Current sensor

Abstract

To provide a manufacturing method of a current sensor capable of achieving high productivity suitable for mass production.SOLUTION: The method for manufacturing the current sensor includes a substrate disposing step, a shield disposing step, and a curing step. In the substrate arrangement step, the wiring substrate on which the sensor element is mounted is brought into contact with the plurality of substrate contact parts. At this time, the adhesive applied to the top surfaces of the plurality of substrate adhering sections is deformed between the top surfaces and the wiring substrate. In the shield arrangement step, a shield as a magnetic shield member is brought into contact with the plurality of shield contact portions. At this time, the adhesive applied to the top surfaces of the plurality of shield bonding portions is deformed between the top surfaces and the shields. In the curing step, both the adhesive positioned between the substrate bonding portion and the wiring substrate and the adhesive positioned between the shield bonding portion and the shield are simultaneously cured.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The disclosure herein relates to a method for manufacturing a current sensor. [Background technology]

[0002] Patent Document 1 discloses a current sensor. The current sensor has a wiring board on which a magnetoelectric conversion unit is mounted. The current sensor also has a plate-shaped magnetic shield for suppressing magnetic noise components. The current sensor has the wiring board and the shield disposed within a sensor housing. The contents of the prior art documents are incorporated by reference as explanations of the technical elements in this specification. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6919609 Summary of the Invention

[0004] In Patent Document 1, a wiring board is bonded to a sensor housing, and then a shield is bonded to the sensor housing. Current sensors are required to have a high degree of productivity suitable for mass production. From another perspective, current sensors are required to have high accuracy in terms of detection performance. Therefore, high accuracy is required for the relative positional relationship of the wiring board and the shield with respect to the bus bar. From the above perspectives and other perspectives not mentioned, further improvements are required in current sensors and current sensor manufacturing methods.

[0005] One disclosed object is to provide a method for manufacturing a current sensor that can achieve high productivity suitable for mass production.

[0006] The method for manufacturing a current sensor disclosed herein includes a preparation step of preparing a sensor housing (21) that holds a conductive member for passing a current and that includes a plurality of substrate contact portions (26a), a plurality of substrate adhesive portions (26b), a plurality of shield contact portions (27a), and a plurality of shield adhesive portions (27b), a wiring board (41) that mounts a sensor element (42) that detects magnetic flux resulting from a current, and a shield (51) that serves as a magnetic shielding member; and a manufacturing method of a current sensor that includes a preparation step of preparing a wiring board (41) that contacts the wiring board with the plurality of substrate contact portions to place the wiring board in a specified position, and a manufacturing step of preparing a shield (51) that adheres to the top surfaces of the plurality of substrate adhesive portions. The method includes a substrate positioning step of contacting the wiring board with (30) to deform the adhesive between the top surface and the wiring board, a shield positioning step of contacting the shield with the plurality of shield contact parts to position the shield in a specified position and deforming the adhesive (30) applied to the top surfaces of the plurality of shield adhesive parts between the top surface and the shield, and a curing step of simultaneously curing both the adhesive positioned between the substrate adhesive parts and the wiring board and the adhesive positioned between the shield adhesive parts and the shield after the substrate positioning step and the shield positioning step.

[0007] The disclosure of this specification provides a method for manufacturing a current sensor. In the method for manufacturing a current sensor, a wiring substrate is brought into contact with adhesive applied to the top surfaces of multiple substrate adhesive portions, thereby deforming the adhesive between the top surface and the wiring substrate. As a result, the wiring substrate is positioned at a predetermined position. Moreover, the adhesive is deformed into a shape suitable for the predetermined position. In the method for manufacturing a current sensor, a shield is brought into contact with adhesive applied to the top surfaces of multiple shield adhesive portions, thereby deforming the adhesive between the top surface and the shield. As a result, the shield is positioned at a predetermined position. Moreover, the adhesive is deformed into a shape suitable for the predetermined position. In the curing process, the adhesives are simultaneously cured after the substrate placement process and the shield placement process. In the curing process, both the adhesive positioned between the substrate adhesive portion and the wiring substrate and the adhesive positioned between the shield adhesive portion and the shield are simultaneously cured. As a result, a high level of productivity suitable for mass production is achieved.

[0008] The various embodiments disclosed in this specification employ different technical means to achieve their respective objectives. The reference numerals in parentheses in the claims and in this section are intended to exemplify the correspondence with the following embodiments and are not intended to limit the technical scope. The objectives, features, and advantages disclosed in this specification will become more apparent by reference to the following detailed description and the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a current sensor according to a first embodiment. [Figure 2] FIG. [Figure 3] FIG. 3 is a plan view taken along the arrow III in FIG. 2. [Figure 4] FIG. [Figure 5] FIG. 2 is a plan view of the first shield. [Figure 6] FIG. 6 is a plan view taken along the arrow VI in FIG. [Figure 7] FIG. 7 is a plan view taken along the arrow VII in FIG. [Figure 8] FIG. 8 is a plan view taken along the arrow VIII in FIG. 2. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 8. [Figure 10] FIG. 1 is a modeled cross-sectional view showing the adhesive state. [Figure 11] FIG. [Figure 12] FIG. [Figure 13] FIG. 2 is a cross-sectional view of a current sensor. [Figure 14] FIG. 2 is a side view showing a magnetic shield. [Figure 15] FIG. 2 is a perspective view showing a magnetic shield. [Figure 16] FIG. [Figure 17] 5A to 5C are process diagrams showing steps of a method for manufacturing a current sensor. [Figure 18] FIG. 10 is a block diagram of an application device in an application step. [Figure 19] FIG. 2 is a plan view showing a wiring substrate. [Figure 20] FIG. 2 is a block diagram illustrating a sensing unit. [Figure 21] FIG. 10 is a plan view of a current sensor according to a second embodiment. [Figure 22] FIG. 4 is a cross-sectional view showing an assembled state of the current sensor. [Figure 23] FIG. 10 is a perspective view showing a magnetic shield according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Several embodiments will be described with reference to the drawings. In several embodiments, functionally and / or structurally corresponding and / or associated parts may be designated by the same reference numerals or reference numerals that differ in the hundredth or more digits. For corresponding and / or associated parts, reference may be made to the descriptions of other embodiments.

[0011] Reference can be made to the description of Japanese Patent No. 6919609, which is disclosed as a patent document, regarding the current sensor 1. The contents of the description of Japanese Patent No. 6919609 are incorporated by reference as an explanation of the technical elements in this specification.

[0012] First embodiment FIG. 1 illustrates a current sensor 1. In the following description, the current sensor 1 will be described assuming a three-axis Cartesian coordinate system. The direction in which a current flows as a detection target in the current sensor 1 is referred to as the axial direction AD. The axial direction AD refers to the direction of the current to be detected. In the illustrated example, it refers to the main current direction in the narrowed portion 11c described below. The direction perpendicular to the axial direction AD and parallel to the planar direction of the conductor member 11 described below is referred to as the width direction WD. The direction perpendicular to the axial direction AD and the width direction WD is referred to as the thickness direction TD. The thickness direction TD is also the opposing direction between the narrowed portion 11c described below and the sensor element 42. The width direction WD may be referred to as the X direction, the axial direction AD as the Y direction, and the thickness direction TD as the Z direction.

[0013] In FIG. 1, the current sensor 1 is used to detect current in a battery control device and / or a rotating electric machine control device. The current can range from several amperes to several hundred amperes. The current sensor 1 is designed with heat dissipation properties and materials to withstand high temperatures caused by heat generation and maintain its functionality. The battery and / or the rotating electric machine are used to provide power for fixed or mobile objects. Fixed objects include a variety of applications, such as air conditioning systems, water pumping systems, and winding devices. Mobile objects include a variety of applications, such as vehicles, ships, and aircraft. Mobile objects include human vehicles and unmanned mobile objects not intended for human occupancy. The battery and / or the rotating electric machine can be used as a power source to move the mobile object. For example, the rotating electric machine may be connected to the drive wheels of a vehicle to allow bidirectional or unidirectional power transmission. For example, the rotating electric machine may be connected to the propeller of a ship or aircraft to allow bidirectional or unidirectional power transmission. The battery and / or the rotating electric machine may be used in various auxiliary devices such as wipers, compressors, automatic doors, etc. In this embodiment, the current sensor 1 is used in a battery control ECU to control the charging current and / or discharging current of the battery. Alternatively, the current sensor 1 may be used in a power conversion device that controls the power running operation and / or regenerative operation of the rotating electric machine. The current sensor 1 may also be used to detect input / output currents in a converter circuit and / or an inverter circuit in the power conversion device.

[0014] The current sensor 1 includes a conductive member 10 through which a current can flow. The conductive member 10 may be provided as a bus bar made of a metal plate, or as a single-core or multi-core wire. In this embodiment, the conductive member 10 includes a conductor member 11 serving as a bus bar. The conductor member 11 is a member that can be called a strip-shaped or plate-shaped member. The longitudinal direction of the conductor member 11 is the direction in which a current flows, i.e., the axial direction AD. The thickness direction of the conductor member 11 is a thickness direction TD. The short side direction of the conductor member 11 is a width direction WD. The conductor member 11 is a member made of a metal such as copper or aluminum.

[0015] The conductor member 11 has connection portions with circuit components at both ends in the axial direction AD. One end 11a of the conductor member 11 is provided with a through hole 11d (bolt hole) for receiving a bolt as the shaft of the connecting mechanism. The through hole 11d is a circular hole that passes through the conductor member 11. The other end 11b of the conductor member 11 is provided with a through hole 11e for receiving a bolt as the shaft of the connecting mechanism. The through hole 11e is a circular hole that passes through the conductor member 11. The diameter of the through hole 11d is equal to the diameter of the through hole 11e. Note that the through holes 11d and 11e may be provided as U-shaped or C-shaped notches with openings on the edges.

[0016] The conductor member 11 has a narrowed portion 11c at the detection site. The narrowed portion 11c is partially narrow in width in the width direction WD. The narrowed portion 11c concentrates the current to be detected. A sensor element (described later) is disposed at a position a predetermined small distance away from the narrowed portion 11c along the thickness direction TD.

[0017] The current sensor 1 includes an insulating member 20. The insulating member 20 is made of an electrically insulating material. The insulating member 20 is made of, for example, an electrically insulating resin material. The insulating member 20 may be made of, for example, ceramics. The insulating member 20 provides a fixing member for fixing the conductive member 10. The insulating member 20 provides a container chamber 23 that houses electrical circuit components of the current sensor 1. The insulating member 20 provides a connector 25 that provides electrical connection for the current sensor 1. Furthermore, the insulating member 20 provides a fixing member for fixing a magnetic shielding member. The insulating member 20 includes a sensor housing 21 and a lid 22. The sensor housing 21 is a member that is also called the main body or body of the current sensor 1. The sensor housing 21 is a main member that forms the container chamber 23. The lid 22 is a member that covers the opening of the container chamber 23.

[0018] The sensor housing 21 fixes the conductive member 10 by inserting the conductive member 10 into it. The sensor housing 21 fixes the conductive member 10 so that one end 11a and the other end 11b are exposed. The sensor housing 21 and the lid 22 define a container chamber 23 therebetween that houses the electrical circuit components constituting the current sensor 1. The container chamber 23 is a slightly flattened rectangular chamber. The sensor housing 21 and the lid 22 fix a shielding member. A portion of the shielding member is housed within the container chamber 23. The remainder of the shielding member is fixed to the outer surface of the sensor housing 21.

[0019] The sensor housing 21 and the lid 22 are provided with a plurality of connecting mechanisms 24. The sensor housing 21 and the lid 22 are connected by the connecting mechanisms 24. The multiple connecting mechanisms 24 are arranged dispersedly in the width direction WD of the insulating member 20. In the illustrated example, two connecting mechanisms 24 are arranged on one side of the width direction WD of the insulating member 20. Two connecting mechanisms 24 are arranged on the other side of the width direction WD of the insulating member 20. The connecting mechanisms 24 are reversible connecting mechanisms that can transition between a connected state and a separated state in both directions. The connected state is illustrated in the figure. The connecting mechanisms 24 utilize the elastic deformation of the material that makes up the lid 22. The connecting mechanisms 24 are also called snap-fit ​​mechanisms that utilize the elastic deformation of the members.

[0020] The connecting mechanism 24 includes an engaging arm 24a with a movable claw and a fixed engaging claw 24b. The engaging arm 24a extends from the cover 22 toward the sensor housing 21 along the thickness direction TD. The engaging claw 24b protrudes in the width direction WD from the side of the sensor housing 21 facing the width direction WD. The engaging arm 24a is elastically deformable so that its tip extending from the cover 22 moves in the width direction WD. In the separated state, the engaging arm 24a is in its natural state with no elastic deformation. During the process of assembling the cover 22 to the sensor housing 21, the engaging arm 24a elastically deforms due to mechanical interference between the engaging arm 24a and the engaging claw 24b. The elastic deformation of the engaging arm 24a enables mechanical engagement between the engaging arm 24a and the engaging claw 24b. The engaging arm 24a can deform to receive the engaging claw 24b. When the relative positions of the engaging arm 24a and the engaging claw 24b reach the engaged position, the engaging arm 24a returns to its natural state due to its elastic force. At this engaged position, the engaging claw 24b restrains the engaging arm 24a. As a result, the sensor housing 21 and the lid 22 are connected and fixed. At this time, the container chamber 23 is sealed by the sensor housing 21 and the lid 22.

[0021] Furthermore, the sensor housing 21 has a side wall surface 24c that protrudes higher in the width direction WD than the engaging arm 24a in the engaged position. The side wall surface 24c defines a groove 24d that receives the engaging arm 24a. The side wall surface 24c defines the groove 24d so as to surround the engaging claw 24b. The groove 24d receives the engaging arm 24a in the connected state. As a result, in the connected state, the engaging arm 24a is disposed so as to be embedded inward from the surface of the sensor housing 21. The dimension of the sensor housing 21 in the width direction WD is determined by the side wall surface 24c. The engaging arm 24a is positioned so as to be recessed from the side wall surface 24c. Therefore, the connecting mechanism 24 can be disposed without increasing the dimension of the sensor housing 21 in the width direction WD.

[0022] The sensor housing 21 provides a connector 25 that provides an electrical connection for the current sensor 1. The connector 25 is a cylindrical member with one open end. The connector 25 has an electrical connection terminal inside. The opening of the connector 25 faces the thickness direction TD. The connector 25 is one of two connector parts that provide an electrical connection. The connector 25 is arranged so that it can be connected to or separated from the other connector by relative movement in a direction perpendicular to the axial direction AD. In the illustrated example, the connection direction and separation direction of the connector 25 are the thickness direction TD. The orientation direction of the connector 25 is also the direction in which the bolts are received in the through holes 11d and 11e.

[0023] 2 is an exploded perspective view of the sensor housing 21, the lid 22, the electric circuit components 40, and the shield member 50. A container chamber 23 is defined between the sensor housing 21 and the lid 22. A wall made of the material of the sensor housing 21 extends to the bottom of the container chamber 23. The conductive member 10 is embedded in the sensor housing 21, even within the container chamber 23.

[0024] The topmost cover 22 has four engaging arms 24a. Each engaging arm 24a has a movable engaging claw 24e that engages with a fixed engaging claw 24b. The engaging claw 24b is also called a fixed claw or a protrusion. The engaging claw 24e is also called a movable claw or a hook. Each engaging arm 24a has two elastic arms 24f that extend parallel to each other in the thickness direction TD from the cover 22. The engaging claw 24e is arranged to connect the tip ends of the two elastic arms 24f. A window 24g is defined between the two elastic arms 24f. The window 24g is slit-shaped and extends elongatedly in the thickness direction TD along the two elastic arms 24f. The window 24g can receive the engaging claws 24b in the connected state.

[0025] The sensor housing 21 shown in the bottom row has a side wall surface 24c that protrudes around the engaging claw 24b to define a groove 24d that surrounds the engaging claw 24b. The opposite is also possible. That is, the groove 24d is defined by recessing the side wall surface 24c in the width direction WD. Furthermore, the engaging claw 24b is defined by protruding a portion of the groove 24d.

[0026] The figure shows the connecting mechanism 24 in a separated state. The assembly process of the insulating member 20 includes a step of bringing the sensor housing 21 and the lid body 22 closer together along the thickness direction TD. In this step, the sensor housing 21 and the lid body 22 transition from a separated state to a connected state. When the engaging arm 24a reaches the range of the groove 24d, the engaging arm 24a collides with the protruding shape of the side wall surface 24c. As a result, the engaging arm 24a is guided along the groove 24d. Eventually, the engaging claw 24e of the engaging arm 24a reaches the engaging claw 24b.

[0027] When the engaging claw 24e collides with the engaging claw 24b, the engaging arm 24a gradually undergoes elastic deformation along the slope of the engaging arm 24a or the engaging claw 24b. This elastic deformation is mainly provided by the deformation of the elastic arm 24f. Even during this elastic deformation, the engaging arm 24a is guided along the groove 24d. Eventually, when the engaging claw 24e overcomes the engaging claw 24b, the engaging arm 24a is restored to its original shape by the elastic force. As a result, the engaging claw 24b is received in the window portion 24g. This completes the connection between the engaging arm 24a and the engaging claw 24b.

[0028] In this embodiment, the engaging arm 24a is guided along the groove 24d by the protrusion of the side wall surface 24c. Therefore, in assembling the insulating member 20, the sensor housing 21 and the lid 22 can be reliably and easily connected. At the same time, the container chamber 23 can be reliably and easily sealed. Such behavior of the connecting mechanisms 24 in the assembly process is performed almost simultaneously for all of the multiple connecting mechanisms 24.

[0029] In the connected state of the connecting mechanism 24, the engaging arm 24a is at least partially embedded in the groove 24d. In the illustrated example, the side wall surface 24c protrudes further than the engaging arm 24a in the width direction WD. This provides a state in which the entire engaging arm 24a is embedded in the groove 24d. As a result, the protrusion of the connecting mechanism 24 from the outer surface of the insulating member 20 is suppressed. From another perspective, the protrusion of the side wall surface 24c protects the engaging arm 24a. As a result, the transition from the connected state to the separated state caused by the operation of the engaging arm 24a is suppressed.

[0030] A wiring board 41, which is one of the electric circuit components 40, is disposed in the container chamber 23. The electric circuit component 40 includes the wiring board 41 and components mounted on the wiring board 41. Circuit elements are disposed on the surface of the wiring board 41. A sensor element 42 is illustrated in the figure. The sensor element 42 is disposed on the lower surface of the wiring board 41 in the figure. The sensor element 42 is disposed on the surface of the wiring board 41 facing the sensor housing 21. In other words, the sensor element 42 is disposed between the wiring board 41 and the conductive member 10. Although one sensor element 42 is illustrated in the figure, the sensor element 42 includes multiple sensing units 121, 122 that form a multiplexed system that can back up each other. The sensor element 42 includes at least two magnetoelectric conversion units 125 that form a multiplexed system that can back up each other.

[0031] Regarding the sensor element 42 and the circuitry associated with the sensor element 42, the contents of Japanese Patent No. 6919609 can be incorporated by reference.

[0032] As shown in FIG. 19, wiring board 41 has a flat plate shape. Wiring board 41 has a thin, flat shape with a small thickness in the thickness direction TD. Wiring board 41 is formed by laminating multiple insulating resin layers and conductive metal layers in the thickness direction TD. The opposing surface 41c, which has the largest area, of wiring board 41 and its rear surface face in the thickness direction TD. FIG. 19 is a bottom view of wiring board 41, showing the surface on which circuit elements are mounted. The surface of wiring board 41 shown in FIG. 19 is called the opposing surface 41c. The opposite surface of wiring board 41 is also called the rear surface.

[0033] The first sensing unit 121 and the second sensing unit 122 shown in FIGS. 19 and 20 are mounted on the opposing surface 41c of the wiring board 41. The first sensing unit 121 and the second sensing unit 122 provide the sensor element 42. The first sensing unit 121 includes an ASIC 123 and a filter 124. The second sensing unit 122 includes the ASIC 123 and the filter 124. The ASIC 123 and the filter 124 are electrically connected via a wiring pattern on the wiring board 41. The connection terminals of the connector 25 are electrically connected to this wiring pattern. ASIC stands for Application Specific Integrated Circuit. It is also possible to adopt a configuration in which the first sensing unit 121 and the second sensing unit 122 are mounted on the back surface. Both the first sensing unit 121 and the second sensing unit 122 have the same configuration as described below.

[0034] ASIC 123 has magnetoelectric converting unit 125, processing circuit 126, connection pin 127, and resin part 128. Magnetoelectric converting unit 125 and processing circuit 126 are electrically connected. One end of connection pin 127 is electrically connected to processing circuit 126. The other end of connection pin 127 is electrically and mechanically connected to wiring board 41. One end of connection pin 127, processing circuit 126, and magnetoelectric converting unit 125 are covered by resin part 128. The other end of connection pin 127 is exposed from resin part 128.

[0035] The magnetoelectric conversion unit 125 has a magneto-resistive effect element whose resistance value varies in response to the magnetic field that passes through it (transmitted magnetic field). The magneto-electric conversion unit 125 has a plurality of magneto-resistive effect elements. The resistance value of each magneto-resistive effect element varies in response to the transmitted magnetic field along the opposing surface 41c. That is, the resistance value of each magneto-resistive effect element varies in response to the component of the transmitted magnetic field along the width direction WD and the component of the transmitted magnetic field along the axial direction AD.

[0036] On the other hand, the resistance value of the magnetoresistive element does not change due to a transmitted magnetic field in the thickness direction TD, so even if external noise in the thickness direction TD passes through the magnetoresistive element, the resistance value of the magnetoresistive element does not change.

[0037] The magnetoresistive element has a pinned layer with a fixed magnetization direction, a free layer whose magnetization direction changes according to a transmitted magnetic field, and a non-magnetic intermediate layer provided between them. If the intermediate layer is non-conductive, the magnetoresistive element is a giant magnetoresistive element. If the intermediate layer is conductive, the magnetoresistive element is a tunneling magnetoresistive element. The magnetoresistive element may also be an anisotropic magnetoresistive element (AMR). Furthermore, the magnetoelectric conversion unit 125 may have a Hall element instead of the magnetoresistive element.

[0038] The resistance value of a magnetoresistive element changes depending on the angle formed by the magnetization directions of the pinned layer and free layer. The magnetization direction of the pinned layer is along the opposing surface. The magnetization direction of the free layer is determined by the transmitted magnetic field along the opposing surface. The resistance value of a magnetoresistive element is smallest when the magnetization directions of the free layer and fixed layer are parallel. The resistance value of a magnetoresistive element is largest when the magnetization directions of the free layer and fixed layer are antiparallel.

[0039] The magnetoelectric converting unit 125 has a first magneto-resistive element 25a and a second magneto-resistive element 25b as the magneto-resistive elements described above. The magnetization directions of the pinned layers of the first magneto-resistive element 25a and the second magneto-resistive element 25b differ by 90°. As a result, the increase and decrease in the resistance values ​​of the first magneto-resistive element 25a and the second magneto-resistive element 25b are reversed. When the resistance value of one of the first magneto-resistive element 25a and the second magneto-resistive element 25b decreases, the resistance value of the other increases by an equal amount.

[0040] The magnetoelectric converting unit 125 has two first magnetoresistance effect elements 25a and two second magnetoresistance effect elements 25b. The first magnetoresistance effect elements 25a and the second magnetoresistance effect elements 25b are connected in series from the power supply potential to the reference potential to form a first half-bridge circuit. The second magnetoresistance effect elements 25b and the first magnetoresistance effect elements 25a are connected in series from the power supply potential to the reference potential to form a second half-bridge circuit.

[0041] In this way, the arrangement of the first magnetoresistance effect element 25a and the second magnetoresistance effect element 25b is reversed in the two half-bridge circuits. Therefore, the midpoint potential of the two half-bridge circuits is configured such that when the potential of one decreases, the potential of the other increases. In the magnetoelectric conversion unit 125, these two half-bridge circuits are combined to form a full-bridge circuit.

[0042] In addition to the magnetoresistive effect elements that form the full-bridge circuit described above, the magnetoelectric conversion unit 125 also includes a differential amplifier 25c, a feedback coil 25d, and a shunt resistor 25e. The midpoint potential of the two half-bridge circuits is input to the inverting input terminal and non-inverting input terminal of the differential amplifier 25c. The feedback coil 25d and the shunt resistor 25e are connected in series in this order from the output terminal of the differential amplifier 25c toward the reference potential.

[0043] With the connection configuration described above, an output corresponding to the change in the resistance value of the first magnetoresistance effect element 25a and the second magnetoresistance effect element 25b that constitute the full-bridge circuit is generated from the output terminal of the differential amplifier 25c. This change in resistance value occurs when a magnetic field along the opposing surfaces passes through the magnetoresistance effect element. A magnetic field (the magnetic field to be measured) generated by the current flowing through the conductive member 10 passes through the magnetoresistance effect element. Therefore, a current corresponding to the magnetic field to be measured flows through the input terminal of the differential amplifier 25c.

[0044] The input and output terminals of the differential amplifier 25c are connected via a feedback circuit (not shown). This virtually shorts the differential amplifier 25c. Therefore, the differential amplifier 25c operates so that the inverting and non-inverting input terminals are at the same potential. In other words, the differential amplifier 25c operates so that the current flowing through the input terminal and the current flowing through the output terminal are zero. As a result, a current (feedback current) corresponding to the magnetic field to be measured flows from the output terminal of the differential amplifier 25c.

[0045] The feedback current flows between the output terminal of the differential amplifier 25c and the reference potential via the feedback coil 25d and the shunt resistor 25e. This flow of the feedback current generates a canceling magnetic field in the feedback coil 25d. This canceling magnetic field passes through the magnetoelectric converter 125, thereby canceling out the magnetic field to be measured that passes through the magnetoelectric converter 125. As a result, the magnetoelectric converter 125 operates so that the magnetic field to be measured that passes through it and the canceling magnetic field are balanced.

[0046] A feedback voltage corresponding to the amount of feedback current that generates the canceling magnetic field is generated at the midpoint between feedback coil 25d and shunt resistor 25e, and this feedback voltage is output to downstream processing circuit 126 as an electrical signal that detects the current to be measured.

[0047] The processing circuit 126 has an adjustment amplifier 126a and a threshold power supply 126b. The non-inverting input terminal of the adjustment amplifier 126a is connected to the midpoint between the feedback coil 25d and the shunt resistor 25e. The inverting input terminal of the adjustment amplifier 126a is connected to the threshold power supply 126b. As a result, a differentially amplified feedback voltage is output from the adjustment amplifier 126a.

[0048] The resistance values ​​of the first magnetoresistance effect element 25a and the second magnetoresistance effect element 25b that make up the full-bridge circuit are temperature-dependent. As a result, the output of the adjustment amplifier 126a fluctuates with temperature changes. Therefore, the processing circuit 126 includes a temperature detection element (not shown) and a nonvolatile memory that stores the relationship between the temperature and resistance values ​​of the magnetoresistance effect elements. This nonvolatile memory is electrically rewritable. The gain and offset of the adjustment amplifier 126a are adjusted by rewriting the values ​​stored in the nonvolatile memory. This cancels out fluctuations in the output of the adjustment amplifier 126a caused by temperature changes.

[0049] The filter 124 has a resistor 124a and a capacitor 124b. As shown in Fig. 20, the wiring board 41 has a power supply wiring 41d, a first output wiring 41e, a second output wiring 41f, and a ground wiring 41g formed as wiring patterns.

[0050] The ASIC 123 of the first sensing unit 121 is connected to the power supply wiring 41d, the first output wiring 41e, and the ground wiring 41g. The output terminal of the adjustment amplifier 126a of the ASIC 123 of the first sensing unit 121 is connected to the first output wiring 41e.

[0051] The resistor 124a of the filter 124 of the first sensing unit 121 is provided on the first output wiring 41e. The capacitor 124b connects the first output wiring 41e and the ground wiring 41g. As a result, the filter 124 of the first sensing unit 121 forms a low-pass filter by the resistor 124a and the capacitor 124b. The output of the ASIC 123 of the first sensing unit 121 is output to the ECU via this low-pass filter. As a result, the output of the first sensing unit 121 from which high-frequency noise has been removed is input to the ECU.

[0052] The ECU 102 is, for example, a battery ECU for a battery that supplies power to a rotating electric machine. For example, the battery ECU, together with an ECU for the rotating electric machine, cooperatively controls the battery and the rotating electric machine. This cooperative control controls the regeneration and power running of the rotating electric machine according to the SOC of the battery. SOC stands for State Of Charge. ECU stands for Electronic Control Unit.

[0053] The ECU 102 has at least one processor circuit that executes the control functions described in this specification. The processor circuit may be provided by a central processing unit (CPU) that executes a program and at least one memory device as a storage medium for storing the program and data. The ECU is provided by a microcomputer equipped with a computer-readable storage medium. The storage medium is a non-transitory tangible storage medium that non-temporarily stores a computer-readable program. The storage medium may be provided by a semiconductor memory, a magnetic disk, or the like. The processor circuit may be provided by an analog arithmetic circuit or a logic circuit including multiple gate circuits.

[0054] The ASIC 123 of the second sensing unit 122 is connected to the power supply wiring 41d, the second output wiring 41f, and the ground wiring 41g. The output terminal of the adjustment amplifier 126a of the ASIC 123 of the second sensing unit 122 is connected to the second output wiring 41f.

[0055] The resistor 124a of the filter 124 of the second sensing unit 122 is provided on the second output wiring 41f. The capacitor 124b connects the second output wiring 41f and the ground wiring 41g. As a result, the filter 124 of the second sensing unit 122 forms a low-pass filter with the resistor 124a and capacitor 124b. The output of the ASIC 123 of the second sensing unit 122 is output to the ECU via this low-pass filter. As a result, the output of the second sensing unit 122 from which high-frequency noise has been removed is input to the ECU.

[0056] As described above, the first sensing unit 121 and the second sensing unit 122 of this embodiment have the same configuration. The magnetoelectric conversion unit 125 of the first sensing unit 121 and the magnetoelectric conversion unit 125 of the second sensing unit 122 are aligned in the axial direction. The magnetic fields that pass through the magnetoelectric conversion unit 125 of the first sensing unit 121 and the magnetoelectric conversion unit 125 of the second sensing unit 122 are the same.

[0057] Assume that a constant current flows through the conductive member 10. In this case, the positions and orientations of the two magnetoelectric converters 125 with respect to the conductive member 10 (narrowed portion 11c) are set so that the same output is obtained from the two magnetoelectric converters 125. In other words, in the above case, the positions and orientations of the two magnetoelectric converters 125 are adjusted so that equivalent magnetic fields having the same strength and vector components pass through them. For example, the positions and orientations of the two magnetoelectric converters 125 with respect to the conductive member 10 depend on the position and orientation of the circuit board 41 with respect to the conductive member 10, the position and orientation of the ASIC 123 on the circuit board 41, and the position and orientation of the magnetoelectric converters 125 within each ASIC 123.

[0058] A virtual straight line is assumed to pass through the center point of the narrowed portion 11c and extend along the axial direction AD. In this embodiment, the two magnetoelectric converting units 125 are arranged side by side on a line parallel to the virtual line. The parallel line is spaced a predetermined distance from the virtual line in the thickness direction TD. In this embodiment, the two magnetoelectric converting units 125 are positioned equidistant from the center point of the narrowed portion 11c in the axial direction AD. In this embodiment, the two magnetoelectric converting units 125 are positioned within the narrowed portion 11c in the axial direction AD. As a result, when a constant current flows through the conductive member 10, the two magnetoelectric converting units 125 produce the same output.

[0059] Therefore, the electrical signal input from the first sensing unit 121 to the ECU is the same as the electrical signal input from the second sensing unit 122 to the ECU. The ECU 102 compares these two input electrical signals to determine whether an abnormality has occurred in either the first sensing unit 121 or the second sensing unit 122. In this way, the current sensor 1 according to this embodiment has redundancy.

[0060] The shunt resistor 25e may be provided inside or outside the resin part 128. When provided outside the resin part 128, the shunt resistor 25e is mounted on the wiring board 41. The shunt resistor 25e is then externally attached to the ASIC 123.

[0061] Furthermore, each of the four resistors constituting the full-bridge circuit does not have to be a magnetoresistive element. At least one of the four resistors must be a magnetoresistive element. Instead of a full-bridge circuit, only one half-bridge circuit may be configured.

[0062] When the above-described redundancy is not required, the current sensor 1 may have either the first sensing unit 121 or the second sensing unit 122. In this case, the sensor element 42 is provided by one sensing unit.

[0063] A first shield 51 serving as a magnetic shield member 50 is disposed in the container chamber 23. The shield member 50 has two shields disposed so as to sandwich the narrowed portion 11c from both sides in the thickness direction TD. Of the two members, one shield 51 is disposed in the container chamber 23. Of the two members, the other shield is disposed on the underside of the sensor housing 21 in the drawing.

[0064] In the container chamber 23, the wiring board 41 and the shield 51 are arranged in a layered manner. The wiring board 41 and the shield 51 are arranged and fixed to the sensor housing 21 with high positional accuracy in the thickness direction TD. In other words, the wiring board 41 and the shield 51 are arranged and fixed to the conductive member 10 with high positional accuracy in the thickness direction TD. The wiring board 41 and the shield 51 are arranged and fixed to the sensor housing 21 with high positional accuracy in the axial direction AD. Furthermore, the wiring board 41 and the shield 51 are arranged and fixed to the sensor housing 21 with high positional accuracy in the width direction WD. The positional accuracy of the wiring board 41 and the shield 51 also affects the accuracy of current detection by the sensor element 42.

[0065] Fig. 3 is a plan view taken along the arrow III in Fig. 2. The insulating member 20 is arranged so as to encase the conductive member 10. The insulating member 20 is a block body arranged in the middle of the conductive member 10. The block body has four connecting mechanisms 24 on its side in the width direction WD. In other words, the four connecting mechanisms 24 connect the block-shaped insulating member 20 at its four corners.

[0066] Figure 4 is a plan view of the wiring board 41. Figure 4 is also a plan view of the wiring board 41 in the direction of arrow VII in Figure 2. The wiring board 41 is a plate-like member made of an insulating material containing an electric circuit. The wiring board 41 can be provided by a single-layer or multilayer printed board. The wiring board 41 has a plurality of through-holes 41a. The plurality of through-holes 41a are through-holes for receiving the terminal pins of the connector 25. The wiring board 41 has a length WD41 in the width direction WD that is greater than the length AD41 in the axial direction AD (AD41 < WD41). Therefore, the wiring board 41 is a rectangular substrate having a longitudinal direction in the width direction WD. The wiring board 41 has a long side and a short side. A plurality of edges of the wiring board 41 are also used as positioning parts.

[0067] The wiring board 41 has a positioning notch 41b. The notch 41b is a portion having a characteristic shape formed in the wiring board 41. The notch 41b is also called a substrate notch or a first notch. The position and shape of the notch 41b specify the posture of the wiring board 41 in the AD-WD plane in the container chamber 23 by fitting with the convex portion 28a described later. The posture of the wiring board 41 in the AD-WD plane defined by the notch 41b and the convex portion 28a is the only posture.

[0068] The wiring board 41 has a plurality of notches 41b. The wiring board 41 has notches 41b on the long side. The wiring board 41 has one notch 41b on one long side and also one notch 41b on the other long side. Assume the center line HF of the length WD41 in the width direction WD. In this case, the notch 41b is located in the half region HR on the terminal side with respect to the center line HF. This arrangement is for facilitating the reception of the through-holes 41a for the terminal pins by accurately positioning the notch 41b. Thereby, the operation of arranging the wiring board 41 on the sensor housing 21 becomes easy.

[0069] The wiring board 41 is substantially symmetrical with respect to the axial direction AD. The two notches 41b are positioned symmetrically with respect to the axial direction AD and have a symmetrical shape. In this embodiment, the notches 41b are provided by cutouts. The notches have a shape that is concave inward with respect to the imaginary rectangular outline of the wiring board 41. The notches 41b define a length AD41b in the axial direction AD. The length AD41b is shorter than the length WD41. The length AD41b is shorter than the length AD41. By defining the length AD41b, the notches 41b prevent the wiring board 41 from being assembled incorrectly.

[0070] FIG. 5 is a plan view of the first shield. FIG. 5 is also a plan view of the shield 51 at the arrow VIII in FIG. 2. The shield 51 is a plate-shaped member formed by stacking multiple magnetic steel plates. The steel plates constituting the shield 51 are made of a magnetically anisotropic material having an easy axis of magnetization in the width direction WD. The multiple steel plates are fixed at multiple press marks 51a. At the press marks 51a, two steel plates are fixed in a stacked state by interlocking with each other, resulting in unevenness.

[0071] The shield 51 has a positioning notch 51b. The shield 51 has multiple notches 51b. The shield 51 has notches 51b at its four corners. The notches 51b are portions formed on the shield 51 and have a characteristic shape. The notches 51b are also called shield notches or second notches. The position and shape of the notches 51b determine the orientation of the shield 51 in the AD-WD plane within the container chamber 23 by fitting with the protrusions 28a and 28b described below. The orientations of the shield 51 in the AD-WD plane determined by the notches 51b and the protrusions 28a, and the notches 51b and the protrusions 28b are two orientations that are 180 degrees inverted.

[0072] The shield 51 is symmetric with respect to the axial direction AD. The shield 51 is also symmetric with respect to the width direction WD. The four notches 51b are positioned symmetrically with respect to the axial direction AD and the width direction WD and exhibit a symmetric shape. In this embodiment, the notch 51b is provided by a notch. The notch is a shape in which the four corners are recessed inward with respect to the virtual outer shape of the square of the shield 51. The notch 51b is provided by a rectangular notch having a longitudinal direction in the axial direction AD.

[0073] The shield 51 has a length AD51 in the axial direction AD. The shield 51 has a length WD51 in the width direction WD. The length AD51 and the length WD51 are equal. The notch 51b defines a length AD51b in the axial direction AD. The notch 51b defines a length WD51b in the width direction WD. The length AD51b is shorter than the length AD51. The length WD51b is shorter than the length WD51. The length AD51b and the length WD51b are different. The length AD51b is shorter than the length WD51b (AD51b < WD51b). The notch 51b suppresses misassembly of the shield 51 by defining the length AD51b and the length WD51b to different lengths.

[0074] FIG. 6 is a plan view in the direction of arrow VI in FIG. 2. The sensor housing 21 partitions the container chamber 23. The sensor housing 21 has a bottom wall 21a. The bottom wall 21a is also a wall made of an insulating member that inserts the conductive member 10. The sensor housing 21 has an outer wall 21b. The outer wall 21b is a wall that extends in the thickness direction TD from the surface of the bottom wall 21a. The outer wall 21b extends annularly in the AD-WD plane. The bottom wall 21a and the outer wall 21b partition many parts of the container chamber 23. The container chamber 23 is partitioned as a rectangular parallelepiped cavity having a longitudinal direction in the width direction WD.

[0075] The sensor housing 21 has a plurality of substrate support members 26 on the bottom wall 21a. The substrate support members 26 position and fix the wiring board 41 in the thickness direction TD within the container chamber 23. The substrate support members 26 are protrusions that protrude from the bottom wall 21a in the thickness direction TD. The substrate support members 26 are columnar members. The substrate support members 26 are cylindrical. Alternatively, the substrate support members 26 can be provided in various cross-sectional shapes, such as hemispherical protrusions, polygonal pillars, or elliptical pillars. The substrate support members 26 are also called substrate supports or substrate protrusions.

[0076] The multiple board support members 26 include multiple board contact portions 26a. The board contact portions 26a provide positioning by contact between the sensor housing 21 and the wiring board 41. The multiple board contact portions 26a are provided by a resin material that is continuous with the sensor housing 21. The multiple board contact portions 26a may be provided by components separate from the sensor housing 21. The board contact portions 26a are also called board contact pins, contact board supports, or board supports. The multiple board support members 26 include multiple board adhesive portions 26b. The board adhesive portions 26b bond the sensor housing 21 and the wiring board 41 via an adhesive layer 31 (described below). The sensor housing 21 and the wiring board 41 are fixed by the adhesive action of the adhesive layer 31. The multiple board contact portions 26a contact the wiring board 41 without the adhesive layer 31, thereby accurately determining the position of the wiring board 41 in the thickness direction TD. The multiple board adhesive portions 26b are provided by a resin material that is continuous with the sensor housing 21. The plurality of substrate adhesive portions 26b may be provided by a member separate from the sensor housing 21. The substrate adhesive portions 26b are also called substrate adhesive pins or adhesive substrate supports. The tip positions of the plurality of substrate adhesive portions 26b are farther from the wiring board 41 than the tip positions of the plurality of substrate contact portions 26a to allow for the presence of the adhesive layer 31. The tip positions may be compared in terms of height from a reference position of the bottom wall 21a. In this case, the height of the plurality of substrate adhesive portions 26b is lower than the height of the plurality of substrate contact portions 26a to allow for the presence of the adhesive layer 31.

[0077] The sensor housing 21 has a plurality of shield support members 27 on the bottom wall 21a. The shield support members 27 position and fix the shield 51 in the thickness direction TD within the container chamber 23. The shield support members 27 are protrusions that protrude from the bottom wall 21a in the thickness direction TD. The shield support members 27 are columnar members. The shield support members 27 are polygonal columnar. The shield support members 27 may extend along the outer wall 21b. Alternatively, the shield support members 27 may have various cross-sectional shapes, such as hemispherical protrusions, cylindrical shapes, or elliptical cylindrical shapes. The shield support members 27 are also called shield supports or shield protrusions.

[0078] The multiple shield support members 27 include multiple shield contact portions 27a. The shield contact portions 27a provide positioning by contact between the sensor housing 21 and the shield 51. The multiple shield contact portions 27a are provided by a resin material that is continuous with the sensor housing 21. The multiple shield contact portions 27a may be provided by members separate from the sensor housing 21. The shield contact portions 27a are also called shield contact pins, contact shield supports, or shield supports. The multiple shield support members 27 include multiple shield adhesive portions 27b. The shield adhesive portions 27b bond the sensor housing 21 and the shield 51 via an adhesive layer 31 (described below). The sensor housing 21 and the shield 51 are fixed by the adhesive action of the adhesive layer 31. The multiple shield contact portions 27a contact the shield 51 without the adhesive layer 31, thereby accurately determining the position of the shield 51 in the thickness direction TD. The multiple shield adhesive portions 27b are provided by a resin material that is continuous with the sensor housing 21. The multiple shield adhesive portions 27b may be provided by separate members from the sensor housing 21. The shield adhesive portions 27b are also called shield adhesive pins or adhesive shield supports. The tip positions of the multiple shield adhesive portions 27b are farther from the wiring board 41 than the tip positions of the multiple shield contact portions 27a to allow for the presence of the adhesive layer 31. The tip positions may be compared in terms of height from a reference position of the bottom wall 21a. In this case, the height of the multiple shield adhesive portions 27b is lower than the height of the multiple shield contact portions 27a to allow for the presence of the adhesive layer 31.

[0079] In order to arrange the wiring board 41 and the shield 51 in a layered manner within the container chamber 23, the tip positions of the multiple board support members 26 are closer to the reference position of the bottom wall 21a than the tip positions of the multiple shield support members 27. In other words, in order to arrange the wiring board 41 and the shield 51 in a layered manner within the container chamber 23, the height of the multiple board support members 26 is lower than the height of the multiple shield support members 27.

[0080] The sensor housing 21 has multiple surrounding portions 28. The surrounding portions 28 position the wiring board 41 and / or the shield 51 in the axial direction AD and the width direction WD within the container chamber 23. The surrounding portions 28 determine the position of the wiring board 41 and the position of the shield 51 in the AD-WD plane. The surrounding portions 28 may fix the wiring board 41 and / or the shield 51. The surrounding portions 28 are disposed at corners between the bottom wall 21a and the outer wall 21b. The surrounding portions 28 are small, plate-like pieces. The surrounding portions 28 have a thickness in the thickness direction TD and are plate-like and extend parallel to the AD-TH plane. The surrounding portions 28 gradually taper toward their ends in the thickness direction TD. The tapered shape guides the wiring board 41 by loosely fitting with the notch 41b of the wiring board 41 as the wiring board 41 is assembled from the opening side of the container chamber 23 toward the bottom wall 21a. The tapered shape allows the fit between the surrounding portion 28 and the notch 41b to transition from a loose fit to a tight fit. The surrounding portion 28 is provided by a resin material that is continuous with the sensor housing 21. Multiple surrounding portions 28 may be provided by members separate from the sensor housing 21. The surrounding portions 28 are also called lateral supports because they are positioned laterally of the wiring board 41 and / or the shield 51 and define their positions.

[0081] The multiple surrounding portions 28 include protrusions 28a. The protrusions 28a are provided by a resin material that is continuous with the sensor housing 21. The multiple protrusions 28a may be provided by separate members from the sensor housing 21. The protrusions 28a are also called first lateral supports. The protrusions 28a position the wiring board 41 in the AD-WD plane. The shape of the protrusions 28a allows them to fit into the notches 41b of the wiring board 41. This fit is relatively tight in both the axial direction AD and the width direction WD to achieve accurate positioning. By fitting into the notches 41b, the protrusions 28a accurately position the wiring board 41 in both the axial direction AD and the width direction WD.

[0082] The protrusion 28a prevents the wiring board 41 from being positioned upside down with respect to the width direction WD. During the process of assembling the wiring board 41 into the container chamber 23, it is conceivable that an incorrect assembly may be attempted with the wiring board 41 in an inverted state with respect to the width direction WD. In the case of incorrect assembly, the protrusion 28a cannot be fitted to the wiring board 41. Therefore, the wiring board 41 will not be positioned in the specified position within the container chamber 23. As a result, the worker can easily notice the incorrect assembly. Therefore, incorrect assembly can be reliably prevented.

[0083] Furthermore, the protrusion 28a also functions as a member for positioning the shield 51 relative to the shield 51. In other words, the protrusion 28a positions both the wiring board 41 and the shield 51 on the AD-WD plane.

[0084] In the case of the above-described incorrect assembly, the wiring board 41 is placed on the protrusion 28a, so even if an attempt is subsequently made to assemble the shield 51, it is impossible to position the shield 51. As a result, the shield 51 cannot be placed in the specified position within the container chamber 23. This allows the worker to easily notice the incorrect assembly. Therefore, incorrect assembly can be reliably prevented.

[0085] The multiple surrounding portions 28 include protrusions 28b. The protrusions 28b are provided by a resin material that is continuous with the sensor housing 21. The multiple protrusions 28b may be provided by members separate from the sensor housing 21. The protrusions 28b are also called second lateral supports. The protrusions 28a and 28b work together to position the shield 51 on the AD-WD plane. The shapes of the protrusions 28a and 28b are such that they can fit into the notches 51b at the four corners of the shield 51.

[0086] The protrusions 28b are disposed at the corners of the outer wall 21b. The protrusions 28b are raised portions whose lengths in the axial direction AD and the width direction WD are different. The protrusions 28b are rectangular raised portions whose length in the axial direction AD is longer than their length in the width direction WD.

[0087] The sensor housing 21 has two protrusions 28b. The two protrusions 28b are spaced apart from each other in the axial direction AD. A gap is formed between the two protrusions 28b in the axial direction AD, which can accommodate the length AD51b. The gap has a length that can accommodate the side of the shield 51 with the length AD51b with high precision. The gap is set so that it cannot accommodate the side of the shield 51 with the length AD51. The two protrusions 28a have a shape that functions as the protrusions 28b. In this respect, the protrusions 28a are also the protrusions 28b. The two protrusions 28a are spaced apart from each other in the axial direction AD. A gap is formed between the two protrusions 28a, which can accommodate the shield 51 with the length AD51b in the axial direction AD. The gap has a length that can accommodate the side of the shield 51 with the length AD51b with high precision. The gap is set so that it cannot accommodate the side of the shield 51 with the length AD51.

[0088] In this way, the two protrusions 28a provide an axial pair of surrounding portions 28 that position the shield 51 with respect to the axial direction AD. Also, the two protrusions 28b provide an axial pair of surrounding portions 28 that position the shield 51 with respect to the axial direction AD. As a result, the sensor housing 21 provides two axial pairs of surrounding portions 28 with four surrounding portions 28.

[0089] Each protrusion 28a and each protrusion 28b are spaced apart from each other in the width direction WD. A gap is formed between the protrusions 28a and 28b in the width direction WD, allowing the shield 51 to be accommodated with a length WD51b. The gap is long enough to accommodate the side of the shield 51 with length WD51b with high precision. The gap is set so that it cannot accommodate the side of the shield 51 with length WD51.

[0090] As described above, the sensor housing 21 has one protrusion 28a and one protrusion 28b positioned apart in the width direction WD. These provide a widthwise pair of surrounding portions 28 that position the shield 51 in the width direction WD. The sensor housing 21 has four surrounding portions 28, providing two pairs of widthwise pairs. These four surrounding portions 28 provide positioning portions in two orthogonal axial directions (axial direction AD and width direction WD).

[0091] The multiple surrounding portions 28 include protrusions 28e. The protrusions 28e are provided by a resin material that is continuous with the sensor housing 21. The multiple protrusions 28e may be provided by separate members from the sensor housing 21. The protrusions 28e are also called third lateral supports. The protrusions 28a and 28e work together to position the wiring board 41 in the AD-WD plane. The shape of the protrusions 28e allows them to come into contact with the edge of the wiring board 41. The shape of the protrusions 28e provides a fitting relationship between the wiring board 41 and the sensor housing 21. The protrusions 28e are lower in the thickness direction TD than the protrusions 28a and 28b. The protrusions 28e contact the wiring board 41 in the axial direction AD and the width direction WD, but do not contact the shield 51 in the axial direction AD and the width direction WD.

[0092] The sensor housing 21 provides two axial pairs and two widthwise pairs by the four enclosing portions 28. The two axial pairs and two widthwise pairs position the shield 51 with high precision in both the axial direction AD and the width direction WD.

[0093] The protrusions 28a and 28b prevent the shield 51 from being positioned with the axial direction AD and the width direction WD reversed. This is effective for aligning the easy axis of magnetization of the shield 51 with the width direction WD. During the process of assembling the shield 51 into the container chamber 23, it is conceivable that an incorrect assembly may be attempted with the shield 51 rotated 90 degrees. In the case of incorrect assembly, the protrusions 28a and 28b will not be able to fit with the shield 51. Therefore, the shield 51 will not be positioned in the correct position within the container chamber 23. As a result, the worker can easily notice the incorrect assembly. Therefore, incorrect assembly can be reliably prevented.

[0094] The plurality of substrate support members 26 and the plurality of shield support members 27 are arranged inside the outer wall 21b in the container chamber 23. The plurality of substrate support members 26 and the plurality of shield support members 27 are arranged in a dispersed manner. The plurality of surrounding portions 28 are arranged on the inner surface of the outer wall 21b. The plurality of surrounding portions 28 are arranged in a dispersed manner inside the outer wall 21b. The plurality of surrounding portions 28 are arranged in the container chamber 23 so that the wiring board 41 can be placed in the container chamber 23 only in a specified orientation. The plurality of surrounding portions 28 are arranged in the container chamber 23 so that the shield 51 can be placed in the container chamber 23 only in a specified orientation.

[0095] The sensor housing 21 has a plurality of connector pins 29. The plurality of connector pins 29 are electrically connected to an electric circuit provided by the wiring board 41 by positioning the wiring board 41 at a specified position.

[0096] A line of symmetry SY can be imagined at the center of the narrowed portion 11c in the axial direction AD. In this case, the shape of the sensor housing 21 is axisymmetric with respect to the line of symmetry SY. The outer wall 21b extends axisymmetrically with respect to the line of symmetry SY. The multiple board support members 26 are arranged axisymmetrically with respect to the line of symmetry SY. The multiple shield support members 27 are arranged axisymmetrically with respect to the line of symmetry SY. The multiple enclosing portions 28 are arranged axisymmetrically with respect to the line of symmetry SY. The multiple connector pins 29 are arranged axisymmetrically with respect to the line of symmetry SY. Furthermore, the multiple elements constituting the current sensor 1 are axisymmetric with respect to the line of symmetry SY. The multiple elements constituting the current sensor 1 are axisymmetric with respect to the line of symmetry SY at least near the narrowed portion 11c. The conductor member 11 has an axisymmetric shape with respect to the line of symmetry SY near the narrowed portion 11c. The insulating member 20 has an axisymmetric shape with respect to the line of symmetry SY. The electrical circuit component 40 has an axisymmetric shape with respect to the line of symmetry SY. The shield member 50 has a shape that is symmetrical with respect to the line of symmetry SY.

[0097] Fig. 7 is a plan view taken along the arrow VII in Fig. 2. Only the wiring board 41 is attached to the sensor housing 21. The multiple board support members 26 are covered and hidden by the wiring board 41. In this state, only the multiple shield support members 27 are visible.

[0098] 8 is a plan view taken along the arrow VIII in FIG. 2. Both the wiring board 41 and the shield 51 are assembled to the sensor housing 21 in a layered manner. The wiring board 41 is disposed between the shield 51 and the sensor housing 21. The plurality of board support members 26 are covered and hidden by the wiring board 41. Furthermore, in this state, the plurality of shield support members 27 are also covered and hidden by the shield 51.

[0099] 9 is a cross-sectional view taken along line IX-IX in FIG. 8. The plurality of connector pins 29 are held in the sensor housing 21. The plurality of connector pins 29 may be embedded in the sensor housing 21 by insert molding. The plurality of connector pins 29 may be inserted into the sensor housing 21, which is a resin-molded product. One ends of the plurality of connector pins 29 protrude into the container chamber 23. Furthermore, the plurality of connector pins 29 are inserted into through holes 41a of a wiring board 41. The plurality of connector pins 29 are electrically connected to an electric circuit provided by the wiring board 41.

[0100] The wiring board 41 is supported by contacting the board contact portion 26a of the sensor housing 21. The wiring board 41 is engaged with the surrounding portion 28 at the notch 41b. The notch 41b and the surrounding portion 28 form a fitting relationship, thereby positioning the wiring board 41 in both the axial direction AD and the thickness direction TD.

[0101] The surrounding portion 28 includes a protrusion 28a and a protrusion 28b. The protrusion 28a is plate-shaped. The protrusion 28a protrudes in a plate-like shape from the inner surface of the surrounding portion 28. The protrusion 28b is ridge-shaped. The protrusion 28a protrudes in a rectangular parallelepiped shape from a corner of the inner surface of the surrounding portion 28. The side shapes of the protrusion 28a and the side shapes of the protrusion 28b correspond to each other and have the same shape. In the following description, the vertical surface 28c and the inclined surface 28d of the surrounding portion 28 are formed in both the side shape of the protrusion 28a and the side shape of the protrusion 28b.

[0102] The surrounding portion 28 has a portion with a vertical surface 28c extending along the thickness direction TD. This vertical surface 28c forms a tight fit with the notch 41b or the notch 51b. Furthermore, the surrounding portion 28 has a tapered shape at its tip in the thickness direction TD. The tapered shape is provided by a slope 28d that is inclined with respect to the thickness direction TD.

[0103] The inclined surface 28d forms a loose fit with the notch 41b during the process of placing the wiring board 41 in the container chamber 23. The inclined surface 28d guides the wiring board 41 by loosely fitting with the notch 41b during the process of inserting the wiring board 41 into the container chamber 23 through the opening of the container chamber 23. During the process of placing the wiring board 41 at a specified position in the container chamber 23, the fit between the notch 41b and the protrusion 28a gradually and smoothly transitions from a loose fit to a tight fit.

[0104] The inclined surfaces 28d form a loose fit with the notches 51b during the process of placing the shield 51 in the container chamber 23. The inclined surfaces 28d guide the shield 51 by the loose fit with the notches 51b during the process of inserting the shield 51 into the container chamber 23 from the opening of the container chamber 23. During the process of placing the shield 51 at a predetermined position in the container chamber 23, the fit between the four notches 51b and the two protrusions 28a and the two protrusions 28b gradually and smoothly transitions from a loose fit to a tight fit.

[0105] 10 is a modeled cross-sectional view, which illustrates the support state (including both the bonded state and the contact state) of wiring board 41 and shield 51 with respect to sensor housing 21.

[0106] The wiring board 41 is supported relative to the sensor housing 21 by a plurality of board support members 26. The wiring board 41 is in mechanical contact with the top surfaces of a plurality of board contact portions 26a. The plurality of board contact portions 26a determine the position of the wiring board 41 relative to the sensor housing 21. Therefore, the wiring board 41 is positioned and supported relative to the sensor housing 21 by the plurality of board contact portions 26a. The wiring board 41 is accurately positioned without any variable factors such as the adhesive layer 31. The number of the plurality of board contact portions 26a is selected from three, four, five, etc. so that the wiring board 41 can be stably supported. Furthermore, the plurality of board contact portions 26a are arranged in a dispersed manner within the container chamber 23 so that the wiring board 41 is stable.

[0107] The wiring substrate 41 is adhered to the sensor housing 21 by an adhesive layer 31 disposed between the wiring substrate 41 and the top surfaces of the substrate adhesive portions 26b. The adhesive layer 31 is adhered to the wiring substrate 41 on one side and to the top surfaces of the substrate adhesive portions 26b on the other side. The substrate adhesive portions 26b and the adhesive layer 31 adhesively fix the wiring substrate 41 to the sensor housing 21. The adhesive layer 31 is a cured adhesive. The adhesive layer 31 is also referred to as a cured adhesive layer. The wiring substrate 41 is fixed via a variable element such as the adhesive layer 31. The number of substrate adhesive portions 26b is selected from three, four, five, etc. so that the wiring substrate 41 can be stably supported and an appropriate adhesive force can be obtained. The substrate adhesive portions 26b are also dispersedly disposed within the container chamber 23 so that the wiring substrate 41 is stable.

[0108] The height of the top surface of the substrate adhesive portion 26b is lower than the height of the top surface of the substrate contact portion 26a so as to allow for the presence of the adhesive layer 31. The difference between the height of the top surface of the substrate contact portion 26a and the height of the top surface of the substrate adhesive portion 26b corresponds to the thickness of the adhesive layer 31. Here, the height of the top surfaces of the plurality of substrate support members 26 can be the height in the thickness direction TD from any portion of the bottom wall 21a that faces the container chamber 23.

[0109] According to the illustrated configuration, the multiple substrate contact portions 26a enable accurate positioning of the wiring substrate 41 relative to the sensor housing 21, and the multiple substrate adhesive portions 26b and adhesive layer 31 enable adhesion, i.e., fixation, of the wiring substrate 41 to the sensor housing 21.

[0110] The shield 51 is supported relative to the sensor housing 21 by a plurality of shield support members 27. The shield 51 is in mechanical contact with the top surfaces of a plurality of shield contact portions 27a. The plurality of shield contact portions 27a determine the position of the shield 51 relative to the sensor housing 21. Thus, the shield 51 is positioned and supported relative to the sensor housing 21 by the plurality of shield contact portions 27a. The shield 51 is accurately positioned without any variable factors such as an adhesive layer 31. The number of the plurality of shield contact portions 27a is selected from three, four, five, etc. so that the shield 51 can be stably supported. Furthermore, the plurality of shield contact portions 27a are arranged in a dispersed manner within the container chamber 23 so that the shield 51 is stable.

[0111] The shield 51 is adhered to the sensor housing 21 by an adhesive layer 31 disposed between the top surfaces of the shield adhesive portions 27b and the shield 51. The adhesive layer 31 is adhered to the shield 51 on one side and to the top surfaces of the shield adhesive portions 27b on the other side. The shield adhesive portions 27b and the adhesive layer 31 adhesively fix the shield 51 to the sensor housing 21. The adhesive layer 31 is a hardened adhesive. The adhesive layer 31 is also referred to as a hardened adhesive layer. The shield 51 is fixed via variable elements such as the adhesive layer 31. The number of the shield adhesive portions 27b is selected from three, four, five, etc. so that the shield 51 can be stably supported and an appropriate adhesive force can be obtained. The shield adhesive portions 27b are also arranged in a dispersed manner within the container chamber 23 so that the shield 51 is stable.

[0112] The height of the top surface of the shield adhesive portion 27b is lower than the height of the top surface of the shield contact portion 27a so as to allow for the presence of the adhesive layer 31. The difference between the height of the top surface of the shield contact portion 27a and the height of the top surface of the shield adhesive portion 27b corresponds to the thickness of the adhesive layer 31. Here, the height of the top surfaces of the multiple shield support members 27 can be the height in the thickness direction TD from any portion of the bottom wall 21a that faces the container chamber 23.

[0113] According to the illustrated configuration, the multiple shield contact portions 27a enable accurate positioning of the shield 51 relative to the sensor housing 21, and the multiple shield adhesive portions 27b and adhesive layer 31 enable adhesion, i.e., fixation, of the shield 51 relative to the sensor housing 21.

[0114] Fig. 11 is a perspective view of the lid 22. Fig. 12 is a rear view showing the inside of the lid 22. These figures illustrate the inner surface of the lid 22.

[0115] The lid 22 has a main body 22a. The main body 22a can be called a rectangular plate or a shallow rectangular dish. The lid 22 has an outer edge 22b at the edge of the main body 22a, which has a predetermined height in the thickness direction TD. The lid 22 further has an inner edge 22c located more inward than the outer edge 22b. The inner edge 22c also has a predetermined height in the thickness direction TD. The outer edge 22b and the inner edge 22c define an annular seal chamber 22d therebetween. The seal chamber 22d can accommodate the outer wall 21b of the sensor housing 21.

[0116] The lid 22 has a plurality of engaging arms 24a. When the engaging arms 24a of the lid 22 and the engaging claws 24b of the sensor housing 21 are coupled together, the seal chamber 22d and the outer wall 21b form a fitted relationship. As a result, the container chamber 23 is defined between the sensor housing 21 and the lid 22. The inner edge 22c can have a slope that comes into contact with the outer wall 21b.

[0117] The cover 22 has at least one shield pressing portion 22e. The cover 22 has multiple shield pressing portions 22e. The multiple shield pressing portions 22e enable stable support of the shield 51. The shield pressing portion 22e protrudes from the inner edge 22c in the thickness direction TD. The shield pressing portion 22e is shaped like a thin column. The shield pressing portion 22e is shaped like a cylinder. The shield pressing portion 22e can also be called a protrusion. Alternatively, the shield pressing portion 22e can be provided in various cross-sectional shapes, such as a hemisphere, a polygonal column, or an elliptical column. The shield pressing portion 22e is provided by a resin material that is continuous with the cover 22. The shield pressing portion 22e may be provided as a separate member from the cover 22. The shield pressing portion 22e is also called a shield pressing pin or a shield back support. The shield pressing portion 22e supports the shield by the elastic force of multiple members included in the cover 22.

[0118] The multiple shield pressing portions 22e are dispersedly arranged along three of the four sides of the inner edge 22c. In other words, the multiple shield pressing portions 22e are dispersedly arranged along the edge of the shield 51. The dispersed arrangement of the multiple shield pressing portions 22e contributes to stable support of the shield 51. In this embodiment, two shield pressing portions 22e are arranged along one side of the inner edge 22c. The remaining side of the four sides of the inner edge 22c is located outside the range of the shield 51. A protrusion 22f is arranged on the remaining side of the four sides of the inner edge 22c instead of a shield pressing portion 22e. The shield pressing portion 22e contacts the shield 51 in a specific range on the other surface of the shield 51. The specific range is a range along the edge of the shield 51. The specific range can be referred to as the opposite side to the contact range of the shield contact portion 27a. In this embodiment, the specific range is a strip-shaped range extending along the edge of the shield 51. As a result, the shield 51 is sandwiched between the shield contact portion 27a and the shield pressing portion 22e. The positions of the shield contact portion 27a and the shield pressing portion 22e are positioned in a substantially opposing relationship on both sides of the shield 51, thereby stably maintaining the position of the shield 51. The positions of the shield contact portion 27a and the shield pressing portion 22e are positioned in a substantially opposing relationship in the thickness direction TD on both sides of the shield 51. Note that the substantially opposing positional relationship is not a mathematical positional relationship. The substantially opposing positional relationship includes a tolerance range that does not cause the shield 51 to tilt. For example, the substantially opposing positional relationship includes a state in which the positions of the shield contact portion 27a and the shield pressing portion 22e are positioned along the same side of the shield 51. Additionally or alternatively, the substantially opposing positional relationship includes a state in which the positions of the shield contact portion 27a and the shield pressing portion 22e are misaligned by a range of several millimeters to several centimeters.

[0119] A line of symmetry SY can be imagined at the center in the axial direction AD of the cover 22. In this case, the shape of the cover 22 is symmetrical with respect to the line of symmetry SY. The multiple shield pressing portions 22e are arranged at approximately equal intervals along the inner edge 22c to ensure uniform contact with the shield 51.

[0120] Fig. 13 is a cross-sectional view of the current sensor 1. The figure shows a cross section taken along line XIII-XIII in Fig. 2. Note that line XIII-XIII is an example, and the cross section may be somewhat complex to help understand the shape of the components.

[0121] The shield pressing portion 22e contacts the shield 51 when the cover 22 is connected to the sensor housing 21. The shield 51 is adhered to the sensor housing 21 by the shield adhesive portion 27b and the adhesive layer 31, and is therefore fixed. The cover 22 prevents the shield 51 from moving in the thickness direction TD by contacting the shield 51 with the shield pressing portion 22e. In other words, the shield 51 is supported by contact with the shield contact portion 27a on one side and by contact with the shield pressing portion 22e on the other side. The shield 51 is disposed between the shield contact portion 27a and the shield pressing portion 22e. As a result, the position of the shield 51 is stably maintained in the thickness direction TD. For example, it is conceivable that the adhesive strength of the adhesive layer 31 may be weakened due to peeling or cracking of the adhesive layer 31. Even in such a case, the shield 51 continues to be accurately positioned by the shield contact portion 27a and the shield pressing portion 22e. In an extreme case, even if the adhesive force of adhesive layer 31 is completely lost, shield pressing portion 22e prevents shield 51 from lifting up.

[0122] 13, the shield member 50 is disposed so as to sandwich the conductive member 10 and the sensor element 42 from both sides in the thickness direction TD. The shield member 50 forms a magnetic path surrounding the conductive member 10. The shield member 50 forms a ring-shaped magnetic path surrounding the conductive member 10 and the sensor element 42. The shield member 50 is disposed so as to magnetically protect the conductive member 10 and the sensor element 42. The shield member 50 has a first shield 51 and a second shield 52. Note that the shield member 50 may be provided by only the shield 51, only the shield 52, or by shields of different shapes.

[0123] The current sensor 1 detects magnetic flux induced by the current flowing through the conductive member 10 and outputs an electrical signal indicating the amount of current. The current flowing through the conductive member 10 generates a normal magnetic flux to be detected. A portion of this magnetic flux is detected by the sensor element 42. In the following description, the magnetic flux generated due to the current flowing through the conductive member 10 may be referred to as the normal magnetic flux. In contrast, if the current sensor 1 is located in the magnetic field of another magnetic source, the magnetic flux caused by the other magnetic source may be referred to as the external magnetic flux. The external magnetic flux imparts noise components to the output of the current sensor 1.

[0124] A magnetic source external to the current sensor 1 may supply external magnetic flux that attempts to reach the sensor element 42 from outside the current sensor 1. The external magnetic flux appears as a noise component in the output of the sensor element 42. The external magnetic flux reduces the detection accuracy of the current sensor 1. The shield member 50 captures the external magnetic flux. The shield member 50 suppresses the external magnetic flux from reaching the sensor element 42. Preferably, the shield member 50 blocks the external magnetic flux from reaching the sensor element 42. Thus, the shield member 50 provides a magnetic shield.

[0125] From another perspective, a portion of the normal magnetic flux tends to leak out of the current sensor 1 as leakage magnetic flux. Fluctuations in the amount of leakage magnetic flux and in the path of the leakage magnetic flux may cause fluctuations in the magnetic flux to be detected that intersects with the sensor element 42. The shield member 50 captures the normal magnetic flux. The shield member 50 suppresses the leakage magnetic flux. As a result, the shield member 50 suppresses fluctuations in the magnetic flux inside the shield member 50, i.e., the normal magnetic flux that intersects with the sensor element 42, that are caused by fluctuations in the leakage magnetic flux. From this perspective as well, the shield member 50 provides a magnetic shield.

[0126] FIG. 14 is a side view showing a magnetic shield. The shield member 50 magnetically protects a sensor system including the conductive member 10 and the sensor element 42. The shield member 50 is disposed around at least a portion of the conductive member 10 and the sensor element 42, defining a magnetic gap G50. The shield 51 has a rectangular plate shape in a TD-WD plane perpendicular to the axial direction AD. The shield 52 has a central portion 52a having a rectangular plate shape. The shield 52 further has an extension portion 52b extending in the thickness direction TD from one end of the central portion 52a in the width direction WD. The shield 52 has an extension portion 52c extending in the thickness direction TD from the other end of the central portion 52a in the width direction WD. The shield 52 has the central portion 52a and two extension portions 52b and 52c. The extension portions 52b and 52c are also called arm portions. As a result, the shield 52 has a shape that can be called a U-shape or a bracket-shape in the TD-WD plane perpendicular to the axial direction AD. A portion of the surface of the shield 51 faces the end face of the extension portion 52b facing in the thickness direction TD. Another portion of the surface of the shield 51 faces the end face of the extension portion 52c facing in the thickness direction TD. A magnetic gap G50 is formed between the shields 51 and 52. The shield member 50 has two gaps G50 corresponding to positions that can be called both ends of the shield 51 or both ends of the shield 52.

[0127] According to this embodiment, even if there is external magnetic flux in the thickness direction TD, the shield 51 and the central portion 52a prevent the external magnetic flux from reaching the sensor element 42. Furthermore, even if there is external magnetic flux in the width direction WD, the extension portions 52b and 52c prevent the external magnetic flux from reaching the sensor element 42.

[0128] In this embodiment, the conductive member 10, the sensor element 42, and the shield member 50 are arranged symmetrically with respect to a line of symmetry SY. The conductive member 10, the sensor element 42, and the shield member 50 are magnetic elements of the current sensor 1. The line of symmetry SY is an axis that passes through the sensor element 42 and extends along the thickness direction TD. The magnetic elements are arranged and shaped symmetrically with respect to the line of symmetry SY. Such a symmetric arrangement and shape contribute to suppressing fluctuations in the magnetic flux in the sensor element 42.

[0129] Returning to FIG. 13 , the insulating material forming the sensor housing 21 and the wiring board 41 are disposed in the magnetic gap G50 between the shield 51 and the shield 52. The magnetic gap G50 is also called an air gap, even if some non-magnetic material is present. The presence of the magnetic gap G50 suppresses magnetic saturation in the shield 51 and / or the shield 52 due to normal magnetic flux. Furthermore, the relative positional relationship between the magnetic gap G50 and the sensor element 42 is set to suppress magnetic flux linking to the sensor element 42 due to residual magnetization in the shield material 50.

[0130] FIG. 15 is a perspective view showing a magnetic shield. Shields 51 and 52 are formed as plate-like members having a predetermined thickness by laminating multiple steel plates. In the following description, the magnetic path cross-sectional area refers to the cross-sectional area in a cross section perpendicular to the annular magnetic path provided by shield member 50. Central portion 52a of shield 52 has magnetic path cross-sectional area S1 in a cross section parallel to the AD-TD plane. In other words, magnetic path cross-sectional area S1 is the magnetic path cross-sectional area of ​​the shield at the portion farthest from magnetic gap G50 in the magnetic path. Extension portion 52b of shield 52 has magnetic path cross-sectional area S2 in a cross section parallel to the AD-WD plane. Extension portion 52c of shield 52 also has magnetic path cross-sectional area S2 in a cross section parallel to the AD-WD plane. In other words, magnetic path cross-sectional area S2 of extension portions 52b and 52c is the magnetic path cross-sectional area of ​​the shield at the portion closest to magnetic gap G50. The magnetic path cross-sectional area S1 is larger than the magnetic path cross-sectional area S2 (S1>S2). Therefore, the magnetic path cross-sectional area S1 of the shield at the portion 52a, which is the farthest from the magnetic gap G50 in the magnetic path, is larger than the magnetic path cross-sectional area S2 of the shield at the portions 52b and 52c, which are closer to the magnetic gap G50.

[0131] The shield member 50 has a first portion that is far from the gap G50 in the magnetic path formed by the shield member 50. The shield member 50 further has a second portion that is closer to the gap G50 than the first portion. The central portion 52a forms the first portion. The first extension portion 52b or the second extension portion 52c forms the second portion. The shield member 50 is formed such that, with respect to the magnetic path cross-sectional area of ​​the magnetic path, the magnetic path cross-sectional area S1 in the first portion (central portion 52a) is larger than the magnetic path cross-sectional area S2 in the second portion (first extension portion 52b and second extension portion 52c).

[0132] Here, it is assumed that partial magnetic saturation occurs in a portion of the shield member 50 in the annular direction. In this case, external magnetic flux may pass through the magnetically saturated portion and reach the sensor element 42. For example, a normal magnetic flux induced by a current flowing through the conductive member 10 may cause partial magnetic saturation. Here, it is assumed that magnetic saturation occurs in a range of the shield member 50 that includes the portion closest to the sensor element 42. In this case, the external magnetic flux may have a significant effect on the sensor element 42.

[0133] Furthermore, if magnetic saturation occurs in a portion of the shield member 50, the normal magnetic flux passing through the sensor element 42 also changes. For example, if magnetic saturation occurs only in the shield 52, the distribution of magnetic flux density around the conductive member 10 fluctuates. In other words, the balance of magnetic flux density around the conductive member 10 fluctuates. As a result, the magnetic flux passing through the sensor element 42 also fluctuates.

[0134] In the shield 52 in which the magnetic path cross-sectional area S1 is set larger than the magnetic path cross-sectional area S2, magnetic saturation is less likely to occur in the magnetic path cross-sectional area S1. As a result, the situation in which external magnetic flux passes through the central portion 52a of the shield 52 and reaches the sensor element 42 is suppressed.

[0135] FIG. 16 is an exploded perspective view of the shield. Shields 51 and 52 are provided by a laminated body formed by stacking and connecting multiple steel plates. In particular, shield 52 is formed by stacking bracket-shaped steel plates 52g1, 52g2, 52g3, and 52g4 and a flat steel plate 52g5 to provide the relationship between magnetic path cross-sectional area S1 and magnetic path cross-sectional area S2. Steel plates 52g1, 52g2, 52g3, and 52g4 are also referred to as first steel plates. Steel plate 52g5 is also referred to as second steel plate. Steel plates 52g1, 52g2, 52g3, and 52g4 each include a central portion 52a, an extension portion 52b, and an extension portion 52c. Extension portion 52b extends from one end of central portion 52a toward first shield 51. The extension portion 52b faces the first shield 51, thereby defining a gap G50. The extension portion 52b is also called a first extension portion. The extension portion 52c extends from the other end of the central portion 52a toward the first shield 51. The extension portion 52c faces the first shield 51, thereby defining a gap G50. The extension portion 52c is also called a second extension portion. The steel plate 52g5 has only the central portion 52a.

[0136] These steel plates 52g1, 52g2, 52g3, 52g4, and 52g5 are stacked and connected by press marks, thereby achieving the relationship between magnetic path cross-sectional area S1 and magnetic path cross-sectional area S2. Even in this configuration, the shielding member 50 has a first portion 52a that is far from gap G50 and second portions 52b and 52c that are closer to gap G50 than the first portion 52a in the magnetic path formed by the shielding member 50. The shielding member 50 is formed so that the number M of stacked steel plates in the first portion 52a is greater than the number N of stacked steel plates in the second portions 52b and 52c (M>N).

[0137] Therefore, the first steel plates 52g1, 52g2, 52g3, and 52g4 are arranged in a stacked manner in the central portion 52a, the first extension portion 52b, and the second extension portion 52c. The first steel plates 52g1, 52g2, 52g3, and 52g4 and the second steel plate 52g5 are arranged in a stacked manner in the central portion 52a. The second steel plate 52g5 is arranged on the opposite side to the extending direction of the first extension portion 52b and the second extension portion 52c.

[0138] The magnetic path cross-sectional area S1 of the shield at portion 52a, which is the farthest from the magnetic gap in the magnetic path, is achieved by stacking M steel plates. The magnetic path cross-sectional area S2 of the shield at portions 52b and 52c, which are closest to the magnetic gap in the magnetic path, is achieved by stacking N steel plates. The number M of steel plates at portion 52a is greater than the number N of steel plates at portions 52b and 52c (M>N). The number P of first steel plates 52g1, 52g2, 52g3, and 52g4 is greater than the number Q of second steel plates 52g5 (P>Q).

[0139] In this embodiment, M=5 steel plates are stacked in the portion 52a. N=4 steel plates are stacked in the portions 52b and 52c. In this embodiment, the second shield 52 has P=4 first steel plates 52g1, 52g2, 52g3, and 52g4 and Q=1 second steel plate 52g5. In other words, the number M of steel plates in the central portion 52a of the shield 52 is greater than the number N of steel plates in the extension portions 52b and 52c. The difference between the number M and the number N can be adjusted to 1, 2, 3, 4, or the like, depending on the expected magnetic flux density.

[0140] 17 is a process diagram showing the procedure of the method for manufacturing the current sensor 1. In particular, the procedure of the bonding step is shown in detail. The method 190 for manufacturing the current sensor 1 is also called an assembly step for assembling the current sensor 1.

[0141] The manufacturing method includes step 191 as a preparation step. In step 191, a plurality of parts are prepared. In step 191, an insulating member 20 including a sensor housing 21 and a cover 22 is prepared. The insulating member 20 includes a conductive member 10. The conductive member 10 may be provided in a state where it is insert-molded into the sensor housing 21. In the preparation step, the sensor housing 21 is prepared to hold the conductive member 10 for passing a current. The sensor housing 21 includes a plurality of board contact portions 26a, a plurality of board adhesive portions 26b, a plurality of shield contact portions 27a, and a plurality of shield adhesive portions 27b.

[0142] In step 191, a wiring board 41 is prepared. A sensor element 42 provided as an IC package is mounted on the wiring board 41. The wiring board 41 is provided with other circuit elements in addition to the sensor element 42. The wiring board 41 is provided with these multiple circuit elements mounted on it. In the preparation step, the wiring board 41 is prepared, on which the sensor element 42 that detects magnetic flux caused by a current is mounted.

[0143] In step 191, the shield member 50 is prepared. At least the shield 51 is prepared as a single independent part. The shield 52 may also be prepared as a single independent part. The shield 52 may be provided in a state where it is insert-molded into the sensor housing 21. Furthermore, in step 191, the adhesive 30 is prepared. The adhesive 30 is in a fluid state before hardening. In the preparation step, the shield 51 is prepared as a magnetic shield member.

[0144] The manufacturing method includes step 192 as an application step. In step 192, adhesive 30 is applied to sensor housing 21. Adhesive 30 is a material that is in a fluid state at an initial temperature that is higher than the expected temperature range of use of current sensor 1 and that hardens in the expected temperature range of use. Adhesive 30 is a silicone-based adhesive. In its fluid state, adhesive 30 can be applied to sensor housing 21 by various methods, such as painting or dripping. Adhesive 30 is applied to the top surface of substrate adhesive portion 26b and the top surface of shield adhesive portion 27b.

[0145] 18 is a block diagram of the application device in the application step. In the application step, adhesive 30 in a fluid state is dispensed from dispenser 32. Adhesive 30 is dispensed onto the top surface of substrate adhesive portion 26b and the top surface of shield adhesive portion 27b of sensor housing 21. Dispenser 32 may include an operable valve 33 for turning on and off the flow of adhesive 30, i.e., for turning on and off the dripping. The dripping position of adhesive 30 is adjusted by moving dispenser 32 and / or sensor housing 21 relative to each other.

[0146] The dropping positions are set on the top surfaces of the plurality of substrate adhesive portions 26b and the top surfaces of the plurality of shield adhesive portions 27b. The relative positional relationship between the dispenser 32 and the sensor housing 21 can be adjusted by a moving device 35. The moving device 35 can be provided by various devices, such as an XY table or a robot. The moving device 35 moves the position of the dispenser 32 and / or the sensor housing 21 so that the dropping position passes through the top surfaces of the plurality of substrate adhesive portions 26b and the top surfaces of the plurality of shield adhesive portions 27b in order. The moving device 35 can be configured to move a nozzle, which is an outlet of the adhesive 30, for example.

[0147] The top surfaces of the plurality of substrate adhesive portions 26b and the top surfaces of the plurality of shield adhesive portions 27b are dispersedly arranged in a ring shape outside the container chamber 23. A plurality of drop positions are set along a path 34 that is set to pass through these plurality of top surfaces in order. The path 34 is set so that it can travel around all of the plurality of top surfaces in a single stroke.

[0148] The application process is performed before the substrate placement process and the shield placement process. In the application process, adhesive 30 is applied to multiple top surfaces along a path 34 that circles the container chamber 23, which houses the wiring substrate 41 and the shield 51, in a single stroke. The multiple substrate bonding portions 26b and the multiple shield bonding portions 27b are arranged in a ring shape in the outer region of the container chamber 23. Furthermore, the path 34 for applying adhesive 30 circles the outer region in a ring shape. The application process is performed by moving the relative position of a nozzle that drips adhesive onto the top surface and the sensor housing 21, which has the container chamber 23, along the path 34. This allows the application process to be performed at high speed.

[0149] The applying step is performed so as to apply adhesive 30 to the top surfaces of the plurality of substrate adhesive portions 26b and the top surfaces of the plurality of shield adhesive portions 27b. The applying step is performed so as not to apply adhesive 30 to the top surfaces of the plurality of substrate contact portions 26a and the top surfaces of the plurality of shield contact portions 27a. This provides accurate positioning of the substrate contact portions 26a and the shield contact portions 27a and reliable adhesion of the plurality of substrate adhesive portions 26b and the plurality of shield adhesive portions 27b.

[0150] Returning to FIG. 17, the manufacturing method includes step 193 as an inspection process. In step 193, it is inspected whether adhesive 30 is applied to all of the top surfaces of the plurality of substrate adhesive portions 26b and the top surfaces of the plurality of shield adhesive portions 27b. The inspection process of step 193 can be performed visually by an operator. The inspection process of step 193 can also be performed automatically by an image recognition device. In either case, intermediate products that pass the inspection process are supplied to the subsequent process.

[0151] The inspection process is performed after the application process and before the substrate placement process and the shield placement process, which will be described later. In the inspection process, it is inspected whether adhesive 30 is applied to the top surfaces of the plurality of substrate adhesive portions 26b and the top surfaces of the plurality of shield adhesive portions 27b. Furthermore, in the inspection process, it is inspected whether adhesive 30 is not applied to the top surfaces of the plurality of substrate contact portions 26a and the top surfaces of the plurality of shield contact portions 27a. This ensures accurate positioning and reliable adhesion.

[0152] The manufacturing method includes step 194 as a board placement process. In step 194, wiring board 41 is placed in sensor housing 21. At this time, wiring board 41 is guided to a specified position by the engagement between protrusion 28a and notch 41b. The engagement between protrusion 28a and notch 41b prevents incorrect assembly in which wiring board 41 is rotated 180 degrees.

[0153] In the process of arranging the wiring board 41 in the specified position, the uncured adhesive 30 applied to the top surfaces of the plurality of board adhesive portions 26b is compressed and deformed. The deformation of the adhesive 30 allows the wiring board 41 to contact the top surfaces of the plurality of board contact portions 26a. As a result, the wiring board 41 is positioned in the specified position.

[0154] In the substrate placement process, the wiring substrate 41 is brought into contact with the plurality of substrate contact portions 26a. This places the wiring substrate 41 in a specified position. At this time, even if a small amount of adhesive 30 adheres to or penetrates the top surfaces of the plurality of substrate contact portions 26a, the adhesive 30 is pushed out. This results in a substantial contact state. Furthermore, in the substrate placement process, the wiring substrate 41 is brought into contact with the adhesive 30 applied to the top surfaces of the plurality of substrate adhesive portions 26b, thereby deforming the adhesive 30 between the top surfaces and the wiring substrate 41. The deformed adhesive 30 has a shape similar to that of the adhesive layer 31 after hardening.

[0155] The manufacturing method includes step 195 as a shield placement process. In step 195, shield 51 is placed on sensor housing 21. The placement of shield 51 is performed without curing adhesive 30. At this time, shield 51 is guided to a specified position by the engagement of protrusions 28a and 28b with notches 51b at the four corners of shield 51. Furthermore, the engagement of protrusions 28a and 28b with notches 51b at the four corners of shield 51 prevents erroneous assembly in which shield 51 is rotated 90 degrees.

[0156] In the process of arranging the shield 51 in a predetermined position, the uncured adhesive 30 applied to the top surfaces of the plurality of shield adhesive portions 27b is compressed and deformed. The deformation of the adhesive 30 allows the shield 51 to contact the top surfaces of the plurality of shield contact portions 27a. As a result, the shield 51 is positioned in a predetermined position. The shield 51 is arranged in a layered manner on the wiring board 41.

[0157] In the shield placement process, the shield 51 is brought into contact with the multiple shield contact portions 27a. This places the shield 51 in a specified position. At this time, even if a small amount of adhesive 30 is attached to or penetrates the top surfaces of the multiple shield contact portions 27a, the adhesive 30 is pushed out. This results in a substantial contact state. Furthermore, in the shield placement process, the adhesive 30 applied to the top surfaces of the multiple shield adhesive portions 27b is deformed between the top surfaces and the shield 51. The deformed adhesive 30 has a shape similar to that of the adhesive layer 31 after hardening.

[0158] The manufacturing method includes step 196 as a curing step. In step 196, both adhesive 30 that bonds wiring substrate 41 and adhesive 30 that bonds shield 51 are cured simultaneously. This step forms multiple adhesive layers 31 between the top surfaces of multiple substrate adhesive portions 26b and wiring substrate 41. At the same time, this step forms multiple adhesive layers 31 between the top surfaces of multiple shield adhesive portions 27b and shield 51.

[0159] In this embodiment, the curing step is performed by lowering the temperature of the fluid adhesive 30 to harden the adhesive 30, i.e., to cause the adhesive 30 to lose its fluidity. In this case, the temperature of the adhesive 30 is gradually lowered after the application step. Therefore, the substrate placement step and the shield placement step are performed while the adhesive 30 is fluid. This allows the adhesive 30 to deform to allow the wiring board 41 and the shield 51 to be positioned in the specified positions. Alternatively, an adhesive 30 that hardens as the temperature increases may be used. In this case, the temperature of the fluid adhesive 30 in the application step is raised to a curing temperature in the curing step. Because the adhesive 30 is deformed in the substrate placement step and the shield placement step, it changes into an adhesive layer 31 in the curing step.

[0160] The curing process is performed after the substrate placement process and the shield placement process. The curing process simultaneously hardens both the adhesive 30 positioned between the substrate adhesive portion 26b and the wiring substrate 41 and the adhesive 30 positioned between the shield adhesive portion 27b and the shield 51. In this manufacturing method, the curing process hardens the adhesive 30 in the deformed shape to form an adhesive layer 31 that bonds the substrate adhesive portion 26b and the wiring substrate 41. The curing process simultaneously hardens the adhesive 30 in the deformed shape to form an adhesive layer 31 that bonds the shield adhesive portion 27b and the shield 51. In this manufacturing method, the adhesive 30 is maintained in a fluid state throughout the period from the substrate placement process to the shield placement process. Moreover, the substrate placement process and the shield placement process are performed consecutively. In this manufacturing method, the adhesive 30 loses its fluidity in the curing process. After the curing process, the adhesive 30 changes into the adhesive layer 31 that has lost its fluidity.

[0161] The manufacturing method includes step 197 as an attachment process. In step 197, the lid 22 is attached to the sensor housing 21. In the attachment process, the sensor housing 21 and the lid 22 are connected by the multiple connecting mechanisms 24. During the attachment process, the engaging arm 24a is manipulated in the thickness direction TD along the groove 24d. The engaging arm 24a is guided in the thickness direction TD along the groove 24d. As a result, the engaging arm 24a can be manipulated so as to be stably and reliably connected to the engaging claw 24b. This stability and reliability are also achieved in the connecting mechanism 24. Therefore, a configuration including multiple connecting mechanisms 24 provides significant benefits. Furthermore, the engaging arm 24a connected to the engaging claw 24b is at least partially housed in the groove 24d. As a result, erroneous operation that would cause the engaging arm 24a to be deformed again can be suppressed.

[0162] The attachment process is also called a lid attachment process. The lid attachment process can be performed after or before the curing process. In the lid attachment process, the lid 22 is connected to the sensor housing 21 to close the container chamber 23. The sensor housing 21 includes a plurality of substrate contact portions 26a, a plurality of substrate adhesive portions 26b, a plurality of shield contact portions 27a, and a plurality of shield adhesive portions 27b. In the lid attachment process, the shield pressing portion 22e provided on the lid 22 is brought into contact with the shield. This allows the position of the shield 51 to be fixedly maintained between the sensor housing 21 and the lid 22. For example, even if peeling or cracks occur in the adhesive layer 31, the position of the shield 51 is stably maintained.

[0163] The disclosure of this specification provides a method for manufacturing a current sensor. In the method for manufacturing the current sensor 1, the wiring substrate 41 is brought into contact with the adhesive 30 applied to the top surfaces of the plurality of substrate adhesive portions 26b. This causes the adhesive 30 to deform between the top surfaces and the wiring substrate 41. As a result, the wiring substrate 41 is positioned at a specified position. Moreover, the adhesive 30 is deformed into a shape appropriate for the specified position. In the method for manufacturing the current sensor 1, the shield 51 is brought into contact with the adhesive 30 applied to the top surfaces of the plurality of shield adhesive portions 27b. This causes the adhesive 30 to deform between the top surfaces and the shield 51. As a result, the shield 51 is positioned at a specified position. Moreover, the adhesive 30 is deformed into a shape appropriate for the specified position. In the curing step, after the substrate placement step and the shield placement step, the adhesive 30 is simultaneously cured. In the curing step, both the adhesive 30 positioned between the substrate adhesive portion 26b and the wiring substrate 41 and the adhesive 30 positioned between the shield adhesive portion 27b and the shield 51 are simultaneously cured. As a result, a high level of productivity suitable for mass production is realized.

[0164] Second embodiment This embodiment is a variation of the previous embodiment, in which the through holes 11d and 11e have the same diameter. Instead of this, in this embodiment, the through holes 211d and 211e have different diameters.

[0165] In FIG. 21, the current sensor 1 has a first through hole 211d and a second through hole 211e. The first diameter Dd of the first through hole 211d is different from the second diameter De of the second through hole 211e. The first diameter Dd of the first through hole 211d is smaller than the second diameter De of the second through hole 211e (Dd <De)。

[0166] Assume that the current sensor 1 takes the posture (A) in FIG. 21 and the posture (B) in FIG. 21. The postures (A) and (B) are obtained by inverting the posture of the current sensor 1 by 180 degrees in a plan view. The posture (A) is, for example, the correct posture. The posture (B) is, for example, an incorrect inverted posture.

[0167] The current sensor 1 has a similar appearance in posture (A) and posture (B). However, the first diameter Dd of the first through hole 211d and the second diameter De of the second through hole 211e clearly indicate the difference in posture. A user of the current sensor 1 can easily and reliably recognize the posture of the current sensor 1 by visual inspection based on the diameter Dd of the first through hole 211d and the second diameter De of the second through hole 211e. The user includes a worker who assembles the current sensor 1 into a device in which the current sensor 1 is used. By recognizing the posture of the current sensor 1, the user can prevent the current sensor 1 from being assembled in the wrong, upside-down posture.

[0168] FIG. 22 shows an exploded view of the coupling structure between the current sensor 1 and a device 202 to which the current sensor 1 is applied. FIG. 22 shows a cross section of the conductor member 11. In FIG. 22, the main body of the current sensor 1, including the insulating member 20, is omitted and indicated by a dashed line. The device 202 is a battery control device, a current sensor assembly, or a power conversion device equipped with the current sensor 1. The device 202 includes conductive members 203 and 204 through which a current to be detected flows. The conductive members 203 and 204 are electrically connected by the conductor member 11. The conductive member 203 has a through hole having an inner diameter equivalent to that of the through hole 211d, at a position allowing axial communication with the through hole 211e. The conductive member 203 and one end 11a are connected by a first coupling member 205. The conductive member 204 has a through hole having an inner diameter equivalent to that of the through hole 211e, at a position allowing axial communication with the through hole 211e. The conductive member 204 and the other end 11b are connected by a second connecting member 206. This allows the current to flow as the detection target.

[0169] The connecting members 205 and 206 are provided by bolts and nuts. The bolts and nuts may be arranged upside down relative to the illustrated position. The bolts or nuts may be fixed to the conductive member 203 and the conductive member 204, or the conductor member 11. The nominal diameters of the bolts and nuts that provide the first connecting member 205 are different from the nominal diameters of the bolts and nuts that provide the second connecting member 206. The difference between the nominal diameters of the bolts and nuts that provide the first connecting member 205 and the nominal diameters of the bolts and nuts that provide the second connecting member 206 is sufficient to prevent incorrect combination of the bolts and nuts. For example, when a bolt that provides the first connecting member 205 is combined with a nut that provides the second connecting member 206, insertion is possible, but no tightening force is generated because the threads do not mesh. For example, when a bolt that provides the second connecting member 206 is combined with a nut that provides the first connecting member 205, insertion is impossible, and no tightening force is generated. The difference between the nominal diameter of the bolts and nuts that provide the first connecting member 205 and the nominal diameter of the bolts and nuts that provide the second connecting member 206 is such that no tightening force is generated.

[0170] The connecting members 205 and 206 have shaft portions that are inserted into the through holes 211d and 211e. The shaft portion of the connecting member 205 has a third diameter D5. The third diameter D5 of the shaft portion of the connecting member 205 is adapted to the through hole 211d. The third diameter D5 is smaller than the first diameter Dd (D5 < Dd). The third diameter D5 is smaller than the second diameter De (D5 < De). The shaft portion of the connecting member 206 has a fourth diameter D6. The fourth diameter D6 of the shaft portion of the connecting member 206 is adapted to the through hole 211e. The fourth diameter D6 is larger than the first diameter Dd (D6 > Dd). The fourth diameter D6 is smaller than the second diameter De (D6 < De). The third diameter D5 and the fourth diameter D6 are different. The third diameter D5 is smaller than the fourth diameter D6 (D5 < D6). The difference between the third diameter D5 and the fourth diameter D6 is a difference that prevents the shaft portion of the second connecting member 206 from being inserted into the first through hole 211d. In other words, the difference between the third diameter D5 and the fourth diameter D6 is a difference that structurally prohibits the use of the second connecting member 206 in the first through hole 211d.

[0171] The connecting member 205 can be used for both the through hole 211d and the through hole 211e. However, when the connecting member 205 is used for the through hole 211e, an appropriate radial clearance cannot be obtained. The connecting member 206 can be used only for the through hole 211e. Since the connecting member 206 cannot be inserted into the through hole 211d, it is not usable for the through hole 211d. The current sensor 1 can be fixed using the connecting members 203 and 204 only in the normal posture (A). The current sensor 1 cannot be fixed using the connecting members 203 and 204 in the posture (B) of the incorrect inverted state. As a result, it is possible to suppress the situation where the current sensor 1 is assembled in the incorrect inverted posture. Moreover, in addition to the user's visual inspection, the above situation can be suppressed structurally.

[0172] Third Embodiment This embodiment is a modification based on the preceding embodiment, in which at least one or both of shield 51 and shield 52 are provided by stacks of steel plates. Alternatively, at least one or both of shield 51 and shield 52 may be provided by a continuous block of magnetic material.

[0173] In FIG. 23 , the shield 352 is provided by a single steel plate. The shield 352 is formed of a continuous material throughout its entirety. The shield 352 is a member that can be called a single steel plate. The shield 352 provides a magnetic path through which a normal magnetic flux induced by a current flowing through the conductive member 10 passes. The shield 352 has an easy axis of magnetization that coincides with the direction of the normal magnetic flux. The shield 352 has a central portion 52a. The central portion 52a is shaped like a quadrilateral plate. The central portion 52a extends parallel to the conductive member 10. The central portion 52a has a magnetic path cross section that is perpendicular to the normal magnetic flux. The shield 352 has two extension portions 52b and 52c that extend from the central portion 52a toward the shield 51. The extension portions 52b and 52c extend from both ends of the central portion 52a in the easy axis of magnetization. The extension portions 52b and 52c have a magnetic path cross section that is perpendicular to the normal magnetic flux. The shield 352 is formed so that the magnetic path cross section area S1 at the central portion 52a is larger than the magnetic path cross section area S2 at the extension portions 52b and 52c. The central portion 52a can also be referred to as a first portion. The extension portions 52b and 52c can also be referred to as a second portion. In this embodiment, the shield 352 can provide magnetic shielding similar to the shield 52 in the previous embodiment.

[0174] Other embodiments The disclosure in this specification and drawings, etc. is not limited to the exemplified embodiments. The disclosure encompasses the exemplified embodiments and variations thereon by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and / or elements shown in the embodiments. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses the omission of parts and / or elements from the embodiments. The disclosure encompasses the substitution or combination of parts and / or elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. Some disclosed technical scopes are defined by the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the claims.

[0175] The disclosure in the specification, drawings, etc. is not limited by the claims. The disclosure in the specification, drawings, etc. encompasses the technical ideas described in the claims, and extends to more diverse and broader technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure in the specification, drawings, etc. without being bound by the claims.

[0176] In the above embodiment, the engagement arm 24a that provides the coupling mechanism 24 is provided on the lid 22, and the engagement claw 24b that provides the coupling mechanism 24 is provided on the sensor housing 21. This arrangement can be called a normal arrangement. Alternatively, the engagement arm 24a and the engagement claw 24b may be arranged in reverse. For example, the engagement arm 24a can be provided on the sensor housing 21. In this case, the engagement claw 24b is provided on the lid 22. This arrangement can be called an inverted arrangement. Furthermore, some of the multiple coupling mechanisms 24 may be in a normal arrangement, and the remaining may be in an inverted arrangement.

[0177] In the above embodiment, the adhesive 30 is a material that is in a fluid state at an initial temperature that is higher than the expected temperature range of use of the current sensor 1 and that hardens in the expected temperature range of use. Alternatively, the adhesive 30 may be a material that is in a fluid state at room temperature and hardens at a hardening temperature that is higher than room temperature. The adhesive 30 is not limited to a thermosetting material such as a high-temperature hardening material or a low-temperature hardening material, and various other materials can be used. The adhesive 30 may be provided, for example, as a two-component mixed material that hardens after two components are mixed.

[0178] In the above embodiment, the shield member 50 has two magnetic gaps between the shield 51 and the shield 52. Alternatively, the shield member 50 may have a single magnetic gap. Furthermore, the shield member 50 may have three or more magnetic gaps. Also, in the above embodiment, the conductive member 10, the sensor element 42, and the shield member 50 are arranged and shaped to be line-symmetric with respect to the line of symmetry SY. Alternatively, the shield member 50 may be arranged and shaped to be point-symmetric with respect to the sensor element 42. The arrangement and shape of the shield member 50 can be designed to achieve a desired level of current detection accuracy.

[0179] In the above embodiment, the shields 51 and 52 that provide the shield member 50 are provided by a plurality of steel plates laminated along the thickness direction TD. Instead of this, at least one of the shields 51 and 52, or both, may be provided by a plurality of steel plates laminated along the axial direction AD. In this case, the number M of steel plates in the portion 52a is equal to the number N of steel plates in the portions 52b and 52c (M = N). Further, in the above embodiment, the number M of steel plates in the portion 52a is larger than the number N of steel plates in the portions 52b and 52c (M > N). Instead of this, the number M of steel plates in the portion 52a may be smaller than the number N of steel plates in the portions 52b and 52c (M < N) or equal (M = N). Further, in the above embodiment, the number P of the first steel plates is larger than the number Q of the second steel plates (P > Q). Instead of this, the number P of the first steel plates may be equal to the number Q of the second steel plates. Further, the number P of the first steel plates may be smaller than the number Q of the second steel plates.

[0180] (Disclosure of Technical Ideas) This specification discloses a plurality of technical ideas described in a plurality of claims listed below. Some claims may be described in a multiple dependent form that selectively cites a preceding claim in subsequent claims. Further, some claims may be described in a multiple dependent form that cites a claim in another multiple dependent form. The claims described in these multiple dependent forms define a plurality of technical ideas.

[0181] (Technical Idea 1) a preparation step of preparing a sensor housing (21) that holds a conductive member for passing a current and has a plurality of board contact portions (26a), a plurality of board adhesive portions (26b), a plurality of shield contact portions (27a), and a plurality of shield adhesive portions (27b), a wiring board (41) that mounts a sensor element (42) that detects a magnetic flux caused by the current, and a shield (51) that serves as a magnetic shielding member; a substrate placement process in which the wiring substrate is placed in a predetermined position by contacting the plurality of substrate contact portions, and the wiring substrate is brought into contact with adhesive (30) applied to the top surfaces of the plurality of substrate adhesive portions, thereby deforming the adhesive between the top surfaces and the wiring substrate; a shield positioning step of placing the shield in a predetermined position by bringing the shield into contact with the plurality of shield contact portions, and deforming adhesive (30) applied to the top surfaces of the plurality of shield adhesive portions between the top surfaces and the shield; A method for manufacturing a current sensor, comprising: a substrate placement process; and, after the shield placement process, a curing process for simultaneously curing both the adhesive positioned between the substrate adhesive portion and the wiring board and the adhesive positioned between the shield adhesive portion and the shield.

[0182] (Technical thought 2) the adhesive maintains fluidity throughout the period from the substrate placement step to the shield placement step; the substrate placement step and the shield placement step are performed consecutively, The method for manufacturing a current sensor according to Technical Idea 1, wherein the adhesive loses its fluidity during the curing process.

[0183] (Technical Thought 3) The curing process forms an adhesive layer that bonds the substrate adhesive portion and the wiring substrate by curing the adhesive in the deformed shape, and simultaneously forms an adhesive layer that bonds the shield adhesive portion and the shield by curing the adhesive in the deformed shape. This is the method for manufacturing a current sensor described in Technical Idea 1 or Technical Idea 2.

[0184] (Technical Thought 4) The method for manufacturing a current sensor according to any one of Technical Ideas 1 to 3 further includes, before the substrate placement step and the shield placement step, an application step of applying the adhesive to the top surfaces of the plurality of substrate adhesive portions and the top surfaces of the plurality of shield adhesive portions along a path (34) that circles the container chamber (23) that houses the wiring substrate and the shield in a single stroke.

[0185] (Technical Thought 5) A method for manufacturing a current sensor described in technical idea 4, wherein a plurality of the substrate adhesive portions and a plurality of the shield adhesive portions are arranged in a ring shape in the outer region of the container chamber, and the path circulates in a ring shape around the outer region.

[0186] (Technical Thought 6) The method for manufacturing a current sensor according to Technical Idea 4 or Technical Idea 5, wherein the application step is performed by moving the relative position of a nozzle that drips the adhesive onto the top surface and a sensor housing (21) having the container chamber along the path (34).

[0187] (Technical Thought 7) The applying step includes: Applying the adhesive to the top surfaces of the plurality of substrate adhesive portions and the top surfaces of the plurality of shield adhesive portions; A method for manufacturing a current sensor according to any one of technical ideas 4 to 6, which is carried out so as not to apply the adhesive to the top surfaces of the plurality of substrate contact portions and the top surfaces of the plurality of shield contact portions.

[0188] (Technical Thought 8) After the applying step and before the substrate disposing step and the shield disposing step, the adhesive is applied to the top surfaces of the plurality of substrate adhesive portions and the top surfaces of the plurality of shield adhesive portions; A method for manufacturing a current sensor according to any one of Technical Ideas 4 to 7, further comprising an inspection step of inspecting that the adhesive is not applied to the top surfaces of the plurality of substrate contact portions and the top surfaces of the plurality of shield contact portions.

[0189] (Technical Thought 9) A method for manufacturing a current sensor according to any one of Technical Ideas 4 to 8, which includes a lid attachment process of connecting a lid (22) to a sensor housing (21) having a plurality of the substrate contact portions, a plurality of the substrate adhesive portions, a plurality of the shield contact portions, and a plurality of the shield adhesive portions after or before the curing process, to close the volume chamber.

[0190] (Technical Thought 10) The method for manufacturing a current sensor according to Technical Idea 9, wherein in the lid mounting step, a shield pressing portion (22e) provided on the lid is brought into contact with the shield.

[0191] (Disclosure of other technical ideas) Furthermore, this specification discloses several technical ideas described in the following paragraphs, which aim to provide a current sensor with high detection accuracy by suppressing magnetic saturation in the shield member.

[0192] (Technical Thought 11) a conductive member (10) for passing an electric current; a sensor element (42) disposed apart from the conductive member and configured to detect magnetic flux resulting from the current; a magnetic shield member (50) disposed at least partially around the conductive member and the sensor element, and defining a magnetic gap (G50); the shield member has a first portion (52a) that is far from the gap and a second portion (52b, 52c) that is closer to the gap than the first portion in a magnetic path formed by the shield member, A current sensor in which the shielding member is formed so that the magnetic path cross-sectional area (S1) in the first portion is larger than the magnetic path cross-sectional area (S2) in the second portion (S1>S2).

[0193] (Technical Thought 12) A current sensor according to Technical Idea 11, wherein the shielding member is provided by a stack of multiple steel plates or a block of a single steel plate.

[0194] (Technical Thought 13) the shield member (50) includes a first shield (51) and a second shield (52, 352) arranged to sandwich the conductive member and the sensor element; the first shield has a quadrilateral shape; the second shield has a central portion (52a) having a quadrilateral shape, a first extension portion (52b) extending from one end of the central portion toward the first shield and opposing the first shield to define the gap, and a second extension portion (52c) extending from the other end of the central portion toward the first shield and opposing the first shield to define the gap; the central portion forms the first portion; The current sensor according to Technical Idea 11 or Technical Idea 12, wherein the first extension portion or the second extension portion forms the second portion.

[0195] (Technical Thought 14) The current sensor according to any one of Technical Ideas 11 to 13, wherein the first portion includes a portion farthest from the gap.

[0196] (Technical Thought 15) a conductive member (10) for passing an electric current; a sensor element (42) disposed apart from the conductive member and configured to detect magnetic flux resulting from the current; a magnetic shield member (50) disposed at least partially around the conductive member and the sensor element, and defining a magnetic gap (G50); The shielding member is formed by laminating a plurality of steel plates, the shield member has a first portion (52a) that is far from the gap and a second portion (52b, 52c) that is closer to the gap than the first portion in a magnetic path formed by the shield member, The current sensor is formed so that the number (M) of stacked steel plates in the first portion is greater than the number (N) of stacked steel plates in the second portion (M>N).

[0197] (Technical Thought 16) the shield member (50) includes a first shield (51) and a second shield (52, 352) arranged to sandwich the conductive member and the sensor element; the first shield has a quadrilateral shape; the second shield has a central portion (52a) having a quadrilateral shape, a first extension portion (52b) extending from one end of the central portion toward the first shield and opposing the first shield to define the gap, and a second extension portion (52c) extending from the other end of the central portion toward the first shield and opposing the first shield to define the gap; the central portion forms the first portion; The current sensor according to Technical Idea 15, wherein the first extension portion or the second extension portion forms the second portion.

[0198] (Technical Thought 17) The second shield comprises: a first steel plate (52g1, 52g2, 52g3, 52g4) having the central portion, the first extension portion, and the second extension portion; a second steel plate (52g5) having only the central portion; The current sensor according to Technical Idea 15 or 16, wherein the first steel plate and the second steel plate are arranged in a stacked manner in the central portion.

[0199] (Technical Thought 18) The current sensor according to Technical Idea 17, wherein the number (P) of the first steel plates is greater than the number (Q) of the second steel plates.

[0200] (Technical Thought 19) The current sensor according to Technical Idea 17 or Technical Idea 18, wherein the second steel plate is arranged on the opposite side to the extending direction of the first extension portion and the second extension portion.

[0201] (Technical Thought 20) The second shield comprises: a plurality of first steel plates (52g1, 52g2, 52g3, 52g4) each having the central portion, the first extension portion, and the second extension portion; A second steel plate (52g5) having only the central portion, the number (Q) of which is less than the number (P) of the first steel plates, a plurality of first steel plates are arranged in a stacked manner in each of the central portion, the first extension portion, and the second extension portion; The current sensor according to Technical Idea 13 or Technical Idea 16, wherein the first steel plate and the second steel plate are arranged in a stacked manner in the central portion.

[0202] (Technical Thought 21) The current sensor according to any one of Technical Ideas 15 to 20, wherein the first portion includes a portion that is farthest from the gap.

[0203] Furthermore, this specification discloses several technical ideas described in the following paragraphs. The technical idea aims to provide a current sensor that maintains detection accuracy by suppressing misalignment of the shield 51 even if the adhesion between the shield 51 and the sensor housing 21 by the adhesive layer 31 becomes unstable. For example, a decrease in detection accuracy may appear as a fluctuation in magnetic flux distribution caused by the misalignment of the shield 51 and an accompanying fluctuation in the detection value.

[0204] (Technical Thought 22) a conductive member (10) for passing an electric current; a sensor element (42) for detecting a magnetic flux caused by the current; a shield (51) as a magnetic shielding member; an insulating member (20) including a sensor housing (21) that positions the conductive member, the sensor element, and the shield in a stacked manner, and a cover (22) that is connected to the sensor housing; an adhesive layer (31) that adheres the shield to the sensor housing on one surface of the shield; The current sensor includes a shield pressing portion (22e) that contacts the other surface of the shield and supports the shield.

[0205] (Technical Thought 23) The current sensor according to Technical Idea 22, wherein the cover body includes a plurality of the shield pressing portions (22e).

[0206] (Technical Thought 24) The current sensor according to Technical Idea 23, wherein the plurality of shield pressing portions (22e) are disposed in a dispersed manner along the edge of the shield.

[0207] (Technical Thought 25) The current sensor according to any one of Technical Ideas 22 to 24, wherein the sensor housing includes a shield adhesive portion (27b) that is adhered to the shield via the adhesive layer.

[0208] (Technical Thought 26) A current sensor described in any one of Technical Ideas 22 to 25, wherein the sensor housing has a shield contact portion (27a) that contacts the shield in a specific area on one side of the shield without the adhesive layer, and the shield pressing portion contacts the shield in the specific area on the other side of the shield.

[0209] Furthermore, this specification discloses several technical ideas described in the following paragraphs. The technical idea aims to provide an insulating member capable of stably maintaining the connection between the sensor housing 21 and the lid 22. This technical idea can be used as a current sensor. The technical idea aims to provide a current sensor that maintains detection accuracy by stably maintaining the connection. For example, a decrease in detection accuracy may occur when the connection between the sensor housing 21 and the lid 22 is unintentionally released.

[0210] (Technical Thought 27) An insulating member comprising: a sensor housing (21) made of an insulating material; and a lid (22) made of an insulating material that is connected to the sensor housing to define a container chamber (23) between the sensor housing and the lid; an elastically deformable engaging arm (24a) that protrudes from one side of the sensor housing and the lid; a side wall surface (24c) that is provided on the other side of the sensor housing and the lid and that defines a groove (24d) that receives the engaging arm; and an engaging claw (24b) that is provided on the other side of the sensor housing and the lid and engages with the engaging arm that is positioned in the groove.

[0211] (Technical Thought 28) The insulating member according to Technical Idea 27, wherein the groove positions the engaging arm so as to be recessed from the side wall surface.

[0212] (Technical Thought 29) An insulating member according to Technical Idea 27 or Technical Idea 28, wherein the engaging arm has two elastic arms (24f) extending parallel to each other and an engaging claw (24e) arranged to connect the tip portions of the two elastic arms and engaging with the engaging claw, and the engaging claw is defined by protruding a portion of the groove.

[0213] (Technical Thought 30) An insulating member according to any one of Technical Ideas 27 to 29, in which the sensor housing and the cover are made up of a conductive member (10) for passing current, a wiring board (41) carrying a sensor element (42) for detecting magnetic flux resulting from the current, and a shield (51) as a magnetic shielding member, which are arranged in a layered manner along the direction in which the engaging arm protrudes.

[0214] (Technical Thought 31) An insulating member according to any one of Technical Ideas 27 to 30, wherein the direction in which the engaging arms protrude is defined as the thickness direction (TD), the direction of the current flowing through the conductive member is defined as the axial direction (AD), and the direction perpendicular to the thickness direction and the axial direction is defined as the width direction (WD), and wherein one of the sensor housing and the cover body has a plurality of the engaging arms at both ends in the width direction, and the other of the sensor housing and the cover body has the side wall surface and the engaging claw at both ends in the width direction.

[0215] Furthermore, this specification discloses several technical ideas described in the following paragraphs, which aim to define the normal posture of a current sensor.

[0216] (Technical Thought 32) a conductive member (10) for passing an electric current; a sensor element (42) for detecting a magnetic flux caused by the current flowing through the conductive member; a first through-hole (211d) provided at one end of the conductive member and having a predetermined first diameter (Dd); a second through-hole (211e) provided at the other end of the conductive member and having a second diameter (De) different from the first diameter;

[0217] (Technical Thought 33) Furthermore, a first connecting member (205) having a shaft portion with a third diameter (D5) that can be inserted into the first through hole; A current sensor described in technical idea 32, comprising a second connecting member (206) having a shaft portion with a fourth diameter (D6) that can be inserted into the second through hole but cannot be inserted into the first through hole.

[0218] (Technical Thought 34) A current sensor described in technical idea 33, wherein the difference between the third diameter and the fourth diameter is a difference that prevents the shaft portion of the second connecting member from being inserted into the first through hole.

[0219] (Technical Thought 35) The current sensor according to technical idea 33 or technical idea 34, wherein the shaft portion is provided by a bolt.

[0220] (Technical Thought 36) A current sensor according to technical idea 35, wherein the difference between the nominal diameter of the bolt and nut providing the first connecting member and the nominal diameter of the bolt and nut providing the second connecting member is different enough to prevent incorrect combination of the bolts and nuts. [Explanation of symbols]

[0221] 1 current sensor, 10 conductive member, 11 conductive member, 11a one end, 11b the other end, 11c constriction, 11d, 11e through hole, 20 insulating member, 21 sensor housing, 22 lid body, 22e shield holding portion, 23 container chamber, 24 connection mechanism, 24a engagement arm, 24b engagement claw, 24c side wall surface, 24d groove, 24e engagement claw, 24f elastic arm, 25 connector, 26 substrate support member, 26a substrate contact portion, 26b substrate adhesive portion, 27 shield support member, 27a Shield contact part, 27b Shield adhesive part, 28 surrounding portion, 28a first convex portion, 28b second convex portion, 28c vertical surface, 28d slope, 30 adhesive, 31 adhesive layer, 32 dispenser, 33 valve, 34 passage, 35 moving device, 40 Electric circuit component, 41 Wiring board, 42 Sensor element, 41a through hole, 41b notch, 50 shield member, 51 first shield, 52 second shield, 51a Press mark, 51b Notch, 52a central part, 52b, 52c extension part, 211d, 211e through holes, 352 second shield.

Claims

1. a preparation step of preparing a sensor housing (21) that holds a conductive member for passing a current and has a plurality of board contact portions (26a), a plurality of board adhesive portions (26b), a plurality of shield contact portions (27a), and a plurality of shield adhesive portions (27b), a wiring board (41) that mounts a sensor element (42) that detects a magnetic flux caused by the current, and a shield (51) as a magnetic shield member; a substrate placement process in which the wiring substrate is placed at a specified position by contacting the wiring substrate with the plurality of substrate contact portions, and the wiring substrate is brought into contact with adhesive (30) applied to the top surfaces of the plurality of substrate adhesive portions, thereby deforming the adhesive between the top surfaces and the wiring substrate; a shield positioning step of placing the shield in a predetermined position by bringing the shield into contact with the plurality of shield contact portions, and deforming adhesive (30) applied to the top surfaces of the plurality of shield adhesive portions between the top surfaces and the shield; A method for manufacturing a current sensor, comprising: a substrate placement process; and, after the shield placement process, a curing process for simultaneously curing both the adhesive positioned between the substrate adhesive portion and the wiring board and the adhesive positioned between the shield adhesive portion and the shield.

2. the adhesive maintains fluidity throughout the period from the substrate placement step to the shield placement step; the substrate placement step and the shield placement step are performed consecutively, The method for manufacturing a current sensor according to claim 1 , wherein the adhesive loses its fluidity in the curing step.

3. 2. The current sensor manufacturing method according to claim 1, wherein the curing step forms an adhesive layer that bonds the substrate adhesive portion and the wiring substrate by curing the adhesive in the deformed shape, and simultaneously forms an adhesive layer that bonds the shield adhesive portion and the shield by curing the adhesive in the deformed shape.

4. 4. The method for manufacturing a current sensor according to claim 1, further comprising, before the substrate placement step and the shield placement step, an application step of applying the adhesive to the top surfaces of the plurality of substrate adhesive portions and the top surfaces of the plurality of shield adhesive portions along a path (34) that goes around a container chamber (23) that houses the wiring substrate and the shield in a single stroke.

5. The method for manufacturing a current sensor according to claim 4 , wherein the plurality of substrate adhesive portions and the plurality of shield adhesive portions are arranged in a ring shape in the outer region of the container chamber, and the path runs around the outer region in a ring shape.

6. 6. The current sensor manufacturing method according to claim 5, wherein the application step is performed by moving the relative position of a nozzle that drips the adhesive onto the top surface and a sensor housing (21) having the container chamber along the path (34).

7. The applying step includes: Applying the adhesive to the top surfaces of the plurality of substrate adhesive portions and the top surfaces of the plurality of shield adhesive portions; The method for manufacturing a current sensor according to claim 4 , wherein the method is performed so that the adhesive is not applied to the top surfaces of the plurality of substrate contact portions and the top surfaces of the plurality of shield contact portions.

8. After the applying step and before the substrate disposing step and the shield disposing step, the adhesive is applied to the top surfaces of the plurality of substrate adhesive portions and the top surfaces of the plurality of shield adhesive portions; The method for manufacturing a current sensor according to claim 4 , further comprising an inspection step of inspecting whether the adhesive is not applied to the top surfaces of the plurality of board contact portions and the top surfaces of the plurality of shield contact portions.

9. 5. The method for manufacturing a current sensor according to claim 4, further comprising a lid attachment step of connecting a lid (22) to a sensor housing (21) having a plurality of the substrate contact portions, a plurality of the substrate adhesive portions, a plurality of the shield contact portions, and a plurality of the shield adhesive portions after the curing step or before the curing step, to close the container chamber.

10. The method for manufacturing a current sensor according to claim 9, wherein in the lid mounting step, a shield pressing portion (22e) provided on the lid is brought into contact with the shield.

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