Estimation device, current sensor, system, and estimation method

Abstract

The invention relates to an estimation device, a current sensor, a system and an estimation method. The estimation device comprises an acquisition part and an estimation part, an acquisition unit that acquires at least one of a current value of a current output from at least one magnetoelectric conversion element in the current sensor and a voltage value of a voltage applied to the at least one magnetoelectric conversion element, and at least one of a current value of a current input to the signal processing IC and a voltage value of a voltage; and an estimation unit. A current sensor is used. Estimating a base on the basis of a predetermined coefficient and / or a heat transfer characteristic between at least one magnetoelectric conversion element and a pad section and / or a heat transfer characteristic between a signal processing IC and the pad section in a substrate having the pad section in contact with a primary terminal of a current sensor and on which the current sensor is mounted, and at least one of the following coefficients The temperature of the plate is at least one of the current value and the voltage value of the at least one magnetoelectric conversion element and at least one of the current value and the voltage value of the signal processing IC.

Description

Technical Field

[0001] The present invention relates to an estimation device, a current sensor, a system, and an estimation method. Background Art

[0002] Patent Document 1 describes detecting overheating of a Hall element by detecting its temperature. Patent Document 2 describes limiting the power supply current to a high-frequency power amplifier using a current limiting transistor when a power supply current abnormality is detected, even when no temperature abnormality is detected. Patent Document 3 describes determining heat dissipation failure in a semiconductor switch based on the difference between the internal temperature estimated from the current supplied to the semiconductor switch and the actual temperature.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6546884

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 9-019048

[0007] Patent Document 3: Japanese Patent Application Laid-Open No. 2023-009339 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] If the current measured by the current sensor is large, the allowable temperature of the substrate on which the current sensor is mounted reaches its limit before the allowable temperature of the internal elements of the current sensor, and a failure may occur in the substrate.

[0010] Means for solving problems

[0011] An inference device according to one embodiment of the present invention may include an acquisition unit and an estimation unit, wherein the acquisition unit acquires at least one of a current value of a current output from at least one magnetoelectric conversion element in a current sensor and a voltage value of a voltage applied to the at least one magnetoelectric conversion element, and at least one of a current value of a current and a voltage value of a voltage input to a signal processing IC, wherein the current sensor comprises: the at least one magnetoelectric conversion element; a primary conductor and a primary terminal, the primary conductor through which a measurement current measured by the at least one magnetoelectric conversion element flows, the primary terminal being electrically connected to the primary conductor; the signal processing IC processing a signal output from the at least one magnetoelectric conversion element; and A sealing portion seals the at least one magnetoelectric conversion element, the primary conductor and the signal processing IC, the estimating portion estimates the temperature of the substrate based on the current sensor, a coefficient predetermined according to at least one of the heat transfer characteristics between the at least one magnetoelectric conversion element in the substrate and the pad portion and the heat transfer characteristics between the signal processing IC and the pad portion, and at least one of the following two: the two are at least one of the current value and the voltage value of the at least one magnetoelectric conversion element and at least one of the current value and the voltage value of the signal processing IC, the substrate having a pad portion in contact with the primary terminal of the current sensor and on which the current sensor is mounted.

[0012] In the estimation device, the estimation unit may estimate the temperature of the substrate based on at least one of the current value and the voltage value of the at least one magnetoelectric conversion element and at least one of the current value and the voltage value of the signal processing IC.

[0013] Any of the above estimation devices may further include a determination unit configured to determine that an abnormality has occurred in the temperature of the substrate when the temperature of the substrate does not satisfy a predetermined temperature condition.

[0014] In any of the estimation devices, the acquisition unit further acquires a current value of the current flowing through the primary conductor, and when the current value of the primary conductor exceeds a predetermined threshold value, the determination unit determines that an overcurrent is flowing through the primary conductor.

[0015] In any of the estimating devices, the estimating unit may estimate a temperature at the pad portion of the substrate as the temperature of the substrate.

[0016] In any of the estimation devices, the estimation unit may estimate the temperature of the substrate based on a coefficient predetermined according to the heat transfer characteristics between the at least one magnetoelectric conversion element and the primary conductor and the heat transfer characteristics between the signal processing IC and the primary conductor, at least one of the current value and the voltage value of the at least one magnetoelectric conversion element, and at least one of the current value and the voltage value of the signal processing IC.

[0017] In any of the estimation devices, the estimation unit may estimate the temperature inside the sealing portion based on at least one of the current value and the voltage value of the at least one magnetoelectric conversion element and at least one of the current value and the voltage value of the signal processing IC and predetermined heat transfer characteristics of the sealing portion, and estimate the temperature of the substrate based on the temperature inside the sealing portion and the predetermined coefficient.

[0018] In any of the estimation devices, it may be that when the estimated temperature change rate of the substrate with respect to time is higher than a predetermined rate of change, even when the estimated temperature of the substrate does not meet the predetermined temperature condition, the determination unit determines that an abnormality has occurred not in the temperature of the substrate but in at least one magnetoelectric conversion element or the signal processing IC.

[0019] A system according to one aspect of the present invention may include: the estimation device; a current sensor having the at least one magnetoelectric conversion element, the primary conductor and the primary terminal, the signal processing IC, and the sealing portion; and the substrate on which the current sensor is mounted.

[0020] In the system, the current sensor may be surface-mounted on the substrate.

[0021] In the system, the substrate may be a FR4 substrate.

[0022] A current sensor according to one aspect of the present invention may include: any of the above-mentioned estimation devices; the at least one magnetoelectric conversion element; the primary conductor and the primary terminal; the signal processing IC; and the sealing portion.

[0023] In the current sensor, the signal processing IC may include the estimating device.

[0024] A system according to one aspect of the present invention may include: the current sensor; the substrate; and a load that operates when supplied with the measurement current.

[0025] In the system, the estimation device may output a first signal to a control unit that controls the load when the temperature of the substrate estimated by the estimation unit exceeds a first threshold value, wherein the first signal indicates that the temperature of the substrate exceeds the first threshold value, and the first signal includes at least one of an indication to output an alarm signal indicating that the temperature of the substrate exceeds the first threshold value, an indication to suppress power consumption by the load, an indication to stop the operation of the load, and an indication to cool the substrate.

[0026] In the system, the estimation device may further include an output unit, which outputs a first signal to a control unit that controls the load when the temperature of the substrate estimated by the estimation unit exceeds a first threshold value, and outputs a second signal to the control unit when the temperature of the substrate estimated by the estimation unit exceeds a second threshold value that is higher than the first threshold value, wherein the first signal indicates that the temperature of the substrate exceeds the first threshold value, and the second signal indicates that the temperature of the substrate exceeds the second threshold value.

[0027] In any of the above systems, the first signal may include an instruction to suppress power consumption by the load, and the second signal may include an instruction to stop an operation of the load.

[0028] In any of the above systems, the load includes an inverter that supplies power to the electric motor.

[0029] In any of the above systems, the substrate may include a plurality of conductor layers, and the measurement current may flow to the primary terminal and the primary conductor via the plurality of conductor layers.

[0030] In any of the above systems, the current sensor may be a surface-mount semiconductor package. The substrate may include: a primary terminal-side pad portion, which is a conductive portion of the substrate that contacts the primary terminal; and at least one of a plurality of through holes and a plurality of vias, surrounding the primary terminal-side pad portion to electrically connect the primary terminal-side pad portion to the plurality of conductive layers.

[0031] In any of the above systems, at least one of the plurality of through holes and the plurality of guide holes may be densely arranged in an area around the land portion on the primary terminal side compared to an area around the land portion on the secondary terminal side.

[0032] An inference method according to one embodiment of the present invention may include the following stages: a stage of obtaining at least one of the current value of the current output from at least one magnetoelectric conversion element in a current sensor and the voltage value of the voltage applied to the at least one magnetoelectric conversion element, and at least one of the current value of the current and the voltage value of the voltage input to a signal processing IC, wherein the current sensor comprises: the at least one magnetoelectric conversion element; a primary conductor and a primary terminal, the primary conductor being passed through by a measurement current measured by the at least one magnetoelectric conversion element, the primary terminal being electrically connected to the primary conductor; the signal processing IC processing a signal output from the at least one magnetoelectric conversion element; and a sealed part, sealing the at least one magnetoelectric conversion element, the primary conductor and the signal processing IC; and a stage of estimating the temperature of the substrate based on the current sensor, a coefficient predetermined according to at least one of the heat transfer characteristics between the at least one magnetoelectric conversion element in the substrate and the pad part and the heat transfer characteristics between the signal processing IC and the pad part, and at least one of the following two, the two being at least one of the current value and the voltage value of the at least one magnetoelectric conversion element and at least one of the current value and the voltage value of the signal processing IC, the substrate having a pad part in contact with the primary terminal of the current sensor and on which the current sensor is mounted.

[0033] The above summary of the invention does not list all the features of the present invention, and subcombinations of these feature groups may also constitute inventions. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1A 1 is a schematic plan view showing a state where the current sensor is mounted on a substrate, as viewed from the top surface side (Z-axis direction) of the current sensor.

[0035] Figure 1B It is equipped with Figure 1A A cross-sectional view of the substrate of the current sensor taken along line AA is shown.

[0036] Figure 2 It is a top view schematically showing the internal structure of the current sensor.

[0037] Figure 3 This is a diagram showing an example of functional blocks of a system including an estimating device for estimating the temperature of a substrate.

[0038] Figure 4A This is a diagram showing an example of relationship information indicating the relationship between the resistance value of the magnetoelectric transducer and the temperature of the magnetoelectric transducer.

[0039] Figure 4BThis is a diagram showing an example of relationship information indicating the relationship between the forward voltage of a diode (Si bandgap voltage) in a signal processing IC and the temperature of the signal processing IC.

[0040] Figure 5 This is a flowchart showing an example of a process for determining abnormality in the temperature of a substrate by the estimation device. DETAILED DESCRIPTION

[0041] The present invention will be described below by way of embodiments of the invention, but the following embodiments do not limit the scope of the claims. In addition, not all combinations of features described in the embodiments are essential for the solution of the invention.

[0042] Figure 1A 1 is a schematic plan view showing a state where the current sensor 10 is mounted on the substrate 200 , viewed from the top surface side (Z-axis direction) of the current sensor 10 . Figure 1B It is equipped with Figure 1A FIG. 2 is a cross-sectional view of the substrate 200 of the current sensor 10 taken along line AA.

[0043] Regarding coordinates, Figure 1A In the diagram, the X-axis direction is defined as the direction parallel to the paper surface and from bottom to top, the Y-axis direction is defined as the direction parallel to the paper surface and from left to right, and the Z-axis direction is defined as the direction perpendicular to the paper surface and from the back to the outside. Any one of the X-axis, Y-axis, and Z-axis is orthogonal to the other. The Y-axis direction is an example of a first direction. The X-axis direction is an example of a second direction. The Z-axis direction is an example of a thickness direction.

[0044] The current sensor 10 includes a primary terminal 140 a through which a current to be measured flows, and a secondary terminal 150 a for inputting power to the current sensor 10 or for outputting a processed signal.

[0045] Substrate 200 includes a conductor layer 202 electrically connected to primary terminal 140a via pad portion 201, and a conductor layer 204 electrically connected to secondary terminal 150a via pad portion 203. Primary terminal 140a is soldered to conductor layer 202 via pad portion 201. Secondary terminal 150a is soldered to conductor layer 204 via pad portion 203. When primary terminal 140a and pad portion 201 are connected via solder, primary terminal 140a and pad portion 201 can be considered to be in contact. Circuit 400, such as an inverter, is connected to conductor layer 202, and current from the electrical equipment is supplied to primary terminal 140a via conductor layer 202. Conductor layer 202 and conductor layer 204 can be, for example, a substrate having wiring formed thereon. Circuit 400 is an example of a load. Circuit 400 can be electrically connected to conductor layer 202 via a conductor such as a cable. The circuit 400 may include an inverter circuit, and a connector and a terminal block for connecting the inverter circuit to an external motor or power supply equipment.

[0046] like Figure 1B As shown, the conductor layer 202 and the conductor layer 204 are composed of multiple layers, and the multiple conductor layers 202 are electrically connected via a through-hole array 206 formed by arranging multiple through-holes in an array. The multiple conductor layers 202 can also be electrically connected via multiple guide holes. The multiple conductor layers 204 can also be electrically connected via multiple guide holes.

[0047] In the conductor layer 204 on the secondary terminal side, multiple through-holes 208 are used to connect wiring or circuits between multiple layers of substrates for the general purpose of connecting wiring or circuits between multiple layers of substrates. Similarly, through-holes are provided in the conductor layer 202 on the primary terminal side. However, it is preferable to arrange multiple through-holes or vias in a concentrated manner, such as via array 206, in an area directly below or near the pads that serve as the soldering points between the primary terminals and the substrate. Specifically, the multiple through-holes comprising via array 206 can be densely arranged in an area near the connection between the pad 201 and the primary terminal 140a. The area densely packed with multiple through-holes has a greater number of through-holes per unit area than other areas. By distributing heat generated within the current sensor 10 to the multiple layers of conductor layer 202 via the multiple through-holes or vias arranged directly below or near the pads, heat dissipation within the current sensor 10 is improved. Furthermore, the current flowing through the substrate's conductor layer is quickly distributed to the multiple layers, thereby minimizing the temperature rise in the substrate caused by the current.

[0048] The plurality of conductor layers 202 and the plurality of conductor layers 204 can each be a metal layer, such as a copper foil layer. For example, the diameter of each through-hole in the through-hole array 206 can be 1.6 mm or less. The spacing between each through-hole in the through-hole array 206 can be 2 mm or less. The substrate 200 can include 20 or more through-holes directly below and within 10 mm of the primary terminal 140a as the through-hole array 206. Each through-hole in the through-hole array 206 can be filled with solder.

[0049] In the current sensor 10 configured as described above, when a large measurement current flows through the circuit 400 to the primary terminal 140a, the internal temperature of the current sensor 10 rises through the primary terminal 140a. Therefore, it is considered possible to detect the internal temperature of the current sensor 10 and notify the external device of this temperature. However, when the measurement current is large, the permissible temperature of the substrate 200 on which the current sensor 10 is mounted may reach its limit before the permissible temperature of the components within the current sensor 10, potentially causing a problem within the substrate 200. For example, the permissible temperature of a typical IC fabricated from a Si wafer is approximately 150°C, the permissible temperature of a typical magnetoelectric transducer element fabricated from a GaAs wafer is approximately 165°C, and the permissible temperature of a typical FR4 substrate fabricated from glass epoxy is approximately 130°C. Therefore, the FR4 substrate may reach its permissible temperature before the temperature of the IC or magnetoelectric transducer element reaches the permissible temperature.

[0050] If substrate 200 is an FR4 substrate and current sensor 10 is surface-mounted on substrate 200, the substrate temperature is likely to reach the allowable temperature before the IC or magnetoelectric converter reaches the allowable temperature. In this case, substrate 200 can be a multilayer FR4 substrate with a copper foil thickness of 70 μm or less and multiple conductor layers.

[0051] On the other hand, when a temperature sensor is provided on substrate 200 to measure the temperature of substrate 200, space for the temperature sensor must be secured on substrate 200. However, securing sufficient space on substrate 200 may be difficult. Furthermore, the addition of a temperature sensor increases the number of components, which in turn reduces reliability and increases costs.

[0052] Therefore, in this embodiment, the temperature of the substrate 200 is estimated and an abnormality associated with a temperature rise of the substrate 200 is detected without adding a separate temperature sensor.

[0053] Figure 2This is a top view schematically showing the internal structure of the current sensor 10. The current sensor 10 includes a signal processing IC 100, a magnetoelectric transducer 20, a magnetoelectric transducer 22, a sealing portion 130, a lead frame 140, and a lead frame 150. The magnetoelectric transducer 20 and the magnetoelectric transducer 22 are electrically connected to the signal processing IC 100 via a wire 30. The signal processing IC 100 is electrically connected to the lead frame 150 via a wire 108. The wire 30 is an example of a first wire, and the wire 108 is an example of a second wire. The current sensor 10 is an example of a surface-mount semiconductor package.

[0054] The lead frame 140 includes a pair of primary terminals 140a protruding from a side surface 130a of the sealing portion 130, and a primary conductor 140b sealed by the sealing portion 130 and arranged to surround at least a portion of the magnetoelectric transducer element 20 and the magnetoelectric transducer element 22. The lead frame 150 includes a plurality of secondary terminals 150a protruding from a side surface 130b opposite the side surface 130a of the sealing portion 130 in the Y-axis direction, and a secondary conductor 150b electrically connected to the signal processing IC 100 via the wire 108.

[0055] The lead frame 140 has a U-shaped portion in a plan view so that the measurement current input from one of the pair of primary terminals 140a is output from the other of the pair of primary terminals 140a. The magnetoelectric transducer 20 is arranged inside the U-shaped portion. The magnetoelectric transducer 22 is arranged outside the U-shaped portion. Figure 1A The shapes of the lead frame 140 and the lead frame 150 shown are merely examples, and the shapes of the lead frame 140 and the lead frame 150 may be any shapes.

[0056] Lead frame 140 and lead frame 150 are physically separated and electrically insulated. Lead frame 140 and lead frame 150 are electrically insulated at a withstand voltage of 480V or higher. Primary terminal 140a is electrically connected to a high-voltage power supply system. Secondary terminal 150a is electrically connected to a low-voltage power supply system that applies a lower voltage than the high-voltage power supply system.

[0057] The sealing portion 130 seals the magnetoelectric transducer element 20, the magnetoelectric transducer element 22, the primary conductor 140b, the secondary conductor 150b, the signal processing IC 100, the lead 30, and the lead 108 with a molded resin. The sealing portion 130 can be formed by compression molding or transfer molding using a mold. The molded resin can be, for example, a thermosetting epoxy resin containing silicon dioxide. The molded resin can also be a thermoplastic resin such as a liquid crystal polymer.

[0058] The magnetoelectric transducers 20 and 22 detect a magnetic field in a specific direction that changes in response to the measurement current flowing through the primary conductor 140b. A signal proportional to the magnitude of the magnetic field is input to the signal processing IC 100. The difference between the magnetoelectric transducers 20 and 22 is calculated to cancel external magnetic noise. After amplifying the signal to a desired gain, the signal is output via the lead frame 150. The magnetoelectric transducers 20 and 22 are an example of an element that outputs a signal corresponding to the current flowing through the lead frame 140. The magnetoelectric transducers 20 and 22 are composed of a compound semiconductor formed on a GaAs substrate and are chips cut into a square or rectangular shape when viewed from above in the Z-axis direction.

[0059] When detecting a magnetic field in the Z-axis direction, the magnetoelectric transducers 20 and 22 may be Hall elements. When detecting a magnetic field in any axial direction in the XY plane, the magnetoelectric transducers 20 and 22 may be magnetoresistive elements such as AMR sensors, TMR sensors, or GMR sensors, or fluxgate elements. When the magnetoelectric transducers 20 and 22 are magnetoresistive elements, the magnetoelectric transducer 20 may be positioned opposite the portion of the U-shaped portion of the lead frame 140 to which one lead terminal is connected, and the magnetoelectric transducer 22 may be positioned opposite the portion of the U-shaped portion of the lead frame 140 to which the other lead terminal is connected.

[0060] The signal processing IC 100 is a large-scale integrated circuit (LSI). It comprises a signal processing circuit and a bias circuit formed from a Si monolithic semiconductor formed on a Si substrate. The bias circuit applies a corrected drive current or drive voltage to the magnetoelectric transducers 20 and 22. The signal processing circuit processes the output signal corresponding to the magnitude of the magnetic field outputted from the magnetoelectric transducers 20 and 22. Based on the output signal, the signal processing circuit corrects the measured current flowing through the lead frame 140 and outputs an output signal representing the accurate current value via the secondary terminal 150a. Based on the difference between the output signal of the magnetoelectric transducer 20 and the output signal of the magnetoelectric transducer 22, the signal processing circuit reduces the noise components contained in the output signals of the magnetoelectric transducer 20 and the output signals of the magnetoelectric transducer 22. The signal processing circuit amplifies the output signals of the magnetoelectric transducer 20 and the output signals of the magnetoelectric transducer 22 after the noise components have been reduced, calculates the current value of the measured current based on the amplified output signal, and outputs an output signal representing the current value.

[0061] In this embodiment, the current sensor 10 is described as including two magnetoelectric transducers. However, the current sensor 10 only needs to include at least one magnetoelectric transducer. Furthermore, in this embodiment, the magnetoelectric transducers 20 and 22 are described as being separate chips from the signal processing IC 100. However, the magnetoelectric transducers 20 and 22 may also be monolithic silicon magnetoelectric transducers embedded within the signal processing IC 100.

[0062] Figure 3 This is an example of a functional block of a system including an estimating device 300 that estimates the temperature of the substrate 200 .

[0063] The estimation device 300 includes a control unit 310 and a storage unit 320. The control unit 310 can be composed of a microprocessor such as a CPU or MPU, a microcontroller such as an MCU, or the like. The signal processing IC 100 can function as the estimation device 300. The storage unit 320 stores information required for the estimation device 300 to estimate the temperature of the substrate 200 of the current sensor 10. The estimation device 300 can also be provided in a device different from the current sensor 10 that can communicate with the current sensor 10. The estimation device 300 is communicatively connected to a circuit 400 for inputting or outputting the measurement current measured by the current sensor 10. The circuit 400 includes a control unit 402 composed of a processor or the like that controls the operation of the circuit 400.

[0064] The control unit 310 includes an acquisition unit 312, an estimation unit 314, a determination unit 316, and an output unit 318. The acquisition unit 312 acquires the current value Ia of the current flowing through the primary conductor 140b. The acquisition unit 312 can acquire the current value derived by the signal processing circuit as the current value I flowing through the primary conductor 140b.

[0065] The acquisition unit 312 acquires the current value Ib of the current output from the magnetoelectric conversion element 20 and the magnetoelectric conversion element 22 and the voltage value Vb of the voltage applied to the magnetoelectric conversion element 20 and the magnetoelectric conversion element 22. The acquisition unit 312 can acquire the current value Ib of the current output from the magnetoelectric conversion element 20 and the magnetoelectric conversion element 22 and the voltage value Vb of the voltage applied to the magnetoelectric conversion element 20 and the magnetoelectric conversion element 22 based on the control information of the signal processing IC 100 that controls the power supplied to the magnetoelectric conversion element 20 and the magnetoelectric conversion element 22.

[0066] The acquisition unit 312 acquires the current value Ic and the voltage value Vc of the current input to the signal processing IC 100. The acquisition unit 312 may acquire the current value Ic and the voltage value Vc from a reference voltage source built into the signal processing IC 100.

[0067] The estimating unit 314 can estimate the temperature of the substrate 200 based on a coefficient predetermined based on at least one of the heat transfer characteristics between each of the magnetoelectric transducers 20 and 22 and the primary conductor 140b, and the heat transfer characteristics between the signal processing IC 100 and the primary conductor 140b, and at least one of the current value Ib and the voltage value Vb of each of the magnetoelectric transducers 20 and 22, and the current value Ic and the voltage value Vc of the signal processing IC 100. The coefficient predetermined based on at least one of the heat transfer characteristics between each of the magnetoelectric transducers 20 and 22 and the primary conductor 140b, and the heat transfer characteristics between the signal processing IC 100 and the primary conductor 140b, can be determined based on a relationship ΔT1 between the temperatures of the magnetoelectric transducers 20 and 22 and the signal processing IC 100, and the temperature of the primary terminal 140a, described later.

[0068] The estimating unit 314 can estimate the temperature of the substrate 200 based on a coefficient predetermined based on at least one of the heat transfer characteristics between each of the magnetoelectric transducers 20 and 22 and the pad portion 201, and the heat transfer characteristics between the signal processing IC 100 and the pad portion 201, and at least one of the current value Ib and the voltage value Vb of each of the magnetoelectric transducers 20 and 22, and the current value Ic and the voltage value Vc of the signal processing IC 100. The coefficient predetermined based on at least one of the heat transfer characteristics between each of the magnetoelectric transducers 20 and 22 and the pad portion 201, and the heat transfer characteristics between the signal processing IC 100 and the pad portion 201 can be determined based on a relationship ΔT1 between the temperatures of the magnetoelectric transducers 20 and 22 and the signal processing IC 100 and the temperature of the primary terminal 140a, and a relationship ΔT2 between the temperature of the primary conductor 140b and the temperature of the pad portion 201 connected to the primary terminal 140a, which will be described later.

[0069] The estimating unit 314 can estimate the temperature of the pad portion 201 of the substrate 200 in contact with the primary terminal 140a as the temperature of the substrate 200. The estimating unit 314 can regard the temperature of the pad portion 201 in contact with the primary terminal 140a via the solder as the temperature of the substrate 200 and estimate it as the temperature of the substrate 200.

[0070] The heat transfer characteristics between the magnetoelectric transducers 20 and 22 and the primary conductor 140 b are predetermined based on at least one of the distance between the magnetoelectric transducers 20 and 22 and the primary conductor 140 b and the thermal conductivity of the mold resin constituting the sealing portion 130 .

[0071] The heat transfer characteristics between the signal processing IC 100 and the primary conductor 140 b are predetermined based on at least one of the distance between the signal processing IC 100 and the primary conductor 140 b and the thermal conductivity of the material constituting the sealing portion 130 .

[0072] Here, the relationship ΔT1 between the temperatures of the magnetoelectric transducers 20 and 22 and the signal processing IC 100, and the temperature of the primary terminal 140a, depends on the heat transfer function of the molded resin between the magnetoelectric transducers 20 and 22, the signal processing IC 100, and the primary conductor 140a. Furthermore, this relationship ΔT1 depends on the arrangement of the magnetoelectric transducers 20 and 22 and the signal processing IC 100, which are sealed within the sealing portion 130, and the primary conductor 140b, as well as the material and shape of the primary conductor 140b. Furthermore, if a heat dissipation member such as a fin is attached to the current sensor 10, the relationship ΔT1 between the temperatures of the magnetoelectric transducers 20 and 22 and the signal processing IC 100 and the temperature of the primary terminal 140a also depends on the heat transfer function of the heat dissipation member.

[0073] The relationship ΔT2 between the temperature of primary conductor 140b and the temperature of pad 201 connected to primary terminal 140a depends on the material and shape of primary terminal 140a, as well as the type of solder forming pad 201, namely, the thermal conductivity of the solder and the thickness of the solder layer. Furthermore, with respect to the distance from pad 201 to the load circuit or current extraction cable on substrate 200, relationship ΔT2 also depends on factors such as the thermal conductivity, which is determined by the width and thickness of the copper foil that forms the current wiring path on substrate 200, or the number of layers. Furthermore, when forced cooling is applied from outside current sensor 10 and substrate 200, relationship ΔT2 also depends on the effectiveness of the cooling.

[0074] The relationship ΔT3 between the temperature of the pad portion 201 and the temperature of any other part of the substrate 200 depends on the thermal conductivity of the substrate 200 based on the width, thickness and number of layers of the copper foil of the substrate 200, the distance to the circuit formed on the substrate 200, the distance to the current lead-out cable, etc.

[0075] Therefore, the heat transfer characteristics between each of the magnetoelectric transducers 20 and 22 and any portion of the substrate 200 depend on the relationship ΔT1, the relationship ΔT2, and the relationship ΔT3. Taking this into account, the coefficients for deriving the temperature of the substrate 200 from the temperatures of the magnetoelectric transducers 20 and 22, and the coefficients for deriving the temperature of the substrate 200 from the temperature of the signal processing IC 100 can be determined in advance based on experimental results, etc.

[0076] For example, when the estimation unit 314 estimates the temperature of the pad portion 201 of the substrate 200 as the temperature of the substrate 200, the above-mentioned heat transfer characteristics are estimated based on the relationship ΔT1 and the relationship ΔT2. When the estimation unit 314 estimates the temperature of any other part of the substrate 200 or the average value of the temperature of the substrate as the temperature of the substrate 200, the above-mentioned heat transfer characteristics are estimated based on the relationship ΔT1, the relationship ΔT2 and the relationship ΔT3.

[0077] The estimation unit 314 of the current sensor 10 can derive the resistance value Rb of the magnetoelectric transducers 20 and 22 based on the current value Ib and voltage value Vb of each of the magnetoelectric transducers 20 and 22, and estimate the temperature of each of the magnetoelectric transducers 20 and 22 based on the relationship information indicating the relationship between the resistance value of the magnetoelectric transducers 20 and 22 and the temperature of the magnetoelectric transducers 20 and 22 and the derived resistance value Rb. Furthermore, the estimation unit 314 can multiply the estimated temperatures T1 and T2 of the magnetoelectric transducers 20 and 22, respectively, by a predetermined coefficient and estimate the temperature of the substrate 200 based on the obtained temperature. The estimation unit 314 can estimate the temperature of the substrate 200 as the average of the two temperatures derived by multiplying the estimated temperatures of the magnetoelectric transducers 20 and 22, respectively, by the predetermined coefficient, or as the higher temperature.

[0078] Figure 4A is an example of relationship information indicating the relationship between the resistance value of the magnetoelectric converter elements 20 and 22 and the temperature of the magnetoelectric converter elements 20 and 22. The estimation unit 314 can estimate the relationship based on the resistance value Rb of the magnetoelectric converter elements 20 and 22 and the temperature of the magnetoelectric converter elements 20 and 22. Figure 4A The acquisition unit 312 can obtain the temperatures T1 and T2 of the magnetoelectric conversion elements 20 and 22 based on the voltage value Vb of the voltage applied to the magnetoelectric conversion elements 20 and 22 and the current value Ib of the current output from the secondary terminal 150a of the magnetoelectric conversion elements 20 and 22, and derive the resistance values ​​R1 and R2 of the magnetoelectric conversion elements 20 and 22.

[0079] Figure 4B This is an example of relationship information indicating the relationship between the forward voltage of the Si diode and the temperature of the signal processing IC 100. Estimation unit 314 can estimate the temperature of the signal processing IC 100 based on the relationship information indicating the relationship between the voltage value of the reference voltage source of the signal processing IC 100, i.e., the bandgap voltage value (the forward voltage of the Si diode), and the temperature of the signal processing IC 100, and the voltage value Vc obtained from the reference voltage source. Furthermore, estimating unit 314 can estimate the temperature of the substrate 200 by multiplying the estimated temperature of the signal processing IC 100 by a predetermined coefficient.

[0080] The estimating unit 314 can estimate the temperature of the substrate 200 based on the temperature of the substrate 200 estimated based on the resistance values ​​of the magnetoelectric conversion elements 20 and 22 and the temperature of the substrate 200 estimated based on the bandgap voltage of the signal processing IC 100. The estimating unit 314 can estimate the temperature of the substrate 200 as the average value or the maximum value of the temperature of the substrate 200 estimated based on the resistance values ​​of the magnetoelectric conversion elements 20 and 22 and the temperature of the substrate 200 estimated based on the bandgap voltage of the signal processing IC 100.

[0081] The portion in contact with primary terminal 140a tends to generate the most heat within current sensor 10 among the components mounted on substrate 200. Therefore, it can be said that pad portion 201 in contact with primary terminal 140a is the hottest portion of the substrate. Specifically, when estimating unit 314 estimates the maximum temperature of substrate 200 as the estimated value of substrate 200 temperature, it can be assumed that the maximum temperature of substrate 200 is the temperature of pad portion 201, for example.

[0082] If the temperature of substrate 200 does not meet a predetermined temperature condition, determination unit 316 determines that a temperature abnormality has occurred in substrate 200. If the temperature of substrate 200 exceeds a first threshold value TH1, determination unit 316 may determine that a temperature rise in substrate 200 should be suppressed. If the temperature of substrate 200 exceeds the first threshold value TH1, determination unit 316 may determine that an alarm signal indicating that the temperature of substrate 200 has exceeded the first threshold value TH1 should be output, that power consumption by circuit 400 should be suppressed, that circuit 400 should be operated in a power saving mode, or that substrate 200 should be cooled. If the temperature of substrate 200 exceeds a second threshold value TH2, which is higher than the first threshold value TH1, determination unit 316 may determine that operation of circuit 400 should be stopped.

[0083] If the circuit 400 includes an inverter circuit that supplies power to the motor, the determination unit 316 may determine that the inverter circuit should be operated so that the motor operates in a power-saving mode when the temperature of the substrate 200 exceeds a first threshold value TH1. The determination unit 316 may also determine that the motor should be stopped when the temperature of the substrate 200 exceeds a second threshold value TH2.

[0084] The determination unit 316 may determine that an overcurrent is flowing in the primary conductor 140 b when the current value Ia of the current flowing through the primary conductor 140 b exceeds a predetermined threshold value THa.

[0085] When the determination result of the determination unit 316 is that the temperature of the substrate 200 exceeds the first threshold value TH1, the output unit 318 may output a signal indicating that the temperature of the substrate 200 exceeds the first threshold value TH1 to the control unit 402 that controls the circuit 400. When the temperature of the substrate 200 exceeds the second threshold value TH2, the output unit 318 may output a signal indicating that the temperature of the substrate 200 exceeds the second threshold value TH2 to the control unit 402.

[0086] When the determination result of the determination unit 316 is that the temperature of the substrate 200 exceeds the first threshold value TH1, the output unit 318 may output a signal including an instruction to suppress the power consumed by the circuit 400 to the control unit 402. When the temperature of the substrate 200 exceeds the second threshold value TH2, the output unit 318 may output a signal including an instruction to stop the operation of the circuit 400 to the control unit 402.

[0087] When the determination result of the determination unit 316 is that the temperature of the substrate 200 exceeds the first threshold value TH1, the output unit 318 can output to the control unit 402 at least one of a signal including an instruction to suppress the power consumed by the circuit 400, an alarm signal indicating that the temperature of the substrate 200 exceeds the first threshold value TH1, and a signal including an instruction to cool the substrate 200.

[0088] As cooling means for the substrate 200, there are the following methods: increasing the rotation speed of a cooling fan arranged near the substrate 200, circulating the coolant flowing in the tube of a water-cooled radiator arranged near the substrate 200 while cooling it or accelerating the circulation speed of the coolant, increasing the current flowing to the Peltier element arranged near the substrate 200, increasing the air supply volume of the compressor arranged near the substrate 200 or lowering the air supply temperature.

[0089] When the current value Ia of the current flowing through the primary conductor 140b exceeds a predetermined threshold value THa, the output unit 318 may output a signal indicating that an overcurrent is flowing through the primary conductor 140b to the control unit 402 .

[0090] Here, due to an abnormality in the magnetoelectric conversion element 20 or the magnetoelectric conversion element 22, or the signal processing IC 100, the temperature of the magnetoelectric conversion element 20 or the magnetoelectric conversion element 22, or the signal processing IC 100 may change rapidly. In this case, before the heat reaches the substrate 200, the temperature of the magnetoelectric conversion element 20 or the magnetoelectric conversion element 22, or the signal processing IC 100 may reach the allowable temperature. In such a case, the accuracy of the temperature of the substrate 200 estimated by the determination unit 316 based on the temperature of the magnetoelectric conversion element 20 or the magnetoelectric conversion element 22, or the signal processing IC 100 is low, and it is preferable not to determine that the temperature of the substrate 200 is abnormal. In such a case, it is preferable that the determination unit 316 determine that the abnormality is in the magnetoelectric conversion element 20 or the magnetoelectric conversion element 22, or the signal processing IC 100. Therefore, the judgment unit 316 can judge that the estimated temperature change rate of the substrate 200 is higher than the predetermined change rate as an abnormality in the magnetoelectric conversion element 20 or the magnetoelectric conversion element 22, or the signal processing IC100. In particular, even if the estimated temperature of the substrate does not meet the predetermined temperature condition, it can be determined that it is not the temperature abnormality of the substrate 200, but the abnormality in the magnetoelectric conversion element 20 or the magnetoelectric conversion element 22, or the signal processing IC100.

[0091] When the estimated temperature of the magnetoelectric conversion element 20 or the magnetoelectric conversion element 22, or the signal processing IC 100 is higher than a predetermined temperature, the determination unit 316 can determine that an abnormality has occurred in the magnetoelectric conversion element 20 or the magnetoelectric conversion element 22, or the signal processing IC 100. In particular, even when the estimated temperature of the substrate 200 does not meet the predetermined temperature condition, it can be determined that the abnormality is not in the temperature of the substrate 200, but in the magnetoelectric conversion element 20 or the magnetoelectric conversion element 22, or the signal processing IC 100.

[0092] When the output unit 318 receives a signal from the determination unit 316 indicating an overcurrent flowing through the primary conductor 140b, it may stop the current flowing from the circuit 400 to the primary conductor 140b of the current sensor 10, thereby notifying the user of the overcurrent. The estimation device 300 may notify a display, etc., of an alarm message corresponding to the type of signal. The control device may log the contents of the signal, i.e., an alarm indicating an abnormality in the temperature of the substrate 200, an abnormality in the magnetoelectric transducer 20 or 22, an abnormality in the signal processing IC 100, or an alarm indicating an overcurrent flowing into the current sensor 10, in a memory.

[0093] Figure 5 This is a flowchart showing an example of a process of determining whether the temperature of the substrate 200 is abnormal by the estimation device 300 .

[0094] The acquisition unit 312 acquires the current value Ia of the current flowing through the primary conductor 140b (S100). The acquisition unit 312 may acquire the current value derived by the signal processing circuit included in the signal processing IC 100 as the current value Ia flowing through the primary conductor 140b. The determination unit 316 determines whether the current value Ia is greater than or equal to the threshold value THa (S102).

[0095] When the current value Ia is greater than the threshold value THa, the output unit 318 outputs an overcurrent abnormality alarm signal indicating that an overcurrent is flowing through the current sensor 10 (S104). On the other hand, when the current value Ia is less than the threshold value THa, the acquisition unit 312 acquires the current value Ia of the current output from the magnetoelectric transducers 20 and 22, the voltage value Vb of the voltage applied to the magnetoelectric transducers 20 and 22, and the current value Ic and voltage value Vc of the current input to the signal processing IC 100 (S106). The acquisition unit 312 can acquire the current value Ib of the current output from the magnetoelectric transducers 20 and 22 and the voltage value Vb of the voltage applied to the magnetoelectric transducers 20 and 22 based on control information from the signal processing IC 100 that controls the power supplied to the magnetoelectric transducers 20 and 22. The acquisition unit 312 can acquire the current value Ic and voltage value Vc from a reference voltage source built into the signal processing IC 100.

[0096] The estimating unit 314 estimates the temperature Tb of the magnetoelectric transducers 20 and 22 and the temperature Tc of the signal processing IC 100 based on at least one of the current value Ib and the voltage value Vb of the magnetoelectric transducers 20 and 22 and at least one of the current value Ic and the voltage value Vc of the signal processing IC (S108). The estimating unit 314 can derive the resistance value Rb of the magnetoelectric transducers 20 and 22 based on the current value Ib and the voltage value Vb of the magnetoelectric transducers 20 and 22, respectively, and estimate the temperature Tb of the magnetoelectric transducers 20 and 22 based on the relationship information indicating the relationship between the resistance value of the magnetoelectric transducers 20 and 22 and the temperature of the magnetoelectric transducers 20 and 22 and the derived resistance value Rb. The estimating unit 314 can estimate the temperature Tc of the signal processing IC 100 based on the relationship information indicating the relationship between the voltage value of the reference voltage source of the signal processing IC 100 and the temperature of the signal processing IC 100 and the voltage value Vc obtained from the reference voltage source.

[0097] The estimating unit 314 estimates the temperature Td of the substrate 200 based on the temperatures Tb of the magnetoelectric conversion elements 20 and 22 and the temperature Tc of the signal processing IC 100 (S110). The estimating unit 314 may estimate the temperature Td of the substrate 200 as the average or maximum value of the temperatures of the substrate 200 estimated based on the temperatures Tb of the magnetoelectric conversion elements 20 and 22 and the temperature Tc of the signal processing IC 100.

[0098] The determination unit 316 determines whether the temperature Td of the substrate 200 is equal to or greater than the second threshold TH2 ( S112 ). If the temperature Td of the substrate 200 is equal to or greater than the second threshold TH2 , the output unit 318 outputs an alarm signal indicating a stop command for the circuit 400 ( S114 ).

[0099] If the temperature Td of the substrate 200 is less than the second threshold value TH2, the determination unit 316 determines whether the temperature Td of the substrate 200 is greater than or equal to the first threshold value TH1 (S116). If the temperature Td of the substrate 200 is greater than or equal to the first threshold value TH1, the output unit 318 outputs an alarm signal indicating that the circuit 400 is to be operated in the power saving mode (S118).

[0100] When the temperature Td of the substrate 200 is lower than the first threshold TH1, the determination unit 316 determines that the temperature of the current sensor 10 and the temperature of the substrate 200 are not abnormal, and the output unit 318 does not output an alarm signal, and the circuit 400 continues normal processing (S120).

[0101] As described above, according to the estimation device 300 of this embodiment, even when the measurement current measured by the current sensor 10 is large, it is possible to prevent the allowable temperature of the substrate 200 on which the current sensor 10 is mounted from reaching the limit before the allowable temperature of the components inside the current sensor 10, thereby preventing a malfunction from occurring in the substrate 200.

[0102] While 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 is apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. As can be seen from the claims, embodiments incorporating such modifications or improvements are also within the technical scope of the present invention.

[0103] It should be noted that the order in which actions, processes, steps, and stages, etc., of the apparatus, system, program, and method described in the claims, specifications, and drawings may be performed in any order, unless otherwise expressly indicated as "before," "before," or the like, and unless the output of a previous process is used in a subsequent process. Even if the action flow in the claims, specifications, and drawings is described using the phrases "first," "next," or the like for convenience, it does not necessarily mean that the actions must be performed in that order.

[0104] Description of Reference Numerals

[0105] 10 Current sensor

[0106] 20, 22 Magnetoelectric conversion element

[0107] 30, 108 wires

[0108] 130 sealing part

[0109] 140 lead frame

[0110] 140a primary terminal

[0111] 140b primary conductor

[0112] 150 lead frame

[0113] 150a secondary terminal

[0114] 150b secondary conductor

[0115] 200 substrates

[0116] 201 pad department

[0117] 202, 204 conductor layers

[0118] 203 pad part

[0119] 206 through-hole array

[0120] 208 through hole

[0121] 300 estimation device

[0122] 310 Control Department

[0123] 312 Acquisition Department

[0124] 314 Presumption Department

[0125] 316 Judgment Department

[0126] 318 output unit

[0127] 320 Storage Department

[0128] 400 circuit

[0129] 402 Control Department

[0130] 100 signal processing ICs.

Claims

1. An estimation device, wherein: It has an acquisition department and an inference department. The acquisition unit acquires at least one of a current value of a current output from at least one magnetoelectric conversion element in the current sensor and a voltage value of a voltage applied to the at least one magnetoelectric conversion element, and at least one of a current value of a current and a voltage value of a voltage input to a signal processing IC, wherein the current sensor comprises: the at least one magnetoelectric conversion element; a primary conductor and a primary terminal, the primary conductor through which a measurement current measured by the at least one magnetoelectric conversion element flows, the primary terminal being electrically connected to the primary conductor; and the signal processing IC processing a signal output from the at least one magnetoelectric conversion element; and a sealing portion for sealing the at least one magnetoelectric conversion element, the primary conductor, and the signal processing IC, The estimating unit estimates the temperature of the substrate based on the current sensor, a coefficient predetermined according to at least one of the heat transfer characteristics between the at least one magnetoelectric conversion element in the substrate and the pad portion and the heat transfer characteristics between the signal processing IC and the pad portion, and at least one of the following two: the two are at least one of the current value and the voltage value of the at least one magnetoelectric conversion element and at least one of the current value and the voltage value of the signal processing IC, the substrate having a pad portion in contact with the primary terminal of the current sensor and on which the current sensor is mounted.

2. The estimation device according to claim 1, wherein: The estimating unit estimates the temperature of the substrate based on at least one of the current value and the voltage value of the at least one magnetoelectric conversion element and at least one of the current value and the voltage value of the signal processing IC.

3. The estimation device according to claim 1, wherein: The estimation device further includes a determination unit configured to determine that an abnormality has occurred in the temperature of the substrate when the temperature of the substrate does not satisfy a predetermined temperature condition.

4. The estimation device according to claim 3, wherein: The acquisition unit further acquires a current value of the current flowing through the primary conductor. The determination unit determines that an overcurrent is flowing through the primary conductor when the current value of the primary conductor exceeds a predetermined threshold value.

5. The estimation device according to claim 1, wherein: The estimating unit estimates a temperature at the pad portion of the substrate as the temperature of the substrate.

6. The estimation device according to claim 1, wherein: The estimation unit estimates the temperature of the substrate based on a coefficient predetermined according to the heat transfer characteristics between the at least one magnetoelectric conversion element and the primary conductor and the heat transfer characteristics between the signal processing IC and the primary conductor, at least one of the current value and the voltage value of the at least one magnetoelectric conversion element, and at least one of the current value and the voltage value of the signal processing IC.

7. The estimation device according to claim 1, wherein: The estimating unit estimates the temperature inside the sealing portion based on at least one of the current value and the voltage value of the at least one magnetoelectric conversion element and at least one of the current value and the voltage value of the signal processing IC and predetermined heat transfer characteristics of the sealing portion, and estimates the temperature of the substrate based on the temperature inside the sealing portion and the predetermined coefficient.

8. The estimation device according to claim 3, wherein: When the estimated temperature change rate of the substrate with respect to time is higher than the predetermined rate of change, even when the estimated temperature of the substrate does not meet the predetermined temperature condition, the determination unit determines that an abnormality has occurred not in the temperature of the substrate but in at least one magnetoelectric conversion element or the signal processing IC.

9. A system, wherein: have: The estimation device according to any one of claims 1 to 8; a current sensor comprising the at least one magnetoelectric conversion element, the primary conductor and the primary terminal, the signal processing IC, and the sealing portion; as well as The substrate is provided with the current sensor.

10. The system according to claim 9, wherein: The current sensor is surface-mounted on the substrate.

11. The system according to claim 9, wherein: The substrate is an FR4 substrate.

12. A current sensor, wherein: have: The estimation device according to any one of claims 1 to 8; said at least one magnetoelectric conversion element; the primary conductor and the primary terminal; the signal processing IC; and The sealing portion.

13. The current sensor according to claim 12, wherein: The signal processing IC includes the estimating device.

14. A system, wherein: have: The current sensor according to claim 12; the substrate; and The load is operated by being supplied with the measurement current.

15. The system according to claim 14, wherein: When the temperature of the substrate estimated by the estimating unit exceeds a first threshold, the estimating device outputs a first signal to a control unit that controls the load, wherein the first signal indicates that the temperature of the substrate exceeds the first threshold. The first signal includes at least one of an instruction to output an alarm signal indicating that the temperature of the substrate exceeds the first threshold, an instruction to suppress power consumption by the load, an instruction to stop operation of the load, and an instruction to cool the substrate.

16. The system of claim 14, wherein: The estimation device further includes an output unit. The output unit outputs a first signal to a control unit that controls the load when the temperature of the substrate estimated by the estimating unit exceeds a first threshold value, and outputs a second signal to the control unit when the temperature of the substrate estimated by the estimating unit exceeds a second threshold value that is higher than the first threshold value. The first signal indicates that the temperature of the substrate exceeds the first threshold value, and the second signal indicates that the temperature of the substrate exceeds the second threshold value.

17. The system according to claim 16, wherein: the first signal comprising an instruction to suppress power consumed by the load, The second signal includes an instruction to stop the operation of the load.

18. The system according to claim 16, wherein: The load includes an inverter that supplies electric power to the electric motor.

19. The system of claim 14, wherein: The substrate comprises a plurality of conductor layers, The measurement current flows toward the primary terminal and the primary conductor via the plurality of conductor layers.

20. The system of claim 19, wherein: The current sensor is a surface-mounted semiconductor package. The substrate has: a pad portion on the primary terminal side, which is a conductive portion of the substrate that contacts the primary terminal; and At least one of the plurality of through holes and the plurality of vias electrically connects the pad portion on the primary terminal side and the plurality of conductor layers around the pad portion on the primary terminal side.

21. The system of claim 20, wherein: At least one of the plurality of through holes and the plurality of vias is densely arranged in an area around the land portion on the primary terminal side, compared to an area around the land portion on the secondary terminal side.

22. A presumption method comprising the following stages: a stage of obtaining at least one of a current value of a current output from at least one magnetoelectric conversion element in a current sensor and a voltage value of a voltage applied to the at least one magnetoelectric conversion element, and at least one of a current value of the current and a voltage value of the voltage input to a signal processing IC, the current sensor comprising: the at least one magnetoelectric conversion element; a primary conductor and a primary terminal, the primary conductor through which a measurement current measured by the at least one magnetoelectric conversion element flows, the primary terminal being electrically connected to the primary conductor; and the signal processing IC processing a signal output from the at least one magnetoelectric conversion element; and a sealing portion for sealing the at least one magnetoelectric conversion element, the primary conductor, and the signal processing IC; as well as A stage of estimating the temperature of the substrate based on the current sensor, a coefficient predetermined according to at least one of the heat transfer characteristics between the at least one magnetoelectric conversion element in the substrate and the pad portion and the heat transfer characteristics between the signal processing IC and the pad portion, and at least one of the following two: the two are at least one of the current value and the voltage value of the at least one magnetoelectric conversion element and at least one of the current value and the voltage value of the signal processing IC, the substrate having a pad portion in contact with the primary terminal of the current sensor and on which the current sensor is mounted.

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