Current sensor and electronic device

Abstract

This current sensor comprises a bus bar and a magnetic sensor. The bus bar may have: a first conductive member and a second conductive member that are disposed facing each other with the magnetic sensor interposed therebetween; a first connection member that is disposed between the first conductive member and the second conductive member and connects the first conductive member and the second conductive member; and a second connection member that is disposed between the first conductive member and the second conductive member with a gap from the first connection member and connects the first conductive member and the second conductive member. The first conductive member may include a first flow path part and a second flow path part extending in a first direction, and a first connection part extending in a second direction forming an angle larger than 0 degrees and smaller than 180 degrees with the first direction and connecting the first flow path part and the second flow path part. The second conductive member may include a third flow path part and a fourth flow path part extending in the first direction, and a second connection part extending in the second direction and connecting the third flow path part and the fourth flow path part.

Description

Current sensor and electronic device

[0001] The present invention relates to a current sensor and an electronic device.

[0002] Patent Documents 1 and 2 disclose that, in a bus bar having two flow paths at different heights in the thickness direction, a magnetic sensor is disposed between the two flow paths so as to overlap the two flow paths in plan view. Patent Document 3 discloses that, in a bus bar having two flow paths at different heights in the thickness direction, a magnetic sensor is disposed between the two flow paths so as to overlap the two flow paths in plan view, or two independent bus bars are disposed at different heights in the thickness direction. [Prior Art Documents] [Patent Documents] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2021-36199 [Patent Document 2] U.S. Patent Application Publication No. 2020 / 0300894 [Patent Document 3] International Publication No. WO 2017 / 010219 General Disclosure

[0003] (Problem to be Solved) It is desired to improve the ease of mounting a magnetic sensor on an electronic module or the like while suppressing fluctuations in magnetic field intensity due to differences in the frequency of an alternating current measured by a current sensor including the magnetic sensor. (Means for Solving the Problem)

[0004] A current sensor according to one aspect of the present invention may include a busbar through which a measurement current flows, and a magnetic sensor having at least two magnetoelectric conversion elements for detecting a magnetic field generated by the measurement current flowing through the busbar. The busbar may have a first conductive member and a second conductive member arranged opposite to each other with the magnetic sensor in between. The busbar may have a first connecting member arranged between the first conductive member and the second conductive member and connecting the first conductive member and the second conductive member. The busbar may have a second connecting member arranged between the first conductive member and the second conductive member with a gap between it and the first connecting member and connecting the first conductive member and the second conductive member. The first conductive member may include a first flow path portion and a second flow path portion extending in a first direction, and a first connecting portion extending in a second direction that forms an angle greater than 0 degrees and less than 180 degrees with the first direction and connecting the first flow path portion and the second flow path portion. The second conductive member may include a third flow channel portion and a fourth flow channel portion extending in the first direction, and a second connecting portion extending in the second direction and connecting the third flow channel portion and the fourth flow channel portion.

[0005] In the current sensor, the first connecting member may be connected to one end of the first conductive member and one end of the second conductive member. The second connecting member may be connected to the other end of the first conductive member and the other end of the second conductive member.

[0006] In any of the current sensors, the first conductive member and the second conductive member may overlap each other when viewed from a third direction intersecting the first and second directions.

[0007] In any of the current sensors, the at least two magnetoelectric conversion elements may have a sensitivity direction in a plane intersecting the first direction.

[0008] In any of the current sensors, the at least two magnetoelectric conversion elements may be a vertical Hall element, a horizontal Hall element with a magnetic focusing plate, or a magnetoresistive element.

[0009] In any of the current sensors, the magnetic sensor may be positioned at a location through which a straight line connecting the centers of gravity of the first and second connecting portions passes.

[0010] In any of the current sensors, the length of the extension of the first connecting portion and the second connecting portion may be smaller than the length of the extension of the first flow path portion, the second flow path portion, the third flow path portion, and the fourth flow path portion.

[0011] In any of the current sensors, the current sensor may be positioned on a protrusion that extends from the edge of a base board on which a power conversion circuit that outputs the measured current to the busbar is mounted, and may be fixed to the busbar at a predetermined position via the base board.

[0012] In any of the current sensors, the magnetic sensor may be arranged on a first surface, and the first surface may be supported by a first connecting portion and a second connecting portion.

[0013] In any of the current sensors, the length of the first connecting portion and the second connecting portion may be greater than the length of the first flow path portion, the second flow path portion, the third flow path portion, and the fourth flow path portion.

[0014] In any of the current sensors, the angle that the second direction makes with respect to the first direction may be greater than 90 degrees and less than 180 degrees.

[0015] In any of the current sensors, the angle that the second direction makes with respect to the first direction may be 35 degrees or more and less than 90 degrees.

[0016] In any of the current sensors, if the distance between the first conductive member and the second conductive member in a third direction intersecting the first and second directions is defined as the first distance, and the distance between the first flow channel and the second flow channel when viewed from the first direction is defined as the second distance, then if the first distance is greater than the second distance, two or more of the at least two magnetoelectric conversion elements may be arranged along the third direction. If the second distance is greater than the first distance, then two or more of the at least two magnetoelectric conversion elements may be arranged along the direction in which the first flow channel and the second flow channel separate from each other when viewed from the first direction.

[0017] In any of the current sensors, the at least two magnetoelectric conversion elements may include a first magnetoelectric conversion element, a second magnetoelectric conversion element, and a third magnetoelectric conversion element. The third magnetoelectric conversion element may be positioned so as not to overlap with the line including the first magnetoelectric conversion element and the second magnetoelectric conversion element.

[0018] In any of the current sensors, the first magnetoelectric conversion element and the second magnetoelectric conversion element may be first type magnetoelectric conversion elements. The third magnetoelectric conversion element may be second type magnetoelectric conversion elements.

[0019] In any of the current sensors, the first magnetoelectric conversion element and the second magnetoelectric conversion element may be magnetoelectric conversion elements having a first magnetic field range. The third magnetoelectric conversion element may be a magnetoelectric conversion element having a second magnetic field range different from the first magnetic field range.

[0020] Any of the current sensors may further include an auxiliary conductive member that extends in the first direction and is provided between the first conductive member and the second conductive member when viewed from the first direction.

[0021] In any of the current sensors, the auxiliary conductive member may be connected to at least one of the first connecting member and the second connecting member.

[0022] In one aspect of the present invention, the electronic device may include the current sensor, a power conversion circuit that converts direct current to alternating current, a housing that houses the power conversion circuit, and a power module that extends from the side of the housing and has an output terminal that outputs the alternating current output from the power conversion circuit. The busbar may be provided outside the housing and electrically connected to the output terminal.

[0023] In one aspect of the present invention, the electronic device may include the current sensor, a power conversion circuit that converts direct current to alternating current and outputs it to the busbar, and a power module having a housing. The current sensor may be provided inside the housing.

[0024] It should be noted that the above summary of the invention does not enumerate all of its features. Subcombinations of these features may also constitute an invention.

[0025] This figure shows an example of a perspective view of an electronic device according to the first embodiment. This is a side view of the electronic device according to the first embodiment, viewed from the side of the busbar. This is a perspective view of the busbar according to the first embodiment. This is a plan view of the busbar according to the first embodiment, viewed from the y-axis direction. This is a plan view of the busbar according to the first embodiment, viewed from the x-axis direction. This figure shows the magnetic flux density distribution when a 100 Hz alternating current is passed through the busbar according to the first embodiment. This is a perspective view of a current sensor according to a comparative example. This figure shows the magnetic flux density distribution when a 100 Hz alternating current is passed through the busbar according to a comparative example. This figure is for explaining the relationship between the current flowing through the busbar and the magnetic flux density distribution. This figure shows a graph of the simulation results regarding the magnetic field strength when using the busbar according to the first embodiment. This figure is for explaining the length of the protrusion on which the magnetic sensor is mounted. This figure is for explaining the relationship between the length of the busbar and the heat dissipation performance. This is a side view of an electronic device according to a modified example in which the arrangement of the magnetic sensor is changed, viewed from the side of the busbar. This is a perspective view of the busbar, protrusion, and magnetic sensor according to a modified example in which the arrangement of the magnetic sensor is changed. This figure is for explaining the angle θ in the second direction in which the first connecting portion and the second connecting portion extend. This figure illustrates the angle θ in the second direction to which the first and second connecting parts extend. This figure illustrates the angle θ in the second direction to which the first and second connecting parts extend. This figure shows the magnetic flux density distribution when a 100 Hz alternating current is passed through a busbar when the angle θ in the second direction to which the first and second connecting parts extend is 45 degrees. This figure shows the relationship between the frequency of the measured current and the rate of change of the magnetic field with respect to 0 Hz detected by the magnetic sensor, for each magnitude of the angle θ in the second direction to which the first and second connecting parts extend. This figure shows an example in which a magnetic sensor having four magnetoelectric conversion elements is arranged on a busbar according to the first embodiment. This figure shows the magnetic flux density distribution when a 100 Hz alternating current is passed through a busbar according to the first embodiment, along with the positions of the four magnetoelectric conversion elements. This is a perspective view of a modified busbar. This is a perspective view of a busbar according to the second embodiment. This figure shows the magnetic flux density distribution when a 50 kHz alternating current is passed through a busbar according to the second embodiment.This figure shows the simulation results illustrating the relationship between the frequency of the measured current flowing through the busbars of the first embodiment and the busbars of the second embodiment, respectively, and the rate of change of the magnetic field, relative to 0 Hz, detected by the magnetic sensor. This figure also shows an example of the circuit configuration of the electronic device 10 equipped with the busbars and the magnetic sensor.

[0026] The following embodiments are not intended to limit the claims of the invention. Not all combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0027] Figure 1A shows an example of a perspective view of an electronic device 10 according to the first embodiment. The electronic device 10 comprises a magnetic sensor 20, a busbar 100, a power module 30, a substrate 40, and a substrate 44. Figure 1B is a side view of the electronic device 10 as seen from the side of the busbar 100.

[0028] The power module 30 has a plurality of output terminals 32. The plurality of output terminals 32 are arranged at intervals along one side of the power module 30. The power module 30 is a power conversion circuit that converts DC to AC. The power module 30 converts DC to three-phase AC. Note that the number and position of the output terminals 32 provided by the power module 30 are not limited to the configuration shown in Figures 1A and 1B.

[0029] In Figure 1A, the direction in which the multiple output terminals 32 are arranged is the x-axis, the direction in which the multiple output terminals 32 protrude is the y-axis, and the direction that intersects the magnetic sensing surface of the magnetic sensor 20 is the z-axis.

[0030] The magnetic sensor 20 is mounted on the substrate 40, and the power module 30 is mounted on the substrate 44. The substrates 40 and 44 may be fixed to a housing that houses the power module 30. In the first embodiment, the substrate 40 on which the magnetic sensor 20 is mounted and the substrate 44 on which the power module 30 is mounted are separate, but the magnetic sensor 20 and the power module 30 may be mounted on a single substrate. The magnetic sensor 20, the substrate 40, and the busbar 100 may be provided inside the housing that houses the power module 30. The magnetic sensor 20, the substrate 40, and the busbar 100 may be provided outside the housing that houses the power module 30.

[0031] The substrate 40 has a plurality of protrusions 42 that protrude from the edge 41. The plurality of magnetic sensors 20 are arranged on each of the plurality of protrusions 42. The magnetic sensors 20 are arranged on the protrusions 42 and may be fixed to a predetermined position relative to the busbar 100 via the substrate 40. The substrates 40 and 44 may constitute a master board on which a power conversion circuit that outputs a measurement current to the busbar 100 is mounted. The master board may consist of separate substrates 40 and 44, or it may consist of a single substrate in which substrates 40 and 44 are integrally formed. The magnetic sensors 20 are arranged on the protrusions 42 that protrude from the edge of the master board and may be fixed to a predetermined position relative to the busbar 100 via the master board. The magnetic sensor 20 has two magnetoelectric conversion elements that detect the magnetic field generated by the measurement current flowing through the busbar 100. The magnetic sensor 20 incorporates two magnetoelectric conversion elements having magnetosensitive surfaces. The magnetic sensor 20 may have three or more magnetoelectric conversion elements.

[0032] In the first embodiment, the multiple magnetic sensors 20 are mounted on the side of the substrate 40 opposite to the side facing the power module 30. However, if the positional relationship between the magnetic sensors 20 and the busbar 100 satisfies the relationship described later, the multiple magnetic sensors 20 may be mounted on the side of the substrate 40 facing the power module 30. The magnetic sensors 20 may be mounted on either side of the protrusion 42. Regardless of which side of the protrusion 42 the magnetic sensors 20 are positioned on, it means that the magnetic sensors 20 are positioned on the protrusion 42.

[0033] Multiple busbars 100 are fixed to each of the multiple output terminals 32. The busbars 100 may be welded to the output terminals 32. A magnetic sensor 20 detects the magnetic field generated by the measured current flowing through the busbars 100, and the magnetic sensor 20 outputs a signal corresponding to the magnitude of the magnetic field as a signal indicating the current value of the measured current flowing through the busbars 100. In other words, the busbars 100 and the magnetic sensor 20 constitute a current sensor.

[0034] It is preferable that the multiple protrusions 42 are arranged so as not to come into contact with the busbar 100. This makes it easier to ensure insulation between the busbar 100 and the magnetic sensor 20.

[0035] Figure 2A is a perspective view of the busbar 100. Figure 2B is a plan view of the busbar 100 as seen from the y-axis direction. Figure 2C is a plan view of the busbar 100 as seen from the x-axis direction.

[0036] The busbar 100 includes a first conductive member 101, a second conductive member 110, a first connecting member 112, and a second connecting member 114. The first conductive member 101 and the second conductive member 110 are arranged facing each other with the magnetic sensor 20 in between. The busbar 100 may be made of a conductive material mainly composed of copper or aluminum.

[0037] The second connecting member 114 may be fixed to the output terminal 32 by welding or the like. The power module 30 converts the DC current from a current source such as a battery into AC current, and the AC current flows from the output terminal 32 through the second connecting member 114 as a measurement current and is supplied to a motor or the like, which is a drive source, via the first conductive member 101, the second conductive member 110, and the first connecting member 112. As the AC current flows through the first conductive member 101 and the second conductive member 110 as a measurement current, the magnetic sensor 20 detects the magnetic field generated by the measurement current flowing through the busbar 100.

[0038] The first connecting member 112 is positioned between the first conductive member 101 and the second conductive member 110, connecting the first conductive member 101 and the second conductive member 110. The second connecting member 114 is positioned between the first conductive member 101 and the second conductive member 110, with a gap between it and the first connecting member 112, connecting the first conductive member 101 and the second conductive member 110. The first connecting member 112 is connected to one end of the first conductive member 101 and one end of the second conductive member 110. The second connecting member 114 is connected to the other end of the first conductive member 101 and the other end of the second conductive member 110.

[0039] The first conductive member 101 includes a first flow channel 102, a second flow channel 104, and a first connecting portion 103. The first flow channel 102 and the second flow channel 104 extend in a first direction (z-axis direction). The first connecting portion 103 extends in a second direction that forms an angle θ greater than 0° and less than 180° with the first direction, connecting the first flow channel 102 and the second flow channel 104. The first flow channel 102 and the second flow channel 104 extend in a direction intersecting the magnetic sensing surfaces 12a and 12b of the magnetoelectric conversion elements 11a and 11b provided by the magnetic sensor 20. The first flow channel 102 and the second flow channel 104 are separated in the y-axis direction when viewed from the z-axis direction. The first flow channel 102 and the second flow channel 104 may extend in a direction perpendicular to the magnetic sensing surfaces 12a and 12b of the magnetoelectric conversion elements 11a and 11b. The first connecting portion 103 may extend in a direction along the magnetic sensing surfaces 12a and 12b of the magnetoelectric conversion elements 11a and 11b. The first connecting portion 103 may extend in a direction along the y-axis. As shown in Figure 2C, the angle θ is determined by the angle between the first connecting portion 103 and the first flow path portion 102 extending in the first direction.

[0040] The second conductive member 110 includes a third flow channel 106, a fourth flow channel 108, and a second connecting portion 107. The third flow channel 106 and the fourth flow channel 108 extend in a first direction (z-axis direction). The second connecting portion 107 extends in a second direction that forms an angle θ greater than 0° and less than 180° with the first direction, connecting the third flow channel 106 and the fourth flow channel 108. The third flow channel 106 and the fourth flow channel 108 extend in a direction intersecting the magnetic sensing surfaces 12a and 12b of the magnetoelectric conversion elements 11a and 11b. The third flow channel 106 and the fourth flow channel 108 are spaced apart in the y-axis direction when viewed from the z-axis direction. The third flow channel 106 and the fourth flow channel 108 may extend in a direction perpendicular to the magnetic sensing surfaces 12a and 12b of the magnetoelectric conversion elements 11a and 11b. The second connecting portion 107 may extend in a direction along the magnetic sensing surfaces 12a and 12b of the magnetoelectric conversion elements 11a and 11b. The second connecting portion 107 may extend in a direction along the y-axis direction.

[0041] The first conductive member 101 and the second conductive member 110 overlap each other when viewed from the first direction and a third direction (x-axis direction) that intersects the second direction. The structure composed of the first flow path section 102, the second flow path section 104, and the first connecting section 103 has the same shape as the structure composed of the third flow path section 106, the fourth flow path section 108, and the second connecting section 107.

[0042] The magnetic sensor 20 is positioned between the first connecting portion 103 and the second connecting portion 107 when viewed from the z-axis direction. The magnetic sensor 20 may be positioned on a line passing through which the centers of gravity of the first connecting portion 103 and the second connecting portion 107 intersect. This improves the magnetic sensitivity of the magnetic sensor 20. The magnetic sensitivity of the magnetic sensor 20 can be further improved by having the magnetosensitive surfaces of the magnetoelectric conversion elements 11a and 12b lie on the line connecting the centers of gravity of the first connecting portion 103 and the second connecting portion 107.

[0043] The magnetic sensor 20 includes magnetoelectric conversion elements 11a and 11b. The magnetoelectric conversion elements 11a and 11b have sensitivity directions in a plane intersecting a first direction (z-axis direction). The magnetoelectric conversion elements 11a and 11b may be transverse magnetic field detection elements. The magnetoelectric conversion elements 11a and 11b may be, for example, vertical Hall elements, horizontal Hall elements provided with a magnetic flux concentrator, or magnetoresistive elements. The magnetoresistive elements may be, for example, semiconductor magnetoresistive elements (SMR), anisotropic magnetoresistive elements (AMR), giant magnetoresistive elements (GMR), or tunnel magnetoresistive elements (TMR).

[0044] FIG. 3 shows the magnetic flux density distribution when an alternating current of 100 Hz is passed through the bus bar 100. FIG. 3 shows the magnetic flux density distribution on the zx plane passing through the magnetoelectric conversion elements 221a and 221b when the bus bar 100 is viewed from the negative z-axis direction. A current flows from the negative direction to the positive direction of the z-axis in the first flow path portion 102, the second flow path portion 104, the third flow path portion 106, and the fourth flow path portion 108. In this case, magnetic flux is generated counterclockwise around each of the first flow path portion 102, the second flow path portion 104, the third flow path portion 106, and the fourth flow path portion 108. That is, magnetic flux in a direction along the magnetosensitive surfaces of the magnetoelectric conversion elements 11a and 11b is generated.

[0045] On the other hand, when the first connecting portion 103 and the second connecting portion 107 extend in the y-axis direction, the current flowing through the first connecting portion 103 and the second connecting portion 107 does not generate magnetic flux in a direction along the magnetosensitive surfaces of the magnetoelectric conversion elements 11a and 11b.

[0046] FIG. 4 is a perspective view of a current sensor according to a comparative example. The current sensor includes a bus bar 200 and a magnetic sensor 220 including magnetoelectric conversion elements 221a and 221b having sensitivity directions in a plane intersecting a first direction (z-axis direction). The bus bar 200 extends in the y-axis direction and includes conductive members 201 arranged at intervals, and a conductive member 210. The bus bar 200 further includes a connecting member 212 disposed between the conductive member 201 and the conductive member 210 for connecting the conductive member 201 and the conductive member 210. The bus bar 200 is formed of a conductive material mainly composed of copper.

[0047] Near the center of the bus bar 100 according to the first embodiment, magnetic flux in a direction along the xy plane is generated. Therefore, as described above, the magnetic sensor 20 having a magnetoelectric conversion element with a sensitivity direction in the xy plane is used. On the other hand, near the center between the conductive member 201 and the conductive member 210 of the bus bar 200, magnetic flux in a direction intersecting the xy plane is generated. Therefore, the magnetic sensor 220 having magnetoelectric conversion elements 221a, 221b such as horizontal Hall elements with a sensitivity direction in the direction intersecting the xy plane is used.

[0048] The conductive member 201 includes a flow path portion 202 and a flow path portion 204 through which a measurement current flows. The flow path portion 202 and the flow path portion 204 are spaced apart from each other and extend in the y-axis direction. The conductive member 201 further includes a connecting portion 203 and a connecting portion 205 which are spaced apart from each other and connect the flow path portion 202 and the flow path portion 204. The connecting portion 203 and the connecting portion 205 respectively connect both ends of the flow path portion 202 and the flow path portion 204.

[0049] The conductive member 210 includes a flow path portion 206 and a flow path portion 208 through which a measurement current flows. The flow path portion 206 and the flow path portion 208 are spaced apart from each other and extend in the y-axis direction. The conductive member 210 further includes a connecting portion 207 and a connecting portion 209 which are spaced apart from each other and connect the flow path portion 206 and the flow path portion 208. The connecting portion 207 and the connecting portion 209 respectively connect both ends of the flow path portion 206 and the flow path portion 208. The connecting portion 203 and the connecting portion 207 are arranged to face each other in the x-axis direction, and the connecting portion 205 and the connecting portion 209 are arranged to face each other in the x-axis direction.

[0050] The bus bar 200 further includes a terminal connection member 214 and a terminal connection member 216 which are connected to the conductive member 201 and the conductive member 210 and are electrically connected to a current source that supplies a measurement current. The terminal connection member 214 and the terminal connection member 216 may be fixed to the output terminal 32 by welding or the like. A direct current from a current source such as a battery may be converted into an alternating current by the power module 30, and the alternating current may be supplied as a measurement current from the terminal connection member 214 and the terminal connection member 216 via the conductive member 201, the conductive member 210, and the connecting member 212 to a driving source such as a motor.

[0051] Figure 5 shows the magnetic flux density distribution when a 100 Hz alternating current is passed through the busbar 200 in the current sensor according to the comparative example shown in Figure 4. In Figure 5, as in Figure 4, the magnetic flux density distribution in the zx plane passing through the magnetoelectric conversion elements 221a and 221b is shown when the busbar 200 is viewed from the negative z-axis direction. Current flows through the flow channels 202, 204, 206, and 208 from the positive y-axis direction to the negative y-axis direction. In this case, a magnetic flux is generated counterclockwise around each of the flow channels 202, 204, 206, and 208. In addition, the total current flowing through each of the flow channels 202, 204, 206, and 208 generates a counterclockwise magnetic flux surrounding them.

[0052] Although busbars 100 and 200 have different conductor member shapes, it can be seen that the magnetic flux density distribution shown in Figure 3 when alternating current is passed through busbar 100 is similar to the magnetic flux density distribution shown in Figure 5 when alternating current is passed through busbar 200.

[0053] As shown in Figure 6, in the case of the busbar 100, when current flows through the first conductive member 101 and the second conductive member 110 in the direction of the solid arrows, unlike the busbar 200, no current flows through the portions indicated by the dashed arrows on the extensions of the first flow path section 102, the second flow path section 104, the third flow path section 106, and the fourth flow path section 108.

[0054] Here, if current were to flow in the area indicated by the dashed arrow, according to the Biot-Savart law, a magnetic flux would exist in the center of the busbar 100 where the magnetic sensor 20 is located. This flux would be a combination of the magnetic flux generated by the currents flowing through the first channel section 102, the second channel section 104, the third channel section 106, and the fourth channel section 108, and the magnetic flux generated by the currents flowing along the dashed arrows on the extensions of the first channel section 102, the second channel section 104, the third channel section 106, and the fourth channel section 108.

[0055] The busbar 100 is a rotationally symmetric structure with respect to an axis 130 passing through the centroids of the first connecting portion 103 and the second connecting portion 107. The magnetic flux density distribution due to the current flowing along the solid arrow is symmetrical to the magnetic flux density distribution due to the current flowing along the dashed arrow. Therefore, even if no current flows along the dashed arrow, the direction of the magnetic flux present in the center of the busbar 100 remains unchanged, and only half the magnitude of the magnetic flux present when current flows along the dashed arrow exists. In other words, although the magnitude of the magnetic flux generated differs between the busbar 100 and the busbar 200, their magnetic flux density distributions are similar.

[0056] Therefore, the magnetic flux density distribution shown in Figure 3 when alternating current is passed through busbar 100 is similar to the magnetic flux density distribution shown in Figure 5 when alternating current is passed through busbar 200.

[0057] Here, referring again to Figures 2A and 2B, the dimensions of the busbar 100 used in the simulation described later will be explained. As shown in Figure 2A, the width between the first conductive member 101 and the second conductive member 110 is defined as w1. The length of the first flow channel 102, the second flow channel 104, the third flow channel 106, and the fourth flow channel 108 is defined as h1. The thickness of the first connecting member 112 and the second connecting member 114 is defined as h2. The length of the first connecting part 103 and the second connecting part 107 is defined as l1. Furthermore, as shown in Figure 2B, when viewed from the y-axis direction, the distance from the center line along the z-axis to the center of the magnetosensitive surfaces of the magnetoelectric conversion elements 11a and 11b is defined as w2.

[0058] Figure 7 shows a graph of the simulation results regarding the magnetic field strength when using the busbar 100. In the simulation, the busbar 100 with the following dimensions was used. The width w1 between the first conductive member 101 and the second conductive member 110 is 12 mm. The length h1 of the first channel section 102, the second channel section 104, the third channel section 106, and the fourth channel section 108 is 12 mm. The thickness h2 of the first connecting member 112 and the second connecting member 114 is 2 mm. When viewed from the y-axis direction, the distance w2 from the center line along the z-axis to the center of the magnetosensitive surfaces of the magnetoelectric conversion elements 11a and 11b is 1.2 mm. Figure 5 shows the results normalized by the ratio to the magnetic field strength when l1 is 15 mm, for cases where the length l1 of the first connecting section 103 and the second connecting section 107 is 15 mm, 12 mm, 9 mm, or 6 mm. As shown in Figure 5, the magnetic field strength can be increased by making the length l1 of the first connecting section 103 and the second connecting section 107 smaller than the length h2 of the first flow path section 102, the second flow path section 104, the third flow path section 106, and the fourth flow path section 108.

[0059] In other words, the length l1 of the first connecting portion 103 and the second connecting portion 107 may be smaller than the length h1 of the first flow channel portion 102, the second flow channel portion 104, the third flow channel portion 106, and the fourth flow channel portion 108. This strengthens the magnetic field near the center of the busbar 100 where the magnetic sensor 20 is located, thereby improving the resolution.

[0060] Furthermore, as shown in Figure 8, the length of the protruding portion 42 on which the magnetic sensor 20 is mounted can be reduced when the length l1 of the first connecting portion 103 and the second connecting portion 107 is smaller than when the length l1 of the first connecting portion 103 and the second connecting portion 107 is larger. This reduces the amplitude when the protruding portion 42 vibrates. Therefore, it is possible to suppress errors in the output of the magnetic sensor 20 caused by a large shift in the positional relationship between the busbar 100 and the magnetic sensor 20 due to vibration.

[0061] Furthermore, as shown in Figure 9, increasing the length h1 of the first channel section 102, the second channel section 104, the third channel section 106, and the fourth channel section 108 improves the heat dissipation effect of the busbar 100. Since the direction of heat convection is in the direction in which the first channel section 102, the second channel section 104, the third channel section 106, and the fourth channel section 108 extend, increasing the length in that direction prevents heat from accumulating and makes it easier for heat to be released from the busbar 100. In other words, the heat transfer coefficient of the busbar 100 can be increased.

[0062] As described above, by making the length l1 of the first connecting portion 103 and the second connecting portion 107 smaller than the length h1 of the first flow path portion 102, the second flow path portion 104, the third flow path portion 106, and the fourth flow path portion 108, it is possible to improve the resolution of the magnetic sensor 20, suppress errors, and improve heat dissipation performance.

[0063] On the other hand, there are different advantages when the length l1 of the first connecting portion 103 and the second connecting portion 107 is greater than the length h1 of the first flow path portion 102, the second flow path portion 104, the third flow path portion 106, and the fourth flow path portion 108. When the length h1 of the first flow path portion 102, the second flow path portion 104, the third flow path portion 106, and the fourth flow path portion 108 is small, the height of the busbar 100 in the z-axis direction can be reduced. In this case, the height of the housing that accommodates the power module 30, the magnetic sensor 20, and the busbar 100 can be reduced.

[0064] Furthermore, if the magnetic sensor 20 and busbar 100 are not built into the housing that houses the power module 30, the busbar 100 will be provided on the side of the housing. In this case, because the length h1 of the first flow path section 102, the second flow path section 104, the third flow path section 106, and the fourth flow path section 108 is small, the area in which the first flow path section 102, the second flow path section 104, the third flow path section 106, and the fourth flow path section 108 face the housing can be reduced. As a result, radiant heat emitted from the first flow path section 102, the second flow path section 104, the third flow path section 106, and the fourth flow path section 108 is less likely to hit the housing. Even when the magnetic sensor 20 and busbar 100 are built into the housing that houses the power module 30, radiant heat is less likely to hit the parts facing the first flow path section 102, the second flow path section 104, the third flow path section 106, and the fourth flow path section 108.

[0065] In addition, when viewed from the z-axis direction, the busbar 100 does not overlap with the protruding portion 42 and the magnetic sensor 20. Therefore, by moving the substrate 40, including the protruding portion 42 on which the magnetic sensor 20 is mounted, along the z-axis direction toward the central portion of the busbar 100, the positional relationship between the busbar 100 and the magnetic sensor 20 can be positioned appropriately. Thus, the ease of assembly when mounting the busbar 100 and the magnetic sensor 20 on the electronic device 10 can be improved.

[0066] Figures 1A and 1B illustrate an example in which the magnetic sensor 20 is positioned on the surface of the substrate 40 opposite to the surface facing the second connecting member 114. However, as shown in Figure 10A, the magnetic sensor 20 may be positioned on the surface 40a of the substrate 40 facing the second connecting member 114. Also, as shown in Figure 10B, the width of the protrusion 42 may be made larger than the width between the first connecting portion 103 and the second connecting portion 107, and the protrusion 42 may be positioned on the first connecting portion 103 and the second connecting portion 107. In other words, the protrusion 42 may be supported by the first connecting portion 103 and the second connecting portion 107. This prevents the positional relationship between the busbar 100 and the magnetic sensor 20 from shifting due to the vibration of the protrusion 42 or the busbar 100 independently, thereby preventing a decrease in measurement accuracy.

[0067] When the substrate 40 is placed on the first connecting portion 103 and the second connecting portion 107, it is necessary to ensure insulation between the substrate 40 and the busbar 100. Therefore, an insulating member such as a die attach film may be placed between the substrate 40 and the busbar 100 to more reliably ensure insulation between the substrate 40 and the busbar 100. The first connecting portion 103 and the second connecting portion 107 may support the protruding portion 42 via an insulating member.

[0068] Next, the angle θ in the second direction in which the first connecting portion 103 and the second connecting portion 107 extend will be explained. As shown in Figure 11A, when the angle θ in the second direction in which the first connecting portion 103 and the second connecting portion 107 extend is 90 degrees, the current A flowing from the center of the first connecting portion 103 and the second connecting portion 107 toward the second flow channel 104 and the fourth flow channel 108, and the current B flowing from the center of the first connecting portion 103 and the second connecting portion 107 toward the first flow channel 102 and the third flow channel 106, do not generate a magnetic field along the xy plane on the magnetosensitive surface of the magnetic sensor 20. Therefore, when the magnetic sensor 20 is misaligned in the z-axis direction relative to the busbar 100, the auxiliary effect of the magnetic field generated by currents A and B is small.

[0069] On the other hand, as shown in Figure 11B, when the angle θ in the second direction in which the first connecting portion 103 and the second connecting portion 107 extend is greater than 90 degrees and less than 180 degrees, the total length of the current flow path of the busbar 100 is shortened, so the resistance can be reduced. Also, when viewed from the x-axis direction, by positioning the magnetic sensing surface of the magnetic sensor 20 on a straight line along the z-axis passing through the centers of the first connecting portion 103 and the second connecting portion 107, the magnetic flux in the direction along the xy plane generated by currents A and B will have a symmetrical distribution when viewed from the plane along the magnetic sensing surface. Therefore, even if the magnetic sensor 20 is misaligned in the z-axis direction relative to the busbar 100, fluctuations in the magnetic field sensitivity of the magnetic sensor 20 can be suppressed. Thus, the ease of mounting the busbar 100 and the magnetic sensor 20 onto the electronic device 10 can be improved.

[0070] Alternatively, as shown in Figure 11C, if the angle θ in the second direction in which the first connecting portion 103 and the second connecting portion 107 extend is less than 90 degrees and greater than 35 degrees, the currents flowing through the first flow path portion 102 and the third flow path portion 106 and the currents flowing through the second flow path portion 104 and the fourth flow path portion 108 flow in the same direction, so the proximity effect (1) acts in a direction that moves them apart. As shown in Figure 11C, the effect acts to cause the currents to be biased in the direction from the solid arrow to the dashed arrow. On the other hand, the currents flowing through the first flow path portion 102 and the third flow path portion 106, or the currents flowing through the second flow path portion 104 and the fourth flow path portion 108, and the currents flowing through the first connecting portion 103 and the second connecting portion 105 flow in opposite directions, so the proximity effect (2) acts in a direction that moves them closer together. As shown in Figure 11C, the effect acts to cause the currents to be biased in the direction from the dashed arrow to the solid arrow. Therefore, these proximity effects (1) and (2) cancel each other out, and the sensitivity of the magnetic sensor 20 to the magnetic field can be improved, especially in the case of high-frequency currents where the current is biased away from the magnetic sensor 20 due to the proximity effect.

[0071] Figure 12 shows the magnetic flux density distribution when a 100 Hz alternating current is passed through the busbar 100, with the angle θ in the second direction extending the first connecting portion 103 and the second connecting portion 107 being 45 degrees. Figure 12 shows the magnetic flux density distribution when the busbar 100 is viewed from the negative z-axis direction. As shown in Figure 12, by positioning the magnetic sensor 20 near the center of the first connecting portion 103 and the second connecting portion 107, the magnetic flux in the direction along the xy plane becomes a symmetrical magnetic field distribution when viewed from the plane along the magnetosensitive surface. Therefore, by setting the angle θ to 45 degrees, even if the magnetic sensor 20 is misaligned in the z-axis direction relative to the busbar 100, fluctuations in the magnetic field sensitivity of the magnetic sensor 20 can be suppressed. This improves the ease of mounting the busbar 100 and the magnetic sensor 20 onto the electronic device 10.

[0072] Figure 13 shows the relationship between the frequency of the measured current and the rate of change of the magnetic field, relative to 0 Hz detected by the magnetic sensor 20, for each angle θ in the second direction in which the first connecting portion 103 and the second connecting portion 107 extend. When the angle θ is 90 degrees, the effect of the proximity effect (1) is large, and when the current is high frequency, the effect of the current moving away from the magnetic sensor 20 becomes large, resulting in large fluctuations in the magnetic field strength. On the other hand, when the angle θ is 25 degrees, the effect of the proximity effect (2) is large, and when the current is high frequency, the effect of the current moving closer to the magnetic sensor 20 becomes large, resulting in large fluctuations in the magnetic field strength. In contrast to these, when the angle θ is 35 degrees or more and less than 90 degrees, the proximity effect (1) and the proximity effect (2) act in a direction that cancels each other out, and even when the current is high frequency, the rate of change of the magnetic field strength relative to the current is less than 5% compared to when the current is low frequency.

[0073] Figure 14 shows an example of arranging a magnetic sensor 20 having four magnetoelectric conversion elements 11a, 11b, 11c, and 11d with respect to a busbar 100 according to the first embodiment. Figure 15 shows the magnetic flux density distribution when a 50 kHz alternating current is passed through the busbar 100. Figure 15 shows an example of the arrangement of the four magnetoelectric conversion elements 11a, 11b, 11c, and 11d. The two magnetoelectric conversion elements 11a and 11b have a magnetic sensing direction along the y-axis and are located on a straight line passing through the centroids of the first connecting portion 103 and the second connecting portion 107. On the other hand, the two magnetoelectric conversion elements 11c and 11d have a magnetic sensing direction along the x-axis and are located on the perpendicular bisector of the straight line passing through the centroids of the first connecting portion 103 and the second connecting portion 107, that is, on a straight line passing through the center between the centroids of the first connecting portion 103 and the centroids of the second connecting portion 107, and along the y-axis.

[0074] If the two magnetoelectric conversion elements 11c and 11d are positioned so as not to overlap with the straight line containing magnetoelectric conversion element 11a and magnetoelectric conversion element 11b, they can detect magnetic fields with magnetic flux in a different direction from that of magnetoelectric conversion element 11a and magnetoelectric conversion element 11b.

[0075] The sensitivity of the four magnetoelectric conversion elements 11a, 11b, 11c, and 11d is the same. In this way, increasing the number of magnetoelectric conversion elements increases the sensor area and suppresses 1 / f noise. Furthermore, by using the same type of element, for example, a vertical Hall element, for the four magnetoelectric conversion elements 11a, 11b, 11c, and 11d, if one of the two magnetoelectric conversion elements 11a, 11b or one of the two magnetoelectric conversion elements 11c, 11d fails, current measurement can be continued using only one of the two non-faulty magnetoelectric conversion elements 11a, 11b or the two magnetoelectric conversion elements 11c, 11d. In other words, redundancy can be provided to the current sensor.

[0076] The types of magnetoelectric elements used in the two magnetoelectric elements 11a and 11b may differ from the types of magnetoelectric elements used in the two magnetoelectric elements 11c and 11d. For example, vertical Hall elements may be used as the two magnetoelectric elements 11a and 11b, and horizontal Hall elements, AMR, GMR, or TMR with magnetic focusing plates may be used as the two magnetoelectric elements 11c and 11d. This allows for redundancy in the current sensor.

[0077] Furthermore, the magnetic field range of the magnetoelectric elements used in the two magnetoelectric elements 11a and 11b may be different from the magnetic field range of the magnetoelectric elements used in the two magnetoelectric elements 11c and 11d. This allows for two-stage output characteristics for the current sensor. For example, the sensitivity of the magnetoelectric elements used in the two magnetoelectric elements 11c and 11d may be lower than that of the magnetoelectric elements used in the two magnetoelectric elements 11a and 11b, and the magnetic field range of the magnetoelectric elements used in the two magnetoelectric elements 11c and 11d may be wider than that of the magnetoelectric elements used in the two magnetoelectric elements 11a and 11b. This allows for high resolution of the current sensor during normal operation, and in the event of abnormal operation, although the resolution of the current sensor is lower, it is possible to continue measuring current in a current range that cannot be measured by a highly sensitive magnetoelectric element. The magnetic field range of the magnetoelectric element refers to the range of magnetic fields that can be measured using the magnetoelectric element.

[0078] Magnetoelectric conversion elements with different magnetic field ranges can be realized using TMRs or GMRs. For example, when using an eddy magnetization TMR, the magnetic field range can be adjusted by changing the diameter of the free layer that makes up the eddy magnetization TMR.

[0079] Furthermore, it is possible to use magnetoelectric elements in which one of the magnetic field ranges of the two magnetoelectric elements 11a and 11b, and the magnetic field range of the two magnetoelectric elements 11c and 11d, saturates at a certain output level, while the other does not saturate. Even with such a configuration, the output characteristics of the current sensor can be made into two stages.

[0080] Depending on the magnetic flux density distribution, arranging the two magnetoelectric conversion elements 11a and 11b along the y-axis direction may result in a stronger magnetic field and improved resolution compared to arranging them along the x-axis direction.

[0081] Here, the distance at which the first conductive member 101 and the second conductive member 110 are separated from each other in the x-axis direction is defined as the first distance (w1), and the distance at which the first flow channel 102 or the third flow channel 106 and the second flow channel 104 or the fourth flow channel 108 are separated from each other when viewed from the z-axis direction is defined as the second distance l1. As shown in the configuration in Figure 2A, when the first distance (w1) is greater than the second distance (l1), the two magnetoelectric conversion elements 11a and 11b are better arranged along the x-axis direction. On the other hand, as shown in the configuration in Figure 16, when the second distance (l1) is greater than the first distance (w1), the two magnetoelectric conversion elements 11a and 11b are better arranged along the direction in which the first flow channel 102 and the second flow channel 104 are separated from each other when viewed from the z-axis direction, i.e., along the y-axis direction. This increases the magnetic field strength and improves the resolution.

[0082] Figure 17 is a perspective view of the busbar 100 according to the second embodiment. The busbar 100 according to the second embodiment differs from the busbar 100 according to the first embodiment in that it includes auxiliary conductive members 120 and 122 for adjusting the direction of magnetic flux.

[0083] The auxiliary conductive member 120 is provided between the first flow channel 102 and the third flow channel 106, extends in the z-axis direction, and one end is connected to the first connecting member 112. The auxiliary conductive member 122 is provided between the second flow channel 104 and the fourth flow channel 108, extends in the z-axis direction, and one end is connected to the second connecting member 114. The auxiliary conductive members 120 and 122 are positioned so as not to overlap with the magnetic sensor 20 when viewed from the z-axis direction. By having the auxiliary conductive members 120 and 122 in the busbar 100, improvements in frequency characteristics and heat dissipation characteristics can be achieved compared to a busbar 100 without the auxiliary conductive members 120 and 122. The auxiliary conductive members 120 and 122 do not need to be connected to the first connecting member 112 and the second connecting member 114, nor do they need to be electrically connected to the first conductive member 101 and the second conductive member 110. In this case, the auxiliary conductive members 120 and 122 may be fixed to the inner wall of the housing that accommodates the busbar 100.

[0084] Figure 18 shows the magnetic flux density distribution when a 50 kHz alternating current is passed through a busbar 100 having auxiliary conductive members 120 and 122.

[0085] Current flows from the negative z-axis direction to the positive z-axis direction in the first channel section 102, the second channel section 104, the third channel section 106, and the fourth channel section 108. In regions 2 and 4 shown in Figure 19, the presence of auxiliary conductive members 120 and 122 causes the direction of the magnetic flux in regions 2 and 4 to bend, as indicated by the dashed arrows. In the parts of regions 2 and 4 closer to region 1, the magnetic flux contains more components in the positive y-axis direction compared to when the auxiliary conductive members 120 and 122 are not present, thus strengthening the magnetic field in region 1. On the other hand, in the parts of regions 2 and 4 closer to region 3, the magnetic flux contains more components in the negative y-axis direction compared to when the auxiliary conductive members 120 and 122 are not present, thus strengthening the magnetic field in region 3.

[0086] Figure 19 shows the simulation results illustrating the relationship between the frequency of the measured current of the busbar 100 in the first embodiment and the busbar 100 in the second embodiment, and the rate of change of the magnetic field relative to 0 Hz detected by the magnetic sensor 20.

[0087] As shown in Figure 19, the rate of fluctuation of the magnetic field at high frequencies is smaller for the busbar 100 of the second embodiment compared to the busbar 100 of the first embodiment. In this way, the frequency characteristics can be improved by providing the auxiliary conductive members 120 and 122. In addition, the total area of ​​the busbar 100 increases due to the presence of the auxiliary conductive members 120 and 122, thereby improving the heat dissipation performance.

[0088] Figure 20 shows an example of the circuit configuration of an electronic device 10 equipped with a busbar 100 and a magnetic sensor 20. The electronic device 10 shown in Figure 20 includes a U-phase circuit 30U, a V-phase circuit 30V, and a W-phase circuit 30W that function as a power module 30. The electronic device 10 is a three-phase inverter that converts DC to three-phase AC. The three-phase AC output from the electronic device 10 is supplied to a motor 60, which is a three-phase AC motor. The motor 60 may be a power source for a mobile vehicle. The electronic device 10 and the motor 60 may be mounted on a mobile vehicle such as a hybrid car or an electric car. Depending on the application, the electronic device 10 may also be a single-phase inverter that converts DC to AC. The U-phase circuit 30U, V-phase circuit 30V, and W-phase circuit 30W are examples of power conversion circuits.

[0089] The U-phase circuit 30U has a high-side power semiconductor 312U and a low-side power semiconductor 314U connected in series. The source or emitter of power semiconductor 312U and the drain or collector of power semiconductor 314U are electrically connected. If power semiconductors 312U and 314U are, for example, MOSFETs, the source of power semiconductor 312U and the drain of power semiconductor 314U are electrically connected. If power semiconductors 312U and 314U are, for example, IGBTs, the emitter of power semiconductor 312U and the collector of power semiconductor 314U are electrically connected.

[0090] The V-phase circuit 30V has a high-side power semiconductor 312V and a low-side power semiconductor 314V connected in series. The source or emitter of power semiconductor 312V is electrically connected to the drain or collector of power semiconductor 314V. The W-phase circuit 30W has a high-side power semiconductor 312W and a low-side power semiconductor 314W connected in series. The source or emitter of power semiconductor 312W is electrically connected to the drain or collector of power semiconductor 314W.

[0091] The electronic device 10 includes a pair of DC terminals 320 and 340, as well as a U-phase terminal 350U, a V-phase terminal 350V, and a W-phase terminal 350W (sometimes collectively referred to as terminal 350). The pair of DC terminals 320 and 340 are an example of an input terminal section. The U-phase terminal 350U, V-phase terminal 350V, and W-phase terminal 350W are an example of an output terminal section. The electronic device 10 further includes a high-side conductor 322 electrically connected to DC terminal 320, and a low-side conductor 342 electrically connected to DC terminal 340. Conductors 322 and 342 are examples of conductors and may be made of a conductive material mainly composed of copper.

[0092] The U-phase circuit 30U, the V-phase circuit 30V, and the W-phase circuit 30W are connected in parallel between conductor 322 and conductor 342. The drain or collector of the high-side power semiconductors 312U, 312V, and 312W (sometimes collectively referred to as power semiconductor 312) is electrically connected to conductor 322. The source or emitter of the low-side power semiconductors 314U, 314V, and 314W (sometimes collectively referred to as power semiconductor 314) is electrically connected to conductor 342.

[0093] The electronic device 10 further comprises a conductor 24U electrically connected to the U-phase terminal 350U, a conductor 24V electrically connected to the V-phase terminal 350V, and a conductor 24W electrically connected to the W-phase terminal 350W. The source or emitter of power semiconductor 312U and the drain or collector of power semiconductor 314U are electrically connected to conductor 24U. The source or emitter of power semiconductor 312V and the drain or collector of power semiconductor 314V are electrically connected to conductor 24V. The source or emitter of power semiconductor 312W and the drain or collector of power semiconductor 314W are electrically connected to conductor 24W.

[0094] Conductors 24U, 24V, and 24W (sometimes collectively referred to as conductor 24) are electrically connected to the motor 60 via busbars 100U, 100V, and 100W.

[0095] The electronic device 10 further includes current sensors 50U, 50V, and 50W (sometimes collectively referred to as current sensor 50). Each of the current sensors 50U, 50V, and 50W has a magnetic sensor 20. Current sensor 50U measures the current value of the U-phase current flowing through the conductor 24U and the busbar 100U. Current sensor 50V measures the current value of the V-phase current flowing through the conductor 24V and the busbar 100V. Current sensor 50W measures the current value of the W-phase current flowing through the conductor 24W and the busbar 100W. Current sensors 50U, 50V, and 50W and busbars 100U, 100V, and 100W are examples of current measurement units.

[0096] The current sensors 50U, 50V, and 50W may be magnetic sensors 20 having two magnetoelectric conversion elements 11a and 11b that detect changes in the magnetic field caused by U-phase current, V-phase current, and W-phase current flowing through conductors 24U, 24V, and 24W. The current sensors 50U, 50V, and 50W further include a signal processing IC that outputs signals indicating the current values ​​of the U-phase current, V-phase current, and W-phase current according to the magnitude of the magnetic field output from the two magnetoelectric conversion elements 11a and 11b. The signal processing IC is a large-scale integrated circuit (LSI). The signal processing IC is a monolithic IC. More specifically, the signal processing IC is a signal processing circuit made of a Si monolithic semiconductor formed on a Si substrate. The signal processing IC may have a circuit surface on which the two magnetoelectric conversion elements 11a and 11b are arranged. The current sensors 50U, 50V, and 50W may be semiconductor packages in which two magnetoelectric conversion elements 11a and 11b and a signal processing IC are sealed in molded resin. The two magnetoelectric conversion elements 11a and 11b and the signal processing IC do not necessarily have to be sealed in molded resin. The current sensors 50U, 50V, and 50W may also be current sensors in which the two magnetoelectric conversion elements 11a and 11b and the signal processing IC are exposed on an insulating substrate. The two magnetoelectric conversion elements 11a and 11b may be electrically connected to the signal processing IC by wire bonding.

[0097] Although the invention has been described using embodiments, the technical scope of the present invention is not limited to the scope described in the embodiments above. It will be apparent to those skilled in the art that various modifications or improvements can be made to the embodiments described above. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0098] It should be noted that the execution order of operations, procedures, steps, and stages in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not explicitly stated as "before," "prior to," etc., and can be implemented in any order unless the output of a previous process is used in a later process. Even if the operation flow in the claims, specifications, and drawings is described using phrases such as "first," "next," etc. for convenience, it does not mean that it is essential to perform them in that order.

[0099] 10 Electronic devices 11a, 11b, 11c, 11d Magnetoelectric conversion elements 12a, 12b Magnetic surface 20 Magnetic sensors 24U, 24V, 24W Conductors 30 Power modules 30U U-phase circuit 30V V-phase circuit 30W W-phase circuit 32 Output terminals 40, 44 Substrate 41 Edge 42 Protrusion 50U, 50V, 50W Current sensors 60 Motors 100, 100U, 100V, 100W Busbars 101 First conductive member 110 Second conductive member 102 First flow path section 103 First connecting section 104 Second flow path section 106 Third flow path section 107 Second connecting section 108 Fourth flow path section 112 First connecting member 114 Second connecting member 120, 122 Auxiliary conductive member 200 Busbars 201, 210 Conductive members 202, 204, 206, 208 Flow channel section 203, 205, 207, 209 Connecting section 212 Connecting member 214, 216 Terminal connecting member 220 Magnetic sensor 312U, 312V, 312W, 314U, 314V, 314W Power semiconductor 320, 340 DC terminal 322, 342 Conductor 350U U-phase terminal 350V V-phase terminal 350W W-phase terminal

Claims

1. A busbar through which a measurement current flows, and a magnetic sensor having at least two magnetoelectric conversion elements for detecting a magnetic field generated by the measurement current flowing through the busbar, wherein the busbar has a first conductive member and a second conductive member arranged opposite to each other with the magnetic sensor in between, a first connecting member arranged between the first conductive member and the second conductive member and connecting the first conductive member and the second conductive member, and a second connecting member arranged between the first conductive member and the second conductive member with a gap from the first connecting member and connecting the first conductive member and the second conductive member, wherein the first conductive member includes a first flow channel portion and a second flow channel portion extending in a first direction, and a first connecting portion extending in a second direction that forms an angle greater than 0 degrees and less than 180 degrees with respect to the first direction and connecting the first flow channel portion and the second flow channel portion, and the second conductive member includes a third flow channel portion and a fourth flow channel portion extending in the first direction, A current sensor including a second connecting portion that extends in the second direction and connects the third flow path portion and the fourth flow path portion.

2. The current sensor according to claim 1, wherein the first connecting member is connected to one end of the first conductive member and one end of the second conductive member, and the second connecting member is connected to the other end of the first conductive member and the other end of the second conductive member.

3. The current sensor according to claim 1, wherein the first conductive member and the second conductive member overlap each other when viewed from a third direction intersecting the first and second directions.

4. The current sensor according to claim 1, wherein the at least two magnetoelectric conversion elements have sensitivity directions in a plane intersecting the first direction.

5. The current sensor according to claim 4, wherein the at least two magnetoelectric conversion elements are a vertical Hall element, a horizontal Hall element with a magnetic focusing plate, or a magnetoresistive element.

6. The current sensor according to claim 1, wherein the magnetic sensor is positioned at a location through which a straight line connecting the centers of gravity of the first connecting portion and the second connecting portion passes.

7. The current sensor according to claim 1, wherein the length of the extension of the first connecting portion and the second connecting portion is smaller than the length of the extension of the first flow path portion, the second flow path portion, the third flow path portion, and the fourth flow path portion.

8. The current sensor according to claim 7, wherein the current sensor is positioned on a protrusion that protrudes from the edge of a base board on which a power conversion circuit that outputs the measured current is mounted on the busbar, and is fixed to the busbar at a predetermined position via the base board.

9. The current sensor according to claim 1, comprising a substrate on which the magnetic sensor is arranged on the first surface and the first surface is supported by the first connecting portion and the second connecting portion.

10. The current sensor according to claim 1, wherein the length of the extension of the first connecting portion and the second connecting portion is greater than the length of the extension of the first flow path portion, the second flow path portion, the third flow path portion, and the fourth flow path portion.

11. The current sensor according to claim 1 or 6, wherein the angle that the second direction makes with respect to the first direction is greater than 90 degrees and less than 180 degrees.

12. The current sensor according to claim 1 or 6, wherein the angle that the second direction makes with respect to the first direction is 35 degrees or more and less than 90 degrees.

13. The current sensor according to claim 1 or 5, wherein the distance at which the first conductive member and the second conductive member are separated from each other in a third direction intersecting the first and second directions is defined as the first distance, and the distance at which the first flow channel and the second flow channel are separated from each other when viewed from the first direction is defined as the second distance, and when the first distance is greater than the second distance, at least two of the at least two magnetoelectric conversion elements are arranged along the third direction, and when the second distance is greater than the first distance, at least two of the at least two magnetoelectric conversion elements are arranged along the direction in which the first flow channel and the second flow channel are separated from each other when viewed from the first direction.

14. The current sensor according to claim 1, wherein the at least two magnetoelectric conversion elements include a first magnetoelectric conversion element, a second magnetoelectric conversion element, and a third magnetoelectric conversion element, and the third magnetoelectric conversion element is positioned so as not to overlap with a straight line including the first magnetoelectric conversion element and the second magnetoelectric conversion element.

15. The current sensor according to claim 14, wherein the first magnetoelectric conversion element and the second magnetoelectric conversion element are first type magnetoelectric conversion elements, and the third magnetoelectric conversion element is second type magnetoelectric conversion element.

16. The current sensor according to claim 14, wherein the first magnetoelectric conversion element and the second magnetoelectric conversion element are magnetoelectric conversion elements having a first magnetic field range, and the third magnetoelectric conversion element is a magnetoelectric conversion element having a second magnetic field range different from the first magnetic field range.

17. The current sensor according to claim 1, further comprising an auxiliary conductive member extending in the first direction and provided between the first conductive member and the second conductive member as viewed from the first direction.

18. The current sensor according to claim 17, wherein the auxiliary conductive member is connected to at least one of the first connecting member and the second connecting member.

19. An electronic device comprising: a current sensor according to claim 10; a power conversion circuit that converts direct current to alternating current; a housing that houses the power conversion circuit; and a power module that extends from the side of the housing and has an output terminal that outputs the alternating current output from the power conversion circuit, wherein the busbar is provided outside the housing and is electrically connected to the output terminal.

20. An electronic device comprising a current sensor as described in claim 10, a power conversion circuit that converts direct current to alternating current and outputs it to the busbar, and a power module having a housing, wherein the current sensor is provided inside the housing.

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