JP2015201537A - Coil component and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil component for which the same mold can be used even when the wire diameter of a conductive wire is changed, and which is higher in mass production and can suppress leakage of magnetic powder and occurrence of burr.SOLUTION: A coil component has a magnetic core 11 obtained by mixing powder magnetic material and a binder and pressure-molding the mixture, a coil element 12 which is spirally wound around a conductive wire and buried in the magnetic core 11, and a terminal portion 15 which is electrically connected to the coil element 12. The terminal portion 15 has a first projecting portion 13a and a second projecting portion 13b which are buried in the magnetic core 11, an end portion 12a of the coil element which is drawn out from the magnetic core and subjected to bending processing, and a holding member 13 which is connected to the end portion 12a of the coil element while superimposed on the end portion 12a, thereby holding the position and shape of the end portion 12a of the coil element. The holding members 13 project from two confronting faces of the magnetic core 11, and the holding member 13 has first projection portions 13a at the end portions of both the sides thereof, and second projection portions 13b along the end portion 12a.

Description

  The present invention relates to a coil component used in various electronic devices and a manufacturing method thereof.

  In recent years, electronic control of automobile drive systems and control systems has been increasingly advanced, and a large number of electronic control devices have been installed in a single automobile, and further downsizing and higher reliability of electronic control devices are desired. It is rare. Furthermore, there are various demands for the characteristics.

  In addition, electronic components used in these electronic control devices are also required to have high reliability that can be surface-mounted for miniaturization and are required for in-vehicle components.

  Next, such a conventional coil component will be described with reference to the drawings.

  8 is a plan view of a conventional coil component, FIG. 9 is a cross-sectional view taken along line AA of FIG. 4, and FIG. 9 shows a state where the coil component is mounted on a mounting board.

  As shown in FIGS. 8 and 9, a conventional coil component is formed by winding a copper wire with an insulating film to form a coil element 1, and the coil element 1 is made of a binder composed of a metal magnetic powder and a thermosetting resin. The body 2 is formed by embedding in the mixed powder and pressure forming, and the lead wires 3 at both ends of the coil element 1 protruding from the side surface of the body 2 are crushed into a flat plate shape and from the side surface of the body 2 The surface mounting type terminal 4 is formed by bending toward the bottom surface, and thus the coil component is configured.

  And this coil component was mounted with the solder 7 on the land 6 of the mounting board | substrate 5 using the reflow furnace.

  As prior art document information related to the invention of this application, for example, Patent Document 1 is known.

JP 2009-123927 A

  For coil parts, there is a demand for standardization of the shape, but for characteristics, there are various demands for an inductance value, a DC resistance value, and the like depending on the application. Therefore, the wire diameter of the conductive wire used for the coil element also needs to be properly used for the characteristics. However, in the case of the above-described conventional pressure molding, if the wire diameters of the conductive wires are different, it is desirable to prepare a mold according to the wire diameter. Although there is a method of preparing a mold matched to the maximum wire diameter and sharing it with a thin wire diameter, magnetic powder is liable to leak and burrs are likely to occur during pressure molding. If a mold is prepared in accordance with the diameter of the conductive wire, the cost of the mold increases and the loss of switching increases, resulting in an increase in cost.

  An object of the present invention is to provide a coil component that can use the same mold even if the wire diameter of the conducting wire changes, and has high mass productivity.

  In order to solve the above-mentioned problems, the present invention provides a magnetic core formed by mixing a magnetic powder material and a binder and press-molding, a coil element formed by winding a conductive wire in a spiral, and embedded in the magnetic core, and a coil element And a terminal portion electrically connected to the first and second protrusions embedded in the magnetic core, the end of the coil element drawn from the magnetic core and bent, and the coil element It is composed of a holding member that holds the position and shape of the end of the coil element by overlapping and connecting to the end, and the holding member protrudes from two opposing surfaces of the magnetic core, and the holding member is placed on both side ends. While having a 1st protrusion part, it has a 2nd protrusion part along the edge part of a coil element.

  With the above configuration, the same mold can be used even if the wire diameter of the conductive wire changes, and it is possible to obtain an effect that mass production is high and a coil component in which leakage of magnetic powder and generation of burrs are suppressed can be obtained. it can.

The disassembled perspective view of the coil components in one embodiment of this invention The principal part top view of the holding member used for another coil component in one embodiment of this invention The figure explaining the manufacturing method of the coil components in one embodiment of this invention The figure explaining the manufacturing method of the coil components in one embodiment of this invention The figure explaining the manufacturing method of the coil components in one embodiment of this invention The figure explaining the manufacturing method of the coil components in one embodiment of this invention The figure explaining the manufacturing method of the coil components in one embodiment of this invention Plan view of conventional coil components Sectional view of the AA line of FIG.

  Hereinafter, a coil component according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an exploded perspective view of a coil component according to an embodiment of the present invention. The coil component according to an embodiment of the present invention is formed by mixing a magnetic metal powder and a binder and press-molding a magnetic core 11 having a rectangular cross section and winding a conductive wire in a spiral shape. And a holding member 13 that is electrically connected to the coil element 12.

The magnetic core 11 is composed of a plurality of green compacts 14 formed by mixing a binder containing a thermosetting resin and a metal magnetic powder in a state where the thermosetting resin is not completely cured, and pressing the mixture at about 1 ton / cm ^2. Is pressed again so as to sandwich the coil element 12, and the coil element 12 is covered with the green compact 14 and is heated and molded so that the thermosetting resin is completely cured. At this time, the re-press molding is performed at a pressure of about 5 ton / cm ² , which is larger than that of the press molding, and the green compact 14 is thinner after the re-press molding than before the re-press molding. Therefore, the molding density is increased. In particular, the number of the green compacts 14 is two, one of the green compacts 14 has a prismatic shape in which a storage portion for completely storing the coil element 12 is formed, and the other green compact 14 covers one of the green compacts 14. The end portion 12a of the coil element and the holding member 13 are projected from the interface of the two green compacts 14 in a lid shape.

  The holding member 13 has two first protrusions 13a on the end face, and a second protrusion 13b along the end 12a of the coil element, and the first protrusion 13a and the second protrusion 13b. Are embedded in two opposing surfaces of the magnetic core 11.

  The coil element 12 is made of an insulation-coated copper wire having a wire diameter of about 0.3 mm, and the holding member 13 is formed by pressing a copper plate having a thickness of about 0.15 mm. The second protrusion 13b has a width of about 0.3 mm and a length of about 0.4 mm, and the distance between the two second protrusions 13b is about 0.6 mm. Between the two second protrusions 13b, a stepped portion 13c is formed by pressing a recess having a depth of about 0.2 mm. By welding to the end 12a of the coil element at this portion, Electrically and mechanically joined.

  The joined end 12a of the coil element and the holding member 13 constitute a terminal portion 15 by bending from the side surface of the magnetic core 11 toward the bottom surface.

  By configuring as described above, the mold for pressure molding has a shape that allows the first projecting portion 13a and the second projecting portion 13b to escape, so that the same mold is used even if the wire diameter changes. Can be used. Furthermore, the shape of the second protrusion 13b is as shown in FIG. 2, the width of the root is about 0.3 mm, the width of the tip is about 0.2 mm, and the tip is made narrower. It is more desirable for the outer shape of the protruding portion 13b to be narrower toward the tip. By doing so, even if there is a gap between the second protrusion 13b and the end 12a of the coil element, the second protrusion 13b is directed toward the end 12a of the coil element during pressure molding. Since the force to be deformed acts, it is possible to suppress the leakage of magnetic powder and the occurrence of burrs from between the second protrusion 13b and the end 12a of the coil element.

  Next, the manufacturing method of the coil component in one embodiment of this invention is demonstrated.

  First, as shown in FIG. 3, a copper wire having an insulating coating on its surface is spirally wound to form a coil element 12 in which the end 12a of the coil element is drawn to the left and right.

  Next, as shown in FIG. 4, a hoop-shaped holding member 13 is formed by punching a copper plate with a metal mold, and an end 12a of the coil element is overlapped on this, and the coil element 12 is welded partially. It is fixed to the holding member 13. Here, the place to be welded is outside the portion where the magnetic core 11 will be formed later. As shown in FIG. 4, the holding member 13 is provided with a first protrusion 13a on both sides of a portion overlapping the coil element 12 and a second protrusion 13b along the end 12a of the coil element, respectively. Is embedded in the magnetic core 11. By doing so, it is possible to make it difficult to remove the holding member 13 from the magnetic core 11 and to bend it easily.

Next, as shown in FIG. 5, a binder containing a thermosetting resin and a metal magnetic powder are mixed in a state where the thermosetting resin is not completely cured, dried and pulverized to obtain a magnetic material. Is pressed at about 1 ton / cm ² to obtain a plurality of green compacts 14, and then re-press-molded at about 5 tons / cm ² so as to sandwich the coil element 12. Then, the coil element 12 is coated to form the magnetic core 11 of the coil component. By heating this at about 180 ° C. or higher, the green compact 14 is completely cured.

  Next, as shown in FIG. 6, the holding member 13 protruding from the magnetic core 11 and the end 12a of the coil element are soldered by separating from the hoop into individual pieces, attaching a flux and soldering dipping. By doing so, it is possible to create a state in which the holding member 13 and the coil element 12 are not joined in the portion embedded in the magnetic core 11 and are joined outside the magnetic core 11.

  Next, the terminal part 15 in which the holding member 13 and the end 12a of the coil element are integrated is cut at a predetermined length and bent, whereby a coil component as shown in FIG. 7 can be obtained.

  Here, FIGS. 5 and 7 are perspective perspective views of the green compact 14 or the magnetic core 11, and the outline of the green compact 14 or the magnetic core 11 is indicated by a broken line.

  In addition, after fixing the coil element 12 to the holding member 13 like FIG. 4, you may deform | transform the front-end | tip part of the 2nd protrusion part 13b toward the edge part 12a of a coil element. By doing in this way, the clearance gap between the 2nd protrusion part 13b and the edge part 12a of a coil element can be made small, and it can suppress that a magnetic powder leaks or a burr | flash generate | occur | produces.

  Moreover, in the said embodiment, although the edge part 12a of the coil element extended along the holding member 13 to the bottom face of a coil component and comprised the terminal part 15, the edge part 12a of a coil element is only a side part, The terminal portion 15 on the bottom surface portion of the coil component may be only the holding member 13.

  The coil component according to the present invention can use the same mold even if the wire diameter of the conducting wire changes, can be obtained in high productivity, and can obtain a coil component that suppresses magnetic powder leakage and burrs. It is useful above.

DESCRIPTION OF SYMBOLS 11 Magnetic core 12 Coil element 12a End part of coil element 13 Holding member 13a 1st protrusion part 13b 2nd protrusion part 13c Step processed part 14 Powder compact 15 Terminal part

Claims (4)

A magnetic core formed by mixing powder magnetic material and a binder and press-molded, a coil element formed by spirally winding a conductive wire, and a terminal portion electrically connected to the coil element; And the terminal portion overlaps the first and second protrusions embedded in the magnetic core, the end of the coil element drawn from the magnetic core and bent, and the end of the coil element. The holding member holds the position and shape of the end of the coil element by connecting together, the holding member protrudes from two opposing surfaces of the magnetic core, and the holding member is at both side ends. A coil component having the first protrusion and the second protrusion along the end of the coil element. The coil component according to claim 1, wherein a tip of the second protrusion is thinner. A step of electrically connecting a coil element in which a conductive wire is spirally wound to a terminal portion, a step of mixing a powder magnetic material and a binder, embedding the coil portion, press forming, and forming a magnetic core by heating; And the terminal portion holds the position and shape of the end portion of the coil element superimposed on the end portion of the coil element and the end portion of the coil element that is bent from the magnetic core. The terminal portion protrudes from two opposing surfaces of the magnetic core, and the holding member has first protrusions on both side end portions thereof, and a second portion along the end portion of the coil element. The manufacturing method of the coil components characterized by having a protrusion part. 4. The method of manufacturing a coil component according to claim 3, wherein after the coil element is connected to the terminal portion, a tip end portion of the second projecting portion is deformed toward an end portion of the coil element.

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