Current sensor

Abstract

To suppress migration in an electrode pad.SOLUTION: A magnetic sensor 60 comprises: a substrate 61; a plurality of magnetoresistive elements 51 arranged on the substrate, wherein a part of the plurality of magnetoresistive elements is incorporated onto a Wheatstone bridge circuit to form a magnetoelectric conversion part 62a, another part thereof is incorporated onto the Wheatstone bridge circuit to form a magnetoelectric conversion part 62b; and a plurality of electrode pads 63#1 to 63#6 arranged on the substrate, and include first and second electrode pads to be respectively connected to a driving terminal VDD and a ground terminal GND of the magnetoelectric conversion parts 62a, 62b, third and fourth electrode pads to be respectively connected to two output terminals Npa1, Npa2 of the magnetoelectric conversion part 62a, and fifth and sixth electrode pads to be respectively connected to two output terminals Npb1, Npb2 of the magnetoelectric conversion part 62b, wherein at least one electrode pad of the third to sixth electrode pads is arranged between the first and second electrode pads.SELECTED DRAWING: Figure 2A

Description

[Technical field]

[0001] The present invention relates to a current sensor. [Background technology]

[0002] A magnetic sensor is equipped with a Wheatstone bridge circuit composed of four resistance arms each including a magnetoresistance element (TMR), and detects the magnetic field strength by inputting a drive voltage from a pair of power supply terminals and acquiring a differential voltage from a pair of output terminals. A current sensor is also known that detects the amount of current by measuring the magnetic field strength around a conductor through which a current to be measured flows using the magnetic sensor (see Patent Documents 1 and 2). The current sensor is equipped with a substrate that supports the magnetic sensor, and inputs a drive voltage to the power supply terminals of the magnetic sensor via a plurality of electrode pads provided on the substrate, and outputs a differential voltage from the output terminals. Here, if the current sensor is used in a humid state, the application of a voltage between the electrode pads may cause migration of the electrode pads, resulting in a decrease in detection sensitivity. Therefore, in Patent Document 3, migration is suppressed by forming a multi-layered electrode pad using silver containing either an oxygen compound, a nitrogen compound, or an oxygen-nitrogen compound. However, since a special material that is not usually used as an electrode material is used, there is a concern that this may lead to process constraints and increased costs. Patent Document 1: International Publication No. 2015 / 107949 Patent Document 2: U.S. Patent Application Publication No. 2020 / 0018780 Patent Document 3: JP 2005-033197 A Summary of the Invention [Means for solving the problem]

[0003] In a first aspect of the present invention, there is provided a magnetic sensor comprising: a substrate; a plurality of magnetic resistance elements arranged on the substrate, some of the plurality of magnetic resistance elements being assembled in a Wheatstone bridge circuit to form a first sensor, and another portion of the plurality of magnetic resistance elements being assembled in a Wheatstone bridge circuit to form a second sensor; and a plurality of electrode pads arranged on the substrate, the plurality of electrode pads including a first electrode pad connected to drive terminals of the first sensor and the second sensor, a second electrode pad connected to ground terminals of the first sensor and the second sensor, a third electrode pad and a fourth electrode pad connected to two output terminals of the first sensor, respectively, and a fifth electrode pad and a sixth electrode pad connected to two output terminals of the second sensor, respectively, and at least one of the third electrode pad to the sixth electrode pad is disposed between the first electrode pad and the second electrode pad in a first direction in which the first electrode pad and the second electrode pad are spaced apart from each other.

[0004] In a second aspect of the present invention, there is provided a current sensor comprising a conductor through which a current to be measured flows, a magnetic sensor of the first aspect arranged on the conductor, and a plurality of output terminals connected respectively to the first electrode pad to the sixth electrode pad of the magnetic sensor.

[0005] In a third aspect of the present invention, there is provided a magnetic sensor comprising: a substrate; a plurality of magnetic resistance elements arranged on the substrate, where some of the plurality of magnetic resistance elements are assembled in a Wheatstone bridge circuit to form a first sensor, and another portion of the plurality of magnetic resistance elements are assembled in a Wheatstone bridge circuit to form a second sensor; and a plurality of dummy pads arranged on the substrate, where the plurality of dummy pads include a first dummy pad connected to drive terminals of the first sensor and the second sensor, a second dummy pad connected to ground terminals of the first sensor and the second sensor, a third dummy pad and a fourth dummy pad connected to two output terminals of the first sensor, respectively, and a fifth dummy pad and a sixth dummy pad connected to two output terminals of the second sensor, respectively, and at least one of the third dummy pad to the sixth dummy pad is arranged between the first dummy pad and the second dummy pad in a first direction in which the first dummy pad and the second dummy pad are separated from each other.

[0006] In a fourth aspect of the present invention, there is provided a current sensor comprising a conductor through which a current to be measured flows, a magnetic sensor of the third aspect arranged on the conductor, and a plurality of output terminals connected respectively to the first dummy pad to the sixth dummy pad of the magnetic sensor.

[0007] The above summary of the invention does not list all of the features of the present invention. Also, subcombinations of these features may also be inventions. [Brief description of the drawings]

[0008] [Figure 1A] 1 shows an internal configuration of a current sensor according to the present embodiment as viewed from above. [Figure 1B] 1 shows an internal configuration of a current sensor according to the present embodiment as viewed from the side. [Figure 2A] 1 shows an example of the arrangement and board layout of a magnetic sensor for detecting a horizontal magnetic field. [Figure 2B]2 shows the configuration of a magnetoresistive element in side view. [Diagram 3] 2 shows the circuit configuration of a magnetic sensor (first and second magnetoelectric conversion units) and the magnetic field detection direction of a magnetoresistance element. [Figure 4A] Examples of combinations of connections between electrode pads and six terminals of a magnetic sensor (Comparative Example, Samples 1 and 2) are shown. [Figure 4B] Examples of combinations of connections between electrode pads and six terminals of a magnetic sensor (samples 3 to 5) are shown. [Diagram 5] 13 shows an example of wiring layout in sample 5, which is a combination of connections between electrode pads and six terminals of a magnetic sensor. [Figure 6] 13 shows another example of wiring layout in sample 5, which is a combination of connections between electrode pads and six terminals of a magnetic sensor. [Figure 7A] 1 shows a state of a lead frame forming step in the manufacturing flow of the current sensor. [Figure 7B] 13 shows a state of a magnetic sensor installation process in the manufacturing flow of the current sensor. [Figure 7C] 1 shows a state of a wire bonding process in the manufacturing flow of the current sensor. [Figure 7D] 1 shows a state of a molding process in the manufacturing flow of the current sensor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0010] 1A and 1B show the internal structure of a current sensor 110 according to this embodiment in a top view and a side view, respectively, with a package 9 seen through. Here, FIG. 1B shows a cross-sectional structure of the current sensor 110 with respect to a reference line BB in FIG. 1A. The up-down direction in FIG. 1A is the vertical direction, the left-right direction in FIGS. 1A and 1B is the horizontal direction, and the up-down direction in FIG. 1B is the height direction. The current sensor 110 is a sensor that measures the amount of current by using a magnetic sensor 60 to detect a magnetic field generated around a conductor 24 when a current to be measured flows through the conductor 24, and in particular, the multiple electrode pads 63 of the magnetic sensor 60. #1 ~63 #6 and a number of dummy pads 64 #1 ~64 #6 The current sensor 110 includes a package 9, a plurality of device terminals 17, a conductor 24, and a magnetic sensor 60.

[0011] The package 9 is a member that seals and protects each component of the current sensor 110, except for the multiple device terminals 17 and the respective terminal portions of the conductor 24. The package 9 is formed into a flat rectangular parallelepiped by molding using a sealing resin with excellent insulating properties, such as epoxy.

[0012] The device terminals 17 (an example of the output terminals) are connected to electrode pads 63 of the magnetic sensor 60, which will be described later. #1 ~63 #6 and are secondary conductors for outputting the detection result of the current to be measured (i.e., magnetic field strength) 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 longitudinal directions facing horizontally. The device terminals 17 are formed into a rectangular plate shape using metal, and their ends are bent downward by bending, and further the tips are bent horizontally to form terminal portions 17a at each of the ends.

[0013] The conductor 24 is a primary conductor that forms a current path through which the current to be measured flows. In this embodiment, the conductor 24 has a substantially U-shaped shape that runs from a current terminal 24a provided on one side of the right side of the package 9 (i.e., the upper side in FIG. 1A), through the inside of the package 9, back to the right side, and to a current terminal 24e provided on the other side of the right side (i.e., the lower side in FIG. 1A). The conductor 24 is formed using a conductive metal. The conductor 24 includes current terminals (also simply referred to as terminal portions) 24a and 24e, body portions 24b and 24d, and a curved portion 24c.

[0014] The terminals 24a and 24e protrude from the right side of the package 9, and are formed into terminals for inputting a current by bending the ends downward and further bending the tips horizontally.

[0015] The body portions 24b and 24d are portions that connect the terminal portions 24a and 24e to the curved portion 24c. As an example, the body portions 24b and 24d are formed in a rectangular shape, and the two terminal portions 24a and 24e are connected to the right sides at a distance from each other, and the two arms 24c1 and 24c2 of the curved portion 24c are connected to the left sides.

[0016] The curved portion 24c has two arms 24c1, 24c2 and a connecting portion 24c3 that physically connects the two arms 24c1, 24c2. The two arms 24c1, 24c2 may extend on the same side with respect to the connecting portion 24c3. Here, the direction in which the width of the arm 24c1 increases is also called the width direction (equivalent to the vertical direction in FIG. 1A), and the direction in which the arm 24c1 extends with respect to the connecting portion 24c3 is also called the extension direction (equivalent to the horizontal direction in FIG. 1A). That is, the width direction and the extension direction intersect. The two arms 24c1, 24c2 have a vertical width smaller than that of the body portions 24b, 24d. The curved portion 24c curves the connecting portion 24c3 in a substantially arc shape, and the two arms 24c1, 24c2 are separated from each other in the width direction from both ends and extend in the horizontal direction. The curved portion 24c may be bent in a U-shape. In the bent portion 24c, the current to be measured is input to one of the two arms 24c1, 24c2, and is output from the other arm via the connecting portion 24c3.

[0017] The conductor 24 is sealed within the package 9 with two arms 24c1, 24c2 included in the bent portion 24c disposed in the center of the package 9 and tips of the terminal portions 24a, 24e protruding from the right side of the package 9.

[0018] 2A shows an example of the arrangement of the magnetic sensor 60 and the position of the board layout. The magnetic sensor 60 is a sensor that detects a magnetic field generated by a current to be measured that is passed through the conductor 24. As an example, the magnetic sensor 60 is configured to detect a vertical magnetic field (an example of a horizontal magnetic field) generated around the conductor 24, and includes a board 61, a plurality of magnetoresistance elements 51, a plurality of electrode pads 63, and a plurality of magnetic resistance elements 51. #1 ~63 #6 , and a number of dummy pads 64 #1 ~64 #6 Includes.

[0019] The substrate 61 is a plate-like member that supports the two magnetoelectric conversion units 62a and 62b. The substrate 61 is formed of, for example, silicon (Si), and has a plurality of wirings (not shown in FIG. 2A) provided on its upper surface.

[0020] The multiple magnetoresistance elements 51 are elements whose resistance value varies when a magnetic field is applied, and are disposed on one side and the other side of the substrate 61 in the vertical direction to form two magnetoelectric conversion units 62a, 62b. The magnetoelectric conversion unit 62a (an example of a first sensor) is formed by assembling some of the multiple magnetoresistance elements 51 (i.e., the magnetoresistance elements 51 disposed on the upper side in FIG. 2A) into a Wheatstone bridge circuit. The magnetoelectric conversion unit 62b (an example of a second sensor) is formed by assembling another part of the multiple magnetoresistance elements 51 (i.e., the magnetoresistance elements 51 disposed on the lower side in FIG. 2A) into a Wheatstone bridge circuit. For example, a tunnel magnetoresistance element or a giant magnetoresistance element can be used as the magnetoresistance element.

[0021] FIG. 2B shows the configuration of the magnetoresistance element 51 in a side view. The magnetoresistance element 51 is an element whose resistance value varies with the application of a magnetic field, and includes 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 magnetized so that its magnetization is oriented in one axial direction within a plane (also called a magnetosensitive surface) in which the magnetic film spreads, or in a direction perpendicular to the magnetosensitive surface. The magnetization direction of the fixed layer 51o determines the magnetic field detection direction of the magnetoresistance element 51. The tunnel layer 51p is, for example, a non-magnetic insulating film having a thickness of several nanometers. The free layer 51q is a magnetic film whose magnetization direction changes with an external magnetic field. The magnetic film may be made of an alloy containing at least one of Co, Fe, B, Ni, and Si, more specifically, cobalt iron (CoFe), cobalt iron boron (CoFeB), and nickel iron (NiFe). The fixed layer 51o, the tunnel layer 51p, and the free layer 51q are stacked to form a stack. Here, electrons tunnel through the tunnel layer 51p and move from the fixed layer 51o to the free layer 51q or from the free layer 51q to the fixed layer 51o, so that a current flows in the stacking direction in the element. The cap layer 51r is a member that covers the stack from above, and may be made of an alloy containing at least one of Ta, Ru, Pt, Mn, Ir, Mg, Cu, Fe, Ni, Cr, Fe, Co, and Al, more specifically, platinum manganese (PtMn) or iridium manganese (IrMn). The magnetoresistance element 51 is covered with an insulating material (not shown), such as silicon dioxide (SiO2), silicon nitride (SiN), or the like.

[0022] When an external magnetic field is applied to the magnetoresistance element 51, the magnetization direction of the free layer 51q changes according to the direction and strength of the magnetic field due to the magnetoresistance effect (MR effect), that is, the magnetization direction of the free layer 51q changes with respect to the magnetization direction of the fixed layer 51o, thereby varying the resistance value between the fixed layer 51o and the free layer 51q. In particular, when the magnetization direction of the free layer 51q is the same as that of the fixed layer 51o (the magnetizations of the two layers are parallel), the resistance value is small, and when they are opposite (the magnetizations of the two layers are antiparallel), the resistance value is large.

[0023] In addition, by connecting multiple magnetoresistance elements 51 in series, the DC voltage resistance can be improved. Here, by connecting the electrode piece 52 to the cap layer 51r via the electrode bar 51s and connecting the electrode piece 53 to the lower surface of the fixed layer 51o, the magnetoresistance element 51 can be connected to another magnetoresistance element 51 via these electrodes 52, 53. That is, multiple magnetoresistance elements 51 can be arranged in a plane. Also, by connecting the cap layer 51r of the magnetoresistance element 51 to the fixed layer 51o of the other magnetoresistance element 51 via the electrode bar 51s, multiple magnetoresistance elements 51 can be arranged in a three-dimensional manner.

[0024] 3 shows the circuit configuration of the magnetic sensor 60 (two magnetoelectric conversion units 62a, 62b) and the magnetic field detection directions of the resistive sides Ra to Rh (the magnetoelectric elements 51 included in each of them). The magnetic sensor 60 includes two magnetoelectric conversion units 62a, 62b connected in parallel between the drive terminal VDD and the ground terminal GND.

[0025] The magnetoelectric conversion unit 62a includes four resistor arms Ra to Rd forming a Wheatstone bridge circuit. Each of the resistor arms Ra to Rd is formed by connecting the above-mentioned multiple magnetoresistance elements 51 in series. Here, the four resistor arms Ra to Rd are such that the resistor arm Ra and the resistor arm Rb are connected in series to form an output terminal Npa1 therebetween, the resistor arm Rc and the resistor arm Rd are connected in series to form an output terminal Npa2 therebetween, and the resistor arms Ra and Rb and the resistor arms Rc and Rd are connected in parallel to form a drive terminal VDD between the resistor arm Rb and the resistor arm Rc, and a ground terminal GND between the resistor arm Ra and the resistor arm Rd.

[0026] In the current sensor 110 according to this embodiment, the magnetic field detection direction (i.e., the magnetic sensing direction) from the resistive side Ra to the resistive side Rd is a uniaxial direction (vertical direction in FIG. 1A) parallel to the upper surface of the conductor 24. The magnetic field detection directions of the resistive side Ra and the resistive side Rc (the magnetic resistance elements 51 forming each of them) are equal to each other (shown by solid black arrows in FIG. 3), and in this example, are vertically upward (or downward) in FIG. 1A. The magnetic field detection directions of the resistive side Rb and the resistive side Rd (the magnetic resistance elements 51 forming each of them) are also equal to each other (shown by hollow arrows in FIG. 3), and in this example, are vertically downward (or upward) in FIG. 1A. The magnetic field detection direction of the resistive side Ra and the resistive side Rc is opposite to the magnetic field detection direction of the resistive side Rb and the resistive side Rd.

[0027] The magnetoelectric conversion unit 62a is disposed on the arm 24c1 of the conductor 24. When a current to be measured flows through the conductor 24 and a magnetic field is generated around the conductor 24, a vertical magnetic field is applied to the resistance sides Ra to Rd (the magnetoresistance elements 51 included in the resistance sides) of the magnetoelectric conversion unit 62a disposed on the arm 24c1 of the conductor 24, and the resistance values ​​of the resistance sides Ra to Rd fluctuate. For example, the resistance values ​​of the resistance sides Ra and Rc increase (or decrease), and the resistance values ​​of the resistance sides Rb and Rd decrease (or increase), which causes the resistance balance of the resistance sides Ra to Rd to be lost. Here, the magnetic field strength can be detected by inputting a drive voltage to the drive terminal VDD with respect to the ground terminal GND and detecting the differential voltage output from the output terminals Npa1 and Npa2. This makes it possible to detect the horizontal magnetic field generated on the upper surface of the arm 24c1.

[0028] The magnetoelectric conversion unit 62b is configured similarly to the magnetoelectric conversion unit 62a, and includes four resistance arms Re to Rh that constitute a Wheatstone bridge circuit. Each of the resistance arms Re to Rh is formed by connecting the above-mentioned multiple magnetoresistance elements 51 in series. Here, the four resistance arms Re to Rh are configured as follows: the resistance arm Re and the resistance arm Rf are connected in series to form an output terminal Npb1 therebetween, the resistance arm Rg and the resistance arm Rh are connected in series to form an output terminal Npb2 therebetween, and the resistance arm Re and the resistance arm Rf and the resistance arm Rg and the resistance arm Rh are connected in parallel to form a drive terminal VDD between the resistance arm Rf and the resistance arm Rg, and a ground terminal GND between the resistance arm Re and the resistance arm Rh.

[0029] In the current sensor 110 according to this embodiment, the magnetic field detection direction (i.e., the magnetic sensing direction) from the resistive side Re to the resistive side Rh is a uniaxial direction (vertical direction in FIG. 1A) parallel to the upper surface of the conductor 24, similar to the resistive side Ra to the resistive side Rd. The magnetic field detection directions of the resistive side Re and the resistive side Rg (the magnetic resistance elements 51 forming each of them) are the same as each other (shown by the open arrow in FIG. 3), and in this example, are the vertical upward (or downward) direction in FIG. 1A. The magnetic field detection directions of the resistive side Rf and the resistive side Rh (the magnetic resistance elements 51 forming each of them) are also the same as each other (shown by the filled arrow in FIG. 3), and in this example, are the vertical downward (or upward) direction in FIG. 1A. The magnetic field detection direction of the resistive side Re and the resistive side Rg is opposite to the magnetic field detection direction of the resistive side Rf and the resistive side Rh.

[0030] The magnetoelectric conversion unit 62b is disposed on the arm 24c2 of the conductor 24. When a current to be measured flows through the conductor 24 and a magnetic field is generated around the conductor 24, a vertical magnetic field is applied to the resistance sides Re to Rh (the magnetoresistance elements 51 included in the resistance sides) of the magnetoelectric conversion unit 62b disposed on the arm 24c2 of the conductor 24, and the respective resistance values ​​fluctuate. For example, the resistance values ​​of the resistance sides Re and Rg increase (or decrease), and the resistance values ​​of the resistance sides Rf and Rh decrease (or increase), thereby destroying the resistance balance of the resistance sides Re to Rh. Here, the magnetic field strength can be detected by inputting a drive voltage to the drive terminal VDD with respect to the ground terminal GND and detecting the differential voltage output from between the output terminals Npb1 and Npb2.

[0031] As described above, the two magnetoelectric converters 62a and 62b can be disposed on the two arms 24c1 and 24c2 of the conductor 24, respectively. This makes it possible to cancel the disturbance magnetic field. Only one of the two magnetoelectric converters 62a and 62b may be disposed on the conductor 24 (the two arms 24c1 and 24c2 or the connecting portion 24c3, etc.).

[0032] The two magnetoelectric conversion units 62a and 62b are disposed on one side and the other side of the substrate 61, spaced apart in the vertical direction (width direction of the arms 24c1 and 24c2). The drive terminals VDD, the ground terminal GND, and the output terminals Npa1, Npa2, Npb1, and Npb2 are connected to electrode pads 63 on the substrate 61. #1 ~63 #6 may be connected to

[0033] Multiple electrode pads 63 #1 ~63 #6 The electrode pad 63 may be disposed on the substrate 61, and may be connected to the power supply terminals and output terminals of the two magnetoelectric conversion units 62a and 62b by wiring, and may be used as a pad for inputting a drive voltage from the outside to the power supply terminals and outputting a differential voltage from the output terminals to the outside. #1 ~63 #6are formed on the substrate 61 using a conductive metal such as gold, copper, or aluminum, and are arranged vertically side by side on one side in the horizontal direction (the left side in FIG. 1A and FIG. 2A) of the region between the two magnetoelectric conversion units 62a and 62b in the vertical direction. #1 ~63 #6 are aligned vertically in a straight line, but may be offset slightly horizontally.

[0034] Multiple electrode pads 63 #1 ~63 #6 may be connected to the drive terminals VDD and ground terminal GND of the two magnetoelectric converters 62a and 62b, the two output terminals Npa1 and Npa2 of the magnetoelectric converter 62a, and the two output terminals Npb1 and Npb2 of the magnetoelectric converter 62b. That is, the electrode pads 63 include electrode pads connected to the drive terminals VDD and ground terminal GND, the output terminals Npa1 and Npa2, and the output terminals Npb1 and Npb2, respectively. #1 ~63 #6 The arrangement will be described in detail later.

[0035] Multiple Dummy Pads 64 #1 ~64 #6 are disposed on the substrate 61, and are connected to the power supply terminals and output terminals of the two magnetoelectric conversion units 62a and 62b by wiring. They are test pads for inputting signals to test the characteristics of the magnetoelectric conversion units 62a and 62b (or the resistance sides Ra to Rh included therein or the magneto-resistive elements 51 constituting these). #1 ~64 #6 are formed on the substrate 61 using a conductive metal such as gold, copper, or aluminum, and are arranged vertically side by side on the other side in the horizontal direction (the right side in FIGS. 1A and 2A) of the region between the two magnetoelectric conversion units 62a and 62b in the vertical direction. #1 ~64 #6 are aligned vertically in a straight line, but may be offset slightly horizontally.

[0036] Multiple Dummy Pads 64 #1 ~64 #6are connected to the drive terminals VDD and ground terminal GND of the two magnetoelectric converters 62a and 62b, the two output terminals Npa1 and Npa2 of the magnetoelectric converter 62a, and the two output terminals Npb1 and Npb2 of the magnetoelectric converter 62b. That is, the dummy pads include dummy pads connected to the drive terminals VDD and ground terminal GND, the output terminals Npa1 and Npa2, and the output terminals Npb1 and Npb2, respectively. #1 ~64 #6 63 includes a plurality of electrode pads #1 ~63 #6 can be arranged similarly.

[0037] Multiple electrode pads 63 #1 ~63 #6 and a number of dummy pads 64 #1 ~64 #6 are disposed on one side and the other side in the horizontal direction between two magnetoelectric conversion units 62a and 62b spaced apart in the vertical direction on the substrate 61. #1 ~63 #6 and a number of dummy pads 64 #1 ~64 #6 can be placed on the substrate 61 within a small area.

[0038] In addition, multiple dummy pads 64 #1 ~64 #6 , each of which includes a plurality of electrode pads 63 #1 ~63 #6 In other words, the plurality of dummy pads 64 may be arranged to face each other in the lateral direction. #1 ~64 #6 , each of which includes a plurality of electrode pads 63 #1 ~63 #6 Among the six terminals of the two magnetoelectric conversion units 62a and 62b, the dummy pads 64 may be arranged laterally opposite to the electrode pads connected to the same terminals. #1 ~64 #6 Among them, the dummy pads connected to the ground terminals GND of the two magnetoelectric conversion units 62a and 62b are a plurality of electrode pads 63. #1 ~63 #6However, the dummy pads 64 may be connected to the electrode pads connected to the ground terminals GND of the two magnetoelectric conversion units 62a and 62b. #1 ~64 #6 Among them, the dummy pads connected to the drive terminals VDD and the output terminals Npa1, Npa2, Npb1, and Npb2 of the two magnetoelectric conversion units 62a and 62b are a plurality of electrode pads 63. #1 ~63 #6 Of these, it is assumed that the electrode pads connected to the drive terminal VDD and the output terminals Npa1, Npa2, Npb1, and Npb2 of the two magnetoelectric conversion units 62a and 62b are not connected.

[0039] The magnetic sensor 60 is disposed on the curved portion 24c of the conductor 24. As a result, two magnetoelectric conversion units 62a and 62b are disposed on two arms 24c1 and 24c2 of the curved portion 24c, respectively, and a plurality of electrode pads 63 on a substrate 61 connected to the drive terminals VDD, the ground terminal GND, and the output terminals Npa1, Npa2, Npb1, and Npb2 are disposed on the substrate 61. #1 ~63 #6 are connected to the device terminals 17 by wire bonding. This makes it possible to apply a drive voltage to the two magnetoelectric conversion units 62a, 62b via the device terminals 17 and output respective differential voltages.

[0040] 4A and 4B, a plurality of electrode pads 63 #1 ~63 #6 The examples (comparative examples, samples 1 to 5) show the combinations of connections between the electrode pad 63 and six terminals (drive terminal VDD, ground terminal GND, and output terminals Npa1, Npa2, Npb1, and Npb2) of the magnetic sensor 60. In the comparative examples, #1 ~63 #6are connected to the output terminal Npa1 (terminal potential Vdd / 2+Vout), output terminal Npa2 (Vdd / 2-Vout), drive terminal VDD (Vdd), ground terminal GND (zero), output terminal Npb1 (Vdd / 2+Vout), and output terminal Npb2 (Vdd / 2-Vout), respectively. Here, the drive voltage between the power supply terminals (drive terminal VDD and ground terminal GND) is Vdd (terminal potential Vdd and zero), the resistance values ​​of the resistor sides Ra and Rb, the resistance values ​​of the resistor sides Rc and Rd, the resistance values ​​of the resistor sides Re and Rf, and the resistance values ​​of the resistor sides Rg and Rh are equal, and a magnetic field is applied to the magnetic sensor 60 (magnetic-electric conversion units 62a and 62b), causing a differential voltage 2Vout to occur between the output terminals Npa1 and Npa2 of the magnetic-electric conversion unit 62a, and a differential voltage 2Vout to occur between the output terminals Npb1 and Npb2 of the magnetic-electric conversion unit 62b. Note that Vout<<Vdd.

[0041] Multiple electrode pads 63 #1 ~63 #6 When a potential difference occurs between the electrode pads, ion migration progresses, that is, the electrode material dissolves and the adjacent electrode pads are shorted, which reduces the detection sensitivity of the magnetic sensor 60. Here, the rate at which the electrode material dissolves due to ion migration is proportional to the amount of current i that flows between the electrode pads due to an oxidation-reduction reaction. According to the Butler-Volmer equation, the amount of current i is proportional to exp(cV). Here, V is the voltage between the adjacent electrode pads, and c is a constant. Therefore, in order to reduce the potential difference between the adjacent electrode pads, the drive terminal VDD and ground terminal GND of the magnetic sensor 60, and the output terminals Npa1, Npa2, and output terminals Npb1, Npb2 are connected to the multiple electrode pads 63. #1 ~63 #6 It is preferable to connect to

[0042] In the comparative example, as described above, six terminals of the magnetic sensor (drive terminal VDD, ground terminal GND, and output terminals Npa1, Npa2, Npb1, and Npb2) are connected to a plurality of electrode pads 63. #1 ~63 #6 63. #1 ,63 #2potential difference (i.e., voltage) between 2Vout and electrode pad 63 #2 ,63 #3 Voltage Vdd / 2 between electrode pad 63 #3 ,63 #4 Voltage Vdd between electrode pad 63 #4 ,63 #5 Voltage Vdd / 2 between electrode pad 63 #5 ,63 #6 The voltage between the electrode pads is 2Vout, which is larger than the maximum voltage between the electrode pads, Vdd.

[0043] In sample 1, electrode pad 63 #1 ~63 #6 are connected to the output terminal Npa1 (terminal potential Vdd / 2+Vout), the drive terminal VDD (Vdd), the output terminal Npa2 (Vdd / 2-Vout), the output terminal Npb1 (Vdd / 2+Vout), the ground terminal GND (zero), and the output terminal Npb2 (Vdd / 2-Vout), respectively. In this case, the electrode pad 63 #1 ,63 #2 potential difference (i.e., voltage) Vdd / 2 between electrode pad 63 #2 ,63 #3 Voltage Vdd / 2 between electrode pad 63 #3 ,63 #4 Voltage between 2Vout and electrode pad 63 #4 ,63 #5 Voltage Vdd / 2 between electrode pad 63 #5 ,63 #6 The voltage between the electrode pads is Vdd / 2, which is half the maximum voltage between the electrode pads, Vdd / 2, of the comparative example, but the number of points to which the maximum voltage is applied increases to four compared to one in the comparative example.

[0044] In sample 2, electrode pad 63 #1 ~63 #6 are connected to the output terminal Npa1 (terminal potential Vdd / 2+Vout), the drive terminal VDD (Vdd), the output terminal Npa2 (Vdd / 2-Vout), the output terminal Npb2 (Vdd / 2-Vout), the ground terminal GND (zero), and the output terminal Npb1 (Vdd / 2+Vout), respectively. #1 ,63#2 potential difference (i.e., voltage) Vdd / 2 between electrode pad 63 #2 ,63 #3 Voltage Vdd / 2 between electrode pad 63 #3 ,63 #4 Zero voltage between electrode pads 63 #4 ,63 #5 Voltage Vdd / 2 between electrode pad 63 #5 ,63 #6 The voltage between the electrode pads is Vdd / 2, which is half the maximum voltage between the electrode pads, Vdd / 2, of the comparative example, but the number of points to which the maximum voltage is applied increases to four compared to one in the comparative example.

[0045] In sample 3, electrode pad 63 #1 ~63 #6 are connected to the drive terminal VDD (terminal potential Vdd), the output terminal Npa1 (Vdd / 2+Vout), the output terminal Npb1 (Vdd / 2+Vout), the output terminal Npa2 (Vdd / 2-Vout), the ground terminal GND (zero), and the output terminal Npb2 (Vdd / 2-Vout), respectively. In this case, the electrode pad 63 #1 ,63 #2 potential difference (i.e., voltage) Vdd / 2 between electrode pad 63 #2 ,63 #3 Zero voltage between electrode pads 63 #3 ,63 #4 Voltage between 2Vout and electrode pad 63 #4 ,63 #5 Voltage Vdd / 2 between electrode pad 63 #5 ,63 #6 The voltage between the electrode pads is Vdd / 2, which is half the maximum voltage between the electrode pads, Vdd / 2, of the comparative example, but the number of points to which the maximum voltage is applied increases to three compared to one in the comparative example. However, the number of points to which the maximum voltage is applied decreases to three compared to four in samples 1 and 2.

[0046] In sample 4, electrode pad 63 #1 ~63 #6are connected to the drive terminal VDD (terminal potential Vdd), the output terminal Npa1 (Vdd / 2+Vout), the output terminal Npb1 (Vdd / 2+Vout), the output terminal Npa2 (Vdd / 2-Vout), the output terminal Npb2 (Vdd / 2-Vout), and the ground terminal GND (zero), respectively. #1 ,63 #2 potential difference (i.e., voltage) Vdd / 2 between electrode pad 63 #2 ,63 #3 Zero voltage between electrode pads 63 #3 ,63 #4 Voltage between 2Vout and electrode pad 63 #4 ,63 #5 Zero voltage between electrode pads 63 #5 ,63 #6 The voltage between the electrode pads is Vdd / 2, which is half the maximum voltage between the electrode pads, Vdd / 2, of the comparative example, but the number of points to which the maximum voltage is applied increases to two compared to one in the comparative example. However, the number of points to which the maximum voltage is applied decreases to two compared to four in samples 1 and 2.

[0047] From the consideration of Samples 1 to 4, since the drive terminal VDD (terminal potential Vdd) provides the maximum potential and the ground terminal GND (zero) provides the minimum potential, the maximum inter-pad voltage can be reduced (about half in this example) by arranging at least one of the electrode pads connected to the output terminal Npa1 (Vdd / 2+Vout), the electrode pad connected to the output terminal Npa2 (Vdd / 2-Vout), the electrode pad connected to the output terminal Npb1 (Vdd / 2+Vout), and the electrode pad connected to the output terminal Npb2 (Vdd / 2-Vout) between the electrode pads connected to these terminals. In particular, it is preferable to have fewer locations where the maximum voltage is applied, since this reduces the number of locations where migration occurs, and Sample 4 of Samples 1 to 4 is suitable.

[0048] Since the substrate 61 of the magnetic sensor 60 is disposed on the conductor 24, the conductor 24 generates heat when the current to be measured flows, and the substrate 61 is heated. #1 ~63 #6Thermoelectromotive force occurs at the interface between the wire and the wire bonding and inside the Wheatstone bridge, and there is concern that the offset will cause a decrease in accuracy. Thermoelectromotive force is a phenomenon in which a potential difference occurs between the two ends of a material when the interface is placed at a certain temperature or when the temperatures of both ends of the material are different.

[0049] It is preferable to arrange the electrode pads connected to the two output terminals Npa1, Npa2 of the magnetoelectric converter 62a on the inside or outside of the electrode pads connected to the two output terminals Npb1, Npb2 of the magnetoelectric converter 62b. As a result, the electrode pads connected to the two output terminals Npa1, Npa2 of the magnetoelectric converter 62a are spaced equidistant or approximately equidistant from the two arms 24c1, 24c2 of the conductor 24, and the electrode pads connected to the two output terminals Npb1, Npb2 of the magnetoelectric converter 62b are spaced equidistant or approximately equidistant from the two arms 24c1, 24c2 of the conductor 24, so that the electrode pads are heated equally by the heat generated by the conductor 24, the temperature difference is reduced, and the offset due to the thermoelectromotive force can be suppressed.

[0050] More preferably, with respect to a line of symmetry L passing through the vertical center of the substrate 61, the electrode pads connected to the two output terminals Npa1, Npa2 of the magneto-electric converter 62a are arranged at symmetrical positions in the vertical direction, and further, the electrode pads connected to the two output terminals Npb1, Npb2 of the magneto-electric converter 62b are arranged at symmetrical positions in the vertical direction. By arranging the magnetic sensor 60 on the conductor 24 so that the symmetry line L of the substrate 61 overlaps the center line of the conductor 24, the electrode pads connected to the two output terminals Npa1, Npa2 of the magnetoelectric conversion unit 62a are spaced equidistant or approximately equidistant from the two arms 24c1, 24c2 of the conductor 24, and the electrode pads connected to the two output terminals Npb1, Npb2 of the magnetoelectric conversion unit 62b are spaced equidistant or approximately equidistant from the two arms 24c1, 24c2 of the conductor 24, so that the electrode pads are heated equally by the heat generated by the conductor 24, reducing the temperature difference and suppressing the offset due to thermoelectromotive force.

[0051] In sample 5, electrode pad 63 #1 ~63 #6 are connected to the drive terminal VDD (terminal potential Vdd), the output terminal Npa1 (Vdd / 2+Vout), the output terminal Npb1 (Vdd / 2+Vout), the output terminal Npb2 (Vdd / 2-Vout), the output terminal Npa2 (Vdd / 2-Vout), and the ground terminal GND (zero), respectively. #1 ,63 #2 The potential difference between Vdd / 2 and electrode pad 63 #2 ,63 #3 Zero potential difference between electrode pads 63 #3 ,63 #4 The potential difference between the electrodes is 2Vout and the electrode pad 63 #4 ,63 #5 Zero potential difference between electrode pads 63 #5 ,63 #6 The potential difference between the electrode pads is Vdd / 2, and the maximum voltage between the electrode pads is Vdd / 2, similar to sample 4, and there are two locations where the maximum voltage is applied. Furthermore, as described above, the two output terminals Npa1 and Npa2 of the magnetoelectric conversion unit 62a are connected to the electrode pads 63, #2 ,63 #5 , and the two output terminals Npb1 and Npb2 of the magnetoelectric conversion unit 62b are connected to the electrode pads 63 #3 ,63 #4 , the electrode pads connected to the two output terminals Npa1, Npa2 of the magnetoelectric converter 62a are symmetrically arranged with respect to the symmetry line L of the substrate 61, and the electrode pads connected to the two output terminals Npb1, Npb2 of the magnetoelectric converter 62b are symmetrically arranged with respect to the symmetry line L of the substrate 61. This makes it possible to suppress offset due to thermoelectromotive force.

[0052] In addition, multiple dummy pads 64 #1 ~64 #6 Also, multiple electrode pads 63 #1 ~63 #6 By disposing the electrodes on the substrate 61 according to the same principle, migration and offset can be suppressed.

[0053] Multiple electrode pads 63 #1 ~63#6 If the resistance balance of the wiring connecting the six terminals of the magnetic sensor to the magnetoelectric conversion units 62a and 62b is lost, the midpoint potential (potential at the output terminals Npa1, Npa2, Npb1, and Npb2) of the Wheatstone bridge circuit included in each of the magnetoelectric conversion units 62a and 62b will shift, causing an offset to occur in the differential voltage output from the output terminals Npa1, Npa2, Npb1, and Npb2 (which will shift the bias point of the differential amplifier circuit connected to the output terminals), and there is a concern that the detection accuracy of the magnetic sensor 60 will decrease. #1 ~63 #6 It is preferable to match the wiring resistance connecting the drive terminal VDD and the ground terminal GND of the magnetic sensor.

[0054] FIG. 5 shows a plurality of electrode pads 63 #1 ~63 #6 4B) of the combination of connections between the electrode pad 63 and six terminals (drive terminal VDD, ground terminal GND, and output terminals Npa1, Npa2, Npb1, and Npb2) of the magnetic sensor 60. In the sample 5, #1 ~63 #6 are connected to the drive terminal VDD, the output terminal Npa1, the output terminal Npb1, the output terminal Npb2, the output terminal Npa2, and the ground terminal GND, respectively. Note that the wiring is connected at the intersections indicated by black circles, and intersections without black circles are separated vertically via, for example, an insulating layer.

[0055] Here, the driving terminal of the magnetoelectric conversion unit 62a (the connection point 65a of the resistor sides Rb and Rc) is connected to the electrode pad 63 #1 The wiring 66a (indicated by a dashed line in the drawing) extends from the drive terminal (connection point 65b of the resistor sides Rf and Rg) of the magneto-electric conversion unit 62b to the electrode pad 63. #1 The wiring 66a has a longer length and a larger cross-sectional area than the wiring 66b (shown by a two-dot chain line in the drawing) that extends to the electrode pad 63. Alternatively, the wiring 66a may be shorter and have a smaller cross-sectional area than the wiring 66b. More preferably, the products of the lengths and cross-sectional areas of the wiring 66a and wiring 66b are equal or approximately equal.#1 The wiring 66a extends from the drive terminal (connection point 65b of the resistor sides Rf and Rg) of the magnetoelectric conversion unit 62b to the electrode pad 63. #1 The wiring 66b has a resistance value equal to or approximately equal to that of the wiring 66b extending to the

[0056] Furthermore, the ground terminal of the magnetoelectric conversion unit 62a (the connection point 67a of the resistor sides Ra and Rd) is connected to the electrode pad 63 #6 The wiring 68a (shown by a thick dotted line in the drawing) extends from the ground terminal (connection point 67b of the resistor sides Re and Rh) of the magneto-electric conversion unit 62b to the electrode pad 63. #6 The wiring 68a is shorter and has a smaller cross-sectional area than the wiring 68b (shown by a thick line in the drawing) that extends to the electrode pad 63. Alternatively, the wiring 68a may be longer and have a larger cross-sectional area than the wiring 68b. #6 The wiring 68a extends from the ground terminal (connection point 67b of the resistor sides Re and Rh) of the magnetoelectric conversion unit 62b to the electrode pad 63. #6 The wiring 68b has a resistance value equal to or substantially equal to that of the wiring 68b extending to the

[0057] As a result, the operating points of the differential voltage output between the output terminals Npa1, Npa2 and the differential voltage output between the output terminals Npb1, Npb2 coincide with each other, and the detection accuracy of the magnetic sensor 60 can be maintained.

[0058] Multiple electrode pads 63 #1 ~63 #6 and six terminals of the magnetic sensor 60 (drive terminal VDD, ground terminal GND, and output terminals Npa1, Npa2, Npb1, and Npb2), a wiring loop is formed, and there is a concern that magnetic flux passing through the loop will generate an induced electromotive force in the wiring, decreasing the detection accuracy of the magnetic sensor 60. Therefore, it is desirable to lay the wiring so that a wiring loop is not formed.

[0059] FIG. 6 shows a plurality of electrode pads 63 #1 ~63 #64B shows another example of wiring layout in sample 5 (see FIG. 4B) in which the electrode pad 63 is connected to six terminals (drive terminal VDD, ground terminal GND, and output terminals Npa1, Npa2, Npb1, and Npb2) of the magnetic sensor 60. In sample 5, #1 ~63 #6 are connected to the drive terminal VDD, the output terminal Npa1, the output terminal Npb1, the output terminal Npb2, the output terminal Npa2, and the ground terminal GND, respectively. Note that the wiring is connected at the intersections indicated by black circles, and intersections without black circles are separated vertically via, for example, an insulating layer.

[0060] A drive terminal (connection point 65a of resistor sides Rb and Rc) of the magnetoelectric conversion unit 62a is connected to an electrode pad 63 #1 A wiring 66a (indicated by a dashed line in the drawing) is extended from the drive terminal of the magneto-electric conversion unit 62b (connection point 65b of the resistor sides Rf and Rg) to the electrode pad 63 #1 The wiring pair including the wiring 66b (indicated by a two-dot chain line in the drawing) extending to the electrode pad 63 is connected from the ground terminal (connection point 67a of the resistor sides Ra and Rd) of the magneto-electric conversion unit 62a to the electrode pad 63 in a top view. #6 A wiring 68a (shown by a thick dotted line in the drawing) is extended from the ground terminal (connection point 67b of the resistor sides Re and Rh) of the magneto-electric converter 62b to the electrode pad 63. #6 The wiring pairs 68a, 68b are disposed on the substrate 61 so as to at least partially overlap with a wiring pair including a wiring 68b (shown by a thick line in the drawing) extending to the wiring 66a, 66b. In this example, the entire length of the wiring pair 68a, 68b overlaps with the wiring pair 66a, 66b. For convenience of illustration, the two wiring pairs (66a, 66b, 68a, 68b) are shown slightly shifted in FIG. This prevents the two wiring pairs from forming a wiring loop, thereby suppressing the generation of induced electromotive force on the wiring, and the detection accuracy of the magnetic sensor 60 can be maintained.

[0061] The six terminals of the magnetic sensor 60 are connected to a plurality of dummy pads 64. #1 ~64 #6 The wiring to be connected to the electrode pads 63 #1 ~63 #6The wiring can be laid on the substrate 61 according to the same principle as the wiring connected to the

[0062] A method for manufacturing the current sensor 110 will now be described.

[0063] 7A, first, a single metal plate is pressed to form a pattern of multiple device terminals 17 and conductors 24. This pattern includes multiple device terminals 17 and conductors 24 with their terminal portions connected inside a rectangular frame (not shown).

[0064] Next, the pattern is subjected to step processing to provide steps in the device terminals 17 and the conductors 24. This raises the inner portion of the pattern relative to the frame and the terminal portions connected to the frame.

[0065] 7B, the magnetic sensor 60 is then installed. Here, the two magnetoelectric converting units 62a and 62b are disposed on the arms 24c1 and 24c2 of the conductor 24, respectively.

[0066] As shown in FIG. 7C, next, the magnetic sensor 60 is connected to the multiple device terminals 17 by wire bonding.

[0067] 7D, the pattern is then molded, leaving behind the frame and a number of device terminals 17 and terminal portions of the conductors 24 connected thereto, thereby forming the package 9, within which the magnetic sensor 60 and the inner portion of the pattern are sealed.

[0068] Finally, the frame exposed from the package 9 is cut from the pattern. As a result, the multiple device terminals 17 and the conductors 24 are separated from each other, and the current sensor 110 is completed.

[0069] The current sensor 110 may further include a signal processing device that processes the output signal of the magnetic sensor 60 to calculate the amount of the current to be measured flowing through the conductor 24, and a base that supports the signal processing device (none of which are shown). The signal processing device may incorporate a memory, a sensitivity correction circuit, an offset correction circuit that corrects the offset of the output, an amplifier circuit that amplifies the output signal from the magnetic sensor 60, and a temperature correction circuit that corrects the output in accordance with temperature. The signal processing device is supported on the base and is connected to the magnetic sensor 60 (including the plurality of electrode pads 63). #1 ~63 #6 ) and a plurality of device terminals 17 may be connected by wire bonding. Alternatively, the signal processing device may be built into a substrate 61 having a magnetic sensor 60, and the electrode pads 63 may be connected to the substrate 61. #1 ~63 #6 may be used as input / output terminals of the signal processing device and connected to the plurality of device terminals 17 by wire bonding. In this way, the signal processing device outputs the calculation result of the amount of the current to be measured flowing through the conductor 24 via the plurality of device terminals 17.

[0070] The magnetic sensor 60 according to this embodiment includes a substrate 61 and a plurality of magnetoresistance elements 51 arranged on the substrate 61, some of the magnetoresistance elements 51 being assembled in a Wheatstone bridge circuit to form a magnetoelectric conversion unit 62a, and another portion of the magnetoresistance elements 51 being assembled in a Wheatstone bridge circuit to form a magnetoelectric conversion unit 62b. #1 ~63 #6The magnetoelectric converter 62 includes a first electrode pad connected to the drive terminal VDD of the magnetoelectric converters 62a and 62b, a second electrode pad connected to the ground terminal GND of the magnetoelectric converters 62a and 62b, a third electrode pad and a fourth electrode pad connected to the two output terminals Npa1 and Npa2 of the magnetoelectric converter 62a, respectively, and a fifth electrode pad and a sixth electrode pad connected to the two output terminals Npb1 and Npb2 of the magnetoelectric converter 62b, respectively, and at least one of the third electrode pad to the sixth electrode pad is disposed between the first electrode pad and the second electrode pad in the direction in which the first electrode pad and the second electrode pad are separated from each other. According to this, by disposing at least one of the third electrode pad to the sixth electrode pad between the first electrode pad and the second electrode pad which generate the maximum potential difference, the voltage difference between the adjacent electrode pads becomes smaller than the maximum voltage difference, and migration of the electrode pads can be suppressed.

[0071] The current sensor 110 according to this embodiment includes a conductor 24 through which a current to be measured flows, a magnetic sensor 60 disposed on the conductor 24, and a plurality of device terminals 17 connected to the first to sixth electrode pads of the magnetic sensor 60, respectively. With this, by using the magnetic sensor 60 in which migration of the electrode pads is suppressed, it is possible to provide a highly reliable current sensor 110.

[0072] Although the magnetic sensor 60 includes the two magnetoelectric conversion units 62a and 62b, it may include only one of them instead.

[0073] In the current sensor 110 according to this embodiment, the plurality of electrode pads 63 of the magnetic sensor 60 #1 ~63 #6 are connected to the device terminals 17 by wire bonding, but instead, a plurality of dummy pads 64 #1 ~64 #6 may be connected to the device terminal 17 by wire bonding. In such a case, the plurality of electrode pads 63 #1 ~63 #6may be used as a test pad for inputting a signal to test the characteristics of the magnetoelectric conversion units 62a, 62b (resistance sides Ra to Rh included therein or the magneto-resistance elements 51 constituting these).

[0074] The magnetic field detection direction (i.e., magnetic sensing direction) of the resistive sides Ra-Rh (magnetic resistance element 51) included in the two magnetoelectric conversion parts 62a, 62b of the magnetic sensor 60 may be set to a direction perpendicular to the upper surface of the conductor 24, and one of the two magnetoelectric conversion parts 62a, 62b may be disposed in a gap region surrounded by the curved part 24c of the conductor 24. This allows the magnetic sensor 60 to detect a vertical magnetic field (a magnetic field in the height direction in FIG. 1A in this example). The other of the two magnetoelectric conversion parts 62a, 62b may be disposed near the outside of one of the two arms 24c1, 24c2 of the conductor 24. This allows the disturbance magnetic field to be canceled.

[0075] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the description of the claims that such modifications and improvements can also be included in the technical scope of the present invention.

[0076] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and may be realized in any order unless the output of a previous process is used in a later process. Even if the operational flow in the claims, specifications, and drawings is explained using "first," "next," etc. for convenience, it does not mean that it is essential to perform the process in this order. [Explanation of symbols]

[0077] 9...package, 17...device terminal, 17a...terminal portion, 24...conductor, 24a, 24e...current terminal (terminal portion), 24b, 24d...body portion, 24c...curved portion, 24c1, 24c2...arm, 24c3...connecting portion, 51...magnetic resistance element, 51o...fixed layer, 51p...tunnel layer, 51q...free layer, 51r...cap layer, 51s...electrode rod, 52, 53...electrode piece, 60...magnetic sensor, 6 1...substrate, 62a, 62b...magnetoelectric conversion unit, 63...electrode pad, 64...dummy pad, 65a, 65b...connection point, 66a, 66b...wiring (wire pair), 67a, 67b...connection point, 68a, 68b...wiring (wire pair), 110...current sensor, GND...ground terminal, L...symmetrical line, Npa1, Npa2, Npb1, Npb2...output terminal, Ra to Rh...resistor side, VDD...drive terminal.

Claims

1. A current sensor comprising a conductor through which a current to be measured flows and a magnetic sensor disposed on the conductor, the magnetic sensor comprising: A substrate; a plurality of magnetoresistance elements disposed on the substrate, some of the magnetoresistance elements being assembled in a Wheatstone bridge circuit to form a first sensor, and another portion of the magnetoresistance elements being assembled in a Wheatstone bridge circuit to form a second sensor; a plurality of electrode pads arranged on the substrate, the plurality of electrode pads including a first electrode pad connected to drive terminals of the first sensor and the second sensor, a second electrode pad connected to ground terminals of the first sensor and the second sensor, a third electrode pad and a fourth electrode pad connected to two output terminals of the first sensor, respectively, and a fifth electrode pad and a sixth electrode pad connected to two output terminals of the second sensor, respectively, and at least one of the third electrode pad to the sixth electrode pad is disposed between the first electrode pad and the second electrode pad in a first direction in which the first electrode pad and the second electrode pad are spaced apart from each other; A current sensor comprising:

2. The current sensor according to claim 1 , wherein the third electrode pad and the fourth electrode pad are disposed inside or outside the fifth electrode pad and the sixth electrode pad in the first direction.

3. the substrate has a line of symmetry passing through a center with respect to the first direction; the third electrode pad and the fourth electrode pad are disposed at positions symmetrical with respect to the line of symmetry in the first direction, The current sensor according to claim 2 , wherein the fifth electrode pad and the sixth electrode pad are disposed at positions symmetrical with respect to the line of symmetry in the first direction.

4. 2. The current sensor of claim 1, wherein a wiring extending from the driving terminal of the first sensor to the first electrode pad is longer and has a larger cross-sectional area, or shorter and has a smaller cross-sectional area, than a wiring extending from the driving terminal of the second sensor to the first electrode pad.

5. 2 . The current sensor according to claim 1 , wherein a wiring extending from the drive terminal of the first sensor to the first electrode pad has a resistance substantially equal to a wiring extending from the drive terminal of the second sensor to the first electrode pad.

6. 2. The current sensor according to claim 1, wherein a wiring extending from the ground terminal of the first sensor to the second electrode pad is shorter and has a smaller cross-sectional area, or longer and has a larger cross-sectional area, than a wiring extending from the ground terminal of the second sensor to the second electrode pad.

7. 2 . The current sensor according to claim 1 , wherein a wiring extending from the ground terminal of the first sensor to the second electrode pad has a resistance substantially equal to a wiring extending from the ground terminal of the second sensor to the second electrode pad.

8. 2. The current sensor according to claim 1, wherein a first wiring pair including a wiring extending from the drive terminal of the first sensor to the first electrode pad and a wiring extending from the drive terminal of the second sensor to the first electrode pad at least partially overlaps, when viewed from above, with a second wiring pair including a wiring extending from the ground terminal of the first sensor to the second electrode pad and a wiring extending from the ground terminal of the second sensor to the second electrode pad.

9. The first sensor and the second sensor are disposed on one side and the other side of the substrate in the first direction, respectively; The current sensor according to claim 1 , wherein the first to sixth electrode pads are disposed on one side of a region between the first sensor and the second sensor on the substrate in a direction intersecting the first direction.

10. the conductor has a first arm and a second arm spaced apart in the first direction, a current to be measured is input to one of the first arm and the second arm and the current to be measured is output from the other arm, The current sensor of claim 9 , wherein the first sensor and the second sensor are disposed on the first arm and the second arm, respectively.

11. the conductor has a connecting portion that physically connects the first arm and the second arm, The first arm and the second arm extend on the same side of the connecting portion. The current sensor according to claim 10.

12. The first sensor and the second sensor are disposed on one side and the other side of the substrate in the first direction, respectively; The current sensor of claim 11 , wherein the first to sixth electrode pads are disposed on one side of a region between the first sensor and the second sensor on the substrate in a direction intersecting the first direction.

13. a plurality of device terminals to which the first electrode pad to the sixth electrode pad are respectively connected; The current sensor of claim 12 further comprising:

14. the magnetic sensor further comprises a plurality of dummy pads arranged on the substrate, the plurality of dummy pads including a first dummy pad connected to drive terminals of the first sensor and the second sensor, a second dummy pad connected to ground terminals of the first sensor and the second sensor, a third dummy pad and a fourth dummy pad connected to two output terminals of the first sensor, respectively, and a fifth dummy pad and a sixth dummy pad connected to two output terminals of the second sensor, respectively; The current sensor of claim 12, wherein the first dummy pad to the sixth dummy pad are arranged opposite the first electrode pad to the sixth electrode pad, respectively, on the other side of a direction intersecting the first direction in an area between the first sensor and the second sensor on the substrate.

15. A current sensor comprising a conductor through which a current to be measured flows and a magnetic sensor disposed on the conductor, the magnetic sensor comprising: A substrate; a plurality of magnetoresistance elements disposed on the substrate, some of the magnetoresistance elements being assembled in a Wheatstone bridge circuit to form a first sensor, and another portion of the magnetoresistance elements being assembled in a Wheatstone bridge circuit to form a second sensor; a plurality of dummy pads arranged on the substrate, the plurality of dummy pads including a first dummy pad connected to drive terminals of the first sensor and the second sensor, a second dummy pad connected to ground terminals of the first sensor and the second sensor, a third dummy pad and a fourth dummy pad connected to two output terminals of the first sensor, respectively, and a fifth dummy pad and a sixth dummy pad connected to two output terminals of the second sensor, respectively, and at least one dummy pad from the third dummy pad to the sixth dummy pad is disposed between the first dummy pad and the second dummy pad in a first direction in which the first dummy pad and the second dummy pad are spaced apart from each other; Current sensor.

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