Current measurement device

Abstract

This current measurement device may include a substrate, a first bus bar disposed on a first surface of the substrate, a second bus bar disposed on a second surface of the substrate opposite to the first surface, a first current sensor which is disposed on the first surface of the substrate and which measures a first current flowing through the first bus bar, and a second current sensor which is disposed on the second surface of the substrate and which measures a second current flowing through the second bus bar. At least a part of a first sealing part of the first current sensor and at least a part of a second sealing part of the second current sensor may overlap in the thickness direction of the substrate. At least one first magnetoelectric conversion element of the first current sensor and a second primary conductor part of the second current sensor may not overlap in the thickness direction of the substrate in a plan view. At least one second magnetoelectric conversion element of the second current sensor and a first primary conductor part of the first current sensor may not overlap in the thickness direction of the substrate in a plan view.

Description

Current measuring device

[0001] The present invention relates to a current measuring device.

[0002] Patent Document 1 discloses a current sensor in which a pair of magnetic sensors are arranged opposite each other via a bus bar, and the other pair of magnetic sensors are arranged at equal distances from another bus bar that is arranged between the other pair of magnetic sensors. Patent Document 2 discloses a current sensor in which a plurality of bus bars having convex portions are arranged offset from each other, and two magnetoelectric conversion units are arranged opposite each other in a plan view, with a portion of each convex portion sandwiched between them. [Prior Art Documents] [Patent Documents] [Patent Document 1] International Publication No. 2015 / 033541 [Patent Document 2] Japanese Patent Application Laid-Open No. 2022-100597 General disclosure

[0003] A current measuring device according to one aspect of the present invention may include a substrate, a first bus bar arranged on a first surface of the substrate, a second bus bar arranged on a second surface of the substrate opposite to the first surface, a first current sensor arranged on the first surface of the substrate and configured to measure a first current flowing through the first bus bar, and a second current sensor arranged on the second surface of the substrate and configured to measure a second current flowing through the second bus bar. The first current sensor may include at least one first magneto-electric transducer, a first primary terminal connected to the first bus bar, and a first primary conductor connected to the first primary terminal, a first primary lead frame through which the first current measured by the at least one first magneto-electric transducer flows via the first primary terminal and the first primary conductor, a first signal processing IC that processes a signal output from the at least one first magneto-electric transducer, and a first sealing portion that seals the at least one first magneto-electric transducer, the first primary conductor, and the first signal processing IC. The second current sensor may include at least one second magnetoelectric transducer, a second primary terminal connected to the second bus bar, and a second primary conductor connected to the second terminal, a second primary lead frame through which the second current measured by the at least one second magnetoelectric transducer flows via the second primary terminal and the second primary conductor, a second signal processing IC that processes a signal output from the at least one second magnetoelectric transducer, and a second sealing portion that seals the at least one second magnetoelectric transducer, the second primary conductor, and the second signal processing IC. At least a portion of the first sealing portion and at least a portion of the second sealing portion may overlap in a thickness direction of the substrate. The at least one first magnetoelectric transducer and the second primary conductor may not overlap in a thickness direction of the substrate in a plan view. The at least one second magnetoelectric transducer and the first primary conductor may not overlap in a thickness direction of the substrate in a plan view.

[0004] In the current measuring device, the first primary conductor and the second primary conductor may not overlap in a thickness direction of the substrate in a plan view.

[0005] A current measuring device according to one aspect of the present invention may include a substrate, a first bus bar arranged on a first surface of the substrate, a second bus bar arranged on a second surface of the substrate opposite to the first surface, a first current sensor arranged on the first surface of the substrate and configured to measure a first current flowing through the first bus bar, and a second current sensor arranged on the second surface of the substrate and configured to measure a second current flowing through the second bus bar. The first current sensor may include at least two first magneto-electric transducers, a first primary terminal connected to the first bus bar, and a first primary conductor connected to the first primary terminal, a first primary lead frame through which the first current measured by the at least two first magneto-electric transducers flows via the first primary terminal and the first primary conductor, a first signal processing IC that processes signals output from the at least two first magneto-electric transducers, and a first sealing portion that seals the at least two first magneto-electric transducers, the first primary conductor, and the first signal processing IC. The second current sensor may include at least two second magnetoelectric transducers, a second primary terminal connected to the second bus bar, and a second primary conductor connected to the second primary terminal, a second primary lead frame through which the second current measured by the at least two second magnetoelectric transducers flows via the second primary terminal and the second primary conductor, a second signal processing IC that processes signals output from the at least two second magnetoelectric transducers, and a second sealing portion that seals the at least two second magnetoelectric transducers, the second primary conductor, and the second signal processing IC. At least a portion of the first sealing portion and at least a portion of the second sealing portion may overlap in a thickness direction of the substrate. When the direction in which the first bus bar extends along the first surface of the substrate is defined as a first direction, and the direction along the first surface of the substrate that intersects the first direction is defined as a second direction, in a planar view, at least one of the at least two second magneto-electric conversion elements may be located between the at least two first magneto-electric conversion elements in the first direction.

[0006] A current measuring device according to one aspect of the present invention may include a substrate, a first bus bar arranged on a first surface of the substrate, a second bus bar arranged on a second surface of the substrate opposite to the first surface, a first current sensor arranged on the first surface of the substrate and configured to measure a first current flowing through the first bus bar, and a second current sensor arranged on the second surface of the substrate and configured to measure a second current flowing through the second bus bar. The first current sensor may include at least one first magneto-electric transducer, a first primary terminal connected to the first bus bar, and a first primary conductor connected to the first primary terminal, a first primary lead frame through which the first current measured by the at least one first magneto-electric transducer flows via the first primary terminal and the first primary conductor, a first signal processing IC that processes a signal output from the at least one first magneto-electric transducer, and a first sealing portion that seals the at least one first magneto-electric transducer, the first primary conductor, and the first signal processing IC. The second current sensor may include at least one second magnetoelectric transducer, a second primary terminal connected to the second bus bar, and a second primary conductor connected to the second terminal, a second primary lead frame through which the second current measured by the at least one second magnetoelectric transducer flows via the second primary terminal and the second primary conductor, a second signal processing IC that processes a signal output from the at least one second magnetoelectric transducer, and a second sealing portion that seals the at least one second magnetoelectric transducer, the second primary conductor, and the second signal processing IC. At least a portion of the first sealing portion and at least a portion of the second sealing portion may overlap in a thickness direction of the substrate. When a direction in which the first bus bar extends along the first surface of the substrate is defined as a first direction and a direction along the first surface of the substrate intersecting the first direction is defined as a second direction, the first bus bar may have two first divided conductor portions extending along the first direction, and the second bus bar may have two second divided conductor portions extending along the first direction. The first current sensor may have a pair of first primary terminals exposed from the first sealing portion. One of the two first divided conductor portions may be coupled to one of the pair of first primary terminals.The other of the two first divided conductor portions may be connected to the other of the pair of first primary terminals. The first primary conductor portion may have a first bent portion connecting one of the pair of first primary terminals to the other of the pair of first primary terminals. The first bent portion may include a first portion and a second portion extending in the second direction, and a connecting portion connecting the first portion and the second portion and extending in the first direction. In a plan view, the at least one second magneto-electric transducer may overlap in the thickness direction with at least a portion of the first portion, the second portion, and the connecting portion of the first bent portion.

[0007] In any of the current measuring devices, the first bus bar may have two first divided conductor portions extending in a first direction along the first surface of the substrate. The second bus bar may have two second divided conductor portions extending in the first direction along the second surface of the substrate. The first sealing portion may have a first side surface and a second side surface opposing each other in a second direction intersecting the first direction along the first surface of the substrate. The first primary terminal portion may have a pair of first primary terminals exposed from the first side surface of the first sealing portion. One of the two first divided conductor portions may be connected to one of the pair of first primary terminals. The other of the two first divided conductor portions may be connected to the other of the pair of first primary terminals. The first primary conductor portion may have a first connecting portion connecting one of the pair of first primary terminals to the other of the pair of first primary terminals. The second sealing portion may have a first side surface and a second side surface opposing each other in the second direction along the second surface of the substrate. The second primary terminal portion may have a pair of second primary terminals exposed from the first side surface of the second sealing portion. One of the two second divided conductor portions may be connected to one of the pair of second primary terminals. The other of the two second divided conductor portions may be connected to the other of the pair of second primary terminals. The second primary conductor portion may have a second connecting portion connecting one of the pair of second primary terminals to the other of the pair of second primary terminals.

[0008] In any of the current measuring devices, the first current sensor may have two first magnetoelectric transducers as the at least one first magnetoelectric transducer. The second current sensor may have two second magnetoelectric transducers as the at least one second magnetoelectric transducer. At least a portion of the two first magnetoelectric transducers may be surrounded by the first connecting portion in a plan view. At least a portion of the two second magnetoelectric transducers may be surrounded by the second connecting portion in a plan view.

[0009] In any of the current measuring devices, the two first magnetoelectric transducers may be arranged opposite each other with a portion of the first connecting portion interposed therebetween, and the two second magnetoelectric transducers may be arranged opposite each other with a portion of the second connecting portion interposed therebetween.

[0010] In any of the current measuring devices, the first connecting portion includes a first portion connected to one of the pair of first primary terminals and extending in the second direction, a first bent portion bent from the first portion, and a second portion extending from the first bent portion in the second direction and connected to the other of the pair of first primary terminals. The second connecting portion includes a third portion connected to one of the pair of second primary terminals and extending in the second direction, a second bent portion bent from the third portion, and a fourth portion extending from the second bent portion in the second direction and connected to the other of the pair of second primary terminals. The two first magnetoelectric transducers may be arranged opposite each other in the first direction with the first portion sandwiched therebetween. The two second magnetoelectric transducers may be arranged opposite each other in the first direction with the third portion sandwiched therebetween.

[0011] In any of the current measuring devices, the perpendicular bisector of the line segment connecting the two first magnetoelectric transducers may not overlap with the perpendicular bisector of the line segment connecting the two second magnetoelectric transducers in a planar view.

[0012] In any one of the current measuring devices, a perpendicular bisector of a line segment connecting the two first magnetoelectric transducers may pass between the two second magnetoelectric transducers in a plan view.

[0013] In any of the current measuring devices, the distance between the perpendicular bisector of the line segment connecting the two first magnetoelectric conversion elements and the perpendicular bisector of the line segment connecting the two second magnetoelectric conversion elements may be, in a planar view, 2.5 times or more the distance between the two first magnetoelectric conversion elements.

[0014] In any of the current measuring devices, the first bus bar may have two first divided conductor portions extending in a first direction along the first surface of the substrate. The second bus bar may have two second divided conductor portions extending in the first direction along the second surface of the substrate. The first sealing portion may have a first side surface and a second side surface opposing each other in a second direction intersecting the first direction along the first surface of the substrate. The first primary terminal portion may have a pair of first primary terminals exposed from the first side surface of the first sealing portion. One of the two first divided conductor portions may be connected to one of the pair of first primary terminals. The other of the two first divided conductor portions may be connected to the other of the pair of first primary terminals. The first primary conductor portion may have a first bent portion connecting one of the pair of first primary terminals to the other of the pair of first primary terminals. The second sealing portion may have a first side surface and a second side surface opposing each other in the second direction along the second surface of the substrate. The second primary terminal portion may have a pair of second primary terminals exposed from the first side surface of the second sealing portion. One of the two second divided conductor portions may be connected to one of the pair of second primary terminals. The other of the two second divided conductor portions may be connected to the other of the pair of second primary terminals. The second primary conductor portion may have a second bent portion connecting one of the pair of second primary terminals to the other of the pair of second primary terminals. The first side surface of the first sealing portion and the second side surface of the second sealing portion may face the same direction in the second direction, and the second side surface of the first sealing portion and the first side surface of the second sealing portion may face the same direction in the second direction.

[0015] In any of the current measuring devices, the first side surface of the first sealing portion and the second side surface of the second sealing portion may face the same direction in the second direction. The second side surface of the first sealing portion and the first side surface of the second sealing portion may face the same direction in the second direction.

[0016] In any of the current measuring devices, the first primary conductor may be located within the first sealing portion on the first side surface side of the first sealing portion with respect to the center of gravity of the first sealing portion in a plan view, and the second primary conductor may be located within the second sealing portion on the first side surface side of the second sealing portion with respect to the center of gravity of the second sealing portion in a plan view.

[0017] In any of the current measuring devices, the first current sensor may further include a first secondary lead frame that is disposed opposite the first primary terminal portion across the first signal processing IC in a plan view, exposed from the second side surface of the first sealing portion, and includes a first secondary terminal portion electrically connected to the first signal processing IC and a first support portion that supports the first signal processing IC, and is electrically insulated from the first primary lead frame. The second current sensor may further include a second secondary lead frame that is disposed opposite the second primary terminal portion across the second signal processing IC in a plan view, exposed from the second side surface of the second sealing portion, and includes a second secondary terminal portion electrically connected to the second signal processing IC and a second support portion that supports the second signal processing IC, and is electrically insulated from the second primary lead frame.

[0018] In any one of the current measuring devices, the first bus bar and the second bus bar may not overlap in the thickness direction of the substrate.

[0019] In any one of the current measuring devices, the first bus bar and the second bus bar may at least partially overlap in a thickness direction of the substrate.

[0020] Any of the current measuring devices may further include a third bus bar arranged on the first surface of the substrate, extending in the first direction, and arranged in the second direction opposite the first current sensor across from the first bus bar, through which a third current flows.

[0021] Any of the current measuring devices may further include a third bus bar disposed on an inner layer of the substrate, extending in the first direction, and through which a third current flows, and a portion of the third bus bar may overlap with the first bus bar and the second bus bar in the thickness direction of the substrate.

[0022] The above summary of the invention does not list all of the features of the present invention, and subcombinations of these features may also be inventions.

[0023] 1A is a schematic plan view of a current sensor used in the current measuring device according to the first embodiment, as seen from the ceiling surface side (Z-axis direction). FIG. 1B is a cross-sectional view of the current sensor shown in FIG. 1A along line A-A. FIG. 1C is a plan view of a substrate, as seen from a first surface side on which one current sensor is mounted, in the current measuring device according to the first embodiment. FIG. 1D is a plan view of a substrate, as seen from a second surface side opposite to the first surface on which the other current sensor is mounted, in the current measuring device according to the first embodiment. FIG. 1E is a schematic cross-sectional view of a substrate, as seen from the negative side toward the positive side in the X-axis direction, in a state in which two current sensors are mounted, in the current measuring device according to the first embodiment. FIG. 1F is a schematic cross-sectional view of a substrate, as seen from the first surface side, in a state in which two current sensors are mounted, in the current measuring device according to the first embodiment. 1 is a diagram showing an example of a simulation result indicating the magnitude of a current error detected by one current sensor or the other current sensor according to the distance (mm) in the X-axis direction between the center of gravity of one current sensor and the center of gravity of the other current sensor in the current measuring device according to the first embodiment when viewed in a plan view. FIG. 1 is a schematic plan view of a modified example in which the other current sensor arranged on the second surface side and the bus bar through which a second phase current flows are indicated by dashed lines when the board is viewed from the first surface side. FIG. 2 is a schematic cross-sectional view of a board according to a modified example in which a bus bar through which a third phase current flows is arranged on an inner layer, with two current sensors mounted thereon, as viewed from the negative side to the positive side in the X-axis direction. FIG. 3 is a plan view of a board as viewed from the first surface side on which one current sensor is mounted, in the current measuring device according to the second embodiment. FIG. 4 is a plan view of a board as viewed from the second surface side opposite to the first surface on which the other current sensor is mounted, in the current measuring device according to the second embodiment. FIG. 5 is a schematic cross-sectional view of a board as viewed from the negative side to the positive side in the X-axis direction, with two current sensors mounted thereon, in the current measuring device according to the second embodiment. 10 is a schematic cross-sectional view of a substrate with two current sensors mounted thereon, viewed from the positive side to the negative side in the Y-axis direction, in a current measuring device according to a second embodiment. FIG.1 is a schematic plan view of a current measuring device according to a second embodiment, viewed from the first surface side of the substrate, in which the other current sensor arranged on the second surface side and the bus bar through which a second-phase current flows are indicated by broken lines.

[0023] FIG. 1 is a diagram showing an example of simulation results showing the magnitude of a current error detected by one current sensor or the other current sensor according to the distance (mm) in the X-axis direction between the center of gravity of one current sensor and the center of gravity of the other current sensor when viewed in plan in the current measuring device according to the second embodiment.

[0024] FIG. 1 is a schematic plan view of a modified example of the current measuring device according to the second embodiment, viewed from the first surface side of the substrate, in which the other current sensor arranged on the second surface side and the bus bar through which a second-phase current flows are indicated by broken lines.

[0025] FIG. 1 is a schematic cross-sectional view of a substrate according to a modified example of the current measuring device according to the second embodiment, in which a bus bar through which a third-phase current flows is arranged in an inner layer, in which two current sensors are mounted, viewed from the negative side to the positive side in the X-axis direction.

[0024] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention as claimed. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0025] 1A and 1B show the internal configuration of a semiconductor package that functions as a current sensor 10 used in the current measurement device according to the first embodiment. FIG. 1A is a schematic plan view of the current sensor 10 as seen from the ceiling surface side (Z-axis direction). FIG. 1B is a cross-sectional view of the current sensor 10 shown in FIG. 1A along line A-A. The current sensor 10 shown in FIGS. 1A and 1B is merely an example, and the current sensor used in the current measurement device according to this embodiment is not limited to the current sensor 10 shown in FIGS. 1A and 1B.

[0026] 1A, the coordinates are defined as the X-axis direction parallel to the paper surface and extending from bottom to top, the Y-axis direction parallel to the paper surface and extending from right to left, and the Z-axis direction perpendicular to the paper surface and extending from back to front. Any one of the X-axis, Y-axis, and Z-axis is orthogonal to the other axes.

[0027] The current sensor 10 includes a signal processing IC 100, two magnetoelectric conversion elements 20, a primary lead frame 140 on the current conductor side, a secondary lead frame 150 on the signal terminal side, a support portion 120, and a sealing portion 130. In this embodiment, an example will be described in which the current sensor 10 includes two magnetoelectric conversion elements 20. However, the number of magnetoelectric conversion elements 20 included in the current sensor 10 is not limited to two. The current sensor 10 only needs to include at least one magnetoelectric conversion element 20.

[0028] The primary lead frame 140 includes a primary conductor 141 and a primary terminal 142. The primary terminal 142 includes a pair of primary terminals 1421, 1422. The primary conductor 141 is sealed within the sealing portion 130 and partially surrounds the two magnetoelectric conversion elements 20. A measurement current flows through the primary terminal 142 and the primary conductor 141. The pair of primary terminals 1421, 1422 are physically integrated with the primary conductor 141 and are exposed to the outside of the sealing portion 130.

[0029] The primary lead frame 140 does not need to be manufactured in a form in which multiple metal plates are connected to form the primary conductor portion 141 and the primary terminal portion 142, but may also be manufactured using individual metal parts.

[0030] The secondary lead frame 150 includes an IC support portion 151 and a secondary terminal portion 152. The secondary terminal portion 152 includes multiple secondary terminals 1521 that are signal terminals. The IC support portion 151 is sealed within the sealing portion 130 and supports the signal processing IC 100. Some of the multiple secondary terminals 1521 are physically integrated with the IC support portion 151. At least a portion of each of the multiple secondary terminals 1521 is exposed outside the sealing portion 130. The primary lead frame 140 and the secondary lead frame 150 may be made of a conductive material primarily composed of copper. The IC support portion 151 may be made of a metal plate separate from the secondary lead frame 150, a plate made of a semiconductor, or an insulating member such as a die attach fill.

[0031] The element support part 120 is supported by the IC support part 151 and supports two magnetoelectric conversion elements 20. The element support part 120 is made of an insulating material such as a separate metal plate, a plate made of semiconductor, or a die attach fill. The element support part 120 may be integrally formed with the IC support part 151.

[0032] The pair of primary terminals 1421, 1422 and the multiple secondary terminals 1521 are arranged opposite each other across the signal processing IC 100 in a direction (Y-axis direction) intersecting the thickness direction (Z-axis direction) of the signal processing IC 100. The direction intersecting the thickness direction may be a direction along a plane (XY plane) perpendicular to the thickness direction. The pair of primary terminals 1421, 1422 are exposed from the side surface 130a of the sealing portion 130. The multiple secondary terminals 1521 are exposed from the side surface 130b of the sealing portion 130 opposite the side surface 130a.

[0033] The pair of primary terminals 1421, 1422 protrude from the side surface 130a toward the negative side in the Y-axis direction and are further bent toward the negative side in the Z-axis direction. The multiple secondary terminals 1521 protrude from the side surface 130b toward the positive side in the Y-axis direction and are further bent toward the negative side in the Z-axis direction. The pair of primary terminals 1421, 1422 may protrude from the side surface 130a toward the negative side in the Y-axis direction and be further bent toward the positive side in the Z-axis direction. The multiple secondary terminals 1521 may protrude from the side surface 130b toward the positive side in the Y-axis direction and be further bent toward the positive side in the Z-axis direction. The pair of primary terminals 1421, 1422 and the multiple secondary terminals 1521 do not have to be bent. That is, the pair of primary terminals 1421, 1422 do not have to protrude from the side surface 130a toward the negative side in the Y-axis direction and be bent toward the positive and negative sides in the Z-axis direction. The multiple secondary terminals 1521 do not have to protrude from the side surface 130b toward the positive side in the Y-axis direction and be bent toward the positive and negative sides in the Z-axis direction.

[0034] The signal processing IC 100 may be fixed to the IC support portion 151 via an adhesive layer. The adhesive layer may be a die attach film. The primary lead frame 140 may have a stepped portion 144 in which the portion facing the signal processing IC 100 protrudes in the thickness direction away from the signal processing IC 100.

[0035] The primary conductor 141 has a bent portion 1410 connecting the primary terminal 1421 and the primary terminal 1422. The bent portion 1410 includes a portion 1411 connected to the primary terminal 1421 and extending in the Y-axis direction, a portion 1413 connected to the primary terminal 1422 and extending in the Y-axis direction, and a connecting portion 1412 extending in the X-axis direction and connecting the portion 1411 and the portion 1413. The bent portion 1410 has a U-shaped portion formed by the portion 1411, the connecting portion 1412, and the portion 1413. The portion 1411, the connecting portion 1412, and the portion 1413 form a slit portion 1416 having an opening on the negative side in the Y-axis direction. The bent portion 1410 also has an extension portion 1414 extending further from the connecting portion 1412 to the negative side in the X-axis direction. The extension portion 1414, the portion 1411, and the connection portion 1415 with the primary terminal 1421 form a slit portion 1417 having an opening on the negative side in the X-axis direction. The portion 1411 is an example of a first portion and a third portion. The portion 1413 is an example of a second portion and a fourth portion.

[0036] One of the magnetoelectric transducers 20 is disposed in the slit 1416 in a plan view, and is thereby partially surrounded by the primary conductor 141. The other of the magnetoelectric transducers 20 is disposed in the slit 1417 in a plan view, and is thereby partially surrounded by the primary conductor 141. The one of the magnetoelectric transducers 20 and the other of the magnetoelectric transducers 20 are disposed opposite each other along the X-axis direction, with the portion 1411 sandwiched between them in a plan view. The shape of the primary conductor 141 is not limited to the shape shown in FIG. 1A and may be any shape.

[0037] The two magnetoelectric conversion elements 20 may be electrically connected to the signal processing IC 100 by wire bonding. That is, the two magnetoelectric conversion elements 20 may be electrically connected to the signal processing IC 100 via a plurality of wires 22. The two magnetoelectric conversion elements 20 output signals to be processed by the signal processing IC 100 to the signal processing IC 100. The two magnetoelectric conversion elements 20 may be configured separately from the signal processing IC 100. That is, the two magnetoelectric conversion elements 20 may be configured on a chip separate from the chip that configures the signal processing IC 100.

[0038] The magnetic sensitive surfaces of the two magnetoelectric conversion elements 20 may be positioned so as to overlap with the side surfaces on which the slit portions 1416 and 1417 are provided, when viewed from a direction (X-axis direction or Y-axis direction) intersecting the thickness direction (Z-axis direction) of the two magnetoelectric conversion elements 20.

[0039] The signal processing IC 100 is electrically connected to the multiple secondary terminals 1521 via wires 108. The wires 22 and 108 may be made of a conductive material containing Au, Ag, Cu, or Al as a main component.

[0040] The magnetoelectric conversion element 20 detects a magnetic field in a specific direction that changes in accordance with the measurement current flowing through the primary conductor 141, and the signal processing IC 100 amplifies a signal corresponding to the magnitude of the magnetic field and outputs the amplified signal via the secondary terminal 1521. The magnetoelectric conversion element 20 is made of a compound semiconductor formed on a GaAs substrate, and may be a chip cut into a square or rectangular shape when viewed from above in the Z-axis direction.

[0041] The magnetoelectric conversion element 20 may have a substrate made of silicon or a compound semiconductor and a magnetoelectric conversion unit provided on the substrate. The thickness of the substrate is adjusted by polishing the surface on the negative side in the Z-axis direction. Since the magnetic field in the Z-axis direction is detected, for example, a Hall element that detects a vertical magnetic field in the thickness direction of the primary conductor 141 is appropriate for the magnetoelectric conversion element 20.

[0042] The signal processing IC 100 is a large-scale integrated circuit (LSI). The signal processing IC 100 is a monolithic IC. More specifically, the signal processing IC 100 is a signal processing circuit made of a Si monolithic semiconductor formed on a Si substrate. The signal processing circuit processes output signals corresponding to the magnitude of the magnetic fields output from the two magnetoelectric conversion elements 20. The signal processing circuit corrects the measurement current flowing through the primary conductor portion 141 based on the output signals and outputs an output signal indicating an accurate current value via the secondary terminal 1521. The signal processing circuit reduces noise components contained in the output signals of one magnetoelectric conversion element 20 and the other magnetoelectric conversion element 20 based on the difference between the output signals of one magnetoelectric conversion element 20 and the other magnetoelectric conversion element 20, amplifies the output signals of the one magnetoelectric conversion element 20 and the other magnetoelectric conversion element 20 with the noise components reduced, calculates the current value of the measurement current based on the amplified output signals, and outputs an output signal indicating the current value.

[0043] The sealing section 130 seals the magnetoelectric conversion element 20, the primary conductor 141, the IC support section 151, the element support section 120, the signal processing IC 100, the wires 22, and the wires 108 with molding resin. The molding resin may be made of, for example, an epoxy-based thermosetting resin to which silica has been added, and may be formed into a semiconductor package by transfer molding.

[0044] A current measuring device that detects two or three phase currents of three phase (U phase, V phase, and W phase) currents (AC) output from a three-phase power supply is configured using a plurality of current sensors 10 configured as described above. In this embodiment, a current measuring device that detects two phase currents will be described as an example.

[0045] The current measurement device according to the first embodiment includes a current sensor 10 A and a current sensor 10 B. The current sensors 10 A and 10 B may have the same configuration as the current sensor 10 described above.

[0046] FIG. 2A is a plan view of the substrate 200 in the first embodiment, as seen from the first surface side on which the current sensor 10A is mounted. FIG. 2B is a plan view of the substrate 200 in the first embodiment, as seen from the second surface side opposite the first surface on which the current sensor 10B is mounted. FIG. 2C is a schematic cross-sectional view of the substrate 200 in the first embodiment, as seen from the negative side to the positive side in the X-axis direction, on which the current sensor 10A and the current sensor 10B are mounted. FIG. 2D is a schematic cross-sectional view of the substrate 200 in the first embodiment, as seen from the positive side to the negative side in the Y-axis direction, on which the current sensor 10A and the current sensor 10B are mounted. FIG. 3 is a schematic plan view of the substrate 200 in the first embodiment, as seen from the first surface side, with the current sensor 10B and the bus bar 220 arranged on the second surface side indicated by dashed lines.

[0047] The current measurement device includes bus bar 210, which extends along the X-axis direction on a first surface of substrate 200 and through which a first phase current flows. The current measurement device further includes bus bar 220, which extends along the X-axis direction on a second surface of substrate 200 and through which a second phase current flows. In addition, the current measurement device further includes bus bar 230, which extends along the X-axis direction on the first surface of substrate 200 and through which a third phase current flows. Bus bar 210, bus bar 220, and bus bar 230 may be arranged parallel to each other in a plan view.

[0048] Current sensor 10A measures a first-phase current flowing through bus bar 210. Current sensor 10B measures a second-phase current flowing through bus bar 220. A circuit 300A including a power supply that supplies power to current sensor 10A and a signal processing circuit that processes signals output from current sensor 10A is connected to secondary terminal 152A of current sensor 10A via pad 202A on the first surface of substrate 200. A circuit 300B including a power supply that supplies power to current sensor 10B and a signal processing circuit that processes signals output from current sensor 10B is connected to secondary terminal 152B of current sensor 10B via pad 202B on the second surface of substrate 200. At least a portion of circuit 300A and circuit 300B may be a common circuit.

[0049] Bus bar 210 has two divided conductor portions 211 and 212 that extend in the Z-axis direction along the first surface of substrate 200. Divided conductor portion 211 and divided conductor portion 212 are spaced apart. Primary terminal 1421A is connected to divided conductor portion 211, and primary terminal 1422A is connected to divided conductor portion 212. A first-phase current flows through divided conductor portion 211, primary lead frame 140, and divided conductor portion 212.

[0050] Similar to bus bar 210, bus bar 220 has two divided conductor portions 221 and 222 that extend in the X-axis direction along the second surface of substrate 200. Divided conductor portion 221 and divided conductor portion 222 are spaced apart. Primary terminal 1421B is connected to divided conductor portion 221, and primary terminal 1422B is connected to divided conductor portion 222. A second-phase current flows through divided conductor portion 221, primary lead frame 140B, and divided conductor portion 222.

[0051] Primary terminal 142A of current sensor 10A and primary terminal 142B of current sensor 10B are arranged to face in opposite directions in the Y-axis direction. Bus bar 210 and bus bar 220 do not overlap in the thickness direction (Z-axis direction) of substrate 200 in a plan view. Sealing portions 130A and 130B are located between bus bar 210 and bus bar 220 in a plan view.

[0052] Furthermore, at least a portion of sealing portion 130A and at least a portion of sealing portion 130B overlap in the thickness direction (Z-axis direction) of substrate 200. Side surface 130aA of sealing portion 130A and side surface 130bB of sealing portion 130B face the same direction in the Y-axis direction, and side surface 130bA of sealing portion 130A and side surface 130aB of sealing portion 130B face the same direction in the Y-axis direction. That is, in a plan view, primary terminal 142A of current sensor 10A and primary terminal 142B of current sensor 10B face in opposite directions in the Y-axis direction.

[0053] The primary conductor 141A of the current sensor 10A may be located within the sealing portion 130A on the side surface 130aA side of the center of gravity of the sealing portion 130A in a plan view. That is, the primary conductor 141A may be shifted toward the side surface 130aA side of the sealing portion 130A from the center of gravity of the sealing portion 130A. Similarly, the primary conductor 141B of the current sensor 10B may be located within the sealing portion 130B on the side surface 130aB side of the center of gravity of the sealing portion 130B in a plan view. That is, the primary conductor 141B may be shifted toward the side surface 130aB side of the sealing portion 130B from the center of gravity of the sealing portion 130B.

[0054] By arranging the primary conductors 141A, 141B in such positions and arranging the primary terminal 142A of current sensor 10A and the primary terminal 142B of current sensor 10B so that they face in opposite directions in the Y-axis direction, the two magnetoelectric conversion elements 20A included in current sensor 10A and the primary conductor 141B included in current sensor 10B do not overlap in a plan view in the thickness direction of the substrate 200. In addition, the two magnetoelectric conversion elements 20B of current sensor 10B and the primary conductor 141A of current sensor 10A do not overlap in a plan view in the thickness direction of the substrate 200.

[0055] With this arrangement, when viewed from the two magneto-electric transducers 20A, the second-phase current flowing through the primary conductor 141B exists only on the positive side of the Y-axis. Therefore, the direction of the magnetic field generated by the second-phase current flowing through the primary conductor 141B, which affects the two magneto-electric transducers 20A, is uniform. Similarly, when viewed from the two magneto-electric transducers 20B, the first-phase current flowing through the primary conductor 141A exists only on the negative side of the Y-axis. Therefore, the direction of the magnetic field generated by the first-phase current flowing through the primary conductor 141A, which affects the two magneto-electric transducers 20B, is uniform.

[0056] As described above, current sensors 10A and 10B reduce noise components contained in the output signals of one magnetoelectric transducer 20A, 20B and the other magnetoelectric transducer 20A, 20B based on the difference between the output signal of one magnetoelectric transducer 20A, 20B and the output signal of the other magnetoelectric transducer 20A, 20B. Therefore, if the influence of the magnetic field applied to the two magnetoelectric transducers 20A, 20B is the same, the influence can be effectively canceled out by taking the difference between the output signals of the two magnetoelectric transducers 20A, 20B. Therefore, by positioning the two magnetoelectric transducers 20A, 20B and the primary conductors 141A, 141B relative to the substrate 200 as described above, current sensor 10A can be made less susceptible to the influence of the current flowing through bus bar 220, and current sensor 10B can be made less susceptible to the influence of the current flowing through bus bar 210.

[0057] Furthermore, by arranging the bus bars 210 and 220 on both sides of the substrate 200, the current sensor 10A can be less susceptible to the magnetic field generated by the second-phase current flowing through the primary conductor 141B. Furthermore, the current sensor 10B can be less susceptible to the magnetic field generated by the first-phase current flowing through the primary conductor 141A. Moreover, the area of ​​the substrate 200 on which the multiple bus bars 210, 220, 230 and the current sensors 10A and 10B are mounted can be reduced.

[0058] It is preferable that primary conductor portion 141A and primary conductor portion 141B do not overlap in a plan view in the thickness direction of substrate 200. This makes it possible to make current sensors 10A and 10B less susceptible to the influence of magnetic fields generated by currents flowing through bus bars 210 and 220.

[0059] 4 shows an example of a simulation result indicating the magnitude of the current error detected by current sensor 10A or current sensor 10B according to the distance (mm) in the X-axis direction between the center of gravity of current sensor 10A and the center of gravity of current sensor 10B when the current measurement device according to the first embodiment is viewed in a plan view. As shown in FIG. 4, it can be seen that the current error is smaller when the center of gravity of current sensor 10B is slightly shifted from the center of gravity of current sensor 10A or when the center of gravity of current sensor 10B is shifted significantly from the center of gravity of current sensor 10A, rather than when the distance between the centers of gravity of current sensor 10A and current sensor 10B is set to zero.

[0060] The current error is smaller when the center of gravity of current sensor 10B is shifted significantly from the center of gravity of current sensor 10A, because increasing the distance between current sensor 10A and current sensor 10B makes the two magnetoelectric conversion elements 20 less susceptible to the influence of the current flowing in the primary conductor portion 141 of the other side.

[0061] The current error becomes smaller when the center of gravity of current sensor 10B is slightly shifted from the center of gravity of current sensor 10A if there is little change in the influence of the current flowing through the primary conductor portion 141 of the other side that is received by the two magnetoelectric conversion elements 20. When there is little change in the influence of the current, the influence can be effectively canceled out by taking the difference between the output signals of the two magnetoelectric conversion elements 20.

[0062] Here, if the primary conductor portion 141 has an axisymmetric shape when viewed in a plane, with the perpendicular bisector of the line segment connecting the two magnetoelectric conversion elements 20 as the axis of symmetry, the variation in the influence of the current flowing through the opposing primary conductor portion 141 that the two magnetoelectric conversion elements 20 receive can be reduced.

[0063] 3, it is preferable that perpendicular bisector 24A of line segment 23A connecting two magnetoelectric conversion elements 20A does not overlap perpendicular bisector 24B of line segment 23B connecting two magnetoelectric conversion elements 20B in a plan view, thereby making current sensor 10A and current sensor 10B less susceptible to the influence of magnetic noise on each other.

[0064] Furthermore, it is preferable that the perpendicular bisector 24A of the line segment 23A connecting the two magnetoelectric conversion elements 20A passes between the two magnetoelectric conversion elements 20B in a plan view. Moreover, it is preferable that the distance k in a plan view between the perpendicular bisector 24A of the line segment 23A connecting the two magnetoelectric conversion elements 20A and the perpendicular bisector 24B of the line segment 23B connecting the two magnetoelectric conversion elements 20B is half the distance between the centers of gravity of the two magnetoelectric conversion elements 20A or the two magnetoelectric conversion elements 20B. In fact, in Figure 4, the condition under which the current error is minimized corresponds to the case where the distance k is half the distance between the centers of gravity of the two magnetoelectric conversion elements 20A or the two magnetoelectric conversion elements 20B.

[0065] Alternatively, as shown in Fig. 4, the current error can be reduced by setting the distance k between the perpendicular bisector 24A of the line segment 23A connecting the two magnetoelectric conversion elements 20A and the perpendicular bisector 24B of the line segment 23B connecting the two magnetoelectric conversion elements 20B to at least 2.5 times the distance between the two magnetoelectric conversion elements 20A in a plan view. Therefore, as shown in Fig. 5, the distance k is preferably at least 2.5 times the distance between the two magnetoelectric conversion elements 20A in a plan view. This makes it possible to reduce the influence of magnetic noise between the current sensors 10A and 10B.

[0066] The bus bar 230 is disposed on the first surface of the substrate 200, extends in the X-axis direction, and is positioned opposite the current sensor 10A in the Y-axis direction, sandwiching the bus bar 210 therebetween, through which a third-phase current flows. The bus bar 230 is disposed on one side of the bus bar 210 opposite the side to which the primary terminal 142A of the current sensor 10A is connected. This allows the bus bar 230 to be positioned away from the secondary terminal 152A of the current sensor 10A. This makes it less likely that magnetic noise generated by the current flowing through the bus bar 230 will affect the signal flowing through the secondary terminal 152A. Furthermore, it is easier to ensure a withstand voltage between the bus bar 230 and the circuit 300A.

[0067] 6, bus bar 230 may extend in the X-axis direction and be disposed on an inner layer of substrate 200. In this case, a portion of bus bar 230 may overlap bus bar 210 and bus bar 220 in the thickness direction of substrate 200. This allows the area of ​​substrate 200 to be further reduced.

[0068] The above describes an example in which busbars 210 and 220 are arranged in positions where they do not overlap in the thickness direction of substrate 200. However, busbars 210 and 220 may be arranged in positions where they overlap in the thickness direction of substrate 200. Also, the above describes an example in which primary terminal 142A of current sensor 10A and primary terminal 142B of current sensor 10B face in opposite directions in the Y-axis direction in a plan view. However, primary terminal 142A of current sensor 10A and primary terminal 142B of current sensor 10B may face in the same direction in the Y-axis direction in a plan view.

[0069] Even in such a modified example, it is preferable that the perpendicular bisector 24A of the line segment 23A connecting the two magnetoelectric conversion elements 20A does not overlap the perpendicular bisector 24B of the line segment 23B connecting the two magnetoelectric conversion elements 20B in a planar view. Furthermore, it is preferable that the distance k between the perpendicular bisector 24A of the line segment 23A connecting the two magnetoelectric conversion elements 20A and the perpendicular bisector 24B of the line segment 23B connecting the two magnetoelectric conversion elements 20B in a planar view is half the distance between the centers of gravity of the two magnetoelectric conversion elements 20A or the two magnetoelectric conversion elements 20B. Alternatively, it is preferable that the distance k between the perpendicular bisector 24A of the line segment 23A connecting the two magnetoelectric conversion elements 20A and the perpendicular bisector 24B of the line segment 23B connecting the two magnetoelectric conversion elements 20B in a planar view is at least 2.5 times the distance between the two magnetoelectric conversion elements 20A in a planar view.

[0070] Next, a current measuring device according to a second embodiment will be described in which, in a plan view, the primary terminal 142A of the current sensor 10A and the primary terminal 142B of the current sensor 10B face in the same direction in the Y-axis direction. The current measuring device according to the second embodiment includes the current sensor 10A and the current sensor 10B. The current sensor 10A and the current sensor 10B may have the same configuration as the current sensor 10 in the first embodiment. That is, they may have the same configuration as the current sensor 10 shown in FIGS. 1A and 1B.

[0071] FIG. 7A is a plan view of the circuit board 200 in the second embodiment, as viewed from the first surface on which the current sensor 10A is mounted. FIG. 7B is a plan view of the circuit board 200 in the second embodiment, as viewed from the second surface opposite the first surface on which the current sensor 10B is mounted. FIG. 7C is a schematic cross-sectional view of the circuit board 200 in the second embodiment, as viewed from the negative side to the positive side in the X-axis direction, on which the current sensor 10A and the current sensor 10B are mounted. FIG. 7D is a schematic cross-sectional view of the circuit board 200 in the second embodiment, as viewed from the positive side to the negative side in the Y-axis direction, on which the current sensor 10A and the current sensor 10B are mounted. FIG. 8 is a schematic plan view of the circuit board 200 in the second embodiment, as viewed from the first surface, with the current sensor 10B and the bus bar 220 arranged on the second surface indicated by dashed lines.

[0072] The current measurement device includes bus bar 210, which extends along the X-axis direction on a first surface of substrate 200 and through which a first phase current flows. The current measurement device further includes bus bar 220, which extends along the X-axis direction on a second surface of substrate 200 and through which a second phase current flows. In addition, the current measurement device further includes bus bar 230, which extends along the X-axis direction on the first surface of substrate 200 and through which a third phase current flows. Bus bar 210, bus bar 220, and bus bar 230 may be arranged parallel to each other in a plan view.

[0073] Current sensor 10A measures a first-phase current flowing through bus bar 210. Current sensor 10B measures a second-phase current flowing through bus bar 220. A circuit 300A including a power supply that supplies power to current sensor 10A and a signal processing circuit that processes signals output from current sensor 10A is connected to secondary terminal 152A of current sensor 10A via pad 202A on the first surface of substrate 200. A circuit 300B including a power supply that supplies power to current sensor 10B and a signal processing circuit that processes signals output from current sensor 10B is connected to secondary terminal 152B of current sensor 10B via pad 202B on the second surface of substrate 200. At least a portion of circuit 300A and circuit 300B may be a common circuit.

[0074] Bus bar 210 has two divided conductor portions 211 and 212 that extend in the Z-axis direction along the first surface of substrate 200. Divided conductor portion 211 and divided conductor portion 212 are spaced apart. Primary terminal 1421A is connected to divided conductor portion 211, and primary terminal 1422A is connected to divided conductor portion 212. A first-phase current flows through divided conductor portion 211, primary lead frame 140, and divided conductor portion 212.

[0075] Like busbar 210, busbar 220 has two divided conductor portions 221 and 222 that extend along the X-axis direction along the second surface of substrate 200. Divided conductor portion 221 and divided conductor portion 222 are spaced apart. Primary terminal 1421B is connected to divided conductor portion 221, and primary terminal 1422B is connected to divided conductor portion 222. A second-phase current flows through divided conductor portion 221, primary lead frame 140B, and divided conductor portion 222. A portion of busbar 220 overlaps busbar 210 when viewed in the thickness direction (Z-axis direction) of substrate 200.

[0076] The primary terminal portion 142A of the current sensor 10A and the primary terminal portion 142B of the current sensor 10B are arranged to face the same direction in the Y-axis direction.

[0077] At least a portion of sealing portion 130A and at least a portion of sealing portion 130B overlap in the thickness direction (Z-axis direction) of substrate 200. Side surface 130aA of sealing portion 130A and side surface 130aB of sealing portion 130B face the same direction in the Y-axis direction, and side surface 130bA of sealing portion 130A and side surface 130bB of sealing portion 130B face the same direction in the Y-axis direction. That is, in a plan view, primary terminal portion 142A of current sensor 10A and primary terminal portion 142B of current sensor 10B face the same direction in the Y-axis direction.

[0078] The primary conductor 141A of the current sensor 10A may be located within the sealing portion 130A on the side surface 130aA side of the center of gravity of the sealing portion 130A in a plan view. That is, the primary conductor 141A may be shifted toward the side surface 130aA side of the sealing portion 130A from the center of gravity of the sealing portion 130A. Similarly, the primary conductor 141B of the current sensor 10B may be located within the sealing portion 130B on the side surface 130aB side of the center of gravity of the sealing portion 130B in a plan view. That is, the primary conductor 141B may be shifted toward the side surface 130aB side of the sealing portion 130B from the center of gravity of the sealing portion 130B.

[0079] The primary conductors 141A and 141B are arranged in such positions, and the primary terminal 142A of the current sensor 10A and the primary terminal 142B of the current sensor 10B are arranged so as to face the same direction in the Y-axis direction. Furthermore, the current sensor 10B may be arranged shifted at least in the X-axis direction relative to the current sensor 10A in a planar view. The primary conductor 141B may be congruent with the primary conductor 141A and may be arranged shifted relative to the primary conductor 141A in a planar view. One of the two magnetoelectric conversion elements 20B may be arranged between the two magnetoelectric conversion elements 20A in the Y-axis direction in a planar view. In a planar view, the two magnetoelectric conversion elements 20B may overlap at least a portion of the portion 1411A, the portion 1413A, and the connecting portion 1412A of the bending portion 1410A in the thickness direction (Z-axis direction). Similarly, the two magnetoelectric transducers 20A may overlap at least a part of the portion 1411B, the portion 1413B, and the connecting portion 1412B of the bent portion 1410B in the thickness direction (Z-axis direction).

[0080] In the current measuring device according to the second embodiment, it is preferable that, in a plan view in the X-axis direction, at least one of the pair of magnetoelectric conversion elements 20B of one current sensor 10B is present between the pair of magnetoelectric conversion elements 20A of the other current sensor 10A, or that at least one of the pair of magnetoelectric conversion elements 20B of the other current sensor 10B overlaps in the thickness direction with at least a part of the portion 1411, the connecting portion 1412, and the portion 1413 of the bent portion 1410 of one current sensor 10A. This makes it possible to make the current sensors 10A and 10B less susceptible to the influence of the magnetic field generated by the current flowing through the bus bars 210 and 220.

[0081] Figure 9 shows an example of a simulation result showing the magnitude of the current error detected by current sensor 10A or current sensor 10B depending on the distance (mm) in the X-axis direction between the center of gravity of current sensor 10A and the center of gravity of current sensor 10B when the current measuring device of the second embodiment is viewed in a plan view.

[0082] 9, it can be seen that the current error is smaller when the center of gravity of current sensor 10B is slightly shifted from the center of gravity of current sensor 10A or when the center of gravity of current sensor 10B is significantly shifted from the center of gravity of current sensor 10A, rather than when the distance between the centers of gravity of current sensor 10A and current sensor 10B is zero. The current error is smaller when the center of gravity of current sensor 10B is significantly shifted from the center of gravity of current sensor 10A because increasing the distance between current sensor 10A and current sensor 10B makes the two magnetoelectric conversion elements 20 less susceptible to the influence of the current flowing in the primary conductor portion 141 of the other current sensor.

[0083] The current error becomes smaller when the center of gravity of current sensor 10B is slightly shifted from the center of gravity of current sensor 10A if there is little change in the influence of the current flowing through the primary conductor portion 141 of the other side that is received by the two magnetoelectric conversion elements 20. When there is little change in the influence of the current, the influence can be effectively canceled out by taking the difference between the output signals of the two magnetoelectric conversion elements 20.

[0084] Here, if the primary conductor portion 141 has an axisymmetric shape when viewed in a plane, with the perpendicular bisector of the line segment connecting the two magnetoelectric conversion elements 20 as the axis of symmetry, the variation in the influence of the current flowing through the opposing primary conductor portion 141 that the two magnetoelectric conversion elements 20 receive can be reduced.

[0085] 8, it is preferable that perpendicular bisector 24A of line segment 23A connecting two magnetoelectric conversion elements 20A does not overlap perpendicular bisector 24B of line segment 23B connecting two magnetoelectric conversion elements 20B in a plan view, thereby making current sensor 10A and current sensor 10B less susceptible to the influence of magnetic noise on each other.

[0086] Furthermore, it is preferable that the perpendicular bisector 24A of the line segment 23A connecting the two magnetoelectric conversion elements 20A passes between the two magnetoelectric conversion elements 20B in a plan view. Furthermore, it is preferable that the distance k in a plan view between the perpendicular bisector 24A of the line segment 23A connecting the two magnetoelectric conversion elements 20A and the perpendicular bisector 24B of the line segment 23B connecting the two magnetoelectric conversion elements 20B is half the distance between the centers of gravity of the two magnetoelectric conversion elements 20A or the two magnetoelectric conversion elements 20B. In fact, in Figure 8, the condition for minimizing the current error corresponds to the case where the distance k is half the distance between the centers of gravity of the two magnetoelectric conversion elements 20A or the two magnetoelectric conversion elements 20B.

[0087] Alternatively, as shown in Fig. 8, the current error can be reduced by setting the distance k between the perpendicular bisector 24A of the line segment 23A connecting the two magnetoelectric conversion elements 20A and the perpendicular bisector 24B of the line segment 23B connecting the two magnetoelectric conversion elements 20B to at least 2.5 times the distance between the two magnetoelectric conversion elements 20A in a plan view. Therefore, as shown in Fig. 10, the distance k is preferably at least 2.5 times the distance between the two magnetoelectric conversion elements 20A in a plan view. This makes it possible to reduce the influence of magnetic noise on the current sensor 10A and the current sensor 10B from each other.

[0088] The bus bar 230 is disposed on the first surface of the substrate 200, extends in the X-axis direction, and is positioned opposite the current sensor 10A in the Y-axis direction, sandwiching the bus bar 210 therebetween, through which a third-phase current flows. The bus bar 230 is disposed on one side of the bus bar 210 opposite the side to which the primary terminal 142A of the current sensor 10A is connected. This allows the bus bar 230 to be positioned away from the secondary terminal 152A of the current sensor 10A. This makes it less likely that magnetic noise generated by the current flowing through the bus bar 230 will affect the signal flowing through the secondary terminal 152A. Furthermore, it is easier to ensure a withstand voltage between the bus bar 230 and the circuit 300A.

[0089] 11 , bus bar 230 may extend in the X-axis direction and be disposed on an inner layer of substrate 200. In this case, a portion of bus bar 230 may overlap bus bar 210 and bus bar 220 in the thickness direction of substrate 200. This allows the area of ​​substrate 200 to be further reduced.

[0090] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0091] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order.

[0092] 10, 10A, 10B Current sensor 20, 20A, 20B Magnetoelectric conversion element 100 Signal processing IC 22, 108 Wire 23A, 23A Line segment 24A, 24B Perpendicular bisector 120 Element support portion 130, 130A, 130B Sealing portion 130a, 130aA, 130aB Side surface 130b, 130bA, 130bB Side surface 140 Primary lead frame 141, 141A, 141B Primary conductor portion 144 Step portion 150 Secondary lead frame 151 IC support portion 152, 152A, 152B Secondary terminal portion 200 Substrate 210, 220, 230 Bus bar 211, 212 Divided conductor portion 221, 222 Divided conductor portion 300A, 300B Circuit 1410 Bent portion 1411 Portion 1412 Connecting portion 1413 Portion 1414 Extension portion 1415 Connection portion 1416, 1417 Slit portion 1421, 1421A, 1421B, 1422, 1422A, 1422B Primary terminal 1521 Secondary terminal

Claims

a first bus bar arranged on a first surface of the substrate; a second bus bar arranged on a second surface of the substrate opposite to the first surface; a first current sensor arranged on the first surface of the substrate and measuring a first current flowing through the first bus bar; and a second current sensor arranged on the second surface of the substrate and measuring a second current flowing through the second bus bar, the first current sensor having at least one first magneto-electric transducer, a first primary terminal portion connected to the first bus bar and a first primary conductor portion connected to the first primary terminal portion, a first primary lead frame through which the first current measured by the at least one first magneto-electric transducer flows via the first primary terminal portion and the first primary conductor portion, a first signal processing IC processing a signal output from the at least one first magneto-electric transducer, and a first sealing portion sealing the at least one first magneto-electric transducer, the first primary conductor portion, and the first signal processing IC, a second primary lead frame including at least one second magnetoelectric transducer; a second primary terminal portion connected to the second bus bar and a second primary conductor portion connected to the second primary terminal portion, the second current measured by the at least one second magnetoelectric transducer flowing through the second primary terminal portion and the second primary conductor portion; a second signal processing IC that processes a signal output from the at least one second magnetoelectric transducer; and a second sealing portion that seals the at least one second magnetoelectric transducer, the second primary conductor portion, and the second signal processing IC, wherein at least a portion of the first sealing portion and at least a portion of the second sealing portion overlap in a thickness direction of the substrate, the at least one first magnetoelectric transducer element and the second primary conductor portion do not overlap in the thickness direction of the substrate in a plan view, and the at least one second magnetoelectric transducer element and the first primary conductor portion do not overlap in the thickness direction of the substrate in a plan view.

2. The current measuring device according to claim 1, wherein the first primary conductor portion and the second primary conductor portion do not overlap in a thickness direction of the substrate in a plan view.

3. A substrate comprising: a first bus bar arranged on a first surface of the substrate; a second bus bar arranged on a second surface of the substrate opposite to the first surface; a first current sensor arranged on the first surface of the substrate and measuring a first current flowing through the first bus bar; and a second current sensor arranged on the second surface of the substrate and measuring a second current flowing through the second bus bar, wherein the first current sensor has: at least two first magneto-electric transducers; a first primary terminal portion connected to the first bus bar and a first primary conductor portion connected to the first primary terminal portion, a first primary lead frame through which the first current measured by the at least two first magneto-electric transducers flows via the first primary terminal portion and the first primary conductor portion; a first signal processing IC that processes signals output from the at least two first magneto-electric transducers; and a first sealing portion that seals the at least two first magneto-electric transducers, the first primary conductor portion, and the first signal processing IC, and the second current sensor has: the substrate has at least two second magnetoelectric transducers; a second primary lead frame including a second primary terminal portion connected to the second bus bar and a second primary conductor portion connected to the second primary terminal portion, the second current measured by the at least two second magnetoelectric transducers flowing through the second primary terminal portion and the second primary conductor portion; a second signal processing IC that processes signals output from the at least two second magnetoelectric transducers; and a second sealing portion that seals the at least two second magnetoelectric transducers, the second primary conductor portion, and the second signal processing IC, wherein at least a portion of the first sealing portion and at least a portion of the second sealing portion overlap in a thickness direction of the substrate, a first direction is a direction in which the first bus bar extends along the first surface of the substrate, and a second direction is a direction intersecting the first direction along the first surface of the substrate, a first magnetoelectric transducer arranged to be in contact with the first magnetoelectric transducer in a first direction; a second magnetoelectric transducer arranged to be in contact with the first magnetoelectric transducer in a first direction; 4. A substrate comprising: a first bus bar arranged on a first surface of the substrate; a second bus bar arranged on a second surface of the substrate opposite to the first surface; a first current sensor arranged on the first surface of the substrate and measuring a first current flowing through the first bus bar; and a second current sensor arranged on the second surface of the substrate and measuring a second current flowing through the second bus bar, the first current sensor having: at least one first magneto-electric transducer; a first primary terminal portion connected to the first bus bar and a first primary conductor portion connected to the first primary terminal portion, a first primary lead frame through which the first current measured by the at least one first magneto-electric transducer flows via the first primary terminal portion and the first primary conductor portion; a first signal processing IC for processing a signal output from the at least one first magneto-electric transducer; and a first sealing portion for sealing the at least one first magneto-electric transducer element, the first primary conductor portion, and the first signal processing IC, the first sealing portion and the second sealing portion are disposed on the first surface of the substrate, the first sealing portion being disposed on the first surface of the substrate, the second sealing portion being disposed on the first surface of the substrate, the first sealing portion being disposed on the first surface of the substrate, the second sealing portion being disposed on the first surface of the substrate, the first sealing portion being disposed on the first surface of the substrate, the first sealing portion being disposed on the first surface of the substrate, the first sealing portion being disposed on the first surface of the substrate, the first sealing portion being disposed on the first surface of the substrate, the first sealing portion being disposed on the first surface of the substrate, the first sealing portion being disposed on the first surface of the substrate, the first sealing portion being disposed on the first surface of the substrate, the first sealing portion being disposed on the first surface of the substrate, the second bus bar has two second divided conductor portions extending along the first direction, the first current sensor has a pair of first primary terminals exposed from the first sealing portion, one of the two first divided conductor portions is connected to one of the pair of first primary terminals,a first primary conductor portion having a first bent portion connecting one of the pair of first primary terminals to the other of the pair of first primary terminals, the first bent portion having a first portion and a second portion each extending in the second direction, and a connecting portion connecting the first portion and the second portion and extending in the first direction, and the at least one second magnetoelectric conversion element overlaps in a thickness direction with at least a portion of the first portion, the second portion and the connecting portion of the first bent portion in a planar view.

5. The first bus bar has two first divided conductor portions extending in a first direction along the first surface of the substrate, the second bus bar has two second divided conductor portions extending in the first direction along the second surface of the substrate, the first sealing portion has a first side and a second side facing each other in a second direction intersecting the first direction along the first surface of the substrate, the first primary terminal portion has a pair of first primary terminals exposed from the first side of the first sealing portion, one of the two first divided conductor portions is connected to one of the pair of first primary terminals, the other of the two first divided conductor portions is connected to the other of the pair of first primary terminals, the first primary conductor portion has a first connecting portion connecting one of the pair of first primary terminals to the other of the pair of first primary terminals, and the second sealing portion has a first side and a second side facing each other in the second direction along the second surface of the substrate, 5. The current measuring device according to claim 1, wherein the second primary terminal portion has a pair of second primary terminals exposed from the first side surface of the second sealing portion, one of the two second divided conductor portions is connected to one of the pair of second primary terminals, the other of the two second divided conductor portions is connected to the other of the pair of second primary terminals, and the second primary conductor portion has a second connecting portion that connects one of the pair of second primary terminals to the other of the pair of second primary terminals.

6. A current measuring device as described in claim 5, wherein the first current sensor has two first magnetoelectric transducers as the at least one first magnetoelectric transducer, the second current sensor has two second magnetoelectric transducers as the at least one second magnetoelectric transducer, at least a portion of the two first magnetoelectric transducers is surrounded by the first connecting portion in a planar view, and at least a portion of the two second magnetoelectric transducers is surrounded by the second connecting portion in a planar view.

7. A current measuring device as described in claim 6, wherein the two first magnetic-electric transducers are arranged opposite each other with a portion of the first connecting portion in between, and the two second magnetic-electric transducers are arranged opposite each other with a portion of the second connecting portion in between.

8. The current measuring device described in claim 6, wherein the first connecting portion includes a first portion connected to one of the pair of first primary terminals and extending in the second direction, a first bent portion bent from the first portion, and a second portion extending from the first bent portion in the second direction and connected to the other of the pair of first primary terminals; the second connecting portion includes a third portion connected to one of the pair of second primary terminals and extending in the second direction, a second bent portion bent from the third portion, and a fourth portion extending from the second bent portion in the second direction and connected to the other of the pair of second primary terminals; the two first magnetic-electric transducers are arranged opposite each other in the first direction with the first portion in between, and the two second magnetic-electric transducers are arranged opposite each other in the first direction with the third portion in between.

9. A current measuring device as described in claim 8, wherein the perpendicular bisector of the line segment connecting the two first magnetic-electric transducers does not overlap with the perpendicular bisector of the line segment connecting the two second magnetic-electric transducers in a planar view.

10. A current measuring device according to claim 8, wherein a perpendicular bisector of a line segment connecting the two first magneto-electric transducers passes between the two second magneto-electric transducers in a plan view.

11. A current measuring device as described in claim 8, wherein the distance between the perpendicular bisector of the line segment connecting the two first magnetic-electric conversion elements and the perpendicular bisector of the line segment connecting the two second magnetic-electric conversion elements is at least 2.5 times the distance between the two first magnetic-electric conversion elements in a planar view.

12. The first bus bar has two first divided conductor portions extending in a first direction along the first surface of the substrate, the second bus bar has two second divided conductor portions extending in the first direction along the second surface of the substrate, the first sealing portion has a first side and a second side facing each other in a second direction intersecting the first direction along the first surface of the substrate, the first primary terminal portion has a pair of first primary terminals exposed from the first side of the first sealing portion, one of the two first divided conductor portions is connected to one of the pair of first primary terminals, the other of the two first divided conductor portions is connected to the other of the pair of first primary terminals, the first primary conductor portion has a first bent portion connecting one of the pair of first primary terminals to the other of the pair of first primary terminals, and the second sealing portion has a first side and a second side facing each other in the second direction along the second surface of the substrate, 2. The current measuring device of claim 1, wherein the second primary terminal portion has a pair of second primary terminals exposed from the first side surface of the second sealing portion, one of the two second divided conductor portions is connected to one of the pair of second primary terminals, the other of the two second divided conductor portions is connected to the other of the pair of second primary terminals, the second primary conductor portion has a second bent portion connecting one of the pair of second primary terminals to the other of the pair of second primary terminals, the first side surface of the first sealing portion and the second side surface of the second sealing portion face in the same direction in the second direction, and the second side surface of the first sealing portion and the first side surface of the second sealing portion face in the same direction in the second direction.

13. A current measuring device as described in claim 12, wherein the first primary conductor portion is located, in a planar view, within the first sealing portion on the first side surface side of the first sealing portion with respect to the center of gravity of the first sealing portion, and the second primary conductor portion is located, in a planar view, within the second sealing portion on the first side surface side of the second sealing portion with respect to the center of gravity of the second sealing portion.

14. The current measuring device described in claim 5, wherein the first current sensor further has a first secondary lead frame that is arranged facing the first primary terminal portion across the first signal processing IC in a planar view, exposed from the second side surface of the first sealing portion, and includes a first secondary terminal portion electrically connected to the first signal processing IC, and a first support portion supporting the first signal processing IC, and is electrically insulated from the first primary lead frame; and the second current sensor further has a second secondary lead frame that is arranged facing the second primary terminal portion across the second signal processing IC in a planar view, exposed from the second side surface of the second sealing portion, and includes a second secondary terminal portion electrically connected to the second signal processing IC, and a second support portion supporting the second signal processing IC, and is electrically insulated from the second primary lead frame.

15. The current measuring device according to claim 1 or 2, wherein the first bus bar and the second bus bar do not overlap in the thickness direction of the substrate.

16. The current measuring device according to claim 3 or 4, wherein the first bus bar and the second bus bar at least partially overlap in the thickness direction of the substrate.

17. The current measuring device of claim 5, further comprising a third bus bar arranged on the first surface of the substrate, extending in the first direction, and arranged in the second direction opposite the first current sensor across from the first bus bar, and through which a third current flows.

18. The current measuring device described in claim 5, further comprising a third bus bar arranged on an inner layer of the substrate, extending in the first direction, and through which a third current flows, a portion of the third bus bar overlapping with the first bus bar and the second bus bar in the thickness direction of the substrate.

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