Current sensor, and semiconductor module

Abstract

To provide a current sensor and a semiconductor module that can reduce the size and cost of the current sensor.SOLUTION: An aspect of the present disclosure is a current sensor 10 that detects a current flowing in bus bars of a semiconductor module 20, and that comprises a magnetic detection element 100 and a pair of magnetic shield plates 120 sandwiching the magnetic detection element 100 and bus bars. The semiconductor module 20 has a first surface 200S-1 on which the bus bars extend from the inside to the outside. The pair of magnetic shield plates 120 are at least partially inserted into and fixed to the first surface 200S-1.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] There is known a current sensor that includes a bus bar, which is a conductor for passing a current, and a magnetic detection element provided on the bus bar, in which the magnetic detection element outputs a signal corresponding to the magnetic flux of a magnetic field formed by a current flowing through the bus bar. This type of current sensor is capable of measuring a large current flowing through the bus bar and can also accurately measure the direction of the current, and is therefore used for current detection in power conversion devices such as inverters and driving devices for electric motors.

[0003] Patent Documents 1 and 2 disclose a current sensor that suppresses the influence of an external magnetic field on a magnetic detection element by disposing a bus bar and the magnetic detection element between a pair of magnetic seal plates. This type of current sensor generally includes a case through which a bus bar extending from a device to be measured to the outside passes, and a pair of magnetic shields are held in the case. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7242887 [Patent Document 2] JP 2020-128960 A Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional current sensors require a holding member, such as a case, for holding the magnetic shield, and this case increases the size and cost of the current sensor.

[0006] The present disclosure aims to provide a current sensor and a semiconductor module that can achieve miniaturization and low cost. [Means for solving the problem]

[0007] A current sensor according to one embodiment of the present disclosure is a current sensor that detects a current flowing through a bus bar of a semiconductor module, and includes a magnetic detection element and a pair of magnetic shielding plates that sandwich the magnetic detection element and the bus bar, wherein the semiconductor module has a first surface from which the bus bar extends from the inside to the outside, and the pair of magnetic shielding plates are fixed with at least a portion of them inserted into each of a pair of first grooves provided on the first surface.

[0008] A semiconductor module according to one embodiment of the present disclosure comprises a module body incorporating a semiconductor element, a bus bar extending from the inside of the module body to the outside, and a current sensor that detects a current flowing through the bus bar, wherein the current sensor comprises a magnetic detection element and a pair of magnetic shielding plates that sandwich the magnetic detection element and the bus bar, and at least a portion of the pair of magnetic shielding plates are embedded in the module body. Effect of the Invention

[0009] According to one aspect of the present disclosure, a current sensor and a semiconductor module that can achieve miniaturization and low cost are obtained. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram illustrating a schematic diagram of a portion of a mechanical configuration of a power conversion device according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a diagram illustrating an example of an electrical configuration of a power conversion device. [Diagram 3] 2 is an enlarged view of a semiconductor module and a current sensor in FIG. 1. [Figure 4]4 is a diagram showing an example of a cross-sectional configuration of a semiconductor module in a state in which a current sensor is not provided, the cross section being the plane indicated by dashed line A in FIG. [Diagram 5] 4 is a diagram showing an example of a cross-sectional configuration of a semiconductor module in a state in which a current sensor is not provided, the cross section being a plane indicated by dashed line B in FIG. [Figure 6] 4 is a diagram showing an example of a cross-sectional configuration of a semiconductor module with a current sensor provided therein, the cross section being taken along the plane indicated by dashed line A in FIG. [Figure 7] 11 is a perspective view showing an example of a semiconductor module according to a first modified example of the present disclosure. FIG. [Figure 8] 11 is a cross-sectional view showing an example of a semiconductor module according to a second modified example of the present disclosure. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a preferred embodiment of the present disclosure will be described with reference to the drawings. In the drawings, the dimensions and scale of each part may differ from the actual ones, and some parts may be shown diagrammatically to facilitate understanding. In addition, unless otherwise specified in the following description to the effect that the present disclosure is limited, the scope of the present disclosure is not limited to the embodiments described in the following description. The scope of the present disclosure includes the equivalent scope of the embodiments.

[0012] 1. Embodiment Fig. 1 is a diagram showing a schematic view of a part of a mechanical configuration of a power conversion device 1 according to an embodiment of the present disclosure. Fig. 2 is a diagram showing an example of an electrical configuration of the power conversion device 1. Note that Fig. 1 shows the configuration of a part of the power conversion device 1 corresponding to the inverter circuit 9 in Fig. 2.

[0013] 1 and 2 is an example of a semiconductor device. The power conversion device 1 of this embodiment is an inverter that converts DC power supplied from a DC power source 2 into AC power, and more precisely, is a three-phase inverter that converts the DC voltage of the DC power source 2 into AC voltages for three phases, namely, U phase, V phase, and W phase.

[0014] First, the electrical configuration of the power conversion device 1 will be described in detail. As shown in FIG. 2, the power conversion device 1 of this embodiment includes a capacitor 5, an inverter circuit 9, a control circuit 6, a drive circuit 7, and a current sensor 10. The capacitor 5 is a voltage smoothing element connected in parallel to the DC power supply 2 . The inverter circuit 9 is a circuit connected to the DC power supply 2 and the capacitor 5 via a positive wiring 8P and a negative wiring 8N. More specifically, the inverter circuit 9 includes three legs 3 connected in parallel to the positive wiring 8P and the negative wiring 8N. Each of the three legs 3 includes an upper arm 4U having a first semiconductor switching element 4-1 and a lower arm 4D having a second semiconductor switching element 4-2. The first semiconductor switching element 4-1 and the second semiconductor switching element 4-2 are examples of "semiconductor elements" in the present disclosure. In the present embodiment, the first semiconductor switching element 4-1 and the second semiconductor switching element 4-2 are both power semiconductor elements. Examples of the power semiconductor elements include an IGBT (Insulated Gate Bipolar Transistor) and a MOSFET (Metal Oxide Semiconductor Field Effect Transistor).

[0015] In each leg 3, the upper arm 4U and the lower arm 4D are connected in series to form a half-bridge circuit, and the first semiconductor switching element 4-1 of the upper arm 4U and the second semiconductor switching element 4-2 of the lower arm 4D are alternately turned on / off, so that each leg 3 outputs one phase of AC voltage from the midpoint between the upper arm 4U and the lower arm 4D through the output terminal 3A. This output terminal 3A is also called a "power terminal." The voltage output from each leg 3 is applied to an electric motor M, which is an example of a load.

[0016] The control circuit 6 is a circuit that outputs a control signal for controlling the inverter circuit 9 to the drive circuit 7. The drive circuit 7 is a circuit that turns on / off the first semiconductor switching element 4-1 and the second semiconductor switching element 4-2 of each leg 3 included in the inverter circuit 9 based on the control signal.

[0017] More specifically, the control circuit 6 calculates a voltage command value for each phase based on a detection value of the output current output by each leg 3 and a current command value for driving the electric motor M. Next, the control circuit 6 PWM-modulates the voltage command value for each phase to generate a PWM modulated signal as a control signal, and outputs the PWM modulated signal to the drive circuit 7. Based on the PWM modulation signal, the drive circuit 7 applies a voltage to each gate terminal of the first semiconductor switching element 4-1 and the second semiconductor switching element 4-2 in each leg 3. As a result, in each leg 3, the first semiconductor switching element 4-1 and the second semiconductor switching element 4-2 are alternately turned on / off based on the PWM modulation signal, and a voltage having a voltage value corresponding to the voltage command value is output from the output terminal 3A of each leg 3.

[0018] The current sensor 10 corresponds to a "current sensor" in this disclosure. The current sensor 10 in this embodiment is a sensor that detects the output current of the leg 3 based on a magnetic flux generated by the output current of the leg 3. Each of the three current sensors 10 inputs a detection value of the output current of the leg 3 to the control circuit 6. In the control circuit 6, these detection values ​​are used to generate the above-mentioned control signal.

[0019] Next, the mechanical configuration of the power conversion device 1 will be described in detail. 1, the power conversion device 1 of this embodiment includes three semiconductor modules 20, each of which outputs a voltage for one phase, and the above-mentioned three current sensors 10 provided in each of the three semiconductor modules 20. In this embodiment, the three semiconductor modules 20 each have the same mechanical configuration, and the three current sensors 10 each have the same mechanical configuration. Each semiconductor module 20 corresponds to a "semiconductor module" in this disclosure.

[0020] In this embodiment, the three semiconductor modules 20 correspond to the above-mentioned inverter circuit 9, and each semiconductor module 20 includes a module body 200 and three bus bars 201 extending from the inside of the module body 200 to the outside. The module body 200 is a portion that incorporates one leg 3, and more specifically, is a portion that includes one leg 3 and a sealing body 200M that resin-moldes the leg 3. The module body 200 may further include a case body that houses the sealing body 200M. In this case, the three bus bars 201 extend from the inside to the outside by penetrating the case body.

[0021] Each of the three bus bars 201 is a plate-like member that is long in one direction and is made mainly of a conductive material. The conductive material may be, for example, a metal such as copper or aluminum. In this embodiment, the three bus bars 201 correspond to a positive bus bar 201P, a negative bus bar 201N, and an output bus bar 201A, respectively. The positive bus bar 201P and the negative bus bar 201N are bus bars 201 that supply power from the DC power source 2 to each leg 3, and correspond to the positive wiring 8P and the negative wiring 8N described with reference to FIG. 2, respectively. More specifically, inside the module main body 200, one end of each of the positive bus bar 201P and the negative bus bar 201N is electrically connected to a mounting board 210 on which the leg 3 is mounted. The mounting board 210 is shown in FIGS. 4 and 6 described below. In addition, each positive bus bar 201P extending from each module main body 200 is connected to the positive electrode of the DC power source 2 via a conductive member not shown. Similarly, each negative bus bar 201N extending from each module main body 200 is connected to the negative electrode of the DC power source 2 via another conductive member not shown. The output bus bar 201A is a bus bar 201 provided for each output terminal 3A of each leg 3. That is, the output bus bar 201A is connected to the output terminal 3A of the leg 3 inside the module body 200, and the other end extends to the outside of the module body 200 and is connected to an electric motor M, which is an example of a load.

[0022] The current sensor 10 is provided for each output bus bar 201A of the semiconductor module 20, and detects the output current flowing through that output bus bar 201A.

[0023] Next, the configuration of the semiconductor module 20 will be described in detail. Fig. 3 is an enlarged view of the semiconductor module 20 and the current sensor 10 in Fig. 1. Figs. 4 and 5 are both diagrams showing an example of a cross-sectional configuration of the semiconductor module 20 in a state where the current sensor 10 is not provided. The cross section shown in Fig. 4 is the plane indicated by the dashed line A in Fig. 3, and the cross section shown in Fig. 5 is the plane indicated by the dashed line B in Fig. 3. Fig. 6 is a diagram showing an example of a cross-sectional configuration of the semiconductor module 20 in a state where the current sensor 10 is provided, and the cross section shown in Fig. 6 is the plane indicated by the dashed line A in Fig. 3.

[0024] 3 and 4, the module body 200 of the semiconductor module 20 has a first surface 200S-1 and a second surface 200S-2 facing each other, and one or two bus bars 201 extend from each surface. The module body 200 of the present embodiment has, as an example, a generally rectangular parallelepiped shape with a relatively small thickness, in other words, a flat plate shape, and has a pair of planar main surfaces 200S-M having a larger area than the other surfaces. In this module body 200, the first surface 200S-1 and the second surface 200S-2 each have a rectangular shape and correspond to a pair of planar side surfaces located in the longitudinal direction of the module body 200. Of first surface 200S-1 and second surface 200S-2, the surface from which output bus bar 201A extends from the inside to the outside is first surface 200S-1, and the surfaces from which positive bus bar 201P and negative bus bar 201N each extend from the inside to the outside are second surface 200S-2. The first surface 200S-1 and the second surface 200S-2 may be surfaces that include a portion having curvature or unevenness in part or in whole of the surface. In addition, a heat sink may be provided on the pair of main surfaces 200S-M.

[0025] Next, the configuration of the current sensor 10 will be described in detail. In the following description, the first surface 200S-1 of the semiconductor module 20 is defined as an XZ surface, and the normal direction of the XZ surface is defined as a Y-axis direction. The direction in which the long side of the rectangular first surface 200S-1 extends is defined as an X-axis direction, and the direction in which the short side extends is defined as a Z-axis direction. Therefore, in this embodiment, the extension direction of each bus bar 201 is the Y-axis direction, and the width direction of each bus bar 201 is the X-axis direction. As shown in FIG. 1, the direction in which the three semiconductor modules 20 are arranged side by side is the X-axis direction.

[0026] The current sensor 10 is a coreless sensor that detects current without using a magnetic core, and specifically includes a magnetic detection element 100, a first substrate 110, and a pair of magnetic shield plates 120. The magnetic detection element 100 is an element that detects the magnetic flux density in only one axial direction, i.e., an element that outputs a signal according to the magnetic flux density in the one axial direction. Representative examples of such a magnetic detection element 100 include a Hall element, or a magnetic resistance element such as a giant magneto resistive element (GMR: Giant Magneto Resistive) or a tunnel magneto resistive element (TMR: Tunnel Magneto Resistive). In this embodiment, the magnetic detection element 100 is disposed in a position facing the main surface 201AS-M of the output bus bar 201A with the detection axis direction facing the X-axis direction.

[0027] First substrate 110 is a substrate on which magnetic detection element 100 is mounted, and is, for example, a printed circuit board. In a plan view seen from the Z-axis direction, first substrate 110 is disposed within the plane of main surface 201AS-M of output bus bar 201A, which is bus bar 201 whose current is to be measured. First substrate 110 may be disposed in contact with main surface 201AS-M, or may be disposed with a gap between it and main surface 201AS-M (i.e., spaced apart).

[0028] Each of the pair of magnetic shield plates 120 is a rectangular flat plate-shaped member mainly made of a magnetic material. The magnetic material may be a soft magnetic material such as permalloy. As shown in Fig. 3, the width Wa of the magnetic shield plate 120 is larger than the width W of the output bus bar 201A, and as shown in Fig. 6, the length La of the magnetic shield plate 120 is longer than the length Lb of the magnetic detection element 100.

[0029] 3, the pair of magnetic shielding plates 120 are arranged in positions sandwiching the first substrate 110, the magnetic detection element 100, and the output bus bar 201A, facing each other (in other words, facing each other). By arranging the magnetic detection element 100 between the pair of magnetic shielding plates 120, the influence of an external magnetic field, such as a magnetic field generated in another semiconductor module 20 (the output bus bar 201A of that semiconductor module 20), on the magnetic detection element 100 is suppressed.

[0030] The width Wa and length La of the pair of magnetic shield plates 120 and the separation distance Ha between the magnetic shield plates 120 (FIG. 5) are predetermined values ​​that provide a required amount of removal of the external magnetic field when the magnetic detection element 100 is placed at a predetermined placement position Ps. The predetermined placement position Ps will be described later with reference to FIG. 6. The predetermined values ​​can be found by using an appropriate method such as a magnetic field simulation.

[0031] The shape of the pair of magnetic shield plates 120 is not limited to a flat plate shape. For example, the pair of magnetic shield plates 120 may each have a C-shaped cross section in the XZ plane. Also, for example, the pair of magnetic shield plates 120 may have different cross-sectional shapes in the XZ plane.

[0032] Here, in the current sensor 10 of this embodiment, the first substrate 110 on which the magnetic detection element 100 is mounted, and the pair of magnetic shielding plates 120 are each fixed to the first surface 200S-1 of the module main body 200, thereby eliminating the need for a holding member such as a case for holding the first substrate 110 and the pair of magnetic shielding plates 120. More specifically, as shown in FIGS. 4 and 5, the first surface 200S-1 of the module body 200 is provided with a pair of first grooves 230-1 and one second groove 230-2. 5, a pair of first grooves 230-1 are provided at positions sandwiching output bus bar 201A and second groove 230-2 therebetween and spaced apart from each other by a separation distance Ha. The opening shapes of first groove 230-1 and second groove 230-2 are formed into shapes into which ends 120T, 110T of magnetic shield plate 120 and first substrate 110 can be inserted. Specifically, an opening width Wc-1 of first groove 230-1 in the width direction of output bus bar 201A is equal to or larger than width Wa of magnetic shield plate 120, that is, equal to or larger than width W of output bus bar 201A. An opening width Wc-2 of second groove 230-2 is equal to or larger than width Wd of first substrate 110 and equal to or smaller than width W of output bus bar 201A.

[0033] The first groove 230-1 and the second groove 230-2 may be formed by any suitable method. For example, the first groove 230-1 and the second groove 230-2 may be formed when the module body 200 is molded by providing a protruding portion for forming the first groove 230-1 and the second groove 230-2 in a mold for molding the module body 200. Furthermore, for example, the first groove 230-1 and the second groove 230-2 may be formed by post-processing after molding the module body 200.

[0034] As shown in FIG. 6, ends 120T of magnetic shield plate 120 are inserted and fixed into each of a pair of first grooves 230-1, and end 110T of first substrate 110 is inserted and fixed into second groove 230-2. The specific method of fixing may be any suitable one. For example, the pair of magnetic shield plates 120 and the first substrate 110 may be fixed by fitting into the first groove 230-1 and the second groove 230-2, respectively. Alternatively, for example, the first groove 230-1 and the second groove 230-2 may be filled with an adhesive, respectively. Alternatively, for example, the first substrate 110 may be fixed to the main surface 201AS-M of the output bus bar 201A by adhesion or the like. When the first substrate 110 is fixed to the output bus bar 201A, the end 110T of the first substrate 110 may or may not be fixed to the second groove 230-2.

[0035] In this way, in the current sensor 10, the pair of magnetic shield plates 120 are fixed to the first surface 200S-1 of the module body 200, so that the current sensor 10 does not need to include a holding member for holding the pair of magnetic shield plates 120. Therefore, since the holding member is not required, the current sensor 10 can be made smaller and the cost can be reduced.

[0036] Furthermore, by inserting the pair of magnetic shield plates 120 and first substrate 110 into first surface 200S-1 of module body 200, the protrusion amounts of each magnetic shield plate 120 and first substrate 110 in the extension direction of output bus bar 201A are reduced by the respective insertion amounts α1 and α2, as shown in Fig. 6. Insertion amount α1 corresponds to the depth of first groove 230-1, and insertion amount α2 corresponds to the depth of second groove 230-2. Therefore, the areas occupied by magnetic shield plate 120 and first substrate 110 are reduced by insertion amount α1 and insertion amount α2, respectively, and thus further miniaturization of current sensor 10 is achieved.

[0037] Here, in a state where the current sensor 10 of this embodiment is provided in the module body 200, the magnetic detection element 100 mounted on the first substrate 110 is disposed at a predetermined arrangement position Ps. As shown in FIG. 6, this arrangement position Ps is the position of the center Lao of the length La of the magnetic shield plate 120 when viewed from the width direction (X-axis direction) of the output bus bar 201A. By setting this arrangement position Ps, the length La of the magnetic shield plate 120 can be minimized. That is, the magnetic detection element 100 needs to be disposed at a position that is a predetermined distance D or more away from each of the ends 120T on both sides of the magnetic shield plate 120 in order to remove the external magnetic field. In this case, by disposing the magnetic detection element 100 at the above-mentioned arrangement position Ps, the length La of the magnetic shield plate 120 only needs to be at least twice the predetermined distance D, so that the length La of the magnetic shield plate 120 can be set to the minimum length required to remove the external magnetic field.

[0038] In this embodiment, the depth of the second groove 230-2 is set in advance based on the dimensions of the first groove 230-1, the magnetic shield plate 120, and the first substrate 110, as well as the mounting position of the magnetic detection element 100 on the first substrate 110, so that the magnetic detection element 100 is disposed at the arrangement position Ps. Therefore, in the process of providing the current sensor 10 in the semiconductor module 20, the first substrate 110 is inserted into the second groove 230-2, whereby the magnetic detection element 100 can be easily and accurately positioned at the predetermined position.

[0039] 5, when viewed from the extension direction (Y-axis direction) of output bus bar 201A, arrangement position Ps in this embodiment is the center Wao of width Wa of magnetic shield plate 120 (center of width W of output bus bar 201A) and also the center of separation distance Ha between the pair of magnetic shield plates 120. According to arrangement position Ps, the influence of an external magnetic field on magnetic detection element 100 is effectively suppressed by magnetic shield plate 120, and magnetic detection element 100 can accurately detect the current flowing through output bus bar 201A. Furthermore, a pair of first grooves 230-1 and second grooves 230-2 are formed on the first surface 200S-1 to position the magnetic detection element 100 at the arrangement position Ps, making it easy to position the magnetic shield plate 120 and the first substrate 110 when installing the current sensor 10 in the semiconductor module 20.

[0040] As described above, the current sensor 10 of this embodiment is a sensor that detects a current flowing through the output bus bar 201A of the semiconductor module 20. The current sensor 10 also includes the magnetic detection element 100 and a pair of magnetic shielding plates 120 that sandwich the magnetic detection element 100 and the output bus bar 201A, and the semiconductor module 20 has a first surface 200S-1 from which the output bus bar 201A extends from the inside to the outside. The pair of magnetic shielding plates 120 are fixed with their ends 120T inserted into the first surface 200S-1. According to this configuration, the current sensor 10 does not need to include a holding member for holding the pair of magnetic shield plates 120. Therefore, since the holding member is not necessary, the current sensor 10 can be made smaller and the cost can be reduced. Furthermore, the amount of protrusion of each of the pair of magnetic shield plates 120 is reduced by inserting them into the first surface 200S-1 of the module body 200. Therefore, the area occupied by the magnetic shield plates 120 is reduced, and the current sensor 10 can be further miniaturized.

[0041] In the current sensor 10 of this embodiment, the pair of magnetic shield plates 120 are fixed in a state in which they are inserted into the pair of first grooves 230-1 provided in the first surface 200S-1, respectively. According to this configuration, the pair of magnetic shield plates 120 can be easily positioned when mounted on the semiconductor module 20 .

[0042] The current sensor 10 of this embodiment includes a first substrate 110 on which the magnetic detection element 100 is mounted, and the first substrate 110 is fixed with its end portion 110T inserted into a second groove 230-2 provided between a pair of first grooves 230-1 on the first surface 200S-1. According to this configuration, positioning of the first substrate 110 when mounting it on the semiconductor module 20 becomes easy.

[0043] In the current sensor 10 of this embodiment, when the first substrate 110 is inserted, the magnetic detection element 100 mounted on the first substrate 110 is positioned at the center Lao of the length La of the magnetic shield plate 120 in the extension direction (Y-axis direction) of the output bus bar 201A. According to this configuration, the length La of the magnetic shield plate 120 can be set to the minimum length required to remove the external magnetic field.

[0044] 2. Variations The following are examples of modified forms that can be added to the above-described embodiment. Two or more forms selected from the following examples may be combined as appropriate within the scope of not being mutually contradictory.

[0045] 7 is a perspective view showing an example of a semiconductor module 20 according to a first modification of the present disclosure. In the drawing, the same reference numerals are used to designate the elements described in the embodiment, and the description thereof will be omitted. In this modified example, the three semiconductor modules 20 shown in Fig. 1 are integrated into one semiconductor module 20. Specifically, as shown in Fig. 7, the semiconductor module 20 according to this modified example includes one module body 200, and a mounting board on which the inverter circuit 9 shown in Fig. 2 is mounted is built into this module body 200. In this case, three output bus bars 201A extend outward from a first surface 200S-1 of the module body 200, and a current sensor 10 is provided on each output bus bar 201A. In each current sensor 10, the pair of magnetic shield plates 120 and the first substrate 110 are fixed in a state of being inserted into a pair of first grooves 230-1 and second grooves 230-2 provided on the first surface 200S-1, as in the embodiment.

[0046] In this modification, instead of each current sensor 10 being provided with a pair of individual magnetic shield plates 120, each current sensor 10 is provided with a common pair of magnetic shield plates 120. That is, the pair of magnetic shield plates 120 has a width Wa that is equal to or greater than the length that covers the three output bus bars 201A aligned in the width direction (X-axis direction). By each current sensor 10 sharing the same pair of magnetic shield plates 120, the number of parts and assembly man-hours of the current sensor 10 can be reduced, and productivity can be improved.

[0047] 8 is a cross-sectional view showing an example of a semiconductor module 20 according to a second modification of the present disclosure. In the drawing, the same reference numerals are used to designate the elements described in the embodiment, and the description thereof will be omitted. In this modification, ends 110T of a pair of magnetic shield plates 120 of a current sensor 10 are embedded in a module body 200 of a semiconductor module 20. Specifically, as shown in FIG. 8, the pair of magnetic shielding plates 120 are integrally molded with the module main body 200 using insert molding or the like during the molding process of the module main body 200, and are fixed in a state in which the end portions 110T are inserted into the module main body 200. According to this configuration, in addition to the effects of the current sensor 10 described in the above embodiment, the process of fixing the pair of magnetic shield plates 120 to the semiconductor module 20 is not required.

[0048] (3) In the above-described embodiment and each modified example, the first substrate 110 does not have to be inserted into the first surface 200S-1 of the semiconductor module 20. In this case, the first substrate 110 may be fixed to the output bus bar 201A by, for example, adhesion or the like.

[0049] (4) In the above-described embodiment and each modified example, the maximum insertion amounts α1 and α2 of the magnetic shield plate 120 and the first substrate 110 may be determined as appropriate depending on the size of the space inside the module body 200. For example, the insertion amount α2 of the first substrate 110 (the depth of the second groove 230-2) may be the amount (depth) of the magnetic detection element 100 mounted therein located inside the module body 200. Also, for example, the magnetic shield plate 120 and the first substrate 110 may be substantially entirely inserted into the module body 200. [Explanation of symbols]

[0050] 1...power conversion device, 3...leg, 4-1...first semiconductor switching element, 4-2...second semiconductor switching element, 4D...lower arm, 4U...upper arm, 8N...negative wiring, 8P...positive wiring, 9...inverter circuit, 10...current sensor, 20...semiconductor module, 100...magnetic detection element, 110...first board, 120...magnetic shield plate, 200...module main body, 200S-1...first surface, 201...bus bar, 201A...output bus bar, 201N...negative bus bar, 201P...positive bus bar, 210...mounting board, 230-1...first groove, 230-2...second groove.

Claims

1. A current sensor for detecting a current flowing through a bus bar of a semiconductor module, A magnetic detection element; a pair of magnetic shield plates sandwiching the magnetic detection element and the bus bar; Equipped with The semiconductor module includes: a first surface from which the bus bar extends from an interior to an exterior; The pair of magnetic shield plates each have At least a part of the first surface is inserted and fixed thereto. Current sensor.

2. the pair of magnetic shield plates are fixed in a state in which they are inserted into a pair of first grooves provided on the first surface, The current sensor according to claim 1 .

3. a first substrate on which the magnetic detection element is mounted, The first substrate is The second groove is fixed in a state where at least a part of the second groove is inserted into the first surface. The current sensor according to claim 1 .

4. When the first board is inserted, the magnetic detection element mounted on the first board is located at the center of the length of the magnetic shield plate in the direction in which the bus bar extends. The current sensor according to claim 3 .

5. A module body having a built-in semiconductor element; A bus bar extending from the inside to the outside of the module body; a current sensor for detecting a current flowing through the bus bar; Equipped with The current sensor is A magnetic detection element; a pair of magnetic shield plates sandwiching the magnetic detection element and the bus bar; Equipped with At least a portion of the pair of magnetic shield plates is embedded in the module body. Semiconductor module.

Images