Current sensor and current sensor module

Abstract

SOLUTION: The sealing portion seals a part of the first current conductor, the first magneto-electric conversion element, a part of the second current conductor, the second magneto-electric conversion element, the signal processing IC, and a part of the signal conductor. At least one of the first magnetoelectric conversion element and the second magnetoelectric conversion element may be disposed on a circuit surface of the signal processing IC. A part of the first current conductor may be exposed from a first surface of the sealing portion. A part of the second current conductor may be exposed from a second surface facing the first surface of the sealing portion in a first direction. A portion of the signal conductor may be exposed from a third surface different from the first surface and the second surface of the sealing portion.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a current sensor capable of measuring currents to be measured for two channels. [Prior art document] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2015 / 033541 Summary of the Invention [Problem to be solved by the invention]

[0004] It is desirable to miniaturize a current sensor that can measure two channels of current to be measured. [Means for solving the problem]

[0005] A current sensor according to an aspect of the present invention may include a first current conductor through which a first current to be measured flows. The current sensor may include a first magnetoelectric transducer that detects a magnetic field generated by the first current to be measured. The current sensor may include a second current conductor through which a second current to be measured flows. The current sensor may include a second magnetoelectric transducer that detects a magnetic field generated by the second current to be measured. The current sensor may include a signal processing IC that processes a signal output from at least one of the first magnetoelectric transducer and the second magnetoelectric transducer. The current sensor may include a signal conductor electrically connected to the signal processing IC and transmitting a signal output from the signal processing IC. The current sensor may include a sealing portion that seals a portion of the first current conductor, the first magnetoelectric transducer, a portion of the second current conductor, the second magnetoelectric transducer, the signal processing IC, and a portion of the signal conductor. At least one of the first magnetoelectric transducer and the second magnetoelectric transducer may be disposed on a circuit surface of the signal processing IC. In a plan view, the first current conductor and the second current conductor may face each other at a position where at least a portion of each overlaps the signal processing IC. In a cross-sectional view, the first current conductor and the second current conductor may be at a different height from the signal conductor within the sealing portion. A resin material constituting the sealing portion may be disposed between the first current conductor and the second current conductor. A portion of the first current conductor may be exposed from a first surface of the sealing portion. A portion of the second current conductor may be exposed from a second surface opposite the first surface of the sealing portion in the first direction. A portion of the signal conductor may be exposed from a third surface of the sealing portion that is different from the first and second surfaces.

[0006] In the current sensor, a distance between portions of the first current conductor and the second current conductor that face each other may be 2 mm or less and 0.1 mm or more in plan view.

[0007] In any of the current sensors, a part of the signal conductor may not be exposed from a fourth surface of the sealing portion that faces the third surface in a second direction that intersects with the first direction.

[0008] Any of the current sensors may further include a third magnetoelectric transducer arranged to face the first magnetoelectric transducer across a portion of the first current conductor in a plan view, and a fourth magnetoelectric transducer arranged to face the second magnetoelectric transducer across a portion of the second current conductor in a plan view. The first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer may be arranged on the circuit surface of the signal processing IC.

[0009] In any one of the current sensors, the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer may be built into a chip that constitutes the signal processing IC.

[0010] In any of the current sensors, the first magnetoelectric conversion element, the second magnetoelectric conversion element, the third magnetoelectric conversion element, and the fourth magnetoelectric conversion element may be configured on a chip separate from a chip that configures the signal processing IC.

[0011] In any of the current sensors, the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer may be electrically connected to the signal processing IC via wires, and the wires may be electrically connected to the first magnetoelectric transducer and the second magnetoelectric transducer and the signal processing IC without spanning the first current conductor and the second current conductor in a plan view.

[0012] In any of the current sensors, the first current conductor or the second current conductor may at least partially overlap with the signal processing IC and the signal conductor in a plan view.

[0013] In any of the current sensors, the first current conductor and the second current conductor may be formed from a first lead frame, and the signal conductor may be formed from a second lead frame.

[0014] In any of the current sensors, in a direction intersecting the circuit surface of the signal processing IC, the first current conductor and the second current conductor may be at the same height within the sealing portion, and the signal conductor may be at a different height from the first current conductor and the second current conductor.

[0015] In any of the current sensors, the first current conductor may include, in a plan view, a first conductor portion and a second conductor portion extending in the first direction and spaced apart in a second direction intersecting the first direction, and a third conductor portion extending in the second direction and connecting the first conductor portion and the second conductor portion. The second current conductor may include, in a plan view, a fourth conductor portion and a fifth conductor portion extending in the first direction and spaced apart in the second direction, and a sixth conductor portion extending in the second direction and connecting the fourth conductor portion and the fifth conductor portion. Portions of the first conductor portion and the second conductor portion may be exposed from the first surface of the sealing portion. Portions of the fourth conductor portion and the fifth conductor portion may be exposed from the second surface of the sealing portion.

[0016] In any of the current sensors, the first magnetoelectric transducer may be surrounded by the first conductor portion, the second conductor portion, and the third conductor portion in a plan view. The second magnetoelectric transducer may be surrounded by the fourth conductor portion, the fifth conductor portion, and the sixth conductor portion in a plan view. A first width in the first direction of the third conductor portion and the sixth conductor portion may be the same as a second width in the second direction of the first conductor portion, the second conductor portion, the fourth conductor portion, and the fifth conductor portion, or the first width may be narrower than the second width.

[0017] In any of the current sensors, in a planar view, the third conductor portion and the sixth conductor portion may face each other at a distance, and the space between the third conductor portion and the sixth conductor portion may be filled with a resin material that constitutes the sealing portion.

[0018] In any of the current sensors, the distance between the opposing portions of the third conductor portion and the sixth conductor portion may be 2 mm or less and 0.1 mm or more in plan view.

[0019] Any of the current sensors may further include, in a plan view, a third magnetoelectric transducer arranged to face the first magnetoelectric transducer in the second direction across a portion of the first conductor portion, and a fourth magnetoelectric transducer arranged to face the second magnetoelectric transducer in the second direction across a portion of the fifth conductor portion. In a plan view, at least a portion of the third magnetoelectric transducer may be located in an area surrounded by the first current conductor. In a plan view, at least a portion of the fourth magnetoelectric transducer may be located in an area surrounded by the second current conductor. In a plan view, a distance between the first magnetoelectric transducer and the sixth conductor portion may be equal to a distance between the third magnetoelectric transducer and the sixth conductor portion. In a plan view, a distance between the second magnetoelectric transducer and the third conductor portion may be equal to a distance between the fourth magnetoelectric transducer and the third conductor portion.

[0020] Any of the current sensors may further include a third magnetoelectric transducer arranged to face the first magnetoelectric transducer across the second conductor portion in a plan view, and a fourth magnetoelectric transducer arranged to face the second magnetoelectric transducer across the fourth conductor portion in a plan view. In a plan view, the first magnetoelectric transducer may be located in an area surrounded by the first current conductor. In a plan view, the second magnetoelectric transducer may be located in an area surrounded by the second current conductor. In a plan view, the distance between the first magnetoelectric transducer and the sixth conductor portion may be equal to the distance between the third magnetoelectric transducer and the sixth conductor portion. In a plan view, the distance between the second magnetoelectric transducer and the third conductor portion may be equal to the distance between the fourth magnetoelectric transducer and the third conductor portion. The first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer may have sensitivity axes in a third direction intersecting the first direction and the second direction.

[0021] In any of the current sensors, in a plan view, the first magnetoelectric transducer may be located on an extension line of the fifth conductor portion. In a plan view, the third magnetoelectric transducer may be located on an extension line of the fourth conductor portion. In a plan view, the second magnetoelectric transducer may be located on an extension line of the second conductor portion. In a plan view, the fourth magnetoelectric transducer may be located on an extension line of the first conductor portion.

[0022] In any of the current sensors, the first magnetoelectric transducer may be located on a perpendicular bisector of a line segment connecting the second magnetoelectric transducer and the fourth magnetoelectric transducer in a plan view, and the second magnetoelectric transducer may be located on a perpendicular bisector of a line segment connecting the first magnetoelectric transducer and the third magnetoelectric transducer in a plan view.

[0023] In any of the current sensors, the shape formed by the first conductor portion, the second conductor portion, and the third conductor portion may be line-symmetrical in plan view with a perpendicular bisector of a line segment connecting the second magneto-electric transducer and the fourth magneto-electric transducer as an axis of symmetry. The shape formed by the fourth conductor portion, the fifth conductor portion, and the sixth conductor portion may be line-symmetrical in plan view with a perpendicular bisector of a line segment connecting the first magneto-electric transducer and the third magneto-electric transducer as an axis of symmetry.

[0024] In any one of the current sensors, the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer may have a sensitivity axis in a direction intersecting a magnetosensitive surface.

[0025] In any one of the current sensors, the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer may be Hall elements that utilize the Hall effect.

[0026] In any of the current sensors, the first current conductor and the second current conductor may have the same shape. The second current conductor may be disposed at a position obtained by symmetrically shifting the first current conductor with a line along the second direction as an axis of symmetry in a plan view. The current sensor may further include a third magnetoelectric transducer disposed opposite the first magnetoelectric transducer in the second direction, and a fourth magnetoelectric transducer disposed opposite the second magnetoelectric transducer in the second direction. The entire magnetic sensitive surface of the first magnetoelectric transducer may overlap the first conductor portion in a plan view. The entire magnetic sensitive surface of the third magnetoelectric transducer may overlap the second conductor portion in a plan view. The entire magnetic sensitive surface of the second magnetoelectric transducer may overlap the fourth conductor portion in a plan view. The entire magnetic sensitive surface of the fourth magnetoelectric transducer may overlap the fifth conductor portion in a plan view. The first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer may have sensitivity axes in the second direction.

[0027] In any of the current sensors, the first magnetoelectric transducer may be disposed at the center of the width in the second direction of a portion of the first conductor portion overlapping with the first magnetoelectric transducer in a plan view. The third magnetoelectric transducer may be disposed at the center of the width in the second direction of a portion of the second conductor portion overlapping with the third magnetoelectric transducer in a plan view. The second magnetoelectric transducer may be disposed at the center of the width in the second direction of a portion of the fourth conductor portion overlapping with the second magnetoelectric transducer in a plan view. The fourth magnetoelectric transducer may be disposed at the center of the width in the second direction of a portion of the fifth conductor portion overlapping with the fourth magnetoelectric transducer in a plan view.

[0028] In any of the current sensors, the first conductor portion may include, in a plan view, a portion overlapping the first magnetoelectric transducer and a portion wider in the second direction than the portion overlapping the first magnetoelectric transducer. The second conductor portion may include, in a plan view, a portion overlapping the third magnetoelectric transducer and a portion wider in the second direction than the portion overlapping the third magnetoelectric transducer. The fourth conductor portion may include, in a plan view, a portion overlapping the second magnetoelectric transducer and a portion wider in the second direction than the portion overlapping the second magnetoelectric transducer. The fifth conductor portion may include, in a plan view, a portion overlapping the fourth magnetoelectric transducer and a portion wider in the second direction than the portion overlapping the fourth magnetoelectric transducer.

[0029] In any one of the current sensors, the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer may be magnetoresistive elements that utilize a magnetoresistive effect.

[0030] In any one of the current sensors, the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer may be built into a chip that constitutes the signal processing IC.

[0031] In any of the current sensors, the respective portions of the first conductor portion and the second conductor portion exposed from the first surface of the sealing portion, and the respective portions of the fourth conductor portion and the fifth conductor portion exposed from the second surface of the sealing portion may have extension portions that extend further in a third direction that intersects the first direction and the second direction than the surface of the sealing portion facing the surface opposite the circuit surface of the signal processing IC.

[0032] In any of the current sensors, the width of the tip of the extension portion may be narrower than the width of the remaining portion of the extension portion.

[0033] In any of the current sensors, the tip of the extension portion may include a plurality of teeth arranged in a comb shape, and the width of each of the plurality of teeth may be 0.5 to 2 times the thickness of each of the first conductor portion, the second conductor portion, the fourth conductor portion, and the fifth conductor portion.

[0034] A current sensor module according to an aspect of the present invention may include the current sensor and a substrate on which the current sensor is mounted, and the extension may be fixed to the mounting surface of the substrate, so that the sealing portion is positioned above the mounting surface.

[0035] In the current sensor module, the width of the tip of the extension portion may be narrower than the width of the remaining portion of the extension portion.

[0036] In the current sensor module, a tip of the extension portion may include a plurality of teeth arranged in a comb shape, and a width of each of the plurality of teeth may be 0.5 to 2 times the thickness of each of the first conductor portion, the second conductor portion, the fourth conductor portion, and the fifth conductor portion.

[0037] In the current sensor module, the distance between the mounting surface of the substrate and the surface of the sealing portion facing the mounting surface may be 1 mm or more.

[0038] 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. [Brief explanation of the drawings]

[0039] [Figure 1A] 2 is a schematic plan view of the current sensor and the substrate according to the first embodiment as viewed from the ceiling surface side (positive direction of the Z axis). FIG. [Figure 1B] 1B is a cross-sectional view of the current sensor and the substrate shown in FIG. 1A taken along the line AA. [Figure 1C] 1B is a side view of the current sensor and the substrate shown in FIG. 1A as viewed from the positive y-axis direction. [Figure 2] 3A and 3B are diagrams for explaining the positional relationship between a magnetoelectric transducer and a current conductor in the first embodiment. [Figure 3] 10A and 10B are diagrams for explaining the positional relationship between a magnetoelectric transducer and a current conductor according to a modified example of the first embodiment. [Figure 4] 10A and 10B are diagrams for explaining a region near a current conductor in which a magnetoelectric transducer is arranged. [Figure 5] 2 is a cross-sectional view of the current sensor of the first embodiment taken along line AA in the case of an insert mounting type. FIG. [Figure 6A] 10 is a schematic plan view of a current sensor and a substrate according to a second embodiment, as viewed from the ceiling surface side (positive direction of the Z axis). FIG. [Figure 6B] 6B is a cross-sectional view taken along the line AA of the current sensor and the substrate shown in FIG. 6A. [Figure 6C] 6B is a side view of the current sensor and the substrate shown in FIG. 6A as viewed from the positive direction of the y-axis. [Figure 7A] 10A and 10B are diagrams for explaining another example of the positional relationship between the magnetoelectric transducer and the current conductor. [Figure 7B] 10A and 10B are diagrams for explaining another example of the positional relationship between the magnetoelectric transducer and the current conductor. [Figure 8] FIG. 2 is a cross-sectional view of the current sensor of the second embodiment taken along line AA in the case of an insert mounting type. [Figure 9A] This is a plan view of the signal processing IC, magnetoelectric conversion element, and current conductor in the original case. [Figure 9B] FIG. 10 is a plan view of a signal processing IC, a magnetoelectric transducer, and a current conductor in Case 1. [Figure 9C] FIG. 10 is a plan view of a signal processing IC, a magnetoelectric transducer, and a current conductor in Case 2. [Figure 9D] FIG. 10 is a plan view of a signal processing IC, a magnetoelectric transducer, and a current conductor in Case 3. [Figure 10] 10 is a table showing the heat generation reduction effect for the original case, case 1, case 2, and case 3. [Figure 11]FIG. 10 is a diagram showing the degree of heat generation reduction effect according to the ratio between the width of the signal processing IC and the width of the current conductor for Case 1, Case 2, and Case 3. DETAILED DESCRIPTION OF THE INVENTION

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

[0041] FIG. 1A is a schematic plan view of a current sensor 10 and a substrate 200 according to the first embodiment, as viewed from the ceiling surface side (positive direction of the z-axis). FIG. 1B is a cross-sectional view of the current sensor 10 and the substrate 200 shown in FIG. 1A, taken along line AA. FIG. 1C is a side view of the current sensor 10 and the substrate 200 shown in FIG. 1A, as viewed from the positive direction of the y-axis. In FIG. 1A, the coordinate system is defined as the x-axis direction, which is parallel to the paper and extends from bottom to top; the y-axis direction, which is parallel to the paper and extends from left to right; and the z-axis direction, which is perpendicular to the paper and extends from back to front. Any one of the x-axis, y-axis, and z-axis is orthogonal to the other axes.

[0042] The current sensor 10 includes a signal processing IC 100, magnetoelectric conversion elements 20A-1, 20A-2, 20B-1, and 20B-2, primary current conductors 140A and 140B, a secondary signal conductor 150, and a sealing portion 130. The current sensor 10 includes two current conductors 140A and 140B for measuring currents to be measured for two channels. The magnetoelectric conversion elements 20A-1, 20A-2, 20B-1, and 20B-2 may be collectively referred to as magnetoelectric conversion elements 20. The magnetoelectric conversion element 20A-1 is an example of a first magnetoelectric conversion element. The magnetoelectric conversion element 20A-2 is an example of a third magnetoelectric conversion element. The magnetoelectric conversion element 20B-1 is an example of a second magnetoelectric conversion element. The magnetoelectric conversion element 20B-2 is an example of a fourth magnetoelectric conversion element. The current conductor 140A is an example of a first current conductor, and the current conductor 140B is an example of a second current conductor.

[0043] The sealing unit 130 seals the magnetoelectric conversion element 20, a portion of the current conductor 140A, a portion of the current conductor 140B, the signal processing IC 100, and the signal conductor 150 with a resin material. The resin material may be, for example, an epoxy-based thermosetting resin with silica added, or a thermoplastic resin such as a liquid crystal polymer. The sealing unit 130 may be formed by compression molding or transfer molding using a mold.

[0044] The current conductor 140A and the current conductor 140B are conductors through which different currents to be measured flow. The current conductors 140A and 140B are electrically connected to two phases (e.g., U-phase and V-phase) of three-phase electric wires in a three-phase AC circuit such as a three-phase motor through which the currents to be measured flow. The current conductors 140A and 140B may have the same shape in a plan view. The current conductors 140A and 140B may be formed from a single lead frame.

[0045] The current conductor 140A includes, in a plan view, conductor portions 141A and 142A that extend in the x-axis direction and are separated from each other in the y-axis direction, and a conductor portion 143A that extends in the y-axis direction and connects the conductor portions 141A and 142A. The conductor portions 141A, 142A, and 143A may form a U-shape in a plan view. One end of the conductor portion 141A and one end of the conductor portion 142A are exposed from the surface 130a of the sealing portion 130. The conductor portion 143A connects the other end of the conductor portion 141A to the other end of the conductor portion 142A. The conductor portion 141A is an example of a first conductor portion, the conductor portion 142A is an example of a second conductor portion, and the conductor portion 143A is an example of a third conductor portion.

[0046] The current conductor 140B includes, in a plan view, conductor portions 141B and 142B that extend in the x-axis direction and are separated from each other in the y-axis direction, and a conductor portion 143B that extends in the y-axis direction and connects the conductor portions 141B and 142B. The conductor portions 141B, 142B, and 143B may form a U-shape in a plan view. One end of the conductor portion 141B and one end of the conductor portion 142B are exposed from the surface 130b of the sealing portion 130 that faces the surface 130a. The conductor portion 143B connects the other end of the conductor portion 141B to the other end of the conductor portion 142B. The conductor portion 141B is an example of a fourth conductor portion, the conductor portion 142B is an example of a fifth conductor portion, and the conductor portion 143B is an example of a sixth conductor portion.

[0047] The signal conductor 150 may be formed of a lead frame different from the lead frames forming the current conductors 140A and 140B. That is, the current conductors 140A and 140B may be at the same height within the sealing portion 130, and the signal conductor 150 may be at a different height from the current conductors 140A and 140B. The signal conductor 150 includes a support portion 151 and a terminal portion 152. The terminal portion 152 is electrically connected to the signal processing IC 100 via the wire 108. A signal output from the signal processing IC 100 is output to the outside via the signal conductor 150. A portion of the terminal portion 152 is exposed from a surface 130c of the sealing portion 130, which is different from the surfaces 130a and 130b that face each other in the x-axis direction. The surface 130c faces a surface 130d in the y-axis direction. The terminal portion 152 is exposed only from the surface 130c and not from the surface 130d. Other signal conductors that transmit signals output from the signal processing IC 100 are not exposed from the surface 130d.

[0048] The support portion 151 is sealed within the sealing portion 130 and supports the signal processing IC 100. The terminal portion 152 has a plurality of terminals, some of which are physically formed integrally with the support portion 151. At least a portion of each of the plurality of terminals is exposed from the surface 130c of the sealing portion 130.

[0049] The current conductor 140A, the current conductor 140B, and the signal conductor 150 may be made of a conductive material mainly composed of copper. The support portion 151 may be made of a metal plate separate from the terminal portion 152, a plate made of a semiconductor, or may be combined with an insulating member such as a die attach fill.

[0050] 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 magnetoelectric conversion element 20 has a sensitivity axis in the z-axis direction. Since the magnetoelectric conversion element 20 detects a magnetic field in the z-axis direction, in the first embodiment, for example, a Hall element that detects a vertical magnetic field in the thickness direction of the current conductor 140A or the current conductor 140B is suitable as the magnetoelectric conversion element 20.

[0051] 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 IC 100 has a circuit surface on which the magnetoelectric conversion element 20 is arranged. In the first embodiment, the circuit surface is surface 100a which corresponds to the ceiling surface of the semiconductor package that constitutes the signal processing IC 100. Surface 100a is an example of the circuit surface of the signal processing IC 100. The signal processing circuit processes an output signal according to the magnitude of the magnetic field output from the magnetoelectric conversion element 20.

[0052] The signal processing circuit cancels noise components due to a common external magnetic field contained in the output signals of magnetoelectric conversion elements 20A-1 and 20A-2 based on the difference between the output signals of magnetoelectric conversion elements 20A-1 and 20A-2, amplifies the output signals of magnetoelectric conversion elements 20A-1 and 20A-2 with reduced noise components, calculates a current value Ia of the current to be measured flowing through current conductor 140A based on the amplified output signal, and outputs an output signal indicating the current value Ia. The signal processing circuit may perform offset adjustment after canceling the noise components due to the disturbance magnetic field. The signal processing circuit may also perform temperature characteristic correction when calculating the current value Ia based on the amplified output signal. That is, the signal processing circuit may cancel noise components due to the external magnetic field commonly applied to magnetoelectric conversion element 20A-1 and magnetoelectric conversion element 20A-2, extract only the output component based on the current flowing through current conductor 140A, and output the output signal after performing offset adjustment, amplification of the output signal, and correction based on temperature characteristics.

[0053] Furthermore, the signal processing circuit cancels noise components due to a common external magnetic field contained in the output signals of magnetoelectric conversion elements 20B-1 and 20B-2 based on the difference between the output signals of magnetoelectric conversion elements 20B-1 and 20B-2, amplifies the output signals of magnetoelectric conversion elements 20B-1 and 20B-2 with reduced noise components, calculates a current value Ib of the current to be measured flowing through current conductor 140B based on the amplified output signal, and outputs an output signal indicating the current value Ib. Similarly, the signal processing circuit may cancel noise components due to an external magnetic field commonly applied to magnetoelectric conversion elements 20B-1 and 20B-2, extract only the output component based on the current flowing through current conductor 140B, and output the output signal after performing offset adjustment, amplification of the output signal, and correction based on temperature characteristics.

[0054] 2 is a diagram illustrating the positional relationship between the magnetoelectric conversion element 20 and the current conductor 140A and current conductor 140B in the first embodiment. In Fig. 2, arrow IA indicates the direction of the current to be measured flowing through the current conductor 140A, and arrow IB indicates the direction of the current to be measured flowing through the current conductor 140B. Marks indicated by symbols Ma and Mb indicate the direction of magnetic flux in the area where the marks are located.

[0055] The magnetoelectric conversion element 20A-1 is arranged in a region surrounded by the current conductor 140A in a plan view. The magnetoelectric conversion element 20A-1 is arranged in a region surrounded by the conductor portion 141A, the conductor portion 143A, and the conductor portion 142A. The magnetoelectric conversion element 20A-2 is arranged opposite the magnetoelectric conversion element 20A-1 with the conductor portion 142A interposed therebetween in a plan view. The magnetoelectric conversion elements 20A-1 and 20A-2 are arranged side by side along the y-axis direction.

[0056] The magnetoelectric conversion element 20B-1 is arranged in a region surrounded by the current conductor 140B in a plan view. The magnetoelectric conversion element 20B-1 is arranged in a region surrounded by the conductor portion 141B, the conductor portion 143B, and the conductor portion 142B. The magnetoelectric conversion element 20B-2 is arranged opposite the magnetoelectric conversion element 20B-1 across the conductor portion 142B in a plan view. The magnetoelectric conversion elements 20B-1 and 20B-2 are arranged side by side along the y-axis direction.

[0057] The shape formed by conductor portion 141A, conductor portion 142A, and conductor portion 143A may be symmetrical about the perpendicular bisector L3 of line segment L4 connecting magnetoelectric conversion element 20B-1 and magnetoelectric conversion element 20B-2 in a plan view. The shape formed by conductor portion 141B, conductor portion 142B, and conductor portion 143B may be symmetrical about the perpendicular bisector L1 of line segment L2 connecting magnetoelectric conversion element 20A-1 and magnetoelectric conversion element 20A-2 in a plan view.

[0058] In a plan view, the magnetoelectric conversion element 20A-1 is located on an extension of the conductor portion 142B. In a plan view, the magnetoelectric conversion element 20A-2 is located on an extension of the conductor portion 141B. In a plan view, the magnetoelectric conversion element 20B-1 is located on an extension of the conductor portion 142A. In a plan view, the magnetoelectric conversion element 20B-2 is located on an extension of the conductor portion 141A. Furthermore, in a plan view, the magnetoelectric conversion element 20A-1 is located on the perpendicular bisector L3 of the line segment L4 connecting the magnetoelectric conversion elements 20B-1 and 20B-2. In a plan view, the magnetoelectric conversion element 20B-1 is located on the perpendicular bisector L1 of the line segment L2 connecting the magnetoelectric conversion elements 20A-1 and 20A-2.

[0059] Conductor portion 143B is a current path extending in a direction along line segment L2 connecting magnetoelectric conversion element 20A-1 and magnetoelectric conversion element 20A-2. In a plan view, distance k1 between magnetoelectric conversion element 20A-1 and conductor portion 143B is equal to distance k2 between magnetoelectric conversion element 20A-2 and conductor portion 143B. Therefore, the magnetic field generated at the position of magnetoelectric conversion element 20A-1 due to the measured current flowing through current conductor 140B is equal to the magnetic field generated at the position of magnetoelectric conversion element 20A-2. As described above, the signal processing circuit calculates the difference between the output signal of magnetoelectric conversion element 20A-1 and the output signal of magnetoelectric conversion element 20A-2. Therefore, by calculating the difference between the output signal of magnetoelectric conversion element 20A-1 and the output signal of magnetoelectric conversion element 20A-2, the signal processing circuit can cancel the influence of the magnetic field generated by the measured current flowing through current conductor 140B. This prevents the magnetic field generated by the current to be measured flowing through current conductor 140B from affecting the measurement results of the current to be measured flowing through current conductor 140A, which are based on the output signals of magnetoelectric conversion element 20A-1 and magnetoelectric conversion element 20A-2.

[0060] Similarly, conductor portion 143A is a current path extending in a direction along line segment L4 connecting magnetoelectric conversion element 20B-1 and magnetoelectric conversion element 20B-2. In a plan view, distance k3 between magnetoelectric conversion element 20B-1 and conductor portion 143A is equal to distance k4 between magnetoelectric conversion element 20B-2 and conductor portion 143A. Therefore, the magnetic field generated at the position of magnetoelectric conversion element 20B-1 due to the measurement current flowing through current conductor 140A is equal to the magnetic field generated at the position of magnetoelectric conversion element 20B-2. Therefore, by the signal processing circuit calculating the difference between the output signal of magnetoelectric conversion element 20B-1 and the output signal of magnetoelectric conversion element 20B-2, the influence of the magnetic field generated by the measurement current flowing through current conductor 140A can be canceled. This prevents the magnetic field generated by the current to be measured flowing through current conductor 140A from affecting the measurement results of the current to be measured flowing through current conductor 140B, which are based on the output signals of magnetoelectric conversion element 20B-1 and magnetoelectric conversion element 20B-2.

[0061] As described above, by mounting the magnetoelectric conversion element 20 on the surface 100a of the signal processing IC 100, the magnetoelectric conversion element 20 and the signal processing IC 100 can be electrically connected by the wire 22 without crossing the current conductors 140A and 140B. This makes it difficult for the wire 22 to deform, making it relatively easy to optimize the shape of the wire 22 and suppressing deterioration of electrical characteristics such as the responsiveness of the current sensor 10. The wire 22 and the wire 108 may be formed from a conductive material containing Au, Ag, Cu, or Al as a main component.

[0062] In this way, by mounting the magnetoelectric transducer 20 on the surface 100a of the signal processing IC 100, it can be connected to the signal processing IC 100 via the wire 22 without crossing the current conductors 140A and 140B. Therefore, in a plan view, the conductor portion 143A and the conductor portion 143B are arranged facing each other at a distance, while the distance between the current conductors 140A and 140B can be shortened. For example, in a plan view, the distance k5 between the portions where the current conductors 140A and 140B face each other, i.e., the conductor portion 143A and the conductor portion 143B, can be 2 mm or less and 0.1 mm or more. This allows the width of the sealing portion 130 in the x-axis direction to be reduced, thereby enabling the miniaturization of the current sensor 10 capable of measuring two channels of current to be measured. The space between the conductor portion 143A and the conductor portion 143B is filled with the resin material that constitutes the sealing portion 130. This also ensures insulation between conductor portion 143A and conductor portion 143B. Furthermore, since wire 22 does not need to straddle current conductor 140A and current conductor 140B and the wire length can be shortened, current sensor 10 is less susceptible to disturbance noise and wiring capacitance is minimized, thereby improving the response speed of current sensor 10.

[0063] FIG. 3 is a diagram illustrating the positional relationship between the magnetoelectric conversion element 20 and the current conductor 140A and the current conductor 140B according to a modification of the first embodiment. In the example illustrated in FIG. 2, the magnetoelectric conversion element 20 and the current conductor 140A and the current conductor 140B are arranged in positions that do not overlap in a planar view. However, as illustrated in FIG. 3, the magnetoelectric conversion element 20 and the current conductor 140A or the current conductor 140B may be arranged in positions that partially overlap in a planar view. The magnetoelectric conversion element 20A-2 may be arranged to face each other across a part of the conductor portion 141A in a planar view. The magnetoelectric conversion element 20B-2 may be arranged to face each other across a part of the conductor portion 141B in a planar view. Half of the magnetically sensitive surface of the magnetoelectric conversion element 20 may overlap with the current conductor 140A or the current conductor 140B in a planar view.

[0064] 3, when the magnetoelectric transducer 20 is disposed at a position where it partially overlaps with the current conductor 140A or 140B in a planar view, the sensitivity axis of the magnetoelectric transducer may detect a magnetic field not only in the z-axis direction but also in any one of the axes in the xy plane or above that is parallel to the magnetic sensing surface. Therefore, in the current sensor according to the modification of the first embodiment shown in FIG. 3, the magnetoelectric transducer 20 may be a Hall element utilizing the Hall effect or a magnetoresistive element utilizing the magnetoresistive effect. The magnetoresistive element may be, for example, a semiconductor magnetoresistive element (SMR), an extraordinary magnetoresistive element (AMR), a giant magnetoresistive element (GMR), or a tunneling magnetoresistive element (TMR).

[0065] 2 and 3 are merely examples of the positional relationship between the magnetoelectric conversion element 20 and the current conductor 140A and the current conductor 140B. The magnetoelectric conversion element 20 may be disposed at another position as long as it is disposed in a vicinity region of the current conductor 140A or the current conductor 140B. Here, as shown in FIG. 4, for example, when the width of the current conductor 140A in the y-axis direction is A and the width of the current conductor 140A in the z-axis direction is B, the vicinity region may be a region that is included in a range that is twice as wide as A in the y-axis direction centered on the axis of symmetry L of the current conductor 140A and that is included in a range of the width of B in the x-axis direction.

[0066] 1A to 1C is a surface-mount type in which current conductors 140A and 140B are disposed on the mounting surface of a substrate 200. If the substrate 200 is provided with a slit or the like to increase the creepage distance on the substrate 200 side, it may be preferable to position the sealing portion 130 of the current sensor 10 away from the substrate 200 so as not to interfere with the creepage distance. That is, it may be preferable to position the sealing portion 130 away from the substrate 200 to prevent dielectric breakdown through the surface of the current sensor 10. Therefore, the portions of the conductor portions 141A and 142A exposed from the surface 130a of the sealing portion 130 and the portions of the conductor portions 141B and 142B exposed from the surface 100b of the sealing portion 130 each have an extension portion 1410 that extends in the z-axis direction beyond the surface 130f of the sealing portion 130 that faces the surface 100b opposite the circuit surface of the signal processing IC 100. By fixing the extension portion 1410 to the mounting surface 200a of the substrate 200, the sealing portion 130 is positioned above the mounting surface 200a. This makes it possible to provide a space between the sealing portion 130 and the substrate 200. It is preferable that the distance between the mounting surface 200a of the substrate 200 and the surface 130f of the sealing portion 130 that faces the mounting surface 200a is 1 mm or more.

[0067] As described above, the current sensor 10 shown in FIGS. 1A to 1C is an example of a surface-mount type. However, the current sensor 10 may also be an insert-mount type in which the current conductors 140A and 140B are inserted into the substrate 200. The insert-mount type allows the current conductors 140A and 140B to be electrically connected directly and with low resistance to the copper foil of the inner layer of the substrate 200 at the shortest distance, thereby reducing heat generation in the substrate 200. Furthermore, when the extension portion 1410 is inserted into the substrate 200, the width of the tip of the extension portion 1410 should be narrower than the width of the remaining portion of the extension portion 1410 to ensure a space between the mounting surface 200a of the substrate 200 and the surface 130f of the sealing portion 130. The narrower portion of the tip of the extension portion 1410 is inserted into the substrate 200, and the remaining portion of the extension portion 1410 contacts the mounting surface 200a of the substrate 200. This ensures a sufficient space between the mounting surface 200a of the substrate 200 and the surface 130f of the sealing portion 130. For example, as shown in FIG. 5, the tip of the extension portion 1410 may include multiple tooth portions 1410a arranged in a comb-like pattern. This allows the tooth portions 1410a to be inserted into multiple circular holes formed in the substrate 200 to establish direct electrical connection with the inner layers of the substrate 200, making it easier to drill holes in the substrate 200 and reducing heat generation in the substrate 200. For example, a drill or the like can be used to drill the holes in the substrate 200. The width of each of the multiple tooth portions 1410a may be 0.5 to 2 times the thickness D (shown in FIG. 1C) of each of the conductor portions 141A, 142A, 141B, and 142B. The cross section of the multiple tooth portions 1410a may be square.

[0068] 1A to 1C, slits may be provided on the surface of the substrate 200 to increase the creepage distance on the surface of the substrate 200. For example, the substrate 200 may have slits extending in the x-axis direction between the conductor portions 141A and 142A and the terminal portion 152 in a plan view. The substrate 200 may have slits extending in the y-axis direction between the conductor portions 141A and 142A and the conductor portions 141B and 142B in a plan view.

[0069] FIG. 6A is a schematic plan view of the current sensor 10 and the substrate 200 according to the second embodiment, as viewed from the ceiling surface side (positive direction of the z-axis). FIG. 6B is a cross-sectional view of the current sensor 10 and the substrate 200 shown in FIG. 6A taken along line AA. FIG. 6C is a side view of the current sensor 10 and the substrate 200 shown in FIG. 6A, as viewed from the positive direction of the y-axis. In FIG. 6A, the coordinate system is defined as the x-axis direction extending from bottom to top and parallel to the paper, the y-axis direction extending from left to right and parallel to the paper, and the z-axis direction extending from back to front and perpendicular to the paper. Any one of the x-axis, y-axis, and z-axis is orthogonal to the other axes.

[0070] The current sensor 10 according to the second embodiment differs from the current sensor 10 according to the first embodiment in that the magnetoelectric transducer 20 is a magnetoresistive element. It also differs in that the magnetoelectric transducer 20 overlaps the current conductor 140A or the current conductor 140B in plan view. The magnetoelectric transducer 20 detects a magnetic field in one of the axial directions on the xy plane. That is, the magnetoelectric transducer 20 has a sensitivity axis parallel to the magnetic sensing surface. The magnetoelectric transducer 20 may be a magnetoresistive element utilizing the magnetoresistive effect. The magnetoresistive element may be, for example, a semiconductor magnetoresistive element (SMR), an extraordinary magnetoresistive element (AMR), a giant magnetoresistive element (GMR), or a tunneling magnetoresistive element (TMR).

[0071] 6A shows a current sensor in which the magnetoelectric conversion element 20 is built into the signal processing IC 100, but similar to Fig. 1A etc., the magnetoelectric conversion element 20 may not be built into the signal processing IC 100 but may be installed on the circuit surface. That is, the current sensor 10 may have a monolithic structure in which the magnetoelectric conversion element 20 is built into the signal processing IC 100, or may not have a monolithic structure in which the magnetoelectric conversion element 20 and the signal processing IC 100 are configured separately.

[0072] FIG. 7A is a diagram for explaining the positional relationship between the magnetoelectric conversion element 20 and the current conductors 140A and 140B.

[0073] The current conductors 140A and 140B have the same shape. The current conductors 140A and 140B are arranged in a positional relationship rotated 180 degrees in a plan view. The current conductor 140B is arranged at a position obtained by symmetrically moving the current conductor 140A with respect to a line L10 along the y direction as an axis of symmetry in a plan view. The magnetoelectric conversion elements 20A-1 and 20A-2 are arranged in a direction to detect a magnetic field in the y-axis direction on the xy plane generated by a current to be measured flowing through the current conductor 140A. The magnetoelectric conversion elements 20A-1 and 20A-2 may be arranged in a position overlapping the current conductor 140A in a plan view. The magnetoelectric conversion elements 20B-1 and 20B-2 are arranged in a direction to detect a magnetic field in the y-axis direction on the xy plane generated by a current to be measured flowing through the current conductor 140B. The magnetoelectric transducer 20B-1 and the magnetoelectric transducer 20B-2 may be disposed at positions overlapping the current conductor 140A in plan view.

[0074] The magnetoelectric conversion element 20A-1 and the magnetoelectric conversion element 20A-2 are arranged opposite each other in the y-axis direction. The magnetoelectric conversion element 20B-1 and the magnetoelectric conversion element 20B-2 are arranged opposite each other in the y-axis direction. The entire magnetically sensitive surface of the magnetoelectric conversion element 20A-1 may overlap with the conductor portion 141A in a planar view, and the entire magnetically sensitive surface of the magnetoelectric conversion element 20A-2 may overlap with the conductor portion 142A in a planar view. The entire magnetically sensitive surface of the magnetoelectric conversion element 20B-1 may overlap with the conductor portion 141B in a planar view, and the entire magnetically sensitive surface of the magnetoelectric conversion element 20B-2 may overlap with the conductor portion 142B in a planar view.

[0075] The shape formed by conductor portions 141A, 142A, and 143A constituting current conductor 140A is symmetrical about a perpendicular bisector L3 of a line segment L4 connecting magnetoelectric conversion elements 20B-1 and 20B-2 in a planar view in terms of the positional relationship between magnetoelectric conversion elements 20B-1 and 20B-2. The shape formed by conductor portions 141B, 142B, and 143C is symmetrical about a perpendicular bisector L1 of a line segment L2 connecting magnetoelectric conversion elements 20A-1 and 20A-2 in a planar view in terms of the positional relationship between magnetoelectric conversion elements 20A-1 and 20A-2.

[0076] Conductor portion 141A includes, in a plan view, a portion 1411A overlapping with magnetoelectric conversion element 20A-1 and a portion 1412A that is wider in the y-axis direction than portion 1411A overlapping with magnetoelectric conversion element 20A-1. Conductor portion 142A includes, in a plan view, a portion 1421A overlapping with magnetoelectric conversion element 20A-2 and a portion 1422A that is wider in the y-axis direction than portion 1421A overlapping with magnetoelectric conversion element 20A-2. Conductor portion 141B includes, in a plan view, a portion 1411B overlapping with magnetoelectric conversion element 20B-1 and a portion 1412B that is wider in the y-axis direction than portion 1411B overlapping with magnetoelectric conversion element 20B-1. In a plan view, the conductor portion 142B includes a portion 1421B that overlaps with the magnetoelectric conversion element 20B-2 and a portion 1422B that is wider in the y-axis direction than the portion 1421B that overlaps with the magnetoelectric conversion element 20B-2. Because the widths of the portions of the current conductors 140A and 140B that overlap with the magnetoelectric conversion element 20 are narrow, the magnetoelectric conversion element 20 can measure the currents flowing through the current conductors 140A and 140B with high sensitivity.

[0077] The magnetoelectric conversion element 20A-1 may be disposed at the center of the width in the y-axis direction of a portion 1411A of the conductor portion 141A that overlaps with the magnetoelectric conversion element 20A-1 in a plan view. The magnetoelectric conversion element 20A-2 may be disposed at the center of the width in the y-axis direction of a portion 1421A of the conductor portion 142A that overlaps with the magnetoelectric conversion element 20A-2 in a plan view. The magnetoelectric conversion element 20B-1 may be disposed at the center of the width in the y-axis direction of a portion 1411B of the conductor portion 141B that overlaps with the magnetoelectric conversion element 20B-1 in a plan view. The magnetoelectric conversion element 20B-2 may be disposed at the center of the width in the y-axis direction of a portion 1421B of the conductor portion 142B that overlaps with the magnetoelectric conversion element 20B-2 in a plan view. This enables the magnetoelectric conversion element 20 to measure the currents flowing through the current conductors 140A and 140B with higher sensitivity.

[0078] However, as shown in FIG. 7B, the magnetoelectric conversion element 20 does not have to be placed at the center of the current conductor 140A or the current conductor 140B, as long as it is placed at the portion of the current conductor 140A or the current conductor 140B that overlaps with the magnetoelectric conversion element 20 in a plan view.

[0079] In the current sensor 10 according to the second embodiment configured as described above, the conductor portion 143A and the conductor portion 143B are arranged facing each other at a distance, while the distance between the current conductors 140A and 140B can be shortened. In a plan view, the distance between the portions where the current conductors 140A and 140B face each other, i.e., the distance between the conductor portion 143A and the conductor portion 143B, can be 2 mm or less and 0.1 mm or more. This allows the width of the sealing portion 130 in the x-axis direction to be reduced, thereby enabling the current sensor 10, capable of measuring two channels of current to be measured, to be miniaturized. The space between the conductor portion 143A and the conductor portion 143B is filled with the resin material that constitutes the sealing portion 130. This ensures insulation between the conductor portion 143A and the conductor portion 143B.

[0080] In one example of current sensor 10 herein, the distance from surface 130a to surface 130b of sealing portion 130 is 10 mm, and the distance from surface 130c to surface 130d is 20 mm. However, current sensor 10 may be sufficiently small; for example, the distance from surface 130a to surface 130b of sealing portion 130 may be 3 to 30 mm, and the distance from surface 130c to surface 130d may be 5 to 50 mm. Conversely, when minimizing current sensor 10, it is preferable to shorten the length of current conductors 140A and 140B in the x-axis direction as much as possible and to shorten the distance between the portions of current conductors 140A and 140B where current conductors 140A and 140B face each other, i.e., between conductor portion 143A and conductor portion 143B.

[0081] The current sensor 10 shown in FIGS. 6A to 6C is an example of a surface-mount type. However, the current sensor 10 may also be an insert-mount type in which the current conductors 140A and 140B are inserted into the substrate 200. In the case of the insert-mount type, the width of the tip of the extension portion 1410 should be narrower than the width of the remaining portion of the extension portion 1410 to ensure a space between the mounting surface 200a of the substrate 200 and the surface 130f of the sealing portion 130 when the extension portion 1410 is inserted into the substrate 200. For example, as shown in FIG. 8, the tip of the extension portion 1410 may include multiple teeth 1410a arranged in a comb-like shape. The width of each of the multiple teeth 1410a may be 0.5 to 2 times the thickness D (shown in FIG. 6C) of each of the conductor portions 141A, 142A, 141B, and 142B. The cross section of the multiple teeth 1410a may be square. The distance between the sealing portion 130 and the mounting surface 200a of the substrate 200 is preferably 1 mm or more, which makes it possible to more reliably ensure insulation between the sealing portion 130 and the substrate 200.

[0082] Incidentally, when a current to be measured is passed through the current conductors 140A and 140B, if the resistance values ​​of the current conductors 140A and 140B are large, heat generation in the current conductors 140A and 140B may change the electrical characteristics of the magnetoelectric conversion element 20, which may affect the accuracy of magnetic field detection by the magnetoelectric conversion element 20. Therefore, it is preferable to make the resistance values ​​of the current conductors 140A and 140B as low as possible.

[0083] 9A shows a plan view of the signal processing IC 100, magnetoelectric transducer 20, and current conductors 140A and 140B in the original case. In the original case, the width W1 in the x-axis direction of conductor portions 143A and 143B constituting current conductors 140A and 140B, and the width W2 in the y-axis direction of conductor portions 141A, 141B and conductor portions 142A and 142B are the same. The resistance values ​​of conductor portions 141A, 141B, conductor portions 141A, 141B, and conductor portions 143A and 142B are also the same and are denoted as R. The width of signal processing IC 100 in the y-axis direction is denoted as A, and the width of signal processing IC 100 in the x-axis direction is denoted as B.

[0084] FIG. 9B shows a plan view of the signal processing IC 100, the magnetoelectric transducer 20, and the current conductors 140A and 140B in Case 1. In Case 1, the width W1 in the x-axis direction of the conductor portions 143A and 143B constituting the current conductors 140A and 140B is narrower than the width W2 in the y-axis direction of the conductor portions 141A and 141B and the conductor portions 142A and 142B. The width W2 is twice the width W1. The resistance value of the conductor portions 143A and 143B is R, and the resistance value of the conductor portions 141A, 141B and the conductor portions 142A and 142B is R / 2. In other words, the resistance value of the conductor portions 143A and 143B is twice the resistance value of the conductor portions 141A, 141B and the conductor portions 142A and 142B.

[0085] 9C shows a plan view of the signal processing IC 100, the magnetoelectric transducer 20, and the current conductors 140A and 140B in Case 2. In Case 2, the width W1 in the x-axis direction of the conductor portions 143A and 143B constituting the current conductors 140A and 140B is greater than the width W2 in the y-axis direction of the conductor portions 141A and 141B and the conductor portions 142A and 142B. The width W2 is half of the width W1. The resistance value of the conductor portions 143A and 143B is R / 2, and the resistance value of the conductor portions 141A, 141B and the conductor portions 142A and 142B is R. In other words, the resistance value of the conductor portions 143A and 143B is half the resistance value of the conductor portions 141A, 141B and the conductor portions 142A and 142B.

[0086] 9D shows a plan view of the signal processing IC 100, the magnetoelectric transducer 20, and the current conductors 140A and 140B in Case 3. In Case 3, the width W1 in the x-axis direction of the conductor portions 143A and 143B constituting the current conductors 140A and 140B is the same as the width W2 in the y-axis direction of the conductor portions 141A and 141B and the conductor portions 142A and 142B. The widths W1 and W2 in Case 3 are twice the widths W1 and W2 in the original case. The resistance value of the conductor portions 143A and 143B is R / 2, and the resistance values ​​of the conductor portions 141A, 141B and the conductor portions 142A and 142B are also R / 2.

[0087] FIG. 10 is a table showing the heat generation reduction effect for the original case, Case 1, Case 2, and Case 3. The heat generation reduction effect is calculated by multiplying the heat generation ratio by the chip area ratio. In FIG. 10, the heat generation ratio for Case 1, Case 2, and Case 3 is shown, assuming that the heat generation ratio for the original case is 1. Also, in FIG. 10, the chip area ratio for Case 1, Case 2, and Case 3 is shown, assuming that the chip area ratio for the original case is 1. The smaller the heat generation reduction effect, the smaller the current sensor 10 that generates heat and is low in cost. That is, the width W1 of the conductor portions 143A and 143B in the x-axis direction is preferably equal to or narrower than the width W2 of the conductor portions 141A, 142A, 141B, and 142B in the y-axis direction. This allows for the current sensor 10 to be small in size and low in cost.

[0088] FIG. 11 shows the degree of heat generation reduction effect depending on the ratio between the width of the signal processing IC 100 and the width of the current conductors 140A and 140B for Cases 1, 2, and 3. As shown in FIG. 11, when the width of the signal processing IC 100 is less than six times the width of the current conductors 140A and 140B, Case 1 has the highest heat generation reduction effect. On the other hand, when the width of the signal processing IC 100 is more than six times the width of the current conductors 140A and 140B, Case 3 has the highest heat generation reduction effect. Here, when the proportion of the circuit area is small and it is required to minimize the chip area required for sensor placement, Case 1 is more effective than Case 3. However, this does not apply when the chip area dominates the circuit area.

[0089] 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.

[0090] It should be noted that the execution order 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. [Explanation of symbols]

[0091] 10 Current Sensor 20, 20A-1, 20A-2, 20B-1, 20B-2 Magnetoelectric conversion element 22, 108 wire 100 Signal Processing IC 130 Sealing part 140A, 140B current conductor 141A, 142A, 143A Conductor parts 141B, 142B, 143B Conductor parts 150 Signal Conductor 151 Support part 152 Terminal section 200 boards 1410 Extension part 1410a Teeth

Claims

1. a first current conductor through which a first current to be measured flows; a first magnetoelectric transducer for detecting a magnetic field generated by the first current to be measured; a second current conductor through which a second current to be measured flows; a second magnetoelectric transducer for detecting a magnetic field generated by the second current to be measured; a signal processing IC that processes a signal output from at least one of the first magnetoelectric transducer and the second magnetoelectric transducer; a signal conductor electrically connected to the signal processing IC and transmitting a signal output from the signal processing IC; a sealing portion that seals a portion of the first current conductor, the first magnetoelectric transducer, a portion of the second current conductor, the second magnetoelectric transducer, the signal processing IC, and a portion of the signal conductor; Equipped with at least one of the first magnetoelectric transducer and the second magnetoelectric transducer is disposed on a circuit surface of the signal processing IC; the first current conductor and the second current conductor face each other at positions where at least a portion of each of them overlaps with the signal processing IC in a plan view, In a cross-sectional view, the first current conductor and the second current conductor are at a different height from the signal conductor within the sealing portion, a resin material that constitutes the sealing portion is disposed between the first current conductor and the second current conductor; a portion of the first current conductor is exposed from a first surface of the sealing portion; a portion of the second current conductor is exposed from a second surface of the sealing portion that faces the first surface in a first direction; A current sensor, wherein a portion of the signal conductor is exposed from a third surface different from the first surface and the second surface of the sealing portion.

2. 2. The current sensor according to claim 1, wherein a distance between portions of the first current conductor and the second current conductor that face each other in a plan view is 2 mm or less and 0.1 mm or more.

3. The current sensor according to claim 1 , wherein a part of the signal conductor is not exposed from a fourth surface of the sealing portion that faces the third surface in a second direction that intersects with the first direction.

4. a third magnetoelectric transducer disposed opposite the first magnetoelectric transducer across a portion of the first current conductor in a plan view; a fourth magnetoelectric transducer arranged to face the second magnetoelectric transducer across a part of the second current conductor in a plan view; Furthermore, The current sensor according to claim 1 , wherein the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer are arranged on the circuit surface of the signal processing IC.

5. 5. The current sensor according to claim 4, wherein the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer are built into a chip that constitutes the signal processing IC.

6. 5. The current sensor according to claim 4, wherein the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer are configured on a chip separate from a chip that configures the signal processing IC.

7. the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer are electrically connected to the signal processing IC via wires; 7. The current sensor according to claim 6, wherein the wire is electrically connected to the first magneto-electric transducer and the second magneto-electric transducer and the signal processing IC without spanning the first current conductor and the second current conductor in a plan view.

8. The current sensor according to claim 1 , wherein the first current conductor or the second current conductor, the signal processing IC, and the signal conductor at least partially overlap each other in a plan view.

9. the first current conductor and the second current conductor are formed from a first lead frame; The current sensor of claim 1 , wherein the signal conductor is comprised of a second lead frame.

10. In a direction intersecting the circuit surface of the signal processing IC, the first current conductor and the second current conductor are at the same height within the sealing portion; the signal conductor is at a different height than the first current conductor and the second current conductor; The current sensor according to claim 1 .

11. the first current conductor includes, in a plan view, a first conductor portion and a second conductor portion that extend in the first direction and are spaced apart in a second direction intersecting the first direction, and a third conductor portion that extends in the second direction and connects the first conductor portion and the second conductor portion; the second current conductor includes, in a plan view, a fourth conductor portion and a fifth conductor portion that extend in the first direction and are spaced apart in the second direction, and a sixth conductor portion that extends in the second direction and connects the fourth conductor portion and the fifth conductor portion; a portion of the first conductor portion and a portion of the second conductor portion are exposed from the first surface of the sealing portion; The current sensor according to claim 1 , wherein a portion of the fourth conductor portion and a portion of the fifth conductor portion are exposed from the second surface of the sealing portion.

12. In a plan view, the first magnetoelectric transducer is surrounded by the first conductor portion, the second conductor portion, and the third conductor portion; In a plan view, the second magnetoelectric transducer is surrounded by the fourth conductor portion, the fifth conductor portion, and the sixth conductor portion; 12. The current sensor of claim 11, wherein a first width in the first direction of the third conductor portion and the sixth conductor portion is the same as a second width in the second direction of the first conductor portion, the second conductor portion, the fourth conductor portion, and the fifth conductor portion, or the first width is narrower than the second width.

13. 12. The current sensor according to claim 11, wherein, in a plan view, the third conductor portion and the sixth conductor portion face each other at a distance from each other, and the space between the third conductor portion and the sixth conductor portion is filled with a resin material that constitutes the sealing portion.

14. 14. The current sensor according to claim 13, wherein a distance between opposing portions of the third conductor portion and the sixth conductor portion is 2 mm or less and 0.1 mm or more in plan view.

15. a third magnetoelectric transducer arranged to face the first magnetoelectric transducer in the second direction across a portion of the first conductor portion in a plan view; a fourth magnetoelectric transducer arranged to face the second magnetoelectric transducer in the second direction with a part of the fifth conductor portion interposed therebetween in a plan view; Furthermore, In a plan view, at least a portion of the third magnetoelectric transducer is located in a region surrounded by the first current conductor, In a plan view, at least a portion of the fourth magnetoelectric transducer is located in a region surrounded by the second current conductor, In a plan view, a distance between the first magnetoelectric transducer and the sixth conductor portion is equal to a distance between the third magnetoelectric transducer and the sixth conductor portion; The current sensor according to claim 11 , wherein, in a plan view, a distance between the second magnetoelectric transducer and the third conductor portion is equal to a distance between the fourth magnetoelectric transducer and the third conductor portion.

16. a third magnetoelectric transducer disposed opposite the first magnetoelectric transducer across the second conductor portion in a plan view; a fourth magnetoelectric transducer arranged to face the second magnetoelectric transducer across the fourth conductor portion in a plan view; and Furthermore, the first magnetoelectric transducer is located in a region surrounded by the first current conductor in a plan view; the second magnetoelectric transducer is located in a region surrounded by the second current conductor in a plan view; In a plan view, a distance between the first magnetoelectric transducer and the sixth conductor portion is equal to a distance between the third magnetoelectric transducer and the sixth conductor portion; In a plan view, a distance between the second magnetoelectric transducer and the third conductor portion is equal to a distance between the fourth magnetoelectric transducer and the third conductor portion; 12. The current sensor according to claim 11, wherein the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer have sensitivity axes in a third direction that intersects the first direction and the second direction.

17. In a plan view, the first magnetoelectric transducer is located on an extension line of the fifth conductor portion, In a plan view, the third magnetoelectric transducer is located on an extension line of the fourth conductor portion, In a plan view, the second magnetoelectric transducer is located on an extension line of the second conductor portion, The current sensor according to claim 16 , wherein the fourth magnetoelectric transducer is located on an extension line of the first conductor portion in plan view.

18. In a plan view, the first magnetoelectric transducer is located on a perpendicular bisector of a line segment connecting the second magnetoelectric transducer and the fourth magnetoelectric transducer, 18. The current sensor according to claim 17, wherein, in a plan view, the second magnetoelectric transducer is located on a perpendicular bisector of a line segment connecting the first magnetoelectric transducer and the third magnetoelectric transducer.

19. a shape formed by the first conductor portion, the second conductor portion, and the third conductor portion is symmetrical in plan view with respect to a perpendicular bisector of a line segment connecting the second magneto-electric transducer and the fourth magneto-electric transducer, 19. The current sensor according to claim 18, wherein the shape formed by the fourth conductor portion, the fifth conductor portion, and the sixth conductor portion is symmetrical in plan view with respect to a perpendicular bisector of a line segment connecting the first magnetoelectric transducer and the third magnetoelectric transducer as an axis of symmetry.

20. The current sensor according to claim 16 , wherein the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer have sensitivity axes in a direction intersecting a magnetosensitive surface.

21. The current sensor according to claim 20 , wherein the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer are Hall elements.

22. the first current conductor and the second current conductor have the same shape; the second current conductor is disposed at a position obtained by symmetrically shifting the first current conductor with a straight line along the second direction as an axis of symmetry in a plan view, The current sensor a third magnetoelectric transducer arranged to face the first magnetoelectric transducer in the second direction; a fourth magnetoelectric transducer arranged to face the second magnetoelectric transducer in the second direction, the entire magnetic sensing surface of the first magnetoelectric conversion element overlaps with the first conductor portion in a plan view; the entire magnetic sensing surface of the third magnetoelectric conversion element overlaps with the second conductor portion in a plan view; the entire magnetic sensing surface of the second magnetoelectric conversion element overlaps with the fourth conductor portion in a plan view, the entire magnetic sensing surface of the fourth magnetoelectric conversion element overlaps with the fifth conductor portion in a plan view, The current sensor according to claim 11 , wherein the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer have sensitivity axes in the second direction.

23. the first magnetoelectric transducer is disposed at the center of a width in the second direction of a portion of the first conductor portion that overlaps with the first magnetoelectric transducer, in a plan view; the third magnetoelectric transducer is disposed at the center of a width in the second direction of a portion of the second conductor portion that overlaps with the third magnetoelectric transducer in a plan view, the second magnetoelectric transducer is disposed at the center of the width in the second direction of a portion of the fourth conductor portion that overlaps with the second magnetoelectric transducer in a plan view, 23 . The current sensor according to claim 22 , wherein the fourth magnetoelectric transducer is disposed at the center of the width in the second direction of a portion of the fifth conductor portion that overlaps with the fourth magnetoelectric transducer in a plan view.

24. the first conductor portion includes, in a plan view, a portion overlapping with the first magneto-electric transducer and a portion having a width in the second direction greater than that of the portion overlapping with the first magneto-electric transducer; the second conductor portion includes, in a plan view, a portion overlapping with the third magnetoelectric transducer and a portion having a width in the second direction greater than that of the portion overlapping with the third magnetoelectric transducer; the fourth conductor portion includes, in a plan view, a portion overlapping with the second magnetoelectric transducer and a portion having a width in the second direction greater than that of the portion overlapping with the second magnetoelectric transducer; 23. The current sensor according to claim 22, wherein the fifth conductor portion includes, in a plan view, a portion that overlaps with the fourth magnetoelectric transducer and a portion that is wider in the second direction than the portion that overlaps with the fourth magnetoelectric transducer.

25. 22. The current sensor according to claim 21, wherein the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer are magnetoresistive elements utilizing a magnetoresistive effect.

26. 26. The current sensor according to claim 25, wherein the first magnetoelectric transducer, the second magnetoelectric transducer, the third magnetoelectric transducer, and the fourth magnetoelectric transducer are built into a chip that constitutes the signal processing IC.

27. 12. The current sensor of claim 11, wherein the respective portions of the first conductor portion and the second conductor portion exposed from the first surface of the sealing portion, and the respective portions of the fourth conductor portion and the fifth conductor portion exposed from the second surface of the sealing portion have extension portions that extend further in a third direction that intersects the first direction and the second direction than the surface of the sealing portion facing the surface opposite the circuit surface of the signal processing IC.

28. 28. The current sensor of claim 27, wherein a width of the tip of the extension portion is narrower than a width of the remaining portion of the extension portion.

29. a tip of the extension portion includes a plurality of teeth arranged in a comb shape; 28. The current sensor of claim 27, wherein the width of each of the plurality of tooth portions is 0.5 to 2 times the thickness of each of the first conductor portion, the second conductor portion, the fourth conductor portion, and the fifth conductor portion.

30. a current sensor according to claim 27; a substrate on which the current sensor is mounted; Equipped with The current sensor module, wherein the extension portion is fixed to the mounting surface of the substrate, so that the sealing portion is positioned above the mounting surface.

31. The current sensor module according to claim 30 , wherein a width of the tip of the extension portion is narrower than a width of the remaining portion of the extension portion.

32. a tip of the extension portion includes a plurality of teeth arranged in a comb shape; 31. The current sensor module of claim 30, wherein the width of each of the plurality of tooth portions is 0.5 to 2 times the thickness of each of the first conductor portion, the second conductor portion, the fourth conductor portion, and the fifth conductor portion.

33. 31. The current sensor module according to claim 30, wherein a distance between the mounting surface of the substrate and a surface of the sealing portion facing the mounting surface is 1 mm or more.

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