Current Sensors

Abstract

The present invention provides a current sensor which suppresses the migration of electrode pads. The magnetic sensor (60) comprises: a substrate (61); a plurality of magnetoresistive elements (51) arranged on the substrate, a part of the plurality of magnetoresistive elements forming a Wheatstone bridge circuit to form a magnetoelectric conversion part (62a), and another part forming a Wheatstone bridge circuit to form a magnetoelectric conversion part (62b); and a plurality of electrode pads (63 #1 ~63 #6 ), arranged on a substrate, comprising first and second electrode pads respectively connected to a driving terminal (VDD) and a ground terminal (GND) of a magnetoelectric conversion unit (62a, 62b), third and fourth electrode pads respectively connected to two output terminals (Npa1, Npa2) of the magnetoelectric conversion unit (62a), fifth and sixth electrode pads respectively connected to two output terminals (Npb1, Npb2) of the magnetoelectric conversion unit (62b), and at least one electrode pad from the third to sixth electrode pads is arranged between the first and second electrode pads.

Description

Technical Field

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

[0002] The following magnetic sensor and current sensor are known, wherein the magnetic sensor has a Wheatstone bridge circuit composed of four magnetoresistive edges each including a magnetoresistive element (TMR), and detects the magnetic field strength by inputting a driving voltage from a pair of power supply terminals and obtaining a differential voltage from a pair of output terminals, and the current sensor detects the current by using the magnetic sensor to measure the magnetic field strength around the conductor in which the measured current flows (refer to patent documents 1 and 2). The current sensor has a substrate that supports the magnetic sensor, and a driving voltage is input to the power supply terminal of the magnetic sensor via a plurality of electrode pads provided on the substrate, and a differential voltage is output from the output terminal. Here, if the current sensor is used in a hygroscopic state, the migration of the electrode pads due to the application of voltage between the electrode pads may decrease the detection sensitivity. Therefore, in patent document 3, silver containing any one of oxides, nitrides and nitrogen oxides is used to form a multilayer structure of electrode pads, thereby suppressing migration. However, in general, due to the use of special materials that are not used as electrode materials, process constraints and cost increases may occur.

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

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

[0005] Patent Document 3: Japanese Patent Application Publication No. 2005-033197 Summary of the invention

[0006] Summary of the Invention

[0007] Solutions to Solve Problems

[0008] In a first embodiment of the present invention, a magnetic sensor is provided, comprising: a substrate; a plurality of magnetoresistive elements arranged on the substrate, a portion of the plurality of magnetoresistive elements forming a Wheatstone bridge circuit to form a first sensor, and another portion of the plurality of magnetoresistive elements forming a Wheatstone bridge circuit to form a second sensor; and a plurality of electrode pads arranged on the substrate, including a first electrode pad connected to a drive terminal of the first sensor and the second sensor, a second electrode pad connected to a ground terminal of the first sensor and the second sensor, a third electrode pad and a fourth electrode pad respectively connected to two output terminals of the first sensor, a fifth electrode pad and a sixth electrode pad respectively connected to two output terminals of the second sensor, and at least one electrode pad from the third electrode pad to the sixth electrode pad is arranged between the first electrode pad and the second electrode pad in a first direction in which the first electrode pad is separated from the second electrode pad.

[0009] In a second aspect of the present invention, a current sensor is provided, comprising: a conductor through which a measured current flows; the magnetic sensor of the first aspect, arranged on the conductor; and a plurality of output terminals, respectively connected to the first electrode pad to the sixth electrode pad of the magnetic sensor.

[0010] In a third embodiment of the present invention, a magnetic sensor is provided, comprising: a substrate; a plurality of magnetoresistive elements arranged on the substrate, a portion of the plurality of magnetoresistive elements forming a Wheatstone bridge circuit to form a first sensor, and another portion of the plurality of magnetoresistive elements forming a Wheatstone bridge circuit to form a second sensor; and a plurality of dummy pads arranged on the substrate, including a first dummy pad connected to a drive terminal of the first sensor and the second sensor, a second dummy pad connected to a ground terminal of the first sensor and the second sensor, a third dummy pad and a fourth dummy pad respectively connected to two output terminals of the first sensor, and a fifth dummy pad and a sixth dummy pad respectively connected to two output terminals of the second sensor, wherein at least one dummy pad from 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 is separated from the second dummy pad.

[0011] In a fourth aspect of the present invention, a current sensor is provided, comprising: a conductor through which a measured current flows; the magnetic sensor of the third aspect, arranged on the conductor; and a plurality of output terminals, respectively connected to the first to sixth dummy pads of the magnetic sensor.

[0012] 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

[0013] Figure 1A The internal structure of the current sensor according to this embodiment is shown in a plan view.

[0014] Figure 1B The internal structure of the current sensor according to this embodiment is shown in a side view.

[0015] Figure 2A An example of the arrangement of magnetic sensors for detecting horizontal magnetic fields and a substrate layout is shown.

[0016] Figure 2B The structure of the magnetoresistive element is shown in a side view.

[0017] Figure 3 The circuit structure of the magnetic sensor (first and second magnetoelectric converters) and the magnetic field sensing direction of the magnetoresistive element are shown.

[0018] Figure 4A Examples of connection combinations between the electrode pads and the six terminals of the magnetic sensor are shown (Comparative Example, Samples 1 and 2).

[0019] Figure 4B Examples of the connection combinations between the electrode pads and the six terminals of the magnetic sensor are shown (Samples 3 to 5).

[0020] Figure 5 An example of wiring layout in Sample 5 showing a combination of connections between electrode pads and six terminals of the magnetic sensor.

[0021] Figure 6 Another example of wiring layout in Sample 5 is shown, which shows a combination of connections between electrode pads and six terminals of the magnetic sensor.

[0022] Fig. 7A The following diagram shows a state of a lead frame forming step in the manufacturing process of the current sensor.

[0023] Figure 7B The following diagram shows a state of a magnetic sensor installation process in a current sensor manufacturing process.

[0024] Figure 7C FIG. 1 shows a state of a wire bonding process in a manufacturing flow of a current sensor.

[0025] Fig.7D The following diagram shows the state of the molding process in the manufacturing flow of the current sensor.

[0026] Description of Reference Numerals

[0027] 9…package, 17…device terminal, 17a…terminal portion, 24…conductor, 24a, 24e…current terminal (terminal portion), 24b, 24d…main body portion, 24c…bend portion, 24c1, 24c2…arm, 24c3…connecting portion, 51…magnetoresistive element, 51o…fixed layer, 51p…channel layer, 51q…free layer, 51r…cap layer, 51s…electrode rod, 52, 53…electrode sheet, 60…magnetic sensor, 61…base Board, 62a, 62b…magnetoelectric conversion unit, 63…electrode pad, 64…dummy pad, 65a, 65b…connection point, 66a, 66b…wiring (wiring pair), 67a, 67b…connection point, 68a, 68b…wiring (wiring pair), 110…current sensor, GND…ground terminal, L…symmetry line, Npa1, Npa2, Npb1, Npb2…output terminal, Ra~Rh…magnetic resistance edge, VDD…drive terminal. DETAILED DESCRIPTION

[0028] The present invention will be described below by way of the embodiments of the invention, but the following embodiments do not limit the invention according to the claims. Furthermore, not all combinations of features described in the embodiments are essential to the solution provided by the invention.

[0029] Figure 1A and Figure 1B In the top view and the side view, the internal structure of the current sensor 110 of this embodiment is shown through the package 9. Figure 1B Show Figure 1A The cross-sectional structure of the current sensor 110 along 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 110 is a sensor that measures the current by using the magnetic sensor 60 to detect the magnetic field generated around the conductor 24 when the measured current flows therein. In particular, the plurality of electrode pads 63 of the magnetic sensor 60 can be suppressed. #1 ~63 #6 and a plurality 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 .

[0030] 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 respective terminal portions of the conductors 24. The package 9 is molded into a flat rectangular parallelepiped by using a sealing resin having excellent insulating properties such as epoxy resin.

[0031] The plurality of device terminals 17 (an example of a plurality of output terminals) are connected to electrode pads 63 of a magnetic sensor 60 described later. #1 ~63 #6 The device terminals 17 are connected to the secondary conductors for outputting the detection result of the measured current (i.e., the magnetic field strength) outputted from the magnetic sensor 60 to the external device. In this example, as an example, eight device terminals 17 are arranged at equal intervals with their lengths oriented horizontally on the left side of the package body 9. The device terminals 17 are formed into a rectangular plate shape using metal, and their ends are bent downward by bending processing, and the front ends are bent horizontally, thereby forming terminal portions 17a at their ends.

[0032] The conductor 24 is a primary conductor that forms a current path for the current to be measured. In the present embodiment, the conductor 24 has a substantially U-shaped structure as follows: the conductor 24 extends from 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, reaching the other side on the right side (ie, Figure 1A The conductor 24 is formed of a conductive 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.

[0033] 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.

[0034] The main body 24b, 24d is a part connecting the terminal 24a, 24e to the bent portion 24c. The main body 24b, 24d is formed in a rectangular shape as an example, and connects the two terminal 24a, 24e separately on the right side and connects the two arms 24c1, 24c2 of the bent portion 24c on the left side.

[0035] The curved portion 24c has two arms 24c1 and 24c2 and a connecting portion 24c3 that physically connects 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 the width of the arm 24c1). 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.

[0036] The conductor 24 is sealed in the package 9 such that two arms 24 c 1 and 24 c 2 included in the bent portion 24 c are arranged at the center of the package 9 and the front ends of the terminal portions 24 a and 24 e protrude from the right side of the package 9 .

[0037] Figure 2A FIG. 6 shows an example of the configuration of the magnetic sensor 60 and the position of the substrate layout. 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 is configured to detect a longitudinal magnetic field (an example of a horizontal magnetic field) generated around the conductor 24, and includes a substrate 61, a plurality of magnetoresistive elements 51, and a plurality of electrode pads 63. #1 ~63 #6 and a plurality of dummy pads 64 #1 ~64 #6 .

[0038] The substrate 61 is a plate-shaped member that supports the two magnetoelectric converters 62a and 62b. The substrate 61 is formed of, for example, silicon (Si), and has a plurality of wirings (on the upper surface) laid out. Figure 2A (not shown in the figure).

[0039] The plurality of magnetoresistive elements 51 are elements whose magnetic resistance value changes due to the application of a magnetic field, and are respectively arranged on one side and the other side in the longitudinal direction of the substrate 61 to form two magnetoelectric conversion parts 62a and 62b. The magnetoelectric conversion part 62a (an example of the first sensor) is formed by placing a part of the plurality of magnetoresistive elements 51 (i.e., Figure 2A The magnetoresistive element 51 disposed on the upper side of the magnetoresistive element 51 is formed into a Wheatstone bridge circuit. The magnetoelectric conversion unit 62b (an example of the second sensor) is formed by connecting another part of the plurality of magnetoresistive elements 51 (i.e., Figure 2A The magnetoresistive element 51 disposed on the lower side of the magnetoresistive element 51 is formed into a Wheatstone bridge circuit. It should be noted that, as the magnetoresistive element, for example, a channel magnetoresistive element or a giant magnetoresistive element can be used.

[0040] Figure 2BThe structure of the magnetoresistive element 51 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 channel 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 channel 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 channel layer 51p, and the free layer 51q are stacked to form a stack. Here, electrons move from the fixed layer 51o to the free layer 51q or from the free layer 51q to the fixed layer 51o through the channel layer 51p, thereby flowing current 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.

[0041] 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 is small, and when they are opposite (the magnetizations of the two layers are antiparallel), the magnetoresistance value becomes large.

[0042] 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.

[0043] Figure 3 The circuit structure of the magnetic sensor 60 (two magnetoelectric converters 62a, 62b) and the magnetic field sensing directions of the magnetoresistive edges Ra to Rh (magnetoresistive elements 51 included in each) are shown. The magnetic sensor 60 includes two magnetoelectric converters 62a, 62b connected in parallel between the drive terminal VDD and the ground terminal GND.

[0044] The magnetoelectric conversion unit 62a includes four magnetoresistive edges Ra to Rd forming a Wheatstone bridge circuit. The magnetoresistive edges Ra to Rd are formed by connecting the aforementioned plurality of magnetoresistive elements 51 in series. Among the four magnetoresistive edges Ra to Rd, the magnetoresistive edge Ra and the magnetoresistive edge Rb are connected in series to form an output terminal Npa1 therebetween, the magnetoresistive edge Rc and the magnetoresistive edge Rd are connected in series to form an output terminal Npa2 therebetween, 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 drive terminal VDD between the magnetoresistive edge Rb and the magnetoresistive edge Rc, and a ground terminal GND is formed between the magnetoresistive edge Ra and the magnetoresistive edge Rd.

[0045] It should be noted that in the current sensor 110 of the present embodiment, the magnetic field sensing direction (i.e., magnetic sensitive direction) from the magnetic resistance side Ra to the magnetic resistance side Rd is set to be a uniaxial direction ( Figure 1A The magnetic field sensing directions of the magnetoresistive edge Ra and the magnetoresistive edge Rc (the magnetoresistive elements 51 forming the magnetoresistive edge Ra and the magnetoresistive edge Rc, respectively) are the same as each other (in the longitudinal direction of the magnetoresistive edge Ra and the magnetoresistive edge Rc, respectively). Figure 3 In this example, it is set to Figure 1A The magnetic field sensing directions of the magnetic resistance edge Rb and the magnetic resistance edge Rd (the magnetic resistance elements 51 forming the magnetic resistance edge Rb and the magnetic resistance edge Rd, respectively) are also the same as each other (in Figure 3 In this example, it is set to Figure 1A The magnetic field sensing direction of the magnetic resistance side Ra and the magnetic resistance side Rc is the opposite direction to the magnetic field sensing direction of the magnetic resistance side Rb and the magnetic resistance side Rd.

[0046] The magnetoelectric conversion unit 62a is arranged on the arm 24c1 of the conductor 24. 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 magnetoresistance sides Ra~Rd (the magnetoresistance element 51 included) of the magnetoelectric conversion unit 62a arranged on the arm 24c1 of the conductor 24, and the respective magnetoresistance values ​​change. For example, the magnetoresistance values ​​of the magnetoresistance sides Ra and Rc increase (or decrease), and the magnetoresistance values ​​of the magnetoresistance sides Rb and Rd decrease (or increase), thereby destroying the magnetoresistance balance of the magnetoresistance sides Ra~Rd. Here, a driving voltage is input to the driving terminal VDD relative to the ground terminal GND, and the differential voltage output from the output terminals Npa1 and Npa2 is detected, thereby detecting the magnetic field strength. As a result, the horizontal magnetic field generated on the upper surface of the arm 24c1 can be detected.

[0047] The magnetoelectric conversion unit 62b is also constructed in the same manner as the magnetoelectric conversion unit 62a, and includes four magnetoresistive edges Re to Rh constituting a Wheatstone bridge circuit. The magnetoresistive edges Re to Rh are respectively formed by connecting the aforementioned plurality of magnetoresistive elements 51 in series. Here, among the four magnetoresistive edges Re to Rh, the magnetoresistive edge Re and the magnetoresistive edge Rf are connected in series to form an output terminal Npb1 therebetween, the magnetoresistive edge Rg and the magnetoresistive edge Rh are connected in series to form an output terminal Npb2 therebetween, the magnetoresistive edge Re and the magnetoresistive edge Rf are connected in parallel with the magnetoresistive edge Rg and the magnetoresistive edge Rh to form a drive terminal VDD between the magnetoresistive edge Rf and the magnetoresistive edge Rg, and a ground terminal GND is formed between the magnetoresistive edge Re and the magnetoresistive edge Rh.

[0048] It should be noted that in the current sensor 110 of the present embodiment, the magnetic field sensing direction (i.e., magnetic sensitive direction) from the magnetoresistive side Re to the magnetoresistive side Rh is set to be a uniaxial direction ( ) parallel to the upper surface of the conductor 24, similarly to the magnetoresistive side Ra to the magnetoresistive side Rd. Figure 1A The magnetic field sensing directions of the magnetoresistive edge Re and the magnetoresistive edge Rg (the magnetoresistive elements 51 forming the magnetoresistive edge Re and the magnetoresistive edge Rg, respectively) are the same as each other (in the longitudinal direction of the magnetoresistive edge Re and the magnetoresistive edge Rg, respectively). Figure 3 In this example, it is set to Figure 1A The magnetic field sensing directions of the magnetoresistive edge Rf and the magnetoresistive edge Rh (the magnetoresistive elements 51 forming the magnetoresistive edge Rf and the magnetoresistive edge Rh, respectively) are also the same as each other (in Figure 3 In this example, it is set to Figure 1A The magnetic field sensing direction of the magnetoresistive side Re and the magnetoresistive side Rg is opposite to the magnetic field sensing direction of the magnetoresistive side Rf and the magnetoresistive side Rh.

[0049] The magnetoelectric conversion unit 62b is arranged on the arm 24c2 of the conductor 24. 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 magnetoresistance sides Re~Rh (the magnetoresistance element 51 included) of the magnetoelectric conversion unit 62b arranged on the arm 24c2 of the conductor 24, and the respective magnetoresistance values ​​change. For example, the magnetoresistance values ​​of the magnetoresistance sides Re and Rg increase (or decrease), and the magnetoresistance values ​​of the magnetoresistance sides Rf and Rh decrease (or increase), thereby destroying the magnetoresistance balance of the magnetoresistance sides Re~Rh. Here, a driving voltage is input to the driving terminal VDD relative to the ground terminal GND, and the differential voltage output from the output terminals Npb1 and Npb2 is detected, thereby detecting the magnetic field strength.

[0050] It should be noted that, as mentioned above, the two magnetoelectric conversion parts 62a and 62b can be respectively arranged on the two arms 24c1 and 24c2 of the conductor 24. In this way, the interfering magnetic field can be eliminated. It should be noted that only one of the two magnetoelectric conversion parts 62a and 62b can be arranged on the conductor 24 (the two arms 24c1 and 24c2 or the connecting part 24c3, etc.).

[0051] The two magnetoelectric converters 62a and 62b are separated in the longitudinal direction (the width direction of the arms 24c1 and 24c2) and are respectively arranged on one side and the other side of the substrate 61. The respective drive terminals VDD, ground terminals GND and output terminals Npa1, Npa2, Npb1 and Npb2 can be connected to the electrode pads 63 on the substrate 61. #1 ~63 #6 .

[0052] Multiple electrode pads 63 #1 ~63 #6 The electrode pad 63 may be disposed on the substrate 61, connected to the power supply terminal and output terminal of the two magnetoelectric converters 62a and 62b by wiring, inputting a driving voltage from the outside to the power supply terminal and outputting a differential voltage to the outside from the output terminal. #1 ~63 #6 The conductive metal such as gold, copper or aluminum is used to form the substrate 61, and the region between the two magnetoelectric converters 62a and 62b in the longitudinal direction is formed on one side in the lateral direction ( Figure 1A and Figure 2A It should be noted that the plurality of electrode pads 63 #1 ~63 #6 They are arranged in a straight line in the longitudinal direction, but may be slightly offset in the lateral direction.

[0053] Multiple electrode pads 63 #1 ~63 #6The plurality of electrode pads 63 may be connected to the drive terminal VDD and the ground terminal GND of the two magnetoelectric conversion units 62a and 62b, the two output terminals Npa1 and Npa2 of the magnetoelectric conversion unit 62a, and the two output terminals Npb1 and Npb2 of the magnetoelectric conversion unit 62b. In other words, the plurality of electrode pads 63 may be connected to the drive terminal VDD and the ground terminal GND, the output terminals Npa1 and Npa2, and the output terminals Npb1 and Npb2. #1 ~63 #6 The configuration details are described later.

[0054] Multiple dummy pads 64 #1 ~64 #6 A test pad disposed on the substrate 61 and connected to the power supply terminals and output terminals of the two magnetoelectric converters 62a and 62b by wiring, for inputting signals to test the characteristics of the magnetoelectric converters 62a and 62b (the magneto-resistance edges Ra to Rh included therein or the magneto-resistance elements 51 constituting them). #1 ~64 #6 The conductive metal such as gold, copper or aluminum is used to form the substrate 61, and the other side ( Figure 1A and Figure 2A It should be noted that the plurality of dummy pads 64 #1 ~64 #6 They are arranged in a straight line in the longitudinal direction, but may be slightly offset in the lateral direction.

[0055] Multiple dummy pads 64 #1 ~64 #6 The dummy pads 64 are respectively connected to the drive terminals VDD and the ground terminals GND of the two magnetoelectric converters 62a and 62b, the two output terminals Npa1 and Npa2 of the magnetoelectric converter 62a, and any one of the two output terminals Npb1 and Npb2 of the magnetoelectric converter 62b. That is, the dummy pads 64 are respectively connected to the drive terminals VDD and the ground terminals GND, the output terminals Npa1 and Npa2, and the output terminals Npb1 and Npb2. #1 ~64 #6 Can be connected with multiple electrode pads 63 #1 ~63 #6 Configure in the same way.

[0056] Multiple electrode pads 63 #1 ~63 #6 and a plurality of dummy pads 64 #1 ~64 #6On the substrate 61, the two magnetoelectric converters 62a and 62b separated in the longitudinal direction are arranged on one side and the other side in the lateral direction. #1 ~63 #6 and a plurality of dummy pads 64 #1 ~64 #6 Configured in a small area on the substrate 61.

[0057] It should be noted that the plurality of dummy pads 64 #1 ~64 #6 can be connected to a plurality of electrode pads 63 #1 ~63 #6 That is, the plurality of dummy pads 64 #1 ~64 #6 can be connected to a plurality of electrode pads 63 #1 ~63 #6 The electrode pads connected to the same terminals among the six terminals of the two magnetoelectric conversion parts 62a and 62b are arranged opposite to each other in the lateral direction. #1 ~64 #6 The dummy pads connected to the ground terminals GND of the two magnetoelectric conversion units 62a and 62b can be connected to the plurality of electrode pads 63 #1 ~63 #6 The electrode pads connected to the ground terminals GND of the two magnetoelectric conversion parts 62a and 62b are connected. #1 ~64 #6 The dummy pads connected to the drive terminals VDD and output terminals Npa1, Npa2, Npb1, and Npb2 of the two magnetoelectric converters 62a and 62b are not connected to the plurality of electrode pads 63. #1 ~63 #6 The electrode pads connected to the drive terminal VDD and the output terminals Npa1, Npa2, Npb1, and Npb2 of the two magneto-electric conversion units 62a and 62b are connected.

[0058] The magnetic sensor 60 is arranged on the bent portion 24c of the conductor 24. Thus, the two magnetoelectric converters 62a and 62b are respectively arranged on the two arms 24c1 and 24c2 of the bent portion 24c, and the plurality of electrode pads 63 on the substrate 61 connected to the drive terminal VDD, the ground terminal GND and the output terminals Npa1, Npa2, Npb1 and Npb2 thereof are connected to the two magnetoelectric converters 62a and 62b. #1 ~63 #6 The device terminals 17 are connected by wire bonding. Thus, a driving voltage can be applied to the two magneto-electric converters 62a and 62b via the device terminals 17, and each differential voltage can be output.

[0059] Figure 4A and Figure 4B A plurality of electrode pads 63 are shown. #1 ~63 #6 Examples of combinations of connections to the six terminals (drive terminal VDD, ground terminal GND, and output terminals Npa1, Npa2, Npb1, and Npb2) of the magnetic sensor 60 (comparative example, samples 1 to 5). #1 ~63 #6 They are respectively connected to output terminal Npa1 (terminal potential Vdd / 2+Vout), output terminal Npa2 (Vdd / 2-Vout), drive terminal VDD (Vdd), ground terminal GND (0), output terminal Npb1 (Vdd / 2+Vout) and output terminal Npb2 (Vdd / 2-Vout). Here, the drive voltage Vdd (terminal potentials Vdd and 0) between the power supply terminals (drive terminal VDD and ground terminal GND), the magnetic resistance values ​​of magnetic resistance sides Ra and Rb, the magnetic resistance values ​​of magnetic resistance sides Rc and Rd, the magnetic resistance values ​​of magnetic resistance sides Re and Rf, and the magnetic resistance values ​​of magnetic resistance sides Rg and Rh are equal, and a magnetic field is applied to the magnetic sensor 60 (magnetoelectric conversion units 62a and 62b) to generate a differential voltage 2Vout between the output terminals Npa1 and Npa2 of the magnetoelectric conversion unit 62a, and a differential voltage 2Vout is generated between the output terminals Npb1 and Npb2 of the magnetoelectric conversion unit 62b. It should be noted that Vout<<Vdd.

[0060] When the plurality of electrode pads 63 #1 ~63 #6 When a potential difference is generated between the electrodes, ion migration progresses, that is, the electrode material dissolves and the adjacent electrode pads are short-circuited, thereby reducing the detection sensitivity of the magnetic sensor 60. Here, the dissolution rate of the electrode material based on ion migration is proportional to the amount of current i flowing between the electrode pads due to the redox reaction. The amount of current i is proportional to exp(cV) according to the Butler-Folmer equation. Here, V is the voltage between adjacent electrode pads, and c is a constant. Therefore, in order to reduce the potential difference between adjacent electrode pads, it is preferred to connect the drive terminal VDD and ground terminal GND, output terminals Npa1, Npa2, and output terminals Npb1, Npb2 of the magnetic sensor 60 to multiple electrode pads 63. #1 ~63 #6 .

[0061] In the comparative example, as described above, the six terminals of the magnetic sensor (the driving terminal VDD, the ground terminal GND, and the output terminals Npa1, Npa2, Npb1, and Npb2) are connected to the plurality of electrode pads 63. #1 ~63 #6 , adjacent electrode pads 63#1 , 63 #2 The potential difference (ie, voltage) between the electrodes becomes 2Vout, and the electrode pad 63 #2 , 63 #3 The voltage between the electrodes becomes Vdd / 2, and the electrode pad 63 #3 , 63 #4 The voltage between the electrodes becomes Vdd, and the electrode pad 63 #4 , 63 #5 The voltage between the electrodes becomes Vdd / 2, and the electrode pad 63 #5 , 63 #6 The voltage between them becomes 2Vout, and the voltage between the largest electrode pads becomes Vdd and is larger.

[0062] In Sample 1, the electrode pad 63 #1 ~63 #6 The electrode pad 63 is 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 (0), and the output terminal Npb2 (Vdd / 2-Vout). #1 , 63 #2 The potential difference (ie, voltage) between the electrodes becomes Vdd / 2, and the electrode pad 63 #2 , 63 #3 The voltage between the electrodes becomes Vdd / 2, and the electrode pad 63 #3 , 63 #4 The voltage between the electrodes becomes 2Vout, and the electrode pad 63 #4 , 63 #5 The voltage between the electrodes becomes Vdd / 2, and the electrode pad 63 #5 , 63 #6 The voltage between the electrodes becomes Vdd / 2, and the maximum voltage between the electrode pads becomes Vdd / 2, which is half of that in the comparative example. However, the number of locations to which the maximum voltage is applied increases to four compared to one in the comparative example.

[0063] In Sample 2, the electrode pad 63 #1 ~63 #6 The electrode pad 63 is 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 (0), and the output terminal Npb1 (Vdd / 2+Vout). #1 , 63 #2 The potential difference (ie, voltage) between the electrodes becomes Vdd / 2, and the electrode pad 63 #2, 63 #3 The voltage between the electrodes becomes Vdd / 2, and the electrode pad 63 #3 , 63 #4 The voltage between the electrodes becomes 0, and the electrode pad 63 #4 , 63 #5 The voltage between the electrodes becomes Vdd / 2, and the electrode pad 63 #5 , 63 #6 The voltage between the electrodes becomes Vdd / 2, and the maximum voltage between the electrode pads becomes Vdd / 2, which is half of that in the comparative example. However, the number of locations to which the maximum voltage is applied increases to four compared to one in the comparative example.

[0064] In sample 3, the electrode pad 63 #1 ~63 #6 The electrode pad 63 is 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 (0), and the output terminal Npb2 (Vdd / 2-Vout). #1 , 63 #2 The potential difference (ie, voltage) between the electrodes becomes Vdd / 2, and the electrode pad 63 #2 , 63 #3 The voltage between the electrodes becomes 0, and the electrode pad 63 #3 , 63 #4 The voltage between the electrodes becomes 2Vout, and the electrode pad 63 #4 , 63 #5 The voltage between the electrodes becomes Vdd / 2, and the electrode pad 63 #5 , 63 #6 The voltage between the electrodes becomes Vdd / 2, and the voltage between the maximum electrode pads becomes Vdd / 2, which is half of that in the comparative example, but the number of locations where the maximum voltage is applied increases to three compared to one in the comparative example. However, the number of locations where the maximum voltage is applied decreases to three compared to four in samples 1 and 2.

[0065] In Sample 4, the electrode pad 63 #1 ~63 #6 The electrode pad 63 is connected to the driving 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 (0). #1 , 63 #2 The potential difference (ie, voltage) between the electrodes becomes Vdd / 2, and the electrode pad 63 #2 , 63#3 The voltage between the electrodes becomes 0, and the electrode pad 63 #3 , 63 #4 The voltage between the electrodes becomes 2Vout, and the electrode pad 63 #4 , 63 #5 The voltage between the electrodes becomes 0, and the electrode pad 63 #5 , 63 #6 The voltage between the electrodes becomes Vdd / 2, and the voltage between the maximum electrode pads becomes Vdd / 2, which is half of that in the comparative example, but the number of locations where the maximum voltage is applied increases to two compared to one in the comparative example. However, the number of locations where the maximum voltage is applied decreases to two compared to four in samples 1 and 2.

[0066] According to the investigation of samples 1 to 4, the maximum potential is applied to the driving terminal VDD (terminal potential Vdd), and the minimum potential is applied to the ground terminal GND (0). Therefore, 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, the maximum voltage between pads can be reduced (in this example, to about one-half). In particular, from the perspective of reducing the number of sites where migration occurs, it is preferred that the number of sites where the maximum voltage is applied is small, and sample 4 among samples 1 to 4 is preferred.

[0067] The substrate 61 of the magnetic sensor 60 is disposed on the conductor 24. Therefore, the conductor 24 generates heat due to the flow of the measured current, and the substrate 61 is heated. #1 ~63 #6 Thermal electromotive force is generated at the bonding surface of the wire bond and inside the Wheatstone bridge, which may cause a decrease in accuracy due to offset. It should be noted that thermal electromotive force is a phenomenon in which a potential difference is generated between the bonding interface when the temperature of the two ends of the material is different when the temperature is left at a certain temperature.

[0068] It is preferable to arrange the electrode pads connected to the two output terminals Npa1 and Npa2 of the magnetoelectric converter 62a on the inner or outer side of the electrode pads connected to the two output terminals Npb1 and Npb2 of the magnetoelectric converter 62b. Thus, the electrode pads connected to the two output terminals Npa1 and Npa2 of the magnetoelectric converter 62a are separated from the two arms 24c1 and 24c2 of the conductor 24 by equal distances or substantially equal distances, and the electrode pads connected to the two output terminals Npb1 and Npb2 of the magnetoelectric converter 62b are separated from the two arms 24c1 and 24c2 of the conductor 24 by equal distances or substantially equal distances, thereby, the conductor 24 is heated evenly due to the heat generated, so that the temperature difference is reduced, and the deviation caused by the thermoelectromotive force can be suppressed.

[0069] More preferably, the electrode pads connected to the two output terminals Npa1 and Npa2 of the magnetoelectric converter 62a are arranged at symmetrical positions in the longitudinal direction, and the electrode pads connected to the two output terminals Npb1 and Npb2 of the magnetoelectric converter 62b are arranged at symmetrical positions in the longitudinal direction, based on the symmetry line L passing through the center of the substrate 61 in the longitudinal direction. The magnetic sensor 60 is arranged on the conductor 24 in such a manner that the symmetry line L of the substrate 61 overlaps with the center line of the conductor 24, thereby the electrode pads connected to the two output terminals Npa1 and Npa2 of the magnetoelectric converter 62a are separated from the two arms 24c1 and 24c2 of the conductor 24 by equal or substantially equal distances, and the electrode pads connected to the two output terminals Npb1 and Npb2 of the magnetoelectric converter 62b are separated from the two arms 24c1 and 24c2 of the conductor 24 by equal or substantially equal distances, and the conductor 24 is heated evenly by heat, so that the temperature difference is reduced, and the offset caused by the thermoelectromotive force can be suppressed.

[0070] In sample 5, the electrode pad 63 #1 ~63 #6 The electrode pad 63 is connected to the driving 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 (0). #1 , 63 #2 The potential difference between the electrodes becomes Vdd / 2, and the electrode pad 63 #2 , 63 #3 The potential difference between the electrodes becomes 0, and the electrode pad 63 #3 , 63 #4 The potential difference between the electrodes becomes 2Vout, and the electrode pad 63 #4 , 63 #5The potential difference between the electrodes becomes 0, and the electrode pad 63 #5 , 63 #6 The potential difference between the electrodes becomes Vdd / 2, and the maximum voltage between the electrode pads becomes Vdd / 2 as in Sample 4, and there are two locations where the maximum voltage is applied. In addition, as described above, the two output terminals Npa1 and Npa2 of the magnetoelectric converter 62a are connected to the electrode pads 63, respectively. #2 , 63 #5 The two output terminals Npb1 and Npb2 of the magnetoelectric converter 62b are connected to the electrode pads 63. #3 , 63 #4 , the electrode pads connected to the two output terminals Npa1 and Npa2 of the magnetoelectric converter 62a are symmetrically arranged, and the electrode pads connected to the two output terminals Npb1 and Npb2 of the magnetoelectric converter 62b are symmetrically arranged based on the symmetry line L of the substrate 61. Thus, the offset caused by the thermoelectromotive force can be suppressed.

[0071] It should be noted that the plurality of dummy pads 64 #1 ~64 #6 Also follows with a plurality of electrode pads 63 #1 ~63 #6 By configuring on the substrate 61 in the same principle, migration and displacement can be suppressed.

[0072] If the plurality of electrode pads 63 #1 ~63 #6 If the magnetic resistance balance of the wiring connected to the six terminals of the magnetic sensor is destroyed, the midpoint potential (the potential at the output terminals Npa1, Npa2, Npb1, and Npb2) of the Wheatstone bridge circuit included in the magnetoelectric conversion units 62a and 62b will shift, and the differential voltage output from the output terminals Npa1, Npa2, Npb1, and Npb2 will shift (thereby, the bias point of the differential amplifier circuit connected to the output terminals will shift), and the detection accuracy of the magnetic sensor 60 may decrease. Therefore, it is particularly preferred to connect the plurality of electrode pads 63 #1 ~63 #6 The magnetic resistance of the wiring connected to the driving terminal VDD and the ground terminal GND of the magnetic sensor is consistent.

[0073] Figure 5 A plurality of electrode pads 63 are shown. #1 ~63 #6 The sample 5 (refer to the sample 5) shows the combination of the connection with the six terminals (drive terminal VDD, ground terminal GND, and output terminals Npa1, Npa2, Npb1, and Npb2) of the magnetic sensor 60. Figure 4B ) is an example of wiring layout in the example. In sample 5, the electrode pad 63 #1 ~63 #6They are respectively 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. It should be noted that the wiring is set to be connected at the intersections indicated by black circles, and at the intersections without black circles, they are separated up and down through, for example, an insulating layer.

[0074] Here, the electrode pad 63 extends from the driving terminal of the magnetoelectric converter 62a (the connection point 65a of the magnetoresistive sides Rb and Rc) to the electrode pad 63. #1 The wiring 66a (indicated by a single-dot chain line in the figure) has a length greater than that extending from the drive terminal of the magnetoelectric converter 62b (the connection point 65b of the magnetoresistance sides Rf and Rg) to the electrode pad 63. #1 The wiring 66a (indicated by a double-dashed line in the figure) is longer and has a larger cross-sectional area. Alternatively, the wiring 66a may have a shorter and smaller cross-sectional area than the wiring 66b. It is more preferable that the product of the length and the cross-sectional area of ​​the wiring 66a and the wiring 66b is equal or approximately equal. That is, the wiring 66a is extended from the drive terminal of the magnetoelectric conversion unit 62a (the connection point 65a of the magnetic resistance edges Rb and Rc) to the electrode pad 63 #1 The wiring 66a has a connection point 65b extending from the drive terminal of the magneto-electric conversion unit 62b (the connection point 65b of the magnetoresistive edges Rf and Rg) to the electrode pad 63. #1 The wiring 66b has equal or substantially equal magnetic resistance values.

[0075] Furthermore, the electrode pad 63 extends from the ground terminal of the magneto-electric conversion unit 62a (the connection point 67a of the magnetoresistive sides Ra and Rd) to the electrode pad 63. #6 The wiring 68a (indicated by a thick dotted line in the figure) has a length greater than that extending from the ground terminal of the magnetoelectric converter 62b (the connection point 67b of the magnetoresistance edges Re and Rh) to the electrode pad 63. #6 Alternatively, the wiring 68a may have a longer cross-sectional area than the wiring 68b. That is, the wiring 68a extends from the ground terminal (the connection point 67a of the magnetic resistance edges Ra and Rd) of the magnetoelectric conversion unit 62a to the electrode pad 63. #6 The wiring 68a has a connection point 67b extending from the ground terminal of the magneto-electric conversion unit 62b (the connection point 67b of the magnetoresistance edges Re and Rh) to the electrode pad 63. #6 The wiring 68b has equal or substantially equal magnetic resistance values.

[0076] As a result, the operating points of the differential voltage outputted between the output terminals Npa1 and Npa2 and the differential voltage outputted from the output terminals Npb1 and Npb2 coincide with each other, and the detection accuracy of the magnetic sensor 60 can be maintained.

[0077] By placing a plurality of electrode pads 63 #1 ~63 #6The six terminals (drive terminal VDD, ground terminal GND, and output terminals Npa1, Npa2, Npb1, and Npb2) of the magnetic sensor 60 are connected to form a wiring loop. Since the magnetic flux passes through the loop, an induced electromotive force is generated on the wiring, and the detection accuracy of the magnetic sensor 60 may be reduced. Therefore, it is preferable to lay the wiring in a way to avoid forming a wiring loop.

[0078] Figure 6 A plurality of electrode pads 63 are shown. #1 ~63 #6 The sample 5 (refer to the sample 5) shows the combination of the connection with the six terminals (drive terminal VDD, ground terminal GND, and output terminals Npa1, Npa2, Npb1, and Npb2) of the magnetic sensor 60. Figure 4B ) is another example of wiring layout. In sample 5, the electrode pad 63 #1 ~63 #6 They are respectively 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. It should be noted that the wiring is set to be connected at the intersections indicated by black circles, and at the intersections without black circles, they are separated up and down through, for example, an insulating layer.

[0079] The electrode pad 63 includes a portion extending from the driving terminal of the magnetoelectric converter 62a (the connection point 65a of the magnetoresistive sides Rb and Rc) to the electrode pad 63. #1 The wiring 66a (indicated by a single-dot chain line in the figure) extends from the drive terminal of the magnetoelectric conversion unit 62b (the connection point 65b of the magnetic resistance sides Rf and Rg) to the electrode pad 63 #1 The wiring pair of the wiring 66b (indicated by a double-dashed line in the figure) is connected to the electrode pad 63 in the top view and includes the ground terminal (connection point 67a of the magnetoresistance side Ra, Rd) extending from the magnetoelectric conversion portion 62a to the electrode pad 63. #6 The wiring 68a (indicated by a thick dotted line in the figure) extends from the ground terminal of the magnetoelectric conversion unit 62b (the connection point 67b of the magnetoresistive edges Re and Rh) to the electrode pad 63 #6 The wiring pair of wiring 68a, 68b (indicated by a thick line in the figure) is arranged on the substrate 61 so as to overlap at least partially. In this example, the entire length of the wiring pair 68a, 68b overlaps the wiring pair 66a, 66b. Figure 6 In the figure, for the convenience of illustration, the two wiring pairs (66a, 66b, 68a, 68b) are slightly offset. Thus, since the two wiring pairs do not form a wiring loop, the generation of induced electromotive force on the wiring can be suppressed, thereby maintaining the detection accuracy of the magnetic sensor 60.

[0080] It should be noted that the six terminals of the magnetic sensor 60 are connected to the plurality of dummy pads 64. #1~64 #6 The wiring can also be connected to the plurality of electrode pads 63 #1 ~63 #6 The wiring is laid on the substrate 61 in the same principle.

[0081] A method for manufacturing the current sensor 110 will be described.

[0082] like Fig. 7A 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).

[0083] Next, the pattern is subjected to step processing to provide steps in the plurality of device terminals 17 and the conductors 24. Thus, the inner portion of the pattern is raised relative to the frame and the above-mentioned terminal portion connected to the frame.

[0084] like Figure 7B As shown, next, the magnetic sensor 60 is provided. Here, two magneto-electric converters 62a and 62b are disposed on the arms 24c1 and 24c2 of the conductor 24, respectively.

[0085] like Figure 7C As shown, next, the magnetic sensor 60 is connected to the plurality of device terminals 17 by wire bonding.

[0086] like Fig.7D As shown, the pattern is then molded while leaving the frame and the plurality of device terminals 17 connected to the frame and the terminal portions of the conductors 24. Thus, the package 9 is formed, in which the magnetic sensor 60 and the inner portion of the pattern are sealed.

[0087] 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.

[0088] It should be noted that the current sensor 110 may also include a signal processing device for processing the output signal of the magnetic sensor 60 to calculate the amount of the measured current flowing through the conductor 24, and a substrate for supporting the signal processing device (both not shown). The signal processing device 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 60, and a temperature correction circuit for correcting the output according to the temperature. The signal processing device may be supported on the substrate and connected to the magnetic sensor 60 (a plurality of electrode pads 63) by wire bonding. #1 ~63 #6) and multiple device terminals 17. Alternatively, the signal processing device can be built into the substrate 61 having the magnetic sensor 60, and the electrode pad 63 #1 ~63 #6 The input / output terminals of the signal processing device are connected to the plurality of device terminals 17 by wire bonding. Thus, the signal processing device outputs the calculation result of the amount of the measured current flowing through the conductor 24 via the plurality of device terminals 17.

[0089] The magnetic sensor 60 of the present embodiment comprises: a substrate 61; a plurality of magnetoresistive elements 51 arranged on the substrate 61, a portion of the plurality of magnetoresistive elements 51 forming a Wheatstone bridge circuit to form a magnetoelectric conversion portion 62a, and another portion of the plurality of magnetoresistive elements 51 forming a Wheatstone bridge circuit to form a magnetoelectric conversion portion 62b; a plurality of electrode pads 63 #1 ~63 #6 , arranged on the substrate 61, including a first electrode pad connected to the driving terminal VDD of the magnetoelectric conversion parts 62a and 62b, a second electrode pad connected to the ground terminal GND of the magnetoelectric conversion parts 62a and 62b, a third electrode pad and a fourth electrode pad respectively connected to the two output terminals Npa1 and Npa2 of the magnetoelectric conversion part 62a, a fifth electrode pad and a sixth electrode pad respectively connected to the two output terminals Npb1 and Npb2 of the magnetoelectric conversion part 62b, and at least one electrode pad from the third electrode pad to the sixth electrode pad is arranged between the first electrode pad and the second electrode pad in the direction of separation from the first electrode pad and the second electrode pad. Thus, by arranging at least one electrode pad from the third to the sixth electrode pads between the first electrode pad and the second electrode pad that generate the maximum potential difference, the voltage difference between the adjacent electrode pads is reduced compared to the maximum voltage difference, thereby being able to suppress the migration of the electrode pads.

[0090] The current sensor 110 of the present embodiment includes: a conductor 24 through which the measured current flows; a magnetic sensor 60 disposed on the conductor 24; and a plurality of device terminals 17 respectively connected to the first electrode pad to the sixth electrode pad of the magnetic sensor 60. Thus, by using the magnetic sensor 60 in which the migration of the electrode pad is suppressed, a highly reliable current sensor 110 can be provided.

[0091] It should be noted that, although the magnetic sensor 60 is assumed to include two magneto-electric converters 62 a and 62 b , it may include only one instead.

[0092] It should be noted that, in the current sensor 110 of the present embodiment, the plurality of electrode pads 63 of the magnetic sensor 60 are set to #1 ~63 #6 The device terminal 17 is connected by wire bonding, but instead of this, a plurality of dummy pads 64 may be connected to the device terminal 17.#1 ~64 #6 The device terminal 17 is connected by wire bonding. In this case, the plurality of electrode pads 63 may be #1 ~63 #6 The test pads are used as signal input pads for testing the characteristics of the magneto-electric converters 62 a and 62 b (the magneto-resistance sides Ra to Rh included therein or the magneto-resistance elements 51 constituting the magneto-resistance sides Ra to Rh).

[0093] It should be noted that the magnetic field sensing direction (i.e., magnetic sensitive direction) of the magnetoresistive edges Ra to Rh (magnetoresistive element 51) included in the two magnetoelectric conversion parts 62a and 62b of the magnetic sensor 60 can be set to a vertical direction perpendicular to the upper surface of the conductor 24, and one of the two magnetoelectric conversion parts 62a and 62b can be arranged in the interval area surrounded by the curved part 24c of the conductor 24. In this way, the magnetic sensor 60 can detect the vertical magnetic field (in this case, Figure 1A Furthermore, the other of the two magneto-electric conversion parts 62a and 62b can be arranged near the outside of one of the two arms 24c1 and 24c2 of the conductor 24. Thus, the interfering magnetic field can be eliminated.

[0094] 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.

[0095] 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 current sensor comprising a conductor through which a current to be measured flows and a magnetic sensor arranged on the conductor, wherein: The magnetic sensor has: substrate; A plurality of magnetoresistive elements are arranged on the substrate, a part of the plurality of magnetoresistive elements forms a Wheatstone bridge circuit to form a first sensor, and another part of the plurality of magnetoresistive elements forms a Wheatstone bridge circuit to form a second sensor; and A plurality of electrode pads are arranged on the substrate, including a first electrode pad connected to the driving terminals of the first sensor and the second sensor, a second electrode pad connected to the ground terminals of the first sensor and the second sensor, a third electrode pad and a fourth electrode pad respectively connected to the two output terminals of the first sensor, and a fifth electrode pad and a sixth electrode pad respectively connected to the two output terminals of the second sensor, and at least one electrode pad from the third electrode pad to the sixth electrode pad is arranged between the first electrode pad and the second electrode pad in a first direction in which the first electrode pad is separated from the second electrode pad.

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

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

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

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

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

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

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

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

10. The current sensor according to claim 9, wherein: The conductor includes a first arm and a second arm separated from each other 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 first sensor and the second sensor are respectively disposed on the first arm and the second arm.

11. The current sensor according to claim 10, wherein: The conductor has a connecting portion that physically connects the first arm and the second arm. The first arm and the second arm extend toward the same side relative to the connection portion.

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

13. The current sensor according to claim 12, wherein: The current sensor further includes a plurality of device terminals, and the plurality of device terminals respectively connect the first electrode pad to the sixth electrode pad.

14. The current sensor according to claim 12, wherein: The magnetic sensor further includes a plurality of dummy pads, which are arranged on the substrate, including a first dummy pad connected to the driving terminals of the first sensor and the second sensor, a second dummy pad connected to the ground terminals of the first sensor and the second sensor, a third dummy pad and a fourth dummy pad respectively connected to the two output terminals of the first sensor, and a fifth dummy pad and a sixth dummy pad respectively connected to the two output terminals of the second sensor. The first to sixth dummy pads are respectively arranged to face the first to sixth electrode pads on the other side of the direction intersecting the first direction in a region 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 arranged on the conductor, wherein: The magnetic sensor has: substrate; A plurality of magnetoresistive elements are arranged on the substrate, a portion of the plurality of magnetoresistive elements form a Wheatstone bridge circuit to form a first sensor, and another portion of the plurality of magnetoresistive elements form a Wheatstone bridge circuit to form a second sensor; and A plurality of dummy pads are arranged on the substrate, including a first dummy pad connected to the driving terminals of the first sensor and the second sensor, a second dummy pad connected to the ground terminals of the first sensor and the second sensor, a third dummy pad and a fourth dummy pad respectively connected to the two output terminals of the first sensor, and a fifth dummy pad and a sixth dummy pad respectively connected to the two output terminals of the second sensor, and at least one dummy pad from 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 is separated from the second dummy pad.

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