Current sensor

Abstract

Provided is a current sensor that functions as a fuse when an overcurrent flows. A current sensor (1) is provided with: a conductor (40); a magnetic sensor (30) disposed on the conductor; and a package that seals the turning portion (43) of the conductor, the first body portion (42a) and the second body portion (42b), and the magnetic sensor, and exposes the first terminal portion (41a) and the second terminal portion (41b), the first body portion and the second body portion including an arrangement section (44a, 44b) in which at least one hole is provided, and in a continuous cross-section of the conductor that perpendicularly intersects an inner contour surface of the conductor, the first terminal portion (41a) and the second terminal portion (41b) are arranged in the arrangement section (44a, 44b). The cross-sectional area of a continuous cross-section defined between the contour surface of the inner side of the conductor in the array section and the inner surface of the hole located closest to the contour surface of the inner side of the conductor is smaller than the cross-sectional area of another continuous cross-section between the contour surface of the inner side of the conductor outside the array section and the contour surface of the outer side of the conductor.

Description

Technical Field

[0001] This invention relates to current sensors. Background Technology

[0002] A current sensor is known to include a conductor through which the measured current flows and a magnetoelectric conversion element located close to the conductor, sealed within a package. The magnetoelectric conversion element detects the strength of the magnetic field generated by the current flowing through the conductor and converts it into an electrical signal, thereby detecting the current quantity. In this current sensor, to concentrate the magnetic field at the magnetoelectric conversion element and improve detection sensitivity, the cross-sectional area of ​​the conductor portion inside the package close to the magnetoelectric conversion element is smaller than the cross-sectional area of ​​the conductor portion located at the periphery of the package, thus increasing the current density in the conductor. Therefore, in the event of a momentary overcurrent (e.g., with a high-frequency component of 1 MHz) flowing due to a fault in the system being measured by the current sensor, the conductor inside the package overheats and melts, enabling the current sensor to function as a fuse. Patent Document 1 discloses a pyroelectric circuit breaker that cuts off the conductor based on an overcurrent, discharging the resulting arc discharge to the separator side, thereby preventing further damage. Thus, it is desirable for the current sensor to function as a fuse when an overcurrent flows without damaging the primary and secondary circuits.

[0003] [Existing technical documents]

[0004] [Patent Literature]

[0005] [Patent Document 1] International Publication No. 2017 / 136221 Summary of the Invention

[0006] [Methods used to solve problems]

[0007] In a first aspect of the present invention, a current sensor is provided, comprising: a conductor having a first terminal portion disposed on one side of a first axial direction for inputting current, a second terminal portion separated from the first terminal portion along a second axial direction intersecting the first axial direction for outputting the current, a bend portion disposed on the other side of the first axial direction relative to the first terminal portion, a first main body portion connecting one end of the bend portion to the first terminal portion, and a second main body portion separated from the first main body portion along the second axial direction and connecting the other end of the bend portion to the second terminal portion; a magnetic sensor disposed on or near the conductor; and a package containing the bend portion, the first main body portion, the second main body portion, and the magnetic sensor. The magnetic sensor is sealed, exposing the first terminal portion and the second terminal portion. At least one of the first body portion and the second body portion includes an arrangement interval, which is provided with at least one hole. Viewed from a third direction that intersects the first axis and the second axis respectively, in a continuous cross section of the conductor that intersects the inner contour surface of the conductor perpendicularly to the inner contour surface of the conductor, the cross-sectional area of ​​the first continuous cross section divided between the inner contour surface of the conductor within the arrangement interval and the inner surface of the hole located on the innermost contour surface side of the conductor in the at least one hole is smaller than the cross-sectional area of ​​other continuous cross sections from the inner contour surface of the conductor outside the arrangement interval to the outer contour surface of the conductor.

[0008] In a second aspect of the present invention, a current sensor is provided, comprising: a conductor having a first terminal portion disposed on one side of a first axial direction for inputting current, a second terminal portion separated from the first terminal portion along a second axial direction intersecting the first axial direction for outputting current, a bend portion disposed on the other side of the first axial direction relative to the first terminal portion, a first main body portion connecting one end of the bend portion to the first terminal portion, and a second main body portion separated from the first main body portion along the second axial direction and connecting the other end of the bend portion to the second terminal portion; a magnetic sensor disposed on or near the conductor; and a package containing the bend portion, the first main body portion, the second main body portion, and the magnetic sensor of the conductor, such that the first terminal portion... The second terminal portion is exposed. At least one of the first body portion and the second body portion includes an arrangement interval, which is provided with at least one hole. Viewed from a third direction that intersects the first axis and the second axis respectively, the cross-section in the arrangement interval is smaller than the cross-section in the portion of the conductor outside the arrangement interval, with respect to the cross-section in the portion of the conductor outside the arrangement interval, which has a size smaller than the sum of the sizes of the multiple cross-sections in the arrangement interval.

[0009] Furthermore, the above summary of the invention does not list all the features of the invention. Additionally, sub-combinations of these feature groups can also constitute inventions. Attached Figure Description

[0010] Figure 1 The internal structure of the current sensor of this embodiment is shown in the top view.

[0011] Figure 2A This shows a rough outline of the sensor section.

[0012] Figure 2B This represents the definition of rectangularity.

[0013] Figure 3A The definition of the shape and size (width of the conductor and width of the internal region) of the conductor used for simulation.

[0014] Figure 3B The analysis results represent the density distribution of surge current (1MHz) flowing in the conductor.

[0015] Figure 3CThis represents the analytical results of the heat generated (average Joule heat) relative to the width of the conductor due to the surge current flowing in the conductor.

[0016] Figure 4A This refers to the definition of the shape and dimensions of the conductor used for simulation (the width of the conductor, the width of the internal region, and the location of the opening).

[0017] Figure 4B This represents the analytical results of the heat generated (mean Joule heat) relative to the location of the void in the conductor due to the current flowing in the conductor.

[0018] Figure 5A This refers to the surge current that flows concentrated inside the guide body due to the proximity effect.

[0019] Figure 5B This represents the DC current flowing throughout the conductor.

[0020] Figure 6A This indicates that the conductor's fuse has tripped (first stage).

[0021] Figure 6B This indicates that the conductor's fuse has tripped (second stage).

[0022] Figure 7A The definition of the shape and size of the conductor used for simulation (the width of the conductor, the width of the internal region, the location of the hole, and the width of the slit).

[0023] Figure 7B This represents the analytical results of the heat generated (average Joule heat) caused by the current flowing in the conductor relative to the width of the slit in the conductor.

[0024] Figure 8 The top view shows the internal structure of a current sensor with fault detection capabilities.

[0025] Figure 9 The top view shows the configuration of the conductor, insulation layer, and magnetic sensor.

[0026] Figure 10A The top view shows the structure of the mounting base on which the current sensor is installed.

[0027] Figure 10B The top view shows the current sensor and the configuration of its occupied area.

[0028] Figure 11A The structure of the current sensor in the first modified example is shown in the top view.

[0029] Figure 11B The structure of the current sensor in the second modified example is shown in the top view.

[0030] Figure 11C The structure of the current sensor in the third variation is shown in the top view.

[0031] Figure 11D The structure of the current sensor in the fourth variation is shown in the top view.

[0032] Figure 11E The structure of the current sensor in the fifth variation is shown in the top view.

[0033] Figure 11F The structure of the current sensor in the sixth variant is shown in the top view.

[0034] [Explanation of reference numerals in the attached figures]

[0035] 1, 1A, 1B, 1C, 1D, 1E, 1F… Current sensor, 2… Primary side circuit, 3… Secondary side circuit, 10… Package, 20… Sensor section, 21, 22, 23, 24… Magnetoelectric conversion element, 25, 26… Terminal, 30… Magnetic sensor, 31… Substrate, 32… Thermometer, 33… Electronic circuit, 39… Insulating layer, 40… Conductor, 41a… First terminal section, 41b… Second terminal section, 42a (42a1, 42a2)… First main body section (first main body portion, first connecting portion (arm)), 42b (42b… 1, 42b2)...Second main body (second main body portion, second connecting portion (arm)), 43...turning portion, 44a, 44b...arrangement interval, 44a0, 44b0...contour surface (inner surface), 44a1~44a3, 44b1~44b3...holes, 44a5, 44b5...contour surface (outer surface), 50, 51, 52...signal terminals, 70, 71, 72...occupying area, 100...mounting substrate, 140...conductor, 142a, 142b...arm, 143...turning portion, P2, S1~S4, S43...section Detailed Implementation

[0036] The present invention will now be described through embodiments thereof, but these embodiments do not limit the invention as defined in the claims. Furthermore, the combinations of features described in the embodiments are not necessarily all necessary for the solutions provided by the invention.

[0037] exist Figure 1In the top view, the internal structure of the current sensor 1 of this embodiment is shown through the package 10. Here, the vertical direction is defined as the longitudinal direction, the horizontal direction as the transverse direction, and the direction intersecting these two directions as the height direction. The current sensor 1 is a sensor that measures the amount of current by detecting the magnetic field generated around the conductor 40 due to the current being measured flowing through it. It includes the package 10, the magnetic sensor 30, the conductor 40, and a plurality of signal terminals 50. In this specification, the conductor 40 is referred to as "contour surface" or "contour line". The contour surface refers to the outer surface or a part thereof that forms the contour (shape) of the conductor 40, and the contour line refers to the outline line that forms the contour (shape) of the conductor 40 in the top view (viewed from the height direction).

[0038] The encapsulation body 10 is a component that protects the various parts of the current sensor 1. It seals the bend 43 of the conductor 40, the first main body 42a, the second main body 42b, the magnetic sensor 30, and the base ends of the plurality of signal terminals 50, so that the first terminal 41a and the second terminal 41b are exposed from one longitudinal side (bottom of the figure), and the front ends of the plurality of signal terminals 50 are exposed from the other longitudinal side (top of the figure). The encapsulation body 10 is molded, for example, using a sealing resin with excellent insulating properties such as epoxy resin, thereby forming a flat cuboid.

[0039] The magnetic sensor 30 is a sensor that detects the magnetic field generated by the flow of a measured current through the conductor 40, and includes a substrate 31 and two sensor portions 20. The magnetic sensor 30 is disposed on the conductor 40. Furthermore, the magnetic sensor 30 includes two sensor portions 20, but it may also include only one.

[0040] The substrate 31 is separated from the insulating layer 39 (see reference). Figure 9 A plate-shaped component disposed on conductor 40 supports two sensor sections 20. Multiple wirings (not shown) connecting to the sensor sections 20 are laid on the upper surface of substrate 31. Substrate 31 is formed, for example, using any one of silicon (Si), gallium arsenide (GaAs), gallium nitride (GaN), aluminum nitride (AlN), sapphire (Si2O3), silicon carbide (SiC), or diamond.

[0041] Figure 2A This diagram shows a schematic structure of the sensor unit 20. The sensor unit 20 is a circuit that changes the output voltage based on magnetic flux density, and includes multiple (four in this example) magnetoelectric conversion elements 21, 22, 23, and 24 assembled in the form of a Wheatstone bridge (full bridge) circuit. Alternatively, two magnetoelectric conversion elements 21 and 23 or 22 and 24 can be assembled in the form of a half bridge circuit.

[0042] Multiple magnetoelectric conversion elements 21, 22, 23, and 24 are elements whose electrical characteristics (i.e., magnetoresistive properties) vary according to the strength of the applied magnetic field. The magnetoelectric conversion elements 21, 22, 23, and 24 are arranged such that their respective magnetization directions are oriented horizontally to detect the horizontal magnetic field generated on conductor 40 due to the flow of the measured current in the direction of the arrow within conductor 40. Specifically, the magnetization directions of magnetoelectric conversion elements 21 and 24 are the same, while the magnetization directions of magnetoelectric conversion elements 22 and 23 are the same but opposite to those of magnetoelectric conversion elements 21 and 24. Any of the following elements can be used as the multiple magnetoelectric conversion elements 21, 22, 23, and 24: tunnel magnetoresistive element (TMR), giant magnetoresistive element (GMR), and anisotropic magnetoresistive element (AMR). These elements are, for example, alloys containing at least one of Co, Fe, B, Ni, and Si; more specifically, cobalt-iron (CoFe), cobalt-iron-boron (CoFeB), and nickel-iron (NiFe) can be used. By using these components, the magnetic field generated by the current flowing through conductor 40 can be precisely measured.

[0043] The output voltage V is the differential voltage between terminal 25 of magnetoelectric conversion elements 21 and 23 and terminal 26 of magnetoelectric conversion elements 22 and 24, using the respective magnetoresistances R1, R2, R3, and R4 of magnetoelectric conversion elements 21, 22, 23, and 24, where V ∝ R1×R4 - R2×R3. Therefore, the magnetic sensor 30 can measure the strength of the magnetic field generated by the current flowing through the conductor 40.

[0044] Two sensor units 20 are respectively disposed on a first main body portion 42a (a first main body portion 42a1 connected to a first terminal portion 41a and a first connecting portion 42a2 connected to one end of a bend portion 43) and a second main body portion 42b (a second main body portion 42b1 connected to a second terminal portion 41b and a second connecting portion 42b2 connected to the other end of a bend portion 43). These connecting portions, as described later, have a rectangular shape when viewed from above. By disposing of the sensor units 20 on them, the transverse magnetic field generated by energizing the conductor 40 can be concentrated on the sensor units 20, enabling high-sensitivity detection of the current. Alternatively, the sensor unit 20 may be disposed only on one of the first connecting portion 42a2 and the second connecting portion 42b2. The first connecting portion 42a2 and the second connecting portion 42b2 may also be rectangular or approximately rectangular when viewed from above.

[0045] Figure 2BThe definition of rectangularity, representing the degree of rectangularity of the first connecting portion 42a2 and the second connecting portion 42b2, is as follows: Assume the outlines of the first connecting portion 42a2 and the second connecting portion 42b2 are represented by solid lines. Rectangularity Sin / Sout is defined as the area of ​​the largest rectangular region (Sin) located inside the outlines of the first connecting portion 42a2 and the second connecting portion 42b2, formed by two parallel sides extending laterally and two parallel sides extending longitudinally, and formed by two parallel sides extending laterally and two parallel sides extending longitudinally, and formed by two parallel sides extending laterally and two parallel sides extending longitudinally, located outside the outlines of the first connecting portion 42a2 and the second connecting portion 42b2. A true rectangle has a rectangularity of 1, and a roughly rectangular shape is defined as having a rectangularity of 0.8 or greater and less than 1. The first connecting portion 42a2 and the second connecting portion 42b2 are not limited to a rectangular shape in top view, but can also be set to a generally rectangular shape, thereby making it easier to form the lead frame when manufacturing the conductor 40, and making it easier for the conductor 40 to fit tightly against the package 10, thus preventing them from peeling off.

[0046] Alternatively, the sensor unit 20 can be constructed using a Hall element, or it can be disposed inside the bend 43 or near the conductor 40 to detect the vertical magnetic field generated by the current flowing through the conductor 40.

[0047] The conductor (also called a busbar) 40 is a conductive component disposed on one longitudinal side (bottom of the drawing) within the package 10 to form a current path for the current to be measured to flow, and has a first terminal portion 41a, a second terminal portion 41b, a first body portion 42a, a second body portion 42b, and a bend portion 43. Furthermore, the thickness of the conductor 40 is approximately constant.

[0048] The first terminal portion 41a is a terminal for inputting the current to be measured (also simply referred to as current). The first terminal portion 41a is disposed on one side in the longitudinal direction (the lower side of the attached drawing) and protrudes from the side of the package 10 on the lower side of the attached drawing.

[0049] The second terminal portion 41b is a terminal for outputting current. The second terminal portion 41b is arranged separately from the first terminal portion 41a in the lateral direction (right side of the figure) and protrudes from the side of the package 10 below the figure. Alternatively, the second terminal portion 41b can be used as a terminal for input current, and the first terminal portion 41a can be used as a terminal for output current.

[0050] The first main body portion 42a is the portion that connects one end of the bend portion 43 to the first terminal portion 41a. The first main body portion 42a includes a first main body portion 42a1 and a first connecting portion 42a2 located on the side of the first terminal portion 41a and the side of the bend portion 43, respectively. The first main body portion 42a1 has a tapered portion 42a3 whose cross-sectional area increases from the connecting portion (first connecting portion 42a2) with the bend portion 43 toward the side of the first terminal portion 41a, and at least one hole 44a is included below the tapered portion (first terminal portion side) where the cross-sectional area is the largest. i (i = 1 to I, I is 3 in this example) The arrangement interval 44a is arranged laterally. The first connecting portion (also called the first arm portion) 42a2 has a top-view rectangular shape connected to the turning portion 43, and the sensor portion 20 of the magnetic sensor 30 is disposed thereon. In addition, the cross-sectional area of ​​the conical portion 42a3 is the cross-sectional area of ​​the section of the conical portion 42a3 that intersects perpendicularly with the contour surface 44a0 of the inner side of the conductor 40.

[0051] The second main body portion 42b is the portion that connects the other end of the bend portion 43 to the second terminal portion 41b, and is arranged separately from the first main body portion 42a in the lateral direction (right side of the figure). The second main body portion 42b includes a second main body portion 42b1 and a second connecting portion 42b2 located on the side of the second terminal portion 41b and the side of the bend portion 43, respectively. The second main body portion 42b1 has a tapered portion 42b3 whose cross-sectional area increases from the connecting portion (second connecting portion 42b2) with the bend portion 43 toward the side of the second terminal portion 41b, and includes at least one hole 44b below the tapered portion (second terminal portion side) in the figure where the cross-sectional area becomes the largest. i (i = 1 to I, I is 3 in this example) The arrangement interval 44b is arranged laterally. The second connecting part (also called the second arm) 42b2 has a top-view rectangular shape connected to the turning part 43, and the sensor part 20 of the magnetic sensor 30 is disposed thereon. In addition, the cross-sectional area of ​​the conical part 42b3 is the cross-sectional area of ​​the section of the conical part 42b3 that intersects perpendicularly with the contour surface 44b0 of the inner side of the conductor 40.

[0052] The turning portion 43 is the part that connects to the two main body portions 42a and 42b at both ends. It is located on the other side of the longitudinal direction (upper side of the drawing) and has a shape that extends from one side of the longitudinal direction (lower side of the drawing) to the other side (upper side of the drawing) and bends laterally back to one side. For example, it has a generally arc shape. It should be noted that the turning portion 43 can also be bent into the shape of the Japanese kana "コ", an inverted V shape, or the Greek letter "Π". The turning portion 43 receives the measured current from the first main body portion 42a and outputs the measured current to the second main body portion 42b.

[0053] By including a first terminal portion 41a, a second terminal portion 41b, a first body portion 42a, a second body portion 42b, and a bend portion 43 as described above, the conductor 40 has a generally U-shaped form, extending from the first terminal portion 41a located on the left side of the lower side of the package 10 through the interior of the package 10 back to the lower side, and reaching the second terminal portion 41b located on the right side of the lower side. The conductor 40 can be formed, for example, using a conductive metal such as copper.

[0054] Multiple signal terminals 50 are components used to transmit the output signal of the magnetic sensor 30 to the secondary side circuit 3. They are separated from the conductor 40 towards the upper side of the drawing, arranged laterally, with their front ends exposed from the upper side of the drawing and sealed within the package 10. The multiple signal terminals 50 can be formed using a conductive metal such as copper. The multiple signal terminals 50 are wire-bonded to the magnetic sensor 30. Furthermore, the front ends exposed from the package 10 are connected to the secondary side circuit 3 on the mounting substrate 100 when the current sensor 1 is mounted on the mounting substrate 100.

[0055] Conductor 40 has a very small resistance, thus generating Joule heating when current flows through it. Here, when a momentary overcurrent (called a surge current) generated during a fault flows through conductor 40, the surge current contains, for example, high-frequency components above 1 MHz, and therefore, due to the skin effect, the current density concentrates on the surface of conductor 40. Furthermore, in cases where current flows in opposite directions between adjacent conductors, as in the first main body portion 42a and the second main body portion 42b, due to the proximity effect, the current density concentrates on the side closest to each other.

[0056] Figure 3A This section defines the shape and dimensions of the conductor 140 used for simulation (the width w of the conductor 140 and the width w_space of the internal region). The conductor 140 has two arms 142a and 142b and a bend 143. The two arms 142a and 142b are rectangular portions of the sensor section 20 on which the magnetic sensor 30 is disposed, simulating the first main body 42a and the second main body 42b of the conductor 40. The bend 143 is the portion connecting the two arms 142a and 142b, simulating the bend 43 of the conductor 40. The width of the conductor 140, i.e., the arm 142b, is defined as w, and half the distance between the opposing inner surfaces of the arms 142a and 142b (equal to the inner radius of curvature of the bend 143) is defined as w_space. The sensor section 20 is disposed at the longitudinal center of the arm 142b, and the current density field of this central portion is obtained by harmonic analysis using the finite element method.

[0057] Figure 3BThis analysis presents the results of the surge current density distribution flowing in conductor 140. Here, a harmonic current with a frequency of 1 MHz is used to simulate the surge current, and the material of conductor 140 is set to copper with a thickness of 0.552 mm, and the width w of arm 142b is 1.5 mm. It can be seen that at a distance w_space = 10 mm, the current flowing through arm 142b is concentrated on the inner and outer surfaces of arm 142b due to the skin effect, and hardly flows through the center in the width direction. Here, there is no significant difference in current density between the inner and outer surfaces of arm 142b. Similarly, at a distance w_space = 5 mm, the current flowing through arm 142b is concentrated on the inner and outer surfaces of arm 142b due to the skin effect, and hardly flows through the center in the width direction. There is no significant difference in current density between the inner and outer surfaces of arm 142b. However, when the distance w_space = 2.5 mm or less, the current flowing through arm 142b is concentrated on the inner surface of arm 142b due to the proximity effect, and the current density on the inner surface is significantly larger than that on the outer surface of arm 142b. When the distance w_space = 0.1 mm, the current density on the inner surface is approximately 9 times that on the outer surface of arm 142b. By bringing the two arms 142a and 142b closer together, especially when the distance w_space = 2.5 mm or less, the surge current can be concentrated on the inner surface side of conductor 140 by utilizing the proximity effect.

[0058] Figure 3C This represents the analytical result of the heat generated (average Joule heat of the cross-section) relative to the width w of conductor 140 due to the surge current flowing in conductor 140. The heat generation is expressed as ∫j, where j is the current density in conductor 140 and S is the cross-sectional area of ​​conductor 140. 2 The surge current frequency is calculated using dS / S. Here, the surge current frequency is set to 1MHz, the material of conductor 140 is copper, the plate thickness is 0.552mm, and the distance w_space = 0.25mm. The smaller the width w of conductor 140, the greater the heat generation of conductor 140. Therefore, by reducing the width w of conductor 140, the heat generation within conductor 140 can be locally increased.

[0059] Figure 4AThis section defines the shape and dimensions of the conductor 140 used for simulation (width w of conductor 140, width w_space of the inner region, and position w_inner of the aperture). Conductor 140 has two arms 142a and 142b and a bend 143. The two arms 142a and 142b are rectangular portions of the sensor section 20 where the magnetic sensor 30 is mounted, simulating the first main body 42a and the second main body 42b of conductor 40. The bend 143 connects the two arms 142a and 142b, simulating the bend 43 of conductor 40. The width of conductor 140, i.e., arm 142b, is defined as w, and half the distance between the opposing inner surfaces of arms 142a and 142b (equal to the inner radius of curvature of bend 143) is defined as w_space. A circular hole 144b1 is disposed in the longitudinal center of the arm 142b. The distance from the inner surface of the arm 142b to the hole 144b1 is set as w_inner. The heat generation of the central part is analyzed by the finite element method.

[0060] Figure 4B This represents the analysis result of the heat generated (average Joule heat of the cross-section) caused by the surge current flowing through conductor 140 relative to the position w_inner of the aperture 144b1 in conductor 140. The heat generated is expressed as ∫j per unit cross-sectional area using the current density j in conductor 140 and the cross-sectional area S of conductor 140. 2 The surge current frequency is calculated using dS / S. Here, the surge current frequency is set to 1MHz, the conductor 140 is made of copper with a thickness of 0.552mm, the arm 42b has a width w = 4.4mm, the distance w_space = 0.25mm, and the aperture 144b1 is a circle with a diameter of 0.6mm. The smaller the position w_inner of the aperture 144b1, the greater the heat generation of the conductor 140. Therefore, by positioning the aperture 144b1 close to the inner surface of the arm 142b relative to a certain conductor 140 width w, the current distribution within the conductor 140 can be further localized to the inner surface side, thereby further increasing the heat generation within the conductor 140.

[0061] Therefore, in the current sensor 1 of this embodiment, in the top view, in a continuous cross section of the conductor 40 that intersects perpendicularly with the inner contour surfaces (i.e., inner surfaces) 44a0 and 44b0 of the conductor 40, the intervals 44a and 44b are arranged with the inner contour surfaces 44a0 and 44b0 of the conductor 40 and at least one hole 44a. i 44b i(i = 1 to I, where I is 1 or more) The cross-sectional area S1 of the continuous cross-section between the inner surfaces of the apertures 44a1 and 44b1 on the innermost contour surfaces 44a0 and 44b0 of the conductor 40 is smaller than the cross-sectional area S43 of the continuous cross-section between the inner contour surfaces 44a0 and 44b0 of the conductor 40 and the outer contour surfaces (i.e., outer surfaces) 44a5 and 44b5 of the conductor 40, such as the cross-sectional area S43 of the bend 43. Therefore, when a surge current (a large instantaneous current) flows through the conductor 40, due to the proximity effect, the current is concentrated in the continuous cross-section S1 within the arrangement intervals 44a and 44b, causing it to heat up and melt, thus performing the function of a fuse. Since the cross section S1 is located at a position separate from the first terminal portion 41a, the second terminal portion 41b and the bend portion 43, damage to the primary circuit disposed on one side of the longitudinal direction of the first terminal portion 41a and the second terminal portion 41b (lower side of the figure) and the secondary circuit disposed on the other side of the longitudinal direction of the bend portion 43 (upper side of the figure) can be prevented.

[0062] Figure 5A This refers to the surge current that concentrates and flows inside the conductor 40 due to the proximity effect. Based on the above analysis, the distance between the outline surfaces of the first main body portion 42a and the second main body portion 42b, which are opposite each other, is set to 5 mm or less. As a result, the surge current enters the conductor 40 from the first terminal portion 41a, concentrates near the inner surface of the first main body portion 42a (the side shown on the right in the drawing), flows upwards in the drawing, changes direction near the inner surface of the turning portion 43, concentrates near the inner surface of the second main body portion 42a (the side shown on the left in the drawing), flows downwards in the drawing, and is output from the second terminal portion 41b. In this way, through the proximity effect, the flow of the surge current can be locally contained in a narrow region near the inner surfaces of the first main body portion 42a and the second main body portion 42b, increasing heat generation only in this locally contained region.

[0063] Furthermore, by bringing the holes 44a1 and 44b1 within the arrangement intervals 44a and 44b close to the inner surfaces of the first main body portion 42a and the second main body portion 42b (for example, setting w_inner to 0.5 mm or less), the surge current flow can be further locally contained in the narrow regions near the inner surfaces of the first main body portion 42a and the second main body portion 42b within the arrangement intervals 44a and 44b, further increasing heat generation in these locally contained regions. Thus, the arrangement intervals 44a of the first main body portion 42a and / or 44b of the second main body portion 42b function as fuses, preventing damage from spreading to the primary and secondary circuits.

[0064] Therefore, in the current sensor 1 of this embodiment, in the top view, as a continuous cross section outside the arrangement intervals 44a, 44b that intersects perpendicularly with the inner contour surfaces 44a0, 44b0 of the conductor 40 and extends from the inner contour surfaces 44a0, 44b0 to the outer contour surfaces 44a5, 44b5 of the conductor 40, there exists a continuous cross section that has a plane that intersects perpendicularly with the inner contour surfaces 44a0, 44b0 of the conductor 40 between the inner contour surfaces 44a0, 44b0 and the outer contour surfaces 44a5, 44b5 of the conductor 40, and is located between the inner contour surfaces 44a0, 44b0 and the outer contour surfaces 44a5, 44b5 of the conductor 40, and is formed by the inner contour surfaces 44a0, 44b0 and at least one hole 44a. i 44b i The total cross-sectional area S1+S2+S3+S4 of the multiple sections divided by the inner surface and the outer contour surfaces 44a5 and 44b5 (i = 1 to I, I is 3 in this example) is the smaller cross-sectional area (S43 < S1+S2+S3+S4). This continuous cross-section is, for example, the cross-sectional area S43 of the bend 43.

[0065] Figure 5B This represents the DC current flowing throughout the conductor 40. Regarding the DC current, the proximity effect contributes almost nothing; therefore, the DC current in the measured current input from the first terminal portion 41a spreads throughout the first body portion 42a and through the aperture 44a. i The cross sections S1 to S4 between (i = 1 to 3) flow within the conductor 40, enter the second main body 42b via the bend 43, expand throughout the second main body 42b, and flow through the hole 44b. i Cross sections S1 to S4 (i = 1 to 3) flow within conductor 40 and exit from the second terminal 41b. The total cross-sectional area S1 + S2 + S3 + S4 of the multiple cross sections within the arrangement intervals 44a and 44b is larger than the cross-sectional area S43 of the bend 43, thereby allowing the measurement of the high-frequency component of the current (refer to...). Figure 5A ) and DC component (refer to Figure 5B Frequency separation enables the provision of a current sensor with low resistance relative to DC current.

[0066] Furthermore, in the top view, the cross-sectional area S43 of the continuous cross-section, such as the bend 43, that intersects perpendicularly with the inner contour surfaces 44a0 and 44b0 of the conductor 40 outside the arrangement intervals 44a and 44b and extends from the inner contour surfaces 44a0 and 44b0 to the outer contour surfaces 44a5 and 44b5 of the conductor 40 has a larger cross-sectional area than the inner contour surfaces 44a0 and 44b0 of the conductor 40 and the outer contour surfaces 44a5 and 44b5 of the conductor 40, and is formed by the inner contour surfaces 44a0 and 44b0 and at least one hole 44a.i 44b i The cross-sectional areas of the multiple sections divided by the inner surface and the outer contour surfaces 44a5 and 44b5 of (i=1~3) are each the largest cross-sectional area of ​​S1, S2, S3 or S4.

[0067] Figure 6A and Figure 6B This indicates that the fuse in conductor 40 has tripped. The hole 44a within the intervals 44a and 44b is also shown. i 44b i The cross sections S1 to S4 between (i = 1 to 3) are smaller than the cross sections outside the arrangement intervals 44a and 44b. Therefore, when an excessive surge current flows through the conductor 40, the current is concentrated in the cross section S1 within the arrangement interval 44a due to the proximity effect (refer to...). Figure 5A ), fever, such as Figure 6A As shown, the conductor 40 melts at its cross-section S1 within the arrangement interval 44a. This forms a slit extending from the inner profile surface 44a0 of the conductor 40 within the arrangement interval 44a to the aperture 44a1. The surge current concentrates near the two inner surfaces of the slit due to the proximity effect, thus generating heat, as... Figure 6B As shown, conductor 40 melts at the next cross section S2 within the arrangement interval 44a. This forms a slit extending from the inner profile surface 44a0 of conductor 40 within the arrangement interval 44a to the aperture 44a2. Surge current concentrates near the two inner surfaces of the slit due to proximity effect, thereby generating heat and potentially affecting the aperture 44a2 arranged within the arrangement interval 44a. i The cross-sections between (i = 1 to 3) melt sequentially along the direction of the arrow, and finally, in the arrangement interval 44a, the first main body 42a melts in a manner that divides it into two longitudinally. Thus, by having voids 44a arranged laterally within the arrangement interval... i (i = 1 to 3) can guide the melting of the conductor 40 in the transverse direction, and prevent the melting from proceeding toward the primary circuit on one side (lower side of the figure) of the first terminal portion 41a and the second terminal portion 41b in the longitudinal direction or the secondary circuit on the other side (upper side of the figure) of the turning portion 43 in the longitudinal direction.

[0068] Figure 7AThis section defines the shape and dimensions of the conductor 140 used for simulation (width w of conductor 140, width w_space of the inner region, position w_inner of the aperture, and width w_slit of the slit). Conductor 140 has two arms 142a and 142b and a bend 143. The two arms 142a and 142b are rectangular portions of the sensor section 20 on which the magnetic sensor 30 is disposed, simulating the first main body 42a and the second main body 42b of conductor 40. The bend 143 is the portion connecting the two arms 142a and 142b, simulating the bend 43 of conductor 40. The width of conductor 140, i.e., arm 142b, is defined as w, and half the distance between the opposing inner surfaces of arms 142a and 142b (equal to the inner radius of curvature of bend 143) is defined as w_space. Two circular holes 144b2 and 144b3 are arranged in the center of the longitudinal direction of the arm 142b. The width of the slit extending from the inner surface of the arm 142b to the hole 144b2 is denoted as w_slit. The heat generation of this central part is analyzed using the finite element method. Three circular holes 144a1 to 144a3 are arranged in the center of the longitudinal direction of the arm 142a. The distance between holes 44b2 and 44b3 and between holes 44a1 and 44a3 is denoted as w0.

[0069] Figure 7B This represents the analysis results of the heat generated (average Joule heat of the cross-section) caused by the surge current flowing in the conductor 140 relative to the width w_slit of the slit in the conductor 140. The heat generation is expressed as ∫j, where j is the current density j in the conductor 140 and S is the cross-sectional area S of the conductor 140. 2 The surge current frequency is calculated using dS / S. Here, the conductor 140 is made of copper with a thickness of 0.552 mm. The width w of the arm 142b is 4.4 mm, the distance w_space is 0.25 mm, and the holes 144b2 and 144b3 are circular with a diameter of 0.6 mm. The distance between the holes is w0 = 1.3 mm. The smaller the slit width w_slit, the greater the heat generated by the conductor 140.

[0070] Therefore, pore 44a i 44b i (i = 1 to I, where I is 3 in this example) In the top view, it has a generally circular, generally elliptical, or generally rectangular shape, and the longitudinal width is set to 5 mm or less, preferably 2 mm, more preferably 1 mm, and even more preferably 0.6 mm or less, 0.5 mm or less, 0.4 mm or less, 0.3 mm or less, 0.2 mm or less, or 0.1 mm or less. Furthermore, to ensure the processability of the conductor 40, the aperture 44a... i 44b iThe longitudinal width of the conductor 40 (i = 1 to I, where I is 3 in this example) is preferably greater than or equal to the thickness of the conductor 40. Here, the thickness of the conductor 40 is, for example, 1 mm, 0.6 mm, 0.5 mm, 0.4 mm, 0.3 mm, 0.2 mm, or 0.1 mm.

[0071] Here, the hole 44a i 44b i (i = 1 to I, where I is 3 in this example) It is not necessary to arrange them in a straight line laterally; at least a portion of each other can be opposite each other laterally, i.e., their regions partially overlap when viewed laterally. Alternatively, if the melting of conductor 40 occurs as a whole laterally, they can be arranged in an interlaced pattern, for example. Thus, in the slit portion formed by the melting of conductor 40 in the cross-section within the arrangement intervals 44a and 44b, the surge current is further concentrated near the inner surface of the slit due to the proximity effect, enabling the arrangement of holes 44a along the arrangement intervals 44a and 44b. i 44b i The transverse conductor 40 (i = 1 to I, I is 3 in this example) is melted.

[0072] Additionally, regarding the cavitation hole 44a i 44b i The number I of (i = 1 to I) and the distance between them can be arbitrarily determined as long as the melting of conductor 40 is carried out as a whole in the transverse direction. For example, it is preferable that the distance from the inner contour surface 44a0, 44b0 of conductor 40 to the hole 44a1, the distance between holes 44a1, 44a2, the distance between holes 44a2, 44a3, and the distance between hole 44a3 and the outer contour surface 44a5, 44b5 of conductor 40 increase sequentially within the arrangement intervals 44a, 44b (i.e., the cross-sectional area S1≤S2≤S3≤S4). Thus, the melting of conductor 40 can be guided from the inner contour surface 44a0, 44b0 of conductor 40 to the outer contour surface 44a5, 44b5 within the arrangement intervals 44a, 44b.

[0073] Figure 8The top view shows the internal structure of the current sensor 1 with fault detection function. The magnetic sensor 30 also includes a thermometer 32, separately disposed on a substrate 31 from the two sensor units 20, and an electronic circuit 33 that receives the temperature measurement results of the two sensor units 20 and the thermometer 32. In this example, the thermometer 32 is disposed in the center of the two sensor units 20. Here, the substrate 31 is disposed at least a portion of the bend 43 of the conductor 40, the first connecting portion 42a2, and the second connecting portion 42b2. The distances from the arrangement intervals 44a and 44b to the two sensor units 20 and the thermometer 32 are different. Here, the two sensor units 20 can also be used as thermometers, for example, by utilizing the temperature characteristics of the resistance value of the magnetoelectric conversion element.

[0074] Electronic circuit 33 independently monitors the temperature using two sensor units 20 and a thermometer 32. If the temperature difference between the two sensor units 20 and the thermometer 32 exceeds a threshold, a signal is sent to the secondary circuit 3 via, for example, multiple signal terminals 50. Normally, the temperature within the current sensor 1 is determined by the external temperature and the heat generated by the flow of the measured current (DC component or low-frequency component) within the conductor. This results in a small temperature gradient within the package 10. However, when a surge current flows through the conductor 40, the fuse function is activated. For example, the cross-section (e.g., cross-section S1) within the arrangement interval 44a melts, forming a slit extending from the inner surface 44a0 of the conductor 40 to the via 44a1. Furthermore, within the arrangement interval 44a, the surge current concentrates at the cross-section P2 between the vias 44a1 and 44a2, generating heat, thereby rapidly increasing the temperature gradient within the package 10. Here, the distances from the two sensor units 20 and the thermometer 32 to the arrangement interval 44a, and particularly to the cross section P2, are different, resulting in a difference in their respective measured temperatures based on the temperature gradient. When this temperature difference exceeds a predetermined threshold temperature, it can be determined that the fuse function has been activated. The melting of the conductor 40 occurs, for example, on the order of 10 milliseconds. Therefore, by using the electronic circuit 33 to detect the difference in measured temperatures between the two sensor units 20 and the thermometer 32, the activation of the fuse function can be detected, and sensor malfunctions can be detected.

[0075] Furthermore, if multiple sensor units 20 are provided on the substrate 31, the thermometer 32 may not be required. However, the two sensor units 20 are arranged on the substrate 31 at different distances from the arrangement intervals 44a and 44b. The electronic circuit 33 can independently monitor the temperature using the two sensor units 20 and send a signal when the temperature difference between at least two sensor units 20 exceeds a threshold.

[0076] Figure 9The top view shows the arrangement of conductor 40, insulating layer 39, and magnetic sensor 30. Insulating layer 39 is a component that insulates and protects magnetic sensor 30 from conductor 40, and is disposed between conductor 40 and magnetic sensor 30. Insulating layer 39 can comprise any of organic layers or ceramics. For example, insulating layer 39 can be formed using polyimide, glass, paper, fluoropolymer (Teflon (registered trademark)), or silicon. Magnetic sensor 30 is disposed on conductor 40 with the insulating layer 39 in between. In the top view, the outline of insulating layer 39 is located outside the outline of substrate 31. To ensure insulation, it is preferable that the outline of insulating layer 39 is located at least 0.4 mm away from the outline of substrate 31. Thus, insulating layer 39 does not cover the entire upper surface of conductor 40, effectively insulating magnetic sensor 30 from conductor 40, and insulating layer 39 does not hinder heat dissipation of conductor 40 without reducing the heat dissipation performance of conductor 40.

[0077] Furthermore, in the top view, the outline of the insulating layer 39, viewed from the arrangement intervals 44a and 44b, is located on the side of the bend 43, meaning that the insulating layer 39 is positioned closer to the bend 43 than the arrangement intervals 44a and 44b. The ignition point of the polyimide or similar material forming the insulating layer 39 is approximately 600°C, which is lower than the melting temperature (approximately 1000°C) of metals such as copper forming the conductor 40. Therefore, by separating the insulating layer 39 from the arrangement intervals 44a and 44b that activate the fuse function, the current sensor 1 can be designed safely.

[0078] Figure 10A The top view shows the structure of the mounting base 100 on which the current sensor 1 is mounted. The mounting base 100 is a base plate that includes the current sensor 1, a primary side circuit 2, and a secondary side circuit 3. In the mounting base 100, the current to be measured is input from the primary side circuit 2 to the current sensor 1, and the output signal of the current sensor 1 is output to the secondary side circuit 3 via a plurality of signal terminals 50. Furthermore, the current sensor 1 is configured as described above.

[0079] The primary circuit 2 is a circuit that inputs the current to be measured to the current sensor 1, and is connected to the first terminal 41a and the second terminal 41b of the conductor 40 of the current sensor 1.

[0080] The secondary circuit 3 is a circuit that operates based on the output signal of the current sensor 1, and has multiple occupancy areas 70 that are respectively connected to multiple circuits (not shown). The multiple occupancy areas 70 are respectively connected to multiple signal terminals 50 (see reference). Figure 10B The output signal of the current sensor 1 is transmitted to each of the multiple circuits via multiple signal terminals 50. The multiple occupancy areas 70 include an occupancy area 71 connected to one of the multiple signal terminals 50 signal terminals 51 and an occupancy area 72 connected to the seven signal terminals 52.

[0081] exist Figure 10B The diagram shows the current sensor 1 and the arrangement of the plurality of occupied areas 70 in a top view. As described above, one signal terminal 51 and seven signal terminals 52 of the plurality of signal terminals 50 are connected to one occupied area 71 and seven occupied areas 72 of the plurality of occupied areas 70, respectively. Here, one signal terminal 51 of the plurality of signal terminals 50 is closer to the bend 43 than the other signal terminals 52. The distance L51 from the signal terminal 51 to the bend 43 is less than the distance L52 from the other signal terminals 52 to the bend 43. As a result, the heat generated at the bend 43 can be dissipated to the outside of the package 10 via the signal terminal 51, which is closest to the bend 43 among the plurality of signal terminals 50. Furthermore, in order to ensure the insulation between the conductor 40 and the secondary circuit 3, the distance L51 from the signal terminal 51 to the bend 43 is preferably 0.4 mm or more.

[0082] Furthermore, signal terminal 51 can be a GND terminal. Since the signal terminal 51 closest to the bend 43 is a GND terminal, in the event of an arc discharge at the bend 43, an induced discharge is generated from the nearby signal terminal 51 to the GND, which can suppress damage to multiple circuits on the secondary side circuit 3 connected to other signal terminals 52.

[0083] Furthermore, when the current sensor 1 is mounted on the mounting substrate 100, the signal terminal 51 is connected to a larger area 71 on the mounting substrate 100 than the area 72 on which other signal terminals 52 are connected. Therefore, the area of ​​the area 71 on the mounting substrate 100 to which the signal terminal 51 is connected is larger than the area of ​​the area 72 on which other signal terminals 52 are connected. This results in the signal terminal 51 having a larger heat dissipation area for heat transfer from the bend 43, enabling efficient heat dissipation and improving the heat dissipation performance of the bend 43, thus preventing malfunctions caused by heat accumulation. Additionally, the area 71 preferably has an area 1.5 to 40 times larger than the other areas 72. This improves heat dissipation in the bend 43, promoting the activation of the fuse function in the arrangement intervals 44a and 44b of the conductor 40.

[0084] As described above, the current sensor 1 according to this embodiment includes: a conductor 40 having a first terminal portion 41a for inputting current disposed on one side of a first axial direction, a second terminal portion 41b for outputting current separated from the first terminal portion 41a along a second axial direction intersecting the first axial direction, a bend portion 43 disposed on the other side of the first axial direction relative to the first terminal portion 41a, a first main body portion 42a connecting one end of the bend portion 43 to the first terminal portion 41a, and a second main body portion 42b separating from the first main body portion 42a along the second axial direction and connecting the other end of the bend portion 43 to the second terminal portion 41b; a magnetic sensor 30 disposed on or near the conductor 40; and a package 10 that houses the bend portion 43, the first main body portion 42a, and the second main body portion 41b of the conductor 40. 2b and magnetic sensor 30 are sealed, exposing the first terminal portion 41a and the second terminal portion 41b. At least one of the first main body portion 42a and the second main body portion 42b includes arrangement intervals 44a and 44b with at least one hole. When viewed from a third direction that intersects the first axis and the second axis respectively, in a continuous cross section of the conductor 40 that intersects the inner contour surface of the conductor 40 perpendicularly, the cross-sectional area S1 of the continuous cross section within the arrangement intervals 44a and 44b that is divided between the inner contour surface of the conductor 40 and the inner surface of the at least one hole located on the innermost contour surface side of the conductor is smaller than the cross-sectional area of ​​other continuous cross sections outside the arrangement intervals 44a and 44b that run from the inner contour surface of the conductor 40 to the outer contour surface of the conductor 40.

[0085] Therefore, in the top view, in the continuous cross-section of the conductor 40 that intersects perpendicularly with the contour surfaces 44a0 and 44b0 on the inner side of the conductor 40, at least one hole 44a is provided in at least one of the first main body portion 42a and the second main body portion 42b. i 44b i Within the arrangement intervals 44a and 44b of (i = 1 to 3), the contour surfaces 44a0 and 44b0 on the inner side of the conductor 40 and at least one hole 44a i 44b iThe cross-sectional area S1 of the continuous cross-section between the inner surfaces of the holes 44a1 and 44b1 on the inner side of the contour surfaces 44a0 and 44b0 closest to the conductor in (i = 1 to 3) is smaller than the cross-sectional area of ​​other continuous cross-sections outside the arrangement intervals 44a and 44b, from the inner contour surfaces 44a0 and 44b0 of the conductor 40 to the outer contour surfaces 44a5 and 44b5 of the conductor 40. As a result, when a surge current (a large instantaneous current) flows through the conductor 40, the current is concentrated in the continuous cross-section S1 within the arrangement intervals 44a and 44b, causing it to heat up and melt, thus functioning as a fuse. This allows for the separation of the primary circuit arranged on one side of the longitudinal direction of the first terminal portion 41a and the second terminal portion 41b (lower side of the attached figure) and the secondary circuit arranged on the other side of the longitudinal direction of the bend portion 43 (upper side of the attached figure), thereby providing a high-voltage withstand current sensor 1.

[0086] Furthermore, in the current sensor 1 of this embodiment, the thickness of the conductor 40 is approximately constant. Viewed from a third direction intersecting the first and second axes respectively, regarding the cross-section extending from the inner contour line of the conductor 40 to the point where it initially intersects the other contour lines of the conductor 40, the size (i.e., width) of the cross-section in the arrangement intervals 44a and 44b is smaller than the size of the cross-section in the portion of the conductor 40 outside the arrangement intervals 44a and 44b. Regarding the cross-section extending from the inner contour line of the conductor 40 to the outer contour line of the conductor 40, a cross-section having a size smaller than the sum of the sizes of the multiple cross-sections in the arrangement intervals 44a and 44b exists in the portion of the conductor 40 outside the arrangement intervals 44a and 44b. Furthermore, since the thickness of the conductor 40 is approximately constant, the size of the cross-section of the conductor 40 is equal to the size of the cross-sectional area described above.

[0087] Figures 11A to 11F The structure of the current sensors 1A, 1B, 1C, 1D, 1E and 1F involved in the modified examples is shown in top view.

[0088] Figure 11A This illustrates the structure of the current sensor 1A in the first modified example. (Compared to...) Figure 1 As shown above, the two sensor sections 20 of the current sensor 1 and magnetic sensor 30 are arranged closer to the center of the conductor 40. This allows for the suppression of in-phase voltages caused by uneven magnetic field distribution around the conductor 40.

[0089] Figure 11B This illustrates the structure of the current sensor 1B in the second modified example. (Compared to...) Figure 1The aforementioned current sensor 1 has a short longitudinal length for the first connecting portion 42a2 and the second connecting portion 42b2 of the conductor 40, for example, one-half the longitudinal width of the magnetic sensor 30 (substrate 31), preferably one-fifth, more preferably one-tenth, even more preferably one-hundredth, and even more preferably one-hundredth, thereby reducing the resistance of the conductor 40 and suppressing the heating caused by the DC current.

[0090] Figure 11C This illustrates the structure of the current sensor 1C involved in the third variation. Relative to... Figure 1 The aforementioned current sensor 1 has holes 44a arranged within the arrangement intervals 44a and 44b of the conductor 40. i 44b i The shape of (i = 1 to 3) is not limited to a circle (or approximately a circle), but can also be an ellipse (or approximately an ellipse) or a polygon containing a rectangle (or approximately a rectangle).

[0091] Figure 11D This illustrates the structure of the current sensor 1D involved in the fourth variation. Relative to... Figure 1 The aforementioned current sensor 1 can also have the bend 43, the first connecting portion 42a2, and the second connecting portion 42b2 of the conductor 40 formed in the shape of the Japanese kana character "コ". This makes the processing of the conductor 40 easier and the design of the signal terminal 50 easier as well.

[0092] Figure 11E This shows the structure of the current sensor 1E, the fifth variation. (Compared to...) Figure 1 The aforementioned current sensor 1 can also have the bend 43 of the conductor 40 formed in an inverted V shape. This allows for a compact design of the bend 43.

[0093] Figure 11F This shows the structure of the current sensor 1F in the sixth modified example. (Compared to...) Figure 1 As shown in the aforementioned current sensor 1, the bend portion 43 of the conductor 40, the first connecting portion 42a2, and the second connecting portion 42b2 can be formed in the shape of the Greek letter "Π". This increases the top-view area of ​​the bend portion 43 and improves its heat dissipation.

[0094] The present invention has been described above using embodiments, but 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 or improvements can be made to the above embodiments. As can be seen from the claims, such modifications or improvements are also included within the technical scope of the present invention.

[0095] It should be noted that the execution order of actions, steps, stages, and other processes in the apparatus, system, program, and method shown in the claims, specification, and drawings can be implemented in any order, unless specifically stated as "first," "before," etc., and unless the output of a previous process is used in a later process. Even if the flow of actions in the claims, specification, and drawings is described using terms such as "firstly" or "next" for convenience, it does not mean that the actions must be performed in that order.

Claims

1. A current sensor, comprising: A conductor having a first terminal portion for inputting current disposed on one side of a first axial direction, a second terminal portion for outputting current separated from the first terminal portion along a second axial direction intersecting the first axial direction, a bend portion disposed on the other side of the first axial direction relative to the first terminal portion, a first main body portion connecting one end of the bend portion to the first terminal portion, and a second main body portion separated from the first main body portion along the second axial direction and connecting the other end of the bend portion to the second terminal portion. A magnetic sensor is disposed on or near the conductor; and The encapsulation body seals the bend of the conductor, the first main body, the second main body, and the magnetic sensor, leaving the first terminal and the second terminal exposed. The first main body has a first connecting portion that connects to the turning portion. The second main body has a second connecting portion that connects to the turning portion. At least a portion of the magnetic sensor is disposed on at least one of the first connection portion and the second connection portion. At least one of the first main body portion and the second main body portion includes an arrangement interval between the first connecting portion and the first terminal portion and between the second connecting portion and the second terminal portion, wherein the arrangement interval is provided with at least one hole. Viewed from a third direction intersecting the first and second axes respectively, in a continuous cross-section of the conductor that intersects the inner contour surface of the conductor perpendicularly to the inner contour surface of the conductor, the cross-sectional area of ​​the first continuous cross-section defined between the inner contour surface of the conductor within the arrangement interval and the inner surface of the at least one hole located on the side of the inner contour surface of the conductor is smaller than the cross-sectional area of ​​other continuous cross-sections from the inner contour surface of the conductor outside the arrangement interval to the outer contour surface of the conductor.

2. The current sensor according to claim 1, wherein, Viewed from the third direction, in a continuous cross section that intersects perpendicularly with the inner contour surface of the conductor outside the arrangement interval and extends from the inner contour surface of the conductor to the outer contour surface of the conductor, there exists a second continuous cross section having a smaller cross section than the sum of the cross section areas of the multiple cross sections divided by the inner contour surface, the inner surface of the at least one hole, and the outer contour surface of the conductor within the arrangement interval, which lie on a plane perpendicularly intersecting the inner contour surface of the conductor and are located by the inner contour surface, the inner surface of the at least one hole, and the outer contour surface.

3. The current sensor according to claim 1, wherein, At least one of the first main body portion and the second main body portion has a conical portion, the cross-sectional area of ​​which increases from the connection portion with the bend portion toward the other side of the first axis toward the other side and perpendicularly intersects the contour surface of the inner side of the conductor.

4. The current sensor according to claim 1, wherein, The first main body has a first connecting portion that connects to the turning portion. The second main body has a second connecting portion that connects to the turning portion. At least one of the first connecting portion and the second connecting portion has a generally rectangular shape when viewed from the third direction. At least a portion of the magnetic sensor is disposed on at least one of the first connection portion and the second connection portion.

5. The current sensor according to claim 1, wherein, The distance between the outlines of the first main body and the second main body, which are opposite to each other, is less than 5 mm.

6. The current sensor according to claim 1, wherein, Viewed from the third direction, the continuous cross section that intersects perpendicularly with the inner contour surface of the conductor outside the arrangement interval and extends from the inner contour surface of the conductor to the outer contour surface of the conductor has a cross section larger than the cross section of each of the plurality of cross sections divided by the inner contour surface, the inner surface of the at least one hole, and the outer contour surface between the inner contour surface and the outer contour surface of the conductor within the arrangement interval.

7. The current sensor according to claim 6, wherein, The at least one cavity includes a plurality of cavities arranged in the second axial direction such that at least a portion thereof is opposite to each other.

8. The current sensor according to claim 1, wherein, The width of the first axial direction of the at least one hole is less than 5 mm.

9. The current sensor according to claim 4, wherein, The current sensor also includes a substrate, which is disposed on the conductor through an insulating layer and supports the magnetic sensor. The substrate is disposed on at least a portion of the bend, the first connecting portion, and the second connecting portion. A thermometer, separate from the magnetic sensor, is provided on the substrate. The distance from the arrangement interval is different for the magnetic sensor and the thermometer.

10. The current sensor according to claim 9, wherein, An electronic circuit is provided on the substrate. The electronic circuit independently monitors the temperature using the magnetic sensor and the thermometer. When the temperature difference between the magnetic sensor and the thermometer exceeds a threshold, a signal is sent.

11. The current sensor according to claim 4, wherein, The current sensor further includes a substrate disposed on the conductor through an insulating layer, and supports at least two of the magnetic sensors. The substrate is disposed on at least a portion of the bend, the first connecting portion, and the second connecting portion. The distance from the arrangement interval is different for at least two of the magnetic sensors.

12. The current sensor according to claim 11, wherein, An electronic circuit is provided on the substrate, which independently monitors the temperature using at least two of the magnetic sensors and sends a signal when the temperature difference between the at least two magnetic sensors exceeds a threshold.

13. The current sensor according to claim 4, wherein, The current sensor also includes a substrate, which is disposed on the conductor through an insulating layer and supports the magnetic sensor. The substrate is disposed on at least a portion of the bend, the first connecting portion, and the second connecting portion. When viewed from the third direction, the outline of the insulating layer is located outside the outline of the substrate.

14. The current sensor according to claim 13, wherein, The insulating layer comprises either an organic layer or a ceramic layer.

15. The current sensor according to claim 14, wherein, The insulating layer comprises polyimide or fluoropolymer. When viewed from the third direction, the outline of the insulating layer is located on the side of the bend when viewed from the arrangement interval.

16. The current sensor according to claim 1, wherein, The current sensor also includes multiple signal terminals, which are separated from the conductor to one side along the first axial direction, exposing the front end and sealing it within the package. At least one of the plurality of signal terminals is closer to the bend than the other signal terminals.

17. The current sensor according to claim 16, wherein, The at least one signal terminal is a GND terminal.

18. The current sensor according to claim 16, wherein, When the current sensor is mounted on a mounting substrate, the at least one signal terminal is connected to an area on the mounting substrate that is larger than the area on which the other signal terminals of the plurality of signal terminals are connected.

19. The current sensor according to claim 1, wherein, The thickness of the conductor is approximately constant.

20. A current sensor, comprising: A conductor having a first terminal portion for inputting current disposed on one side of a first axial direction, a second terminal portion for outputting current separated from the first terminal portion along a second axial direction intersecting the first axial direction, a bend portion disposed on the other side of the first axial direction relative to the first terminal portion, a first main body portion connecting one end of the bend portion to the first terminal portion, and a second main body portion separated from the first main body portion along the second axial direction and connecting the other end of the bend portion to the second terminal portion. A magnetic sensor is disposed on or near the conductor; and The encapsulation body seals the bend of the conductor, the first main body, the second main body, and the magnetic sensor, leaving the first terminal and the second terminal exposed. At least one of the first main body portion and the second main body portion includes an arrangement interval, wherein the arrangement interval is provided with at least one hole. Viewed from a third direction that intersects the first axis and the second axis, respectively. Regarding the cross-section extending from the inner contour line of the conductor, perpendicularly intersecting the contour line, to the point where it initially intersects other contour lines of the conductor, the dimension of the cross-section within the arrangement interval is smaller than the dimension of the cross-section in the portion of the conductor outside the arrangement interval. Regarding the section extending from the inner contour line of the conductor to the outer contour line of the conductor, a section having a size smaller than the sum of the sizes of the multiple sections in the arrangement interval exists in the portion of the conductor outside the arrangement interval.

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