JP5083135B2 - Current sensor and method of manufacturing current sensor - Google Patents

Description

  The present invention relates to a current sensor in which a magnetoelectric conversion element is disposed in a gap of a core, and a method for manufacturing the current sensor.

  Conventionally, for example, as shown in Patent Documents 1 and 2, a current sensor having a structure in which a substrate having a magnetoelectric conversion element mounted on a surface side and a core having a gap is accommodated in a resin case is known.

  In the current sensor disclosed in Patent Document 1, the substrate and the core are housed in this order from the bottom surface side of the housing portion in the housing portion of the current sensor body (resin case) made of synthetic resin.

Moreover, in the current sensor shown in Patent Document 2, the core and the substrate are arranged in this order from the bottom side of the housing portion in the component housing chamber (housing portion) of the case (resin case). In other words, the substrate is arranged on the core with the front surface as an opposing surface, and the Hall element (magnetoelectric conversion element) arranged in the gap is covered with the substrate when viewed from the back side (upper side) of the substrate. ing.
JP 2002-296305 A JP 2006-112957 A

  By the way, as shown in Patent Documents 1 and 2, in a configuration in which a core as a separate member is accommodated in the resin case, the core is generally filled with a potting material such as an epoxy resin and cured. Suppresses misalignment. In this case, it takes several tens of minutes or more to thermally cure the potting material. For example, if the process of fixing the core is a batch type, a large number of high-temperature tanks for thermosetting are required, and it becomes difficult to make the current sensor manufacturing process one continuous production line. Moreover, when using the continuous high temperature furnace in which the line for thermosetting time enters, a production line becomes long and an installation will become large. Moreover, since the resin case accommodates a core as a separate member and requires a space for filling the potting material, it is difficult to reduce the size of the resin case (current sensor).

  On the other hand, by integrally molding the core with the resin case (insert molding), it is possible to simplify the manufacturing process by eliminating the above-described core fixing process and to reduce the size of the current sensor. In this case, since the magnetoelectric conversion element has to be disposed in the gap of the core integrated with the resin case, the surface of the substrate (mounting surface of the magnetoelectric conversion element) faces the opposite surface as in the structure shown in Patent Document 2. It will be arranged on the gap of the core. That is, when viewed from the back side (upper side) of the substrate, the magnetoelectric conversion element arranged in the gap is covered with the substrate. Therefore, the positional relationship between the gap and the magnetoelectric conversion element cannot be confirmed by an optical method such as a camera, and the magnetoelectric conversion element with respect to the center position between the both end faces of the core constituting the gap (the center position of the gap). There is a risk that a misalignment of the above will occur. As described above, when the magnetoelectric conversion element is displaced toward the one end face with respect to the center position of the gap, the characteristic variation due to the disturbance magnetic field becomes larger as the displacement amount is larger. This point has also been confirmed by the present inventors.

  In view of the above problems, the present invention provides a current sensor and a method for manufacturing the current sensor that can improve the positional accuracy of the magnetoelectric transducer with respect to the gap of the core in a configuration in which the core is integrally formed with the resin case. Objective.

  In order to achieve the above object, according to a first aspect of the present invention, in the current sensor, a ring-shaped core having a gap of a predetermined width between both end faces that are substantially parallel to each other is integrally formed with the resin case. A current sensor in which at least a part of the gap is exposed in the part, a substrate on which the magnetoelectric conversion element is mounted on the surface side is accommodated in the accommodation part and disposed on the gap, and the magnetoelectric conversion element is disposed in the gap. The resin case has a pair of guide portions that are in contact with only one of the both end surfaces of the core, and the guide portion is opposite to the other in the thickness direction of the core. The guide portion has a tapered surface with a short facing distance. In the guide portion, the lower end portion of the tapered surface that is farthest from the substrate is substantially parallel to the end surface and at least in the thickness direction. Between the end portion on the substrate side to the lower end portion, and the thickness from the end face at the lower end portion is substantially equal to each other at the pair of guide portions. In the width direction of the gap, it is opposed to both tapered surfaces of the pair of guide portions.

  In the present invention, as a part of the resin case, guide portions having tapered surfaces are provided in contact with both end surfaces of the core constituting the gap. Therefore, when the substrate on which the magnetoelectric conversion element is mounted is disposed in the housing portion of the resin case in which the core is integrally formed, the position of the magnetoelectric conversion element is between the both end faces of the core constituting the gap in the gap width direction. The magnetoelectric transducer is inserted into the back side of the gap in contact with at least one taper surface even if it is shifted to one end face side with respect to the approximate center (hereinafter simply referred to as the approximate center of the gap). The position of the conversion element can be approximately the center of the gap. As described above, since the magnetoelectric conversion element can be guided to the substantially center of the gap by the guide portion having the tapered surface, the position accuracy of the magnetoelectric conversion element with respect to the gap of the core is improved in the configuration in which the core is integrally formed with the resin case. As a result, it is possible to obtain a current sensor in which the characteristic variation due to the disturbance magnetic field is reduced. Further, since the guide part is a part of the resin case, the manufacturing process can be simplified and the position accuracy of the guide part can be improved.

  As described in claim 2, the paired guide portions are connected to the lower end portion of the taper surface, have parallel surfaces substantially parallel to the end surfaces, and face each other between the lower end portions in the guide portions in contact with the end surfaces. The distance may be wider than the width of the magnetoelectric conversion element, and the magnetoelectric conversion element may be configured to face both tapered surfaces and both parallel surfaces in the pair of guide portions in the width direction of the gap. In this case, since the magnetoelectric conversion element is not constrained by both guide portions in a state where the substrate is assembled to the resin case, the stress based on the difference in linear expansion coefficient between the materials constituting the resin case and the magnetoelectric conversion element, or the resin case The action of the external force applied to the magnetoelectric conversion element can be suppressed.

  As described in claim 3, in the width direction of the gap, the tapered surfaces of the pair of guide portions are symmetrical with respect to the center line between the both end faces of the core (the center of the gap). The opposing distance between the lower end portions of the guide portion in contact with the end surface may be narrower than the width of the magnetoelectric conversion element, and the magnetoelectric conversion element may be configured to be in contact with both tapered surfaces in the paired guide portions. In this case, since the position of the magnetoelectric conversion element is determined by the magnetoelectric conversion element being in contact with both symmetrical tapered surfaces, the position accuracy of the magnetoelectric conversion element with respect to the gap of the core can be further improved.

  According to a fourth aspect of the present invention, the facing distance between the lower end portions of the guide portions in contact with the end faces is made narrower than the width of the magnetoelectric conversion element in a state where the magnetoelectric conversion element is not disposed, and the magnetoelectric conversion element is elastically deformed. It is good also as a structure contacted with each made guide part and press-fitting and arrange | positioning in a gap.

  In this case, as described above, even if the position of the magnetoelectric conversion element is shifted toward one end face with respect to the approximate center of the gap in the width direction of the gap, the magnetoelectric conversion element is in contact with at least one tapered surface. Since it is inserted into the back side of the gap, the position of the magnetoelectric conversion element can be approximately the center of the gap. Further, the magnetoelectric conversion element is inserted (press-fitted) into the back side of the gap while crushing (elastically deforming) the pair of guide portions. Thus, since the magnetoelectric transducer can be guided to the approximate center of the gap by the elastically deformable guide portions provided on both end faces constituting the gap, the core is integrally molded with the resin case. The position accuracy of the magnetoelectric conversion element with respect to the gap can be improved, and as a result, a current sensor in which characteristic fluctuation due to a disturbance magnetic field is reduced can be obtained. Further, since the guide portion is elastically deformed, the stress of the magnetoelectric conversion element received by contacting the guide portion when the substrate is disposed in the housing portion of the resin case can be reduced. Furthermore, since the guide part is a part of the resin case, the manufacturing process can be simplified and the position accuracy of the guide part can be improved.

According to a fifth aspect of the present invention, a ring-shaped core having a gap of a predetermined width between both end faces that are substantially parallel to each other is integrally formed with the resin case, and at least a part of the gap is accommodated in the housing portion of the resin case. Is a current sensor in which a substrate on which a magnetoelectric conversion element is mounted on the surface side is housed in a housing portion and disposed on a gap, and the magnetoelectric conversion element is disposed in the gap. As a portion, a guide portion having a predetermined thickness that is in contact with only one end surface of both end surfaces of the core is provided, and the magnetoelectric transducer is in contact with the back surface of the contact surface with the end surface of the guide portion in the width direction of the gap. It is characterized by.

  In the present invention, as a part of the resin case, a guide portion having a predetermined thickness is provided in contact with only one end surface of both end surfaces of the core constituting the gap. And the magnetoelectric conversion element is made to contact the back surface of the contact surface with the end surface in a guide part. That is, in the width direction of the gap, the magnetoelectric conversion element is in contact with the end face provided with the guide portion via the guide portion having a predetermined thickness. Therefore, by setting the thickness of the guide portion to a predetermined thickness, the position of the magnetoelectric conversion element can be set to the approximate center of the gap with reference to the end face provided with the guide portion. Thereby, in the configuration in which the core is integrally formed with the resin case, the position accuracy of the magnetoelectric conversion element with respect to the gap of the core is improved, and as a result, a current sensor in which the characteristic fluctuation due to the disturbance magnetic field is reduced can be obtained. Further, since the guide part is a part of the resin case, the manufacturing process can be simplified and the position accuracy of the guide part can be improved.

Next, the invention described in claim 6 is a substrate-preparing step of preparing a substrate on which a magnetoelectric conversion element is mounted on the front surface side, and a ring shape having a gap of a predetermined width between both end faces that are substantially parallel to each other. A case preparation step of preparing a resin case in which the core is integrally formed and at least a part of the gap is exposed in the accommodating portion, and the substrate is positioned on the core in the accommodating portion so that the magnetoelectric transducer is positioned in the gap of the core And a fixing step of fixing the substrate to the resin case in a positioned state. In the case preparation step, in the case preparation step, a predetermined contact with only one end surface of both end surfaces of the core Prepare a resin case having a thickness guide part, and in the fixing step, arrange the magnetoelectric conversion element in the gap, and then the back surface of the contact surface of the magnetoelectric conversion element with the end face in the guide part To move by contacting stops, magneto-electric transducer moves the substrate or the resin case in a width direction of the gap so as to approach the guide portion, and wherein the positioning the magneto-electric conversion element.

  In the present invention, as a part of the resin case, a guide portion having a predetermined thickness is provided so as to be in contact with only one end face among the both end faces of the core constituting the gap. Then, the magnetoelectric conversion element is arranged in the gap by moving the substrate. Next, the substrate or the resin case is moved in the width direction of the gap so that the magnetoelectric conversion element approaches the guide portion until the magnetoelectric conversion element comes into contact with the back surface of the contact surface with the end surface of the guide portion and stops moving. That is, the magnetoelectric conversion element is stopped against the guide portion. Thus, the magnetoelectric conversion element is brought into contact with the back surface of the contact surface with the end surface of the guide portion by the two-stage movement. Therefore, by setting the thickness of the guide portion to a predetermined thickness, the position of the magnetoelectric conversion element can be set to the approximate center of the gap with reference to the end face provided with the guide portion. Thereby, in the configuration in which the core is integrally formed with the resin case, the position accuracy of the magnetoelectric conversion element with respect to the gap of the core is improved, and as a result, a current sensor in which the characteristic fluctuation due to the disturbance magnetic field is reduced can be obtained. Further, since the guide portion is provided as a part of the resin case, the manufacturing process can be simplified and the position accuracy of the guide portion can be improved.

According to a seventh aspect of the present invention, a magnetic sensor chip and a lead are electrically connected, and a magnetic sensor chip and a mold IC in which a connection portion between the magnetic sensor chip and the lead is covered with a sealing resin A substrate preparation step for preparing a substrate having a magnetoelectric conversion element mounted on the surface side, in which a lead is inserted into the through hole and soldered to a land formed around the through hole, and is substantially parallel to each other A ring-shaped core having a gap of a predetermined width between both end faces formed, and preparing a resin case in which at least a part of the gap is exposed in the accommodating portion; and a magnetoelectric conversion to the core gap The substrate is positioned on the core in the housing so that the element's magnetic sensor chip is positioned, and the substrate is fixed to the resin case in the positioned state. A fixing step, and in the substrate preparation step, in the substrate preparation step, a substrate in which the leads are bent in a state inclined with respect to the thickness direction of the substrate is prepared, and the case preparation In the process, one of both end faces of the core is in contact with the facing surface of the substrate connected to the end surface, and the other end of the core is separated from the substrate in the thickness direction of the core at the corner between the end surface and the facing surface. A resin case having a tapered surface with a short facing distance to the end surface and having a guide portion with a predetermined thickness at a portion in contact with the end surface is prepared. In the fixing step, a magnetoelectric conversion element is formed on the tapered surface in the thickness direction of the core. The surface of the substrate is brought close to the core while the magnet is in contact, and the magnetoelectric conversion element is brought into contact with the back surface of the contact surface with the end surface of the guide portion, thereby positioning.

  In the present invention, as a part of the resin case, a taper surface is provided at a corner on the substrate side, a guide portion having a predetermined thickness at a contact portion with the end surface, and one of both end surfaces of the core constituting the gap. Provide to contact only the end face. Further, by bending the lead, spring property is imparted to the lead. Then, in the core thickness direction, the substrate or the resin case is moved in the core thickness direction so that the surface of the substrate approaches the core. At this time, since the magnetoelectric conversion element is brought into contact with the tapered surface of the guide portion, the magnetoelectric conversion element is inserted into the back side of the gap along the tapered surface. Further, due to the reaction force of the spring of Lee, the magnetoelectric conversion element is pressed against the back surface of the contact surface with the end surface of the guide portion, and is brought into contact with the back surface. Thus, the magnetoelectric conversion element is brought into contact with the back surface of the contact surface with the end surface of the guide portion by one-step movement. Therefore, by setting the thickness of the guide portion to a predetermined thickness, the position of the magnetoelectric conversion element can be set to the approximate center of the gap with reference to the end face provided with the guide portion. Thereby, in the configuration in which the core is integrally formed with the resin case, the position accuracy of the magnetoelectric conversion element with respect to the gap of the core is improved, and as a result, a current sensor in which the characteristic fluctuation due to the disturbance magnetic field is reduced can be obtained. Further, since the guide portion is provided as a part of the resin case, the manufacturing process can be simplified and the position accuracy of the guide portion can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The current sensor shown in the present embodiment is suitable as a current sensor for measuring the current of a battery mounted on an automobile.
(First embodiment)
FIG. 1 is a cross-sectional view showing a schematic configuration of a current sensor according to the first embodiment of the present invention. FIG. 2 is a plan view of the current sensor shown in FIG. 1, and the lid is omitted for convenience. FIG. 3 is a plan view of the current sensor shown in FIG. 1, and the substrate and the lid are omitted for convenience. In the following, in the current sensor, the thickness direction of the substrate and the thickness direction (stacking direction) of the core are the vertical direction, the direction along the front surface (back surface) of the substrate is the horizontal direction, and the width of the gap in the horizontal direction. The direction (distance direction between the end faces of the core) is defined as the width direction.

  As shown in FIGS. 1 to 3, the current sensor 100 includes, as main parts, a resin case 10, a core 20 having a gap 20 </ b> G, a magnetoelectric conversion element 30, and a substrate 40 on which the magnetoelectric conversion element 30 is mounted. ,have. And the resin case 10 contains the guide part 18 mentioned later as the part. This guide part 18 is a characteristic part of the current sensor 100 according to the present embodiment.

  The resin case 10 is formed by molding a resin material into a predetermined shape so as to accommodate the core 20 and the substrate 40, and the accommodating portion 11 and the guide portion 18 that accommodate at least a part of the core 20 including the gap 20G and the substrate 40. At least. In this embodiment, it has the fixing | fixed part 12 and the connector part 13 with the above-mentioned accommodating part 11. As shown in FIG.

  The accommodating portion 11 has a planar substantially rectangular box structure in which an end surface 11a (hereinafter referred to as an upper end surface 11a) on the upper side in the vertical direction is opened, and an upper portion on which the substrate 40 is disposed as an area inside the box. It has the area | region 14 and the lower area | region 15 where at least one part of the gap 20G was exposed. In the present embodiment, as shown in FIGS. 1 and 3, a part of the gap 20 </ b> G and a part of the core 20 are exposed in the lower region 15. The upper region 14 is a region extending vertically downward from the upper end surface 11a to a predetermined depth, and a part of the bottom portion 14a of the upper region 14 is opened to communicate with the lower region 15 having a predetermined depth. Accordingly, the size in the horizontal direction is smaller in the lower region 15 than in the upper region 14. Further, the upper region 14 has a shape in the horizontal direction substantially coincident with the outer peripheral shape of the substrate 40, and the size thereof is larger than that of the substrate 40. In the state where the substrate 40 is disposed in the upper region 14, as shown in FIGS. 1 and 2, the exposed region of the core 20 including the lower region 15, that is, the gap 20 </ b> G, is covered with the substrate 40. A plurality of support pins 16 are provided on the bottom portion 14 a of the upper region 14 to support the substrate 40 on the bottom portion 14 a while temporarily positioning the substrate 40. In the present embodiment, the support pin 16 is also configured as a part of the resin case 10 and has an enlarged diameter portion 16a in a predetermined range from the bottom portion 14a side as shown in FIG. Then, with the diameter-enlarged portion 16a coming into contact with the surface 40a of the substrate 40 while being inserted into a through hole (not shown) of the substrate 40, the support pins 16 support the substrate 40 on the bottom portion 14a. . In other words, the substrate 40 is positioned in the vertical direction.

  As shown in FIG. 1, the accommodating portion 11 has a lid 50 fixed to the upper end surface 11 a so as to cover the open surface in a state where the substrate 40 is accommodated in the upper region 14. Is a closed area (space).

  The fixing part 12 is a part for fixing the current sensor 100 to a member to be measured through which a current to be measured flows, and has a through hole 12a through which the member to be measured is inserted. And most of the ring-shaped (substantially C-shaped) core 20 is enclosed in the fixing | fixed part 12 so that the through-hole 12a may be surrounded. The connector portion 13 is a portion that electrically connects the magnetoelectric conversion element 30 and an external device via a wiring portion (not shown) formed on the substrate 40. One end of a terminal 17 made of metal, for example, integrally formed with the resin case 10 is exposed at the connector portion 13. Note that the other end of the terminal 17 protrudes from the bottom portion 14 a and extends in the vertical direction, and is disposed in the upper region 14 of the accommodating portion 11.

  The guide portion 18 is a portion for guiding the magnetoelectric conversion element 30 to the approximate center of the gap 20G in the width direction. As shown in FIG. 1, the guide portion 18 is in contact with only one end surface 21 of the both end surfaces 21 of the core 20. ing. In this embodiment, as shown in FIG.1 and FIG.3, it has a pair of guide part 18 which respectively contacts only one end surface 21 among the both end surfaces 21 of the core 20. As shown in FIG. Each guide portion 18 has a tapered surface 18a whose opposing distance to the other end surface 21 (the end surface 21 on the non-contact side) opposed in the width direction is shorter as it is away from the substrate 40 in the vertical direction.

  The tapered surface 18 a has a lower end portion farthest from the substrate 40 in the vertical direction and is substantially parallel to the end surface 21 of the core 20. In addition, the lower end portion described above is the portion having the shortest distance from the other end surface 21 between the end portion (upper end) on the substrate 40 side and the lower end portion in the vertical direction. That is, the tapered surface 18a has a shape closer to the approximate center of the gap 20G toward the bottom surface 15a side of the lower region 15. In the width direction, the resin thickness of the guide portion 18 at the lower end portion of the tapered surface 18a is substantially equal to each other at the pair of guide portions 18, and the opposing distance between the lower end portions of the pair of guide portions 18 is The width of the sealing resin 33 in the magnetoelectric conversion element 30 is wider.

  Furthermore, in this embodiment, as shown in FIG. 1, the parallel surface 18b substantially parallel to the end surface 21 is connected to the lower end portion of the tapered surface 18a. And the part (magnetic sensor chip 31) coat | covered with the sealing resin 33 in the magnetoelectric conversion element 30 has both the taper surfaces 18a and both parallel surfaces in the guide part 18 which makes a pair in the width direction, as shown in FIG. It arrange | positions between 18b and opposes both the taper surfaces 18a and both the parallel surfaces 18b.

  In this way, a part of the gap 20G is occupied by the guide part 18, and a gap narrower than the gap 20G is formed between the paired guide parts 18. The magnetoelectric conversion element 30 is disposed in the gap between the guide portions 18. That is, the guide portion 18 provided in the gap 20G narrows the range (play) in which the magnetoelectric conversion element 30 can be displaced from the approximate center of the gap 20G in the width direction.

  In the present embodiment, as an example, the guide portion 18 is connected to other portions of the resin case 10 only by the bottom surface 15a of the lower region 15, and has a columnar shape protruding from the bottom surface 15a to the substrate 40 side. Further, the length of the guide portion 18 in the horizontal direction and substantially perpendicular to the width direction is substantially equal to the width of the core 20, and the height of the guide portion 18 to the upper end portion on the substrate 40 side is the core 20. It is made substantially equal to the upper end of the end surface 21. That is, the entire end surface 21 is covered with the guide portion 18. In the vertical direction, a linear (planar) tapered surface 18a having a constant inclination angle of 45 degrees or less with respect to the vertical direction is provided in a part of the range from the upper end (the end on the substrate 40 side). The parallel surface 18b connected to the tapered surface 18a is also connected to the bottom surface 15a of the lower region 15. That is, in the guide portion 18, the lower end portion of the tapered surface 18 a and the portion of the parallel surface 18 b are the portions with the shortest facing distance from the other end surface 21. Further, in the width direction, the pair of guide portions 18 are configured to satisfy a line-symmetrical relationship with respect to a center line 21c (see FIG. 4 described later) between both end faces 21 (gap 20G). .

  The core 20 is made of a magnetic material such as iron, an iron-based alloy, or permalloy, and is a ring-shaped member in which a gap 20G having a predetermined width is formed between the end faces 21 that are substantially parallel to each other. It is. Such a core 20 is generally formed by laminating and fixing a plurality of members formed by shearing the magnetic material. In this embodiment, a substantially C-shaped laminated core is employed. As described above, the core 20 is integrally formed with the resin case 10, that is, insert-molded with respect to the resin case 10. Of the substantially C-shaped core 20, only the gap 20G and the vicinity of the both end faces 21 constituting the gap 20G are arranged in the accommodating portion 11, and a part of the gap 20G and a part of the core 20 are It is exposed in the lower region 15.

  The magnetoelectric conversion element 30 detects magnetic flux generated by the current to be measured flowing through the member to be measured, and outputs a signal proportional to the current value, and is mounted on the surface 40a side of the substrate 40 to be described later. It is accommodated in the accommodating portion 11 of the resin case 10 and disposed in the gap 20G of the core 20. In the present embodiment, the magnetic sensor chip 31 (broken line portion shown in FIG. 1) and the lead 32 are electrically connected as the magnetoelectric conversion element 30, and the magnetic sensor chip 31 and the connection portion between the magnetic sensor chip 31 and the lead 32. Employs a mold IC covered with a sealing resin 33. In the width direction, the width from the surface of the magnetic sensor chip 31 to the outer surface of the sealing resin 33 (in other words, the thickness of the sealing resin 33 on the magnetic sensor chip 31) is the magnetic sensor chip 31 in the width direction. The front surface and the back surface are substantially equal. Furthermore, a magnetic sensor chip having a Hall element is adopted as the magnetic sensor chip 31, and the current sensor 100 is a so-called magnetic proportional current sensor. In addition to the Hall element, a magnetic sensor chip having a magnetoresistive element can also be employed.

  As shown in FIG. 1, the magnetoelectric conversion element 30 configured as described above has a portion covered with a sealing resin 33 disposed in the gap 20 </ b> G of the core 20 and in the gap formed by the pair of guide portions 18. The Hall element formed in the chip 31 is disposed in the gap 20G of the core 20. And in the width direction, the magnetic sensor chip 31 is located in the approximate center of the gap 20G. Further, the magnetoelectric conversion element 30 is separated from the bottom surface 15a of the lower region 15 in the housing portion 11 of the resin case 10, and thereby, the linear expansion between the resin case 10 and the magnetoelectric conversion element 30 (for example, the sealing resin 33). The generation of stress based on the coefficient difference is suppressed, and the transmission of an external force applied to the resin case 10 to the magnetoelectric conversion element 30 is suppressed. However, a configuration in which the lower end of the magnetoelectric conversion element 30 (sealing resin 33) is in contact with the bottom surface 15a of the lower region 15 may be employed.

  The substrate 40 is a part for electrically connecting the connector part 13 and the magnetoelectric conversion element 30 configured in the resin case 10, and has a wiring part (not shown) for electrically connecting the magnetoelectric conversion element 30 and the terminal 17. doing. And it accommodates in the accommodating part 11 (upper area | region 14) of the resin case 10, and is arrange | positioned so that the site | part of the core 20 including the gap 20G exposed in the accommodating part 11 may be covered. Moreover, in this embodiment, it has two types of through-holes 41 and 42 which penetrate from the surface 40a facing the core 20 to the back surface 40b. The first through hole 41 is a portion into which the end portion exposed in the accommodating portion 11 of the terminal 17 is inserted, and fulfills the function of temporarily positioning the position of the substrate 40 in the horizontal direction (width direction). The terminal 17 is solder-bonded to a land of a wiring portion (not shown) in a state where an end portion of the terminal 17 is inserted through the first through hole 41 from the front surface 40a side to the back surface 40b side. The second through hole 42 is a part into which the lead 32 in the magnetoelectric conversion element 30 is inserted. The magnetic sensor chip 31 of the magnetoelectric conversion element 30 is disposed on the front surface 40a side, and is soldered to a land of a wiring portion (not shown) in a state where the lead 32 is inserted from the front surface 40a side to the back surface 40b side. In the present embodiment, in these two types of through holes 41 and 42, the gap (clearance) between the first through hole 41 and the terminal 17 is larger than the gap (clearance) between the second through hole 42 and the lead 32. It has a configuration.

  A processing circuit for the magnetoelectric conversion element 30 may be configured on the substrate 40. In the present embodiment, as shown in FIG. 1, an electronic component 43 such as a capacitor or a chip thermistor is mounted on the back surface 40 b of the substrate 40. Thus, when the temperature sensor element such as a chip thermistor is mounted as the electronic component 43, a current sensor with a temperature sensor that can measure temperature as well as current can be obtained.

  Next, a method for manufacturing the above-described current sensor 100 will be described. FIG. 4 is a cross-sectional view showing a case preparation step in the manufacturing process of the current sensor shown in FIG. 5 and 6 are cross-sectional views showing a substrate positioning process in the current sensor manufacturing process.

  Although not shown in the drawing, first, a substrate preparation step for preparing the substrate 40 on which the magnetoelectric conversion element 30 is mounted on the surface 40a side is performed. In the present embodiment, a substrate 40 is prepared in which the above-described two types of through holes 41 and 42 and a wiring portion (not shown) are formed, and an electronic component 43 different from the magnetoelectric conversion element 30 is mounted. The magnetoelectric conversion element 30 is mounted with the leads 32 inserted through the second through holes 42. In addition, the two types of through holes 41 and 42 are formed so that the clearance (clearance) between the first through hole 41 and the terminal 17 is larger than the clearance (clearance) between the second through hole 42 and the lead 32. Form. The magnetoelectric conversion element 30 is mounted on the substrate 40 such that the direction in which the magnetoelectric conversion element 30 extends from the surface 40a of the substrate 40 substantially coincides with the vertical direction.

  Further, as shown in FIG. 4, the ring-shaped core 20 having the gap 20G is integrally molded (insert molding), and the gap 20G of the core 20 is exposed in the accommodating portion 11 (lower region 15). A case preparation step of preparing the resin case 10 having the structure guide portion 18 is performed. That is, in this case preparation process, the resin case 10 having the core 20 as an insert part and having the guide portion 18 as a part thereof is formed by injection molding. By this process, only a part of the core 20 including a part of the gap 20G is exposed in the housing portion 11 of the resin case 10 (exposed to the upper region 14 side through the bottom portion 14a of the upper region 14). The other part is wrapped and surrounded by the resin case 10 and is positioned and held. In the present embodiment, the resin case 10 having the above-described accommodating portion 11, fixing portion 12, connector portion 13, and guide portion 18 is formed. In addition to the core 20, the terminal 17 made of a conductive material is also integrally formed. The terminal 17 is held by the resin case 10 with one end exposed at the connector portion 13 and the other end exposed at the accommodating portion 11 (upper region 14).

  Next, as shown in FIG. 5, the substrate 40 is positioned in the housing portion 11 of the resin case 10 so that the magnetoelectric conversion element 30 is positioned in the gap 20 </ b> G of the core 20 and the exposed core 20 is covered with the substrate 40. The positioning process to arrange is implemented. In the present embodiment, the surface 40a faces the core 20, the terminal 17 is inserted through the first through hole 41, and the support pin 16 (see FIGS. 2 and 3) is inserted through the through hole (not shown) in the vertical direction. The substrate 40 is moved in a direction approaching the core 20 (a direction indicated by a white arrow in FIG. 5, hereinafter simply referred to as a downward direction). At this time, the clearance (clearance) between the first through hole 41 and the terminal 17 and the clearance (clearance) between the through hole and the support pin 16 are approximately the same. In the (width direction), the position of the substrate 40 is provisionally positioned (the approximate position of the substrate 40 is determined). In other words, even if a dimensional variation or positional shift described later occurs, the terminals are arranged such that the magnetoelectric conversion element 30 (the magnetic sensor chip 31 covered with the sealing resin 33) is in contact with the tapered surface 18a of the guide portion 18. The clearance between 17 and the corresponding through hole of the support pin 16 is determined. Further, the surface 40a of the substrate 40 abuts on the enlarged diameter portions 16a (see FIG. 3) of the plurality of support pins 16, and thereby the position of the substrate 40 is determined in the vertical direction.

  Here, in order to accurately detect the current to be measured by the current sensor 100, the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) in the width direction is set between the both end faces 21 of the core 20 constituting the gap 20G. It is preferable to match the center line 21c between the two ends 21 (gap 20G) as much as possible. However, the dimensional variation of the resin case 10, the core 20, the substrate 40, and the magnetoelectric conversion element 30, the dimensional variation and the formation position of the first through hole 41 and the second through hole 42, the core 20 relative to the resin case 10 at the time of insert molding, The position of the magnetoelectric conversion element 30 does not become substantially the center between the both end faces 21 due to factors such as the positional deviation of the terminal 17 (positional variation) and the positional variation of the magnetoelectric conversion element 30 mounted on the substrate 40. For example, FIG. As shown in FIG. 5, it is also possible that the arrangement is shifted to the one end face 21 side.

  On the other hand, in this embodiment, as a part of the resin case 10, the guide portion 18 having the tapered surface 18a having the above-described structure is provided in contact with both end surfaces 21 of the core 20 constituting the gap 20G. . Therefore, even if the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) is shifted toward the one end face 21 with respect to the approximate center (center line 21c) of the gap 20G in the width direction, the first through hole 41 is By moving the substrate 40 downward so that the terminal 17 is inserted and the support pin 16 is inserted through a through hole (not shown), the magnetoelectric transducer 30 is formed on the tapered surface 18a of one guide portion 18 as shown in FIG. (Sealing resin 33) can be contacted. In addition, as described above, the through hole through which the support pin 16 is inserted and the first through hole 41 through which the terminal 17 is inserted have a predetermined clearance between the support pin 16 and the terminal 17. By moving the substrate 40 further downward in contact with the tapered surface 18a, the magnetoelectric conversion element 30 is moved along the tapered surface 18a, and the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) in the width direction is changed. , The gap 20G can be brought close to the approximate center (center line 21c). And the position of the magnetoelectric conversion element 30 can be made into the approximate center of the gap 20G in the state which the surface 40a of the board | substrate 40 contact | abutted to the enlarged diameter part 16a of the some support pin 16. FIG.

  Since the guide portions 18 are provided in contact with both end faces 21 of the core 20, even if the magnetoelectric conversion element 30 is shifted to the end face 21 side opposite to that in FIG. be able to. In the present embodiment, in the width direction, the width of the gap 20G is about 3 mm, the width of the magnetoelectric conversion element 30 (sealing resin 33) is about 1.5 mm, the lower end portion of the tapered surface 18a in the guide portion 18 and the parallel surface 18b. In a state where the thickness of the portion is about 0.65 mm and the magnetic sensor chip 31 substantially coincides with the substantially center (center line 21c) of the gap 20G, the parallel surface 18b and the lower end portions of the tapered surface 18a and the magnetoelectric conversion in both guide portions 18 The clearance of the element 30 (sealing resin 33) is about 0.1 mm. Therefore, when inserting the magnetoelectric conversion element 30 into the gap 20G, if the magnetic sensor chip 31 is substantially coincident with the substantially center (center line 21c) of the gap 20G, any of the guide portions 18 (tapered surface 18a). Without making contact with each other, the position of the magnetoelectric conversion element 30 can be approximately the center of the gap 20G.

  Then, the substrate 40 is fixed to the resin case 10 in a state where the position of the substrate 40 is determined with respect to the resin case 10 (core 20). In this embodiment, the board | substrate 40 is fixed to the resin case 10 via the terminal 17 by solder-joining the several terminal 17 which penetrates the 1st through-hole 41, and a corresponding land. As a result, the magnetoelectric conversion element 30 (magnetic sensor chip 31) is positioned and fixed substantially at the center (center line 21c) of the gap 20G. Then, the current sensor 100 shown in FIG. 1 can be obtained by placing the lid 50 (not shown) on the upper end surface 11a of the housing portion 11 of the resin case 10 and fixing it by adhesion or welding.

  Next, effects of the characteristic portions of the current sensor 100 and the manufacturing method thereof according to the present embodiment will be described. First, as a part of the resin case 10, guide portions 18 having tapered surfaces 18a are provided in contact with both end surfaces 21 of the core 20 constituting the gap 20G. Therefore, when the substrate 40 on which the magnetoelectric conversion element 30 is mounted is disposed in the housing portion 11 of the resin case 10 in which the core 20 is integrally molded, the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) in the width direction. Although the magnetoelectric conversion element 30 (sealing resin 33) is in contact with at least one of the tapered surfaces 18a even if the gap 20G is displaced toward either one of the end surfaces 21 with respect to the approximate center (center line 21c) of the gap 20G. Since it is inserted in the back side of 20G, the position of the magnetoelectric conversion element 30 can be made into the approximate center of the gap 20G. Thus, since the magnetoelectric conversion element 30 can be guided to the approximate center of the gap 20G by the guide portion 18 having the tapered surface 18a, in the configuration in which the core 20 is integrally formed with the resin case 10, the core 20 with respect to the gap 20G. The position accuracy of the magnetoelectric conversion element 30 (magnetic sensor chip 31) is improved, and as a result, the current sensor 100 in which the characteristic variation due to the disturbance magnetic field is reduced can be obtained.

  In addition, this inventor has confirmed the relationship between the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) with respect to the gap 20G, and the characteristic fluctuation | variation by a disturbance magnetic field (disturbance noise). FIG. 7 is a plan view schematically showing the relationship between the position of the magnetoelectric transducer and the disturbance magnetic field with respect to the gap of the core. FIG. 8 is a diagram showing the relationship between the positional deviation of the magnetoelectric transducer and the error current generated by the disturbance magnetic field. As shown in FIG. 7, a disturbance magnetic field of 2.0 mT acts along the horizontal direction and in a direction substantially perpendicular to the width direction (direction of magnetic flux acting between the end faces 21). . As a result, from FIG. 8, the error current increases, that is, the characteristic fluctuation increases, as the magnetoelectric conversion element 30 (magnetic sensor chip 31) is displaced from the center position (center line 21c) of the both end faces 21 of the core 20. it is obvious. On the other hand, according to the present embodiment, since the magnetoelectric conversion element 30 is accurately positioned with respect to the gap 20G of the core 20, it is possible to obtain the current sensor 100 in which the characteristic variation due to the disturbance magnetic field is reduced.

  Moreover, in this embodiment, since the guide part 18 is provided as a part of the resin case 10, the manufacturing process can be simplified. Furthermore, the positional accuracy of the guide portion 18 in the gap 20G can be improved as compared with the configuration in which the guide portion 18 is fixed to the resin case 10 with a guide portion different from the resin case 10.

  In the present embodiment, the pair of guide portions 18 has a parallel surface 18b connected to the tapered surface 18a, and in the width direction, between the lower end portions of the tapered surface 18a in each guide portion 18 (between the parallel surfaces 18b). ) Is made wider than the width of the magnetoelectric conversion element 30 (sealing resin 33). Therefore, the resin case 10 and the magnetoelectric conversion element 30 are configured since the magnetoelectric conversion element 30 is not constrained by the both guide portions 18 in the width direction in a state where the substrate 40 is positioned and arranged on the resin case 10 and fixed. The stress based on the difference in linear expansion coefficient of the material can be suppressed. Further, the action of the external force applied to the resin case 10 on the magnetoelectric conversion element 30 can also be suppressed.

  However, in the width direction, the tapered surfaces 18a of the pair of guide portions 18 are symmetrical with respect to the approximate center of the gap 20G (center line 21c), and the opposing distance between the lower end portions of the tapered surface 18a is as follows. It is good also as a structure narrowed rather than the width | variety of the magnetoelectric conversion element 30 (sealing resin 33), and the magnetoelectric conversion element 30 contacting the taper surface 18a in both the guide parts 18. FIG. In the example shown in FIG. 9, the guide portion 18 that covers each end surface 21 has a tapered surface 18 a from the upper end to the bottom surface 15 a of the lower region 15, and in the vertical direction, than the lower end portions of both tapered surfaces 18 a. The magnetoelectric conversion element 30 is in contact with the upper (substrate 40 side) position. In this case, since the position of the magnetoelectric conversion element 30 is determined by the magnetoelectric conversion element 30 coming into contact with the two tapered surfaces 18a having a symmetrical shape, the positional accuracy of the magnetoelectric conversion element 30 with respect to the gap 20G of the core 20 is further improved. be able to. In this case, the magnetoelectric conversion element 30 (sealing resin 33) from the substrate 40 so that the surface 40a of the substrate 40 is in contact with the enlarged diameter portion 16a of the support pin 16 and the magnetoelectric conversion element 30 is in contact with both tapered surfaces 18a. And the shape of the guide portion 18 (tapered surface 18a) are determined in advance. FIG. 9 is a cross-sectional view illustrating a schematic configuration of a modification of the current sensor.

In the present embodiment, an example in which the shape of the pair of guide portions 18 is symmetrical with respect to the center line 21c is shown. However, in the positioning state, the configuration in which the magnetoelectric conversion element 30 is not in contact with both the guide portions 18 (the width of the narrowest portion among the portions facing the magnetoelectric conversion element 30 in the gap formed between the guide portions 18 is magnetoelectric. Configuration wider than the width of the conversion element 30)
In this case, the shape of the guide portion 18 can be asymmetrical as long as the resin thicknesses at the narrowest portion satisfy the substantially equal relationship. For example, the angle of the taper surface 18a can be set to a different angle between the pair of guide portions 18. Furthermore, it is also possible to adopt a configuration in which the forming range of the tapered surface 18a is different between the pair of guide portions 18 in the vertical direction. Further, in the present embodiment, an example in which the tapered surface 18a is a flat surface is shown, but a curved surface may be adopted.

(Second Embodiment)
Next, 2nd Embodiment of this invention is described based on FIG.10 and FIG.11. FIG. 10 is a plan view showing the periphery of the guide portion before the magnetoelectric conversion element is arranged in the current sensor according to the second embodiment. FIG. 11 is a cross-sectional view illustrating a schematic configuration of a current sensor according to the second embodiment. In FIG. 10, for the sake of convenience, the magnetoelectric conversion element is indicated by a broken line, and the resin case portion excluding the substrate and the guide portion is omitted.

  Since the current sensor and the manufacturing method thereof according to the second embodiment are common in common with the current sensor and the manufacturing method shown in the first embodiment, the detailed description of the common parts is omitted below, and different parts are emphasized. I will explain it. In addition, the same code | symbol shall be provided to the element same as the element shown in 1st Embodiment.

  In 1st Embodiment, the example which makes the magnetoelectric conversion element 30 contact the taper surface 18a of the guide part 18 provided on the both end surfaces 21 was shown as the modification (refer FIG. 9). However, in this case, the surface 40a of the substrate 40 is in contact with the enlarged diameter portion 16a of the support pin 16, and the magnetoelectric conversion element 30 must be in contact with both tapered surfaces 18a.

  On the other hand, in this embodiment, as shown in FIG. 10, the opposing distance between the lower end portions of the tapered surfaces 18 a in both guide portions 18 is the width of the magnetoelectric conversion element 30 in a state where the magnetoelectric conversion element 30 is not disposed. It is narrower than. The magnetoelectric conversion element 30 is brought into contact with the elastically deformed guide portion 18 and is press-fitted and arranged in the gap 20G as shown in FIG.

  Specifically, as shown in FIG. 10, two opposing sets (four in total) of guide portions 18 are arranged along the horizontal direction and substantially perpendicular to the width direction (hereinafter simply referred to as the width direction). In the vertical direction, it is provided from the bottom surface 15a of the lower region 15 to the upper end of the end surface 21 in the vertical direction. Further, the four guide portions 18 are planar triangles whose lengths in the direction perpendicular to the width direction are shorter as they are separated from the corresponding end surfaces 21 and have the same shape and size. That is, each guide portion 18 has a triangular prism shape that can be elastically deformed. Thus, if the planar shape along the horizontal direction is a triangle, the resin thickness in the width direction and the rectangle having the same resin thickness at the contact portion with the end surface 21 in the horizontal direction and substantially perpendicular to the width direction are used. Since the spring constant is small, the magnetoelectric conversion element 30 can be easily inserted into the gap 20G. In each of the triangular prism-shaped guide portions 18, a tapered surface 18 a is provided in a partial range from the upper end portion that substantially coincides with the upper end of the end surface 21. Further, in the width direction, the facing distance between the apex portions of the triangles (hereinafter simply referred to as apexes) separated from the corresponding end face 21 is narrower than the width of the magnetoelectric transducer 30 as shown in FIG. Yes.

  In this case, as shown in the first embodiment, in the width direction, the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) is closer to the one end face 21 than the approximate center (center line 21c) of the gap 20G. Even if they are misaligned, the substrate 40 is further moved downward with the magnetoelectric conversion element 30 in contact with one of the tapered surfaces 18a, so that the position of the magnetoelectric conversion element 30 can be set to the approximate center of the gap 20G. it can. Further, by moving the substrate 40 further downward, the magnetoelectric conversion element 30 positioned at the approximate center of the gap 20G is elastically deformed by the tapered surface 18a while the pair of guide portions 18 are elastically deformed. Is inserted (press-fit). Specifically, it is inserted (press-fitted) into the back side of the gap 20G while crushing the vicinity of the apex of each guide portion 18 of the plane triangle. Therefore, the position of the magnetoelectric conversion element 30 can be set to the approximate center of the gap 20G in a state where the surface 40a of the substrate 40 is in contact with the enlarged diameter portion 16a of the support pin 16. In addition, the magnetoelectric conversion element 30 can be held by the pair of guide portions 18 that can be elastically deformed.

  Thus, in the present embodiment, the magnetoelectric conversion element 30 (magnetic sensor chip 31) can be guided to the approximate center of the gap 20G by the elastically deformable guide portions 18 provided on the both end faces 21 constituting the gap 20G. . Therefore, in the configuration in which the core 20 is integrally formed with the resin case 10, the positional accuracy of the magnetoelectric conversion element 30 with respect to the gap 20G of the core 20 is improved, and as a result, the current sensor 100 in which the characteristic fluctuation due to the disturbance magnetic field is reduced can be obtained. it can. Furthermore, also in this embodiment, since the guide part 18 is provided as a part of the resin case 10, the manufacturing process can be simplified and the positional accuracy of the guide part 18 can be improved.

  Further, since the guide portion 18 is elastically deformed when the magnetoelectric conversion element 30 is inserted and disposed in the gap 20G, the stress of the magnetoelectric conversion element 30 received by contacting the guide portion 18 can be reduced.

  In the present embodiment, an example in which the planar shape of the guide portion 18 is a triangle is shown, but the planar shape is not limited to the above example.

(Third embodiment)
Next, 3rd Embodiment of this invention is described based on FIG.12 and FIG.13. FIG. 12 is a cross-sectional view illustrating a schematic configuration of the current sensor according to the third embodiment. 13 is a cross-sectional view showing a substrate positioning step in the manufacturing process of the current sensor shown in FIG.

  Since the current sensor and its manufacturing method according to the third embodiment are in common with the current sensor and its manufacturing method shown in each of the above embodiments, detailed description of the common parts will be omitted below, and different parts will be emphasized. I will explain it. In addition, the same code | symbol shall be provided to the element same as the element shown to the said embodiment.

  In each of the embodiments described above, the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) in the width direction is set to the substantially center (center line 21c) of the gap 20G by the guide portion 18 provided as a part of the resin case 10. An example is shown. On the other hand, in the present embodiment, the taper portion 33a is provided in the sealing resin 33 constituting the magnetoelectric conversion element 30, so that the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) in the width direction is substantially the same as the gap 20G. It is characterized by a point that is the center (center line 21c).

  As shown in FIG. 12, also in this embodiment, as the magnetoelectric conversion element 30, the magnetic sensor chip 31 and the lead 32 are electrically connected, and the magnetic sensor chip 31 and the connection between the magnetic sensor chip 31 and the lead 32 are connected. A mold IC whose part is covered with a sealing resin 33 is employed. The sealing resin 33 is provided with a taper portion 33a whose thickness in the width direction is reduced as it is farther from the substrate 40 in the vertical direction, and at least a part of the tapered outer surface of the taper portion 33a is formed at both end surfaces 21. It is relative to. As an example, in the present embodiment, as shown in FIG. 12, a tapered portion 33a is provided in a predetermined range from a portion farthest from the substrate 40 in the vertical direction, that is, at the insertion tip of the magnetoelectric transducer 30 into the gap 20G. Yes. Further, in the taper portion 33a, the resin thickness of the portion where the resin thickness in the width direction is the thickest (the portion closest to the substrate 40 in the taper portion 33a) is thinner than the width of the gap 20G, and the entire taper portion 33a is the gap 20G. It is inserted and placed inside. The entire tapered outer surface of the tapered portion 33 a is opposed to both end surfaces 21.

  When the magnetoelectric conversion element 30 having the taper portion 33a is used in this way, the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) is one end face 21 with respect to the approximate center (center line 21c) of the gap 20G in the width direction. Even if it is shifted to the side, the magnetoelectric conversion element 30 has the taper surface of the taper portion 33a of the sealing resin 33 at the upper end of any one end surface 21, that is, the upper surface of the end surface 21 and the core 20 (the surface facing the substrate 40). ), And is inserted into the back side of the gap 20G. Therefore, the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) can be set to the approximate center of the gap G. Thus, in the configuration in which the core 20 is integrally formed with the resin case 10, the position accuracy of the magnetoelectric conversion element 30 with respect to the gap 20G of the core 20 is improved, and as a result, the current sensor 100 in which the characteristic fluctuation due to the disturbance magnetic field is reduced is obtained. Can do.

  In the present embodiment, in the width direction, the width of the gap 20G is about 3 mm, and the resin thickness of the thickest portion of the tapered portion 33a in the magnetoelectric conversion element 30 is about 2.8 mm. Therefore, when inserting the magnetoelectric conversion element 30 into the gap 20G, if the magnetic sensor chip 31 is substantially coincident with the approximate center (center line 21c) of the gap 20G, the magnetic sensor chip 31 is not brought into contact with any corner portion 22. The position of the magnetoelectric conversion element 30 can be approximately the center of the gap 20G.

  In the present embodiment, an example in which the entire taper portion 33a of the sealing resin 33 is disposed in the gap 20G is shown. However, for example, as shown in FIG. 14, in the width direction, the tapered outer surface of the taper portion 33a has a line-symmetric shape with the center in the thickness direction of the magnetic sensor chip 31 as the center line, and the taper portion 33a has both angles. It is good also as a structure which contacts the part 22. FIG. In the example shown in FIG. 14, the entire sealing resin 33 is a tapered portion 33 a in the vertical direction. In this case, the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) is determined by the outer surface of the tapered portion 33a having a symmetric shape being in contact with both corner portions 22, and therefore, the magnetoelectric conversion element 30 with respect to the gap 20G of the core 20 is determined. The position accuracy can be further improved. FIG. 14 is a cross-sectional view showing a schematic configuration of a modification of the current sensor.

(Fourth embodiment)
Next, 4th Embodiment of this invention is described based on FIG.15 and FIG.16. FIG. 15 is a cross-sectional view illustrating a schematic configuration of a current sensor according to the fourth embodiment. 16 is a cross-sectional view showing a substrate positioning step in the manufacturing process of the current sensor shown in FIG.

  Since the current sensor and the manufacturing method thereof according to the fourth embodiment are in common with the current sensor and the manufacturing method shown in each of the above embodiments, detailed descriptions of the common parts are omitted below, and different parts are emphasized. I will explain it. In addition, the same code | symbol shall be provided to the element same as the element shown to the said embodiment.

  In 1st Embodiment and 2nd Embodiment, the example which provides the guide part 18 which makes a pair in the both end surfaces 21 of the core 20 was shown. On the other hand, in the present embodiment, as shown in FIG. 15, for example, as a part of the resin case 10, a guide portion 18 having a predetermined thickness is provided only on one of both end faces 21 of the core 20. The magnetoelectric conversion element 30 is characterized in that it is in contact with the back surface of the contact surface with the end surface 21 of the guide portion 18 in the width direction.

  In the example shown in FIG. 15, the end surface 21 on the side where the guide portion 18 is provided and the vicinity thereof are covered with the resin case 10. The guide portion 18 includes a corner portion 22 and is formed from the upper surface of the core 20 to the end surface 21. Note that the length of the taper surface 18a in the width direction is not limited to the magnetoelectric conversion element 30 (sealing) at the time of positioning the substrate 40, even if the cause of position variation in the width direction of the magnetoelectric conversion element 30 shown in the first embodiment occurs. The resin 33) is set to a predetermined length so as to come into contact. Also in this embodiment, the parallel surface 18b is connected to the tapered surface 18a, and the resin thickness of the portion of the guide portion 18 with the parallel surface 18b as the surface in the width direction is equal to the resin thickness and the magnetoelectric conversion element. 30 is set so that the sum of the thickness from the center of the magnetic sensor chip 31 to the surface of the sealing resin 33 substantially matches the distance from the end face 21 to the center line 21c. The sealing resin 33 of the magnetoelectric conversion element 30 is in contact with the parallel surface 18 b of the guide portion 18.

  Such a current sensor 100 can be formed by, for example, a manufacturing method described below. First, the resin case 10 including the guide portion 18 having the above-described configuration in which the core 20 is integrally formed and is in contact with one end surface 21 of the core 20 is prepared. Further, as shown in FIG. 16, the magnetoresistive conversion element in which the lead 32 is bent with respect to the vertical direction at the bent portion 32 a on the surface 40 a side of the substrate 40 and is covered with the sealing resin 33. A substrate 40 is prepared in which a flat plate portion 30 (in other words, the magnetic sensor chip 31) is inclined at a predetermined angle to the side where the guide portion 18 is provided with respect to the vertical direction. Such a substrate 40 is formed by bending the leads 32 before mounting the magnetoelectric conversion element 30 on the substrate 40 or by bending the leads 32 while being mounted on the substrate 40. Can be obtained. The angle (inclination angle) of the flat portion (magnetic sensor chip 31) in the magnetoelectric conversion element 30 with respect to the vertical direction is the above even if there is a cause of positional variation in the width direction of the magnetoelectric conversion element 30. The magnetoelectric conversion element 30 is set in contact with the tapered surface 18a.

  Then, using the prepared substrate 40 and the resin case 10, the substrate 40 is positioned and fixed to the resin case 10. In the present embodiment, the substrate 40 is moved downward so that the terminal 17 passes through the first through hole 41 and the support pin 16 passes through the through hole (not shown). At this time, the magnetoelectric conversion element 30 comes into contact with the tapered surface 18a of the guide portion 18 by setting the inclination angle and the tapered surface 18a. When the substrate 40 is further moved downward, spring properties are imparted to the leads 32 bent at the bent portion 32a, so that the magnetoelectric conversion element 30 is in contact with the taper surface 18a and the gap 20G. It is inserted into the back side and is brought into contact with the parallel surface 18b of the guide portion 18. Further, the lead 32 is deformed in a direction in which bending is eliminated as the magnetoelectric conversion element 30 approaches the approximate center of the gap 20G, and thereby, a flat portion of the magnetoelectric conversion element 30 is brought into contact with the parallel surface 18b. The resin thickness of the portion of the guide portion 18 having the parallel surface 18b as the surface is the above-described predetermined thickness, and in this contact state, the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) is set substantially at the center of the gap 20G. (Center line 21c).

  As described above, according to the present embodiment, as a part of the resin case 10, the guide portion 18 having a predetermined thickness is provided in contact with only one end face 21 of the both end faces 21 of the core 20 constituting the gap 20G. ing. The magnetoelectric conversion element 30 is brought into contact with the parallel surface 18 b of the guide portion 18. That is, in the width direction, the magnetoelectric conversion element 30 is in contact with the end surface 21 provided with the guide portion 18 via the guide portion 18 having a predetermined thickness. Therefore, the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) can be set to the approximate center (center line 21c) of the gap 20G with the end face 21 provided with the guide portion 18 as a reference. Thus, in the configuration in which the core 20 is integrally formed with the resin case 10, the position accuracy of the magnetoelectric conversion element 30 with respect to the gap 20G of the core 20 is improved, and as a result, the current sensor 100 in which the characteristic fluctuation due to the disturbance magnetic field is reduced is obtained. Can do.

  Further, such a current sensor 100 can be obtained only by moving the substrate 40 downward. Furthermore, since the guide part 18 is provided as a part of the resin case 10, the manufacturing process can be simplified and the positional accuracy of the guide part 18 can be improved.

  Note that the current sensor 100 having the same basic configuration as the above-described current sensor 100 can be formed by another manufacturing method. For example, the current sensor 100 shown in FIG. 17 has substantially the same configuration as the current sensor 100 shown in FIG. The difference is that the guide portion 18 has a columnar shape that covers only the end surface 21 of the core 20, and a predetermined range from the upper end of the guide portion 18 that substantially coincides with the upper end of the end surface 21 is a tapered surface 18 a.

  In order to form the current sensor 100 shown in FIG. 17, the resin case 10 including the guide portion 18 in which the core 20 is integrally formed and is in contact with one of the end surfaces 21 of the core 20 is prepared as described above. Further, as shown in FIG. 18, a substrate 40 in which the leads 32 are not bent is prepared. Then, as shown in FIG. 18, for example, the substrate 40 is moved at least downward so that the terminal 17 is inserted through the first through hole 41 and the support pin 16 is inserted through the through hole (not shown). (Sealing resin 33) is arranged in a region excluding the guide portion 18 in the gap 20G. At this point, the surface 40a of the substrate 40 is in contact with the enlarged diameter portion 16a of the support pin 16. Next, as shown in FIG. 19, the magnetoelectric conversion element 30 approaches the guide part 18 until the movement stops when the magnetoelectric conversion element 30 (sealing resin 33) contacts the parallel surface 18 b of the guide part 18. For example, the substrate 40 is moved in the width direction, and the magnetoelectric conversion element 30 is positioned. That is, the magnetoelectric conversion element 30 is stopped against the guide portion 18. Similarly to the above, the resin thickness of the portion of the guide portion 18 having the parallel surface 18b as the surface is a predetermined thickness, and in this contact state, the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) is set to the approximate center of the gap 20G. (Center line 21c).

Thus, the current sensor 100 shown in FIGS. 15 and 17 can also be formed by bringing the magnetoelectric conversion element into contact with the back surface of the contact surface with the end surface of the guide portion by two-stage movement. In this case, bending of the lead 32 can be made unnecessary. Further, according to the manufacturing method using the two-stage movement, the guide portion 18 that does not have the tapered surface 18a can be employed. However, since the guide portion 18 is provided in the gap 20G, considering that the magnetoelectric conversion element 30 is in contact with the upper portion of the guide portion 18 on the substrate side, it is preferable to have a tapered surface 18a. FIG. 17 is a cross-sectional view illustrating a schematic configuration of a modification of the current sensor. 18 and 19 are sectional views showing a substrate positioning step in the manufacturing process of the current sensor shown in FIG. 17 (fifth embodiment).
Next, 5th Embodiment of this invention is described based on FIGS. FIG. 20 is a cross-sectional view illustrating a schematic configuration of the current sensor according to the fifth embodiment. 21 and 22 are sectional views showing a substrate positioning step in the manufacturing process of the current sensor shown in FIG.

  Since the current sensor and the manufacturing method thereof according to the fifth embodiment are in common with the current sensor and the manufacturing method thereof described in the above embodiments, detailed descriptions of the common parts are omitted below, and different parts are emphasized. I will explain it. In addition, the same code | symbol shall be provided to the element same as the element shown to the said embodiment.

  In the fourth embodiment, the magnetoelectric conversion element 30 is brought into contact with the guide portion 18 having a predetermined thickness provided on the one end face 21, so that the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) is substantially the gap 20G. An example of the center (center line 21c) is shown. On the other hand, in this embodiment, for example, as shown in FIG. 20, the sealing resin 33 covering the magnetic sensor chip 31 has a thickness on one surface of the magnetic sensor chip 31 on the back surface of the one surface in the width direction. The predetermined thickness is greater than the thickness. Specifically, the thickness from the surface of the sealing resin 33 located on one surface of the magnetic sensor chip 31 to the center of the magnetic sensor chip 31 is set so as to substantially match the distance from the end surface 21 to the center line 21c. Yes. Then, the magnetoelectric conversion element 30 (magnetic sensor chip 31) is positioned at the gap 20G by bringing the magnetoelectric conversion element 30 into contact with one of the end faces 21 of the core 20 with the outer surface on the thick side of the sealing resin 33 as a contact surface. This is characterized in that it is approximately at the center (center line 21c).

  Such a current sensor 100 can be formed by the following manufacturing method, for example. First, the resin case 10 in which the core 20 is integrally formed is prepared. Moreover, the board | substrate 40 with which the magnetoelectric conversion element 30 was mounted in the surface 40a side is prepared. At this time, as shown in FIG. 20, the resin thickness of the sealing resin 33 in the width direction is different between the one surface of the magnetic sensor chip 31 and the back surface thereof, and the magnetoelectric conversion has a predetermined thickness that is thicker on the one surface. Element 30 is used. Such a magnetoelectric conversion element 30 can be obtained by adjusting a mold used in the transfer molding method.

  Then, using the prepared substrate 40 and the resin case 10, the substrate 40 is positioned and fixed to the resin case 10. First, as shown in FIG. 21, for example, the substrate 40 is moved at least downward so that the terminal 17 is inserted through the first through hole 41 and the support pin 16 is inserted through the through hole (not shown). The sealing resin 33) is arranged in the gap 20G. At this point, the surface 40a of the substrate 40 is in contact with the enlarged diameter portion 16a of the support pin 16. Next, as shown in FIG. 22, the magnetoelectric conversion element 30 approaches the end face 21 until the movement stops when the thicker surface of the sealing resin 33 in the magnetoelectric conversion element 30 comes into contact with the one end face 21. For example, the substrate 40 is moved in the width direction, and the magnetoelectric conversion element 30 is positioned. That is, the magnetoelectric conversion element 30 is stopped against the end face 21. As described above, the thickness of the sealing resin 33 on one surface of the magnetic sensor chip 31 is a predetermined thickness, and in this contact state, the position of the magnetoelectric conversion element 30 (magnetic sensor chip 31) is set to the gap 20G. The center can be substantially the center (center line 21c).

  Thus, according to the present embodiment, in the sealing resin 33 constituting the mold IC as the magnetoelectric conversion element 30, the thickness on one surface of the magnetic sensor chip 31 is larger than the thickness on the back surface of the one surface. Thickness. The magnetoelectric conversion element 30 is brought into contact with one of the end surfaces 21 of the core 20 with the outer surface on the thick side of the sealing resin 33 as the contact surface. Therefore, the magnetic sensor chip 31 can be set to the approximate center of the gap 20G with the end surface 21 as a reference and the sealing resin 33 having a predetermined thickness. As a result, in the configuration in which the core 20 is integrally formed with the resin case 10, the position accuracy of the magnetoelectric conversion element 30 with respect to the gap 20G of the core 20 is improved, and as a result, the current sensor 100 in which characteristic fluctuation due to a disturbance magnetic field is reduced Can do.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

It is sectional drawing which shows schematic structure of the current sensor which concerns on 1st Embodiment. It is a top view of the current sensor shown in FIG. 1, and shows a state without a lid. It is a top view of the current sensor shown in FIG. 1, and shows a state without a lid and a substrate. It is sectional drawing which shows a case preparation process among the manufacturing processes of the current sensor shown in FIG. It is sectional drawing which shows the positioning process of a board | substrate among the manufacturing processes of an electric current sensor. It is sectional drawing which shows the positioning process of a board | substrate among the manufacturing processes of an electric current sensor. It is the top view which showed typically the relationship between the position of the magnetoelectric conversion element with respect to the gap of a core, and a disturbance magnetic field. It is a figure which shows the relationship between the position shift of a magnetoelectric conversion element, and the error electric current produced by a disturbance magnetic field. It is sectional drawing which shows schematic structure of the modification of a current sensor. In the current sensor which concerns on 2nd Embodiment, it is a top view which shows the guide part periphery before a magnetoelectric conversion element is arrange | positioned. It is sectional drawing which shows schematic structure of the current sensor which concerns on 2nd Embodiment. It is sectional drawing which shows schematic structure of the current sensor which concerns on 3rd Embodiment. It is sectional drawing which shows the positioning process of a board | substrate among the manufacturing processes of the current sensor shown in FIG. It is sectional drawing which shows schematic structure of the modification of a current sensor. It is sectional drawing which shows schematic structure of the current sensor which concerns on 4th Embodiment. It is sectional drawing which shows the positioning process of a board | substrate among the manufacturing processes of the current sensor shown in FIG. It is sectional drawing which shows schematic structure of the modification of a current sensor. It is sectional drawing which shows a board | substrate positioning process among the manufacturing processes of the current sensor shown in FIG. It is sectional drawing which shows the positioning process of a board | substrate among the manufacturing processes of the current sensor shown in FIG. It is sectional drawing which shows schematic structure of the current sensor which concerns on 6th Embodiment. It is sectional drawing which shows a board | substrate positioning process among the manufacturing processes of the current sensor shown in FIG. It is sectional drawing which shows the positioning process of a board | substrate among the manufacturing processes of the current sensor shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Resin case 11 ... Storage part 18 ... Guide part 18a ... Tapered surface 18b ... Parallel surface 20 ... Core 20G ... Gap 21 ... End surface 21c ... Center Wire 30 ... Magnetoelectric transducer 31 ... Magnetic sensor chip 32 ... Lead 33 ... Sealing resin 33a ... Tapered portion 40 ... Substrate 40a ... Surface 100 ... Current sensor

Claims (7)

A ring-shaped core having a gap of a predetermined width between both end faces that are substantially parallel to each other is integrally formed with the resin case, and at least a part of the gap is exposed in the housing portion of the resin case, and on the surface side. A substrate on which a magnetoelectric conversion element is mounted is housed in the housing portion and disposed on the gap, and the current sensor includes the magnetoelectric conversion element disposed in the gap,
The resin case has a pair of guide portions that are in contact with only one of the end faces of the both end faces of the core,
The guide portion has a tapered surface with a short facing distance from the other end surface facing away from the substrate in the thickness direction of the core,
In the guide portion, a lower end portion farthest from the substrate in the tapered surface is substantially parallel to the end surface, and at least between the end portion on the substrate side in the thickness direction and the lower end portion. It is a part with the shortest facing distance, and the thickness from the end face in the lower end part is substantially equal to each other in the pair of guide parts,
The magnetoelectric conversion element is opposed to both tapered surfaces of the pair of guide portions in the width direction of the gap. The pair of guide portions are connected to a lower end portion of the tapered surface, and each has a parallel surface substantially parallel to the end surface,
The facing distance between the lower end portions of the guide portion in contact with each end face is wider than the width of the magnetoelectric conversion element,
2. The current sensor according to claim 1, wherein the magnetoelectric conversion element is opposed to both the tapered surfaces and the two parallel surfaces of the pair of guide portions in the width direction of the gap. In the width direction of the gap, the tapered surfaces of the pair of guide portions are symmetrical with respect to the center line between both end surfaces of the core,
The facing distance between the lower end portions in the guide portion that contacts each end face is narrower than the width of the magnetoelectric conversion element,
The current sensor according to claim 1, wherein the magnetoelectric conversion element is in contact with both tapered surfaces of the pair of guide portions. The facing distance between the lower end portions of the guide portion in contact with each end face is narrower than the width of the magnetoelectric conversion element in a state where the magnetoelectric conversion element is not disposed,
The current sensor according to claim 1, wherein the magnetoelectric conversion element is in contact with each elastically deformed guide portion and press-fitted and disposed in the gap. A ring-shaped core having a gap of a predetermined width between both end faces that are substantially parallel to each other is integrally formed with the resin case, and at least a part of the gap is exposed in the housing portion of the resin case, and on the surface side. A substrate on which a magnetoelectric conversion element is mounted is housed in the housing portion and disposed on the gap, and the current sensor includes the magnetoelectric conversion element disposed in the gap,
As a part of the resin case, a guide portion having a predetermined thickness that is in contact with only one of the end faces of the both end faces of the core is provided,
The magnetoelectric conversion element is in contact with the back surface of the contact surface with the end surface of the guide portion in the width direction of the gap. A substrate preparation step of preparing a substrate on which a magnetoelectric conversion element is mounted on the surface side;
A case preparation step of preparing a resin case in which a ring-shaped core having a gap of a predetermined width is formed between both end faces that are substantially parallel to each other, and at least a part of the gap is exposed in the housing portion;
A fixing step of positioning the substrate on the core in the housing portion so that the magnetoelectric conversion element is positioned in the gap of the core, and fixing the substrate to the resin case in the positioned state; A method of manufacturing a current sensor comprising:
In the case preparation step, the resin case having a guide portion with a predetermined thickness in contact with only one of the end faces of the both end faces of the core is prepared,
In the fixing step, the magnetoelectric conversion element is arranged in the gap, and then the magnetoelectric conversion element is moved until the magnetoelectric conversion element comes into contact with the back surface of the contact surface with the end surface of the guide portion until movement stops. A method of manufacturing a current sensor, comprising: moving the substrate or the resin case in a width direction of the gap so as to approach the guide portion, and positioning the magnetoelectric conversion element. A magnetic sensor chip and a lead are electrically connected, and the magnetic sensor chip and a mold IC in which a connection portion between the magnetic sensor chip and the lead is covered with a sealing resin is used as a magnetoelectric conversion element, and the lead is a through hole. A substrate preparing step of preparing a substrate on which the magnetoelectric conversion element is mounted on the surface side, which is inserted into the land and solder-bonded to a land formed around the through hole;
A case preparation step of preparing a resin case in which a ring-shaped core having a gap of a predetermined width is formed between both end faces that are substantially parallel to each other, and at least a part of the gap is exposed in the housing portion;
The substrate is positioned and arranged on the core in the housing portion so that the magnetic sensor chip of the magnetoelectric conversion element is positioned in the gap of the core, and the substrate is fixed to the resin case in the positioned state. A process for producing a current sensor comprising:
In the substrate preparation step, on the front surface side, the lead is prepared by bending the lead to be inclined with respect to the thickness direction of the substrate,
In the case preparing step, the thickness of the core is formed at a corner of the end surface and the facing surface while contacting one of both end surfaces of the core and the facing surface of the substrate connected to the end surface. Preparing the resin case having a taper surface whose opposing distance to the other end surface is shorter as it is farther from the substrate in the direction, and having a guide portion in which a portion in contact with the end surface has a predetermined thickness;
In the fixing step, in the thickness direction of the core, the surface of the substrate is brought close to the core while bringing the magnetoelectric conversion element into contact with the tapered surface, and the magnetoelectric element is placed on the back surface of the contact surface with the end surface of the guide portion. A method of manufacturing a current sensor, wherein the conversion element is contacted and positioned.

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