the fourth magnetic resistance side are arranged along the width direction. The respective fourth unit regions of the first to fourth magnetic resistance sides are arranged in an order opposite to that of the third unit regions along the width direction.

7. The magnetic sensor according to claim 5, wherein: The first unit region and the second unit region included in each of the first to fourth magnetoresistive sides are arranged on the first arm in 180-degree rotational symmetry.

8. The magnetic sensor according to claim 1, wherein: In the unit area, at least a portion of the magnetoresistive elements are arranged three-dimensionally.

9. The magnetic sensor according to claim 1, wherein: The plurality of magnetoresistive elements are tunnel magnetoresistive elements or giant magnetoresistive elements.

10. The magnetic sensor according to claim 1, wherein The magnetic sensitive direction from the first magnetic resistance edge to the fourth magnetic resistance edge is parallel to the width direction.

11. The magnetic sensor according to claim 2, wherein: The magnetic sensor also has a second magnetoelectric conversion unit, which includes a fifth magnetoresistive edge, a sixth magnetoresistive edge, a seventh magnetoresistive edge and an eighth magnetoresistive edge formed by connecting a plurality of magnetoresistive elements in series, respectively. The magnetic sensitivity directions of the fifth magnetoresistive edge and the eighth magnetoresistive edge are the same as each other, the magnetic sensitivity directions of the sixth magnetoresistive edge and the seventh magnetoresistive edge are the same as each other and are opposite to the magnetic sensitivity directions of the fifth magnetoresistive edge and the eighth magnetoresistive edge. The fifth magnetoresistive edge and the sixth magnetoresistive edge are connected in series, the seventh magnetoresistive edge and the eighth magnetoresistive edge are connected in series and in parallel with the fifth magnetoresistive edge and the sixth magnetoresistive edge to form a Wheatstone bridge circuit. At least a portion of the second magnetoelectric conversion unit is arranged on the second arm and connected in parallel with the first magnetoelectric conversion unit.

12. The magnetic sensor according to claim 11, wherein: Unit regions in which at least a portion of the plurality of magnetoresistive elements forming the fifth magnetoresistive side, the sixth magnetoresistive side, the seventh magnetoresistive side, and the eighth magnetoresistive side are adjacently arranged are arranged along the width direction.

13. The magnetic sensor according to claim 12, wherein: The fifth magnetic resistance side to the eighth magnetic resistance side respectively include a fifth unit area and a sixth unit area respectively arranged on one side and the other side of the conducting direction of the current, The respective fifth unit regions of the fifth magnetic resistance side to the eighth magnetic resistance side are arranged along the width direction, The sixth unit regions of the fifth to eighth magnetic resistance sides are arranged in an order opposite to that of the fifth unit regions along the width direction.

14. The magnetic sensor according to claim 13, wherein: The fifth magnetic resistance side to the eighth magnetic resistance side further include a seventh unit area and an eighth unit area respectively arranged on one side and the other side of the conducting direction of the current, The seventh unit regions of the fifth magnetic resistance side to the eighth magnetic resistance side are arranged along the width direction. The eighth unit regions of the fifth to eighth magnetic resistance sides are arranged in an order opposite to that of the seventh unit region along the width direction.

15. A current sensor comprising: The magnetic sensor according to any one of claims 1 to 14; and The conductor through which the current to be measured flows.

16. The current sensor according to claim 15, wherein: The conductor through which the measured current flows includes a first arm, a second arm separated from the first arm in the width direction, and a connecting portion connecting the first arm and the second arm, and The first arm and the second arm extend toward the same side with respect to the connection portion.

17. The current sensor according to claim 15, wherein: The distance from the surface of the conductor on the side having the magnetoelectric converter to the magnetosensitive surface is greater than 0.16 mm.

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