JP2012169587A - Coil component and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil component with improved vibration resistance and solderability, and its manufacturing method.SOLUTION: The coil component includes a coil electrode 11 and an exterior body 12 for embedding the coil electrode 11, an end part 11a of the coil electrode is projected from a bottom surface of the exterior body 12 and is bent toward a first side face 12b farther from the projected part 16, the end part 11a of the coil electrode is locked by a locking part 13 provided on a first side face 12b, and thus a terminal electrode 14 is formed. When the side of the first side face 12b from the projection part 16 is defined as a first bottom part 12c, the opposite side is defined as a second bottom part 12d and the terminal electrode 14 is turned up, the first bottom part 12c is made higher than the second bottom part 12d.

Description

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

  In recent years, in a coil component used in a DC / DC converter circuit near the engine of an automobile, the coil 1 wound edgewise is used as a magnetic body 2 as shown in FIG. 9 in order to improve electrical performance and reliability. The terminal 3 was bent by embedding and projecting the end of the coil 1 from the magnetic body 2, and the recess 4 was provided in the portion of the bottom surface of the magnetic body 2 where the terminal 3 abuts. By providing the recess 4, the positioning of the terminal 3 and the flatness of the terminal 3 were ensured.

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

JP 2003-309024 A

  However, in order to cope with an increase in current in a coil component for automobiles, it is required to reduce the direct current resistance value. For this reason, it is necessary to increase the thickness of the coil electrode, leading to an increase in the size of the coil component. In coil parts, problems have arisen in vibration resistance and solderability. On the other hand, an object of this invention is to provide the coil components excellent in vibration resistance and solderability.

  In order to solve the above-mentioned problems, the present invention includes an edgewise coil electrode formed by winding a wide surface of a flat conducting wire perpendicularly to a winding axis, and an exterior body in which the coil electrode is embedded, The end of the electrode protrudes from the bottom surface of the exterior body, is bent toward the first side far from the protruding portion, and the end of the coil electrode is engaged with the locking portion provided on the first side. The terminal electrode is formed by stopping, the first side surface side from the protruding portion of the coil electrode is the first bottom portion, the opposite side is the second bottom portion, and when the terminal electrode is on the top, The bottom of the second base is higher than the second bottom.

  With the above configuration, when the coil component is mounted on the mounting board, soldering can be performed on the bottom surface having a large area, and reliability such as vibration resistance can be improved. When the size of the coil component is increased, heat is absorbed into the coil component during reflow soldering, the temperature of the terminal electrode portion is lowered, and solderability is liable to deteriorate. In particular, when a concave portion is provided on the bottom surface and a terminal is accommodated here as in a conventional coil component, the side surface of the terminal is partially hidden by the concave portion, so that the hot air during heating during reflow soldering is blocked. As a result, the temperature of the terminal portion is less likely to rise and the solderability is deteriorated.

  On the other hand, according to the configuration of the present invention, even if the area of the terminal electrode is increased, both end portions thereof, that is, both the locking portion portion and the protruding portion portion are visible from the side surface direction. Heat can be easily absorbed at both ends of the terminal electrode, and the solderability can be improved throughout the terminal electrode, and the effect of improving vibration resistance can be obtained.

The perspective view of the coil components in one embodiment of this invention 1 is an exploded perspective view of a coil component according to an embodiment of the present invention before forming an exterior body. The figure explaining the manufacturing method of the coil components in one embodiment of this invention The figure explaining the metal mold | die in the manufacturing method of the coil components in one embodiment of this invention Sectional drawing of the DD line in FIG. Sectional drawing which shows the other example of the protrusion part in the manufacturing method of the coil components in one embodiment of this invention The perspective view of the coil components which shows the other example in one embodiment of this invention The perspective view of the coil components which shows another example in one embodiment of this invention Schematic diagram of conventional coil parts

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

  In FIG. 1 and FIG. 2, an insulating sleeve 18 is provided at the center of the coil electrode 11 obtained by so-called edgewise winding obtained by winding a wide surface of a rectangular conductor wire with insulation coating perpendicularly to the winding axis. The outer body 12 is formed by inserting the magnetic core 19 into the core and the peripheral portion and molding the whole with a resin such as a liquid crystal polymer. The end portions 11a of the coil electrodes are protruded from one surface of the outer package 12 parallel to the winding axis (surface that becomes the bottom surface of the coil component), and the first side surface 12b far from the protruding portion 16 is formed. The terminal electrode 14 is formed by being bent toward and locked by a locking portion 13 provided on the side surface of the exterior body 12.

  Here, when the terminal electrode 14 is faced up, when the first side surface 12b side from the protrusion 16 of the coil electrode 11 is the first bottom portion 12c and the opposite side is the second bottom portion 12d, the first bottom portion 12c is The height is higher than the second bottom portion 12d. At this time, the height difference between the first bottom portion 12c and the second bottom portion 12d is set to be more than half of the thickness of the end portion 11a of the coil electrode. Further, crushing portions 15 are provided on both sides of the end portion 11a of the coil electrode in the protruding portion 16 on the first bottom portion 12c side.

  By doing so, even if the area of the terminal electrode 14 is increased, both end portions thereof, that is, both the locking portion 13 portion and the protruding portion 16 portion can be seen from the side surface direction. Can be easily absorbed at both ends of the terminal electrode 14, and the solderability can be improved throughout the terminal electrode 14. Further, by providing the crushing portion 15, the end portion 11a of the coil electrode can be easily bent, and the flatness of the terminal electrode 14 can be improved.

  As shown in FIG. 1, it is more desirable that the height of the region between the terminal electrode 14 and the near side surface along the terminal electrode 14 is the same as the height of the second bottom portion 12d. By doing so, since the terminal electrode 14 can be seen from the side surface along the terminal electrode 14, the heat of the reflow solder is easily absorbed by the terminal electrode 14, and the solderability is further improved. be able to.

  Next, the manufacturing method of the coil component in this Embodiment is demonstrated using FIG.

  First, as shown in FIG. 3A, the coil electrode 11 is formed by so-called edgewise winding, in which a wide surface of a flat conducting wire with insulation coating is wound perpendicularly to a winding axis. At this time, the width of the coil electrode 11 is about 2.5 mm, the thickness is about 0.2 mm, and the end portions 11a of the coil electrode extend in the same direction perpendicular to the winding axis. By doing so, since the exterior body 12 is directly connected to the mounting substrate, the magnetic efficiency can be increased, and as a result, a coil component having a low DC resistance can be obtained.

  Next, as shown in FIG. 3B, the insulating sleeve 18 is inserted into the core part of the coil electrode 11, and the magnetic core 19 is attached to the core part and the peripheral part.

  Next, as shown in FIG. 3C, the whole body is molded with a resin such as a liquid crystal polymer using a mold to form the outer package 12. At this time, with the surface from which the end 11a of the coil electrode protrudes facing upward, the first side surface 12b far from the protrusion 16 from which the end 11a of the coil electrode protrudes is the first bottom 12c, and vice versa. When the side is the second bottom 12d, the first bottom 12c is higher than the second bottom 12d. Further, crushing portions 15 are provided on both sides of the end portion 11a of the coil electrode in the protruding portion 16 on the first bottom portion 12c side.

  Next, the insulation coating of the end portion 11a of the coil electrode protruding from the exterior body 12 is peeled off, and the end portion 11a of the coil electrode protruding from the bottom surface 12a of the exterior body is separated from the protruding portion 16 that is protruded. The terminal electrode 14 is formed by bending toward the one side surface 12b and locking the end portion 11a of the coil electrode with the locking portion 13 provided on the first side surface 12b, as shown in FIG. A coil component can be obtained.

  Here, the process of forming the exterior body 12 will be described in detail. 4 is a cross-sectional view showing the shape of the mold in the process of forming the exterior body 12, FIG. 5 is a cross-sectional view taken along the line DD in FIG. 4, and FIG. 5 (a) is a state in which the mold is opened. FIG. 5B shows a state in which the mold is closed.

  Although the crushing part 15 is provided in the both sides by the side of the 1st bottom part 12c of the edge part 11a of the coil electrode in the protrusion part 16, this provides the projection part 20 in the metal mold | die 17 of the part which wants to form the crushing part 15. The crushing portion 15 is formed by crushing the end portion 11a of the coil electrode with the protruding portion 20 during mold clamping.

  When molding is performed by projecting the end portion 11a of the coil electrode as in the present embodiment, it is necessary to release the mold 17 of the portion from which the end portion 11a of the coil electrode projects. At this time, in order to cope with variations in the shape and position of the end portion 11a of the coil electrode, it is necessary to provide a clearance 21 on both sides of the end portion 11a of the coil electrode with the relief of the mold. If the clearance 21 is large, the mold resin may leak and burrs may occur. On the other hand, according to the present embodiment, the projecting portion 20 hits the end portion 11a of the coil electrode by clamping and forms the crushing portion 15 on the end portion 11a of the coil electrode, and the end portion 11a of the coil electrode. Since it spreads in both directions, the clearance 21 is reduced. Therefore, it becomes difficult for the resin to leak out when molding with the mold resin, and the generation of burrs can be suppressed.

  Further, when the terminal electrode 14 is formed by bending the end portion 11a of the coil electrode in the next step, since the crushing portion 15 is formed inside the portion to be bent, the portion is bent starting from this portion. It becomes easy to bend and the flatness of the terminal electrode 14 can be improved.

  Moreover, when the height of the 1st bottom part 12c and the 2nd bottom part 12d is the same, the 2nd bottom part 12d of the part which opposes the projection part 20 provided in the metal mold | die 17 by the side of the 1st bottom part 12c. The mold 17 on the side is just the corner of the mold. If the mold clamping is performed in such a state, a shear stress is applied to the end 11a of the coil electrode, so that the terminal strength is weakened and the vibration resistance is inferior. On the other hand, when the first bottom portion 12c is made higher than the second bottom portion 12d as in the present embodiment, as shown in FIG. 4, the mold facing the protruding portion 20 is received by the surface. Therefore, it is possible to spread the coil electrode in the direction on both sides of the end portion 11a of the coil electrode while providing the crushing portion 15 without applying a shear stress to the end portion 11a of the coil electrode. In order not to apply this shear stress, it is desirable that the difference in height between the first bottom portion 12c and the second bottom portion 12d be half or more of the thickness of the end portion 11a of the coil electrode.

  Further, it is desirable that the size of the protrusion 20 is approximately the same as the clearance 21 with the mold 17. However, if the depth of the crushed portion 15 is too large, the terminal strength may become weak. Therefore, the depth of the crushed portion 15 may be less than 2/3 of the thickness of the end portion 11a of the coil electrode. desirable.

  Further, in order to spread the coil electrode in the direction of both sides of the end portion of the coil electrode, as shown in FIG. 5, the shape of the protrusion 20 is changed to an R shape at the portion facing the outside of the end portion 11a of the coil electrode, or as shown in FIG. Thus, it is desirable to have a tapered shape.

  In the present embodiment, the height of the portion sandwiched between the two terminal electrodes 14 is also the same as the height of the portion facing the terminal electrode 14, but the portion facing the terminal electrode 14 as shown in FIG. It may be configured to increase only the height. By comprising in this way, it becomes easy to absorb the heat | fever of reflow solder and can improve solderability further.

  Further, the shape of the bottom surface sandwiched between the terminal electrodes 14 as shown in FIG. 1 may be a cylindrical shape as shown in FIG. 8 instead of a flat shape. At this time, the cylindrical central axis substantially coincides with the central axis of the coil electrode 11. By doing so, the distance between the coil electrode 11 and the exterior body 12 can be made uniform at the bottom of the exterior body, and the resin can be easily rotated when the exterior body 12 is resin-molded, so that stable moldability is obtained. In addition, since the portion along the terminal electrode 14 is low, the solderability is also good. At this time, it is desirable that the height at the highest position of the cylindrical bottom surface sandwiched between the terminal electrodes 14 is higher than that of the first bottom portion 12 c and lower than the height of the terminal electrodes 14. By doing in this way, sufficient strength of the exterior body 12 is obtained, and no problem is caused in mountability.

  In this embodiment, the insulating sleeve 18 and the magnetic core 19 are mounted on the coil electrode 11 and the whole is molded with resin. However, the coil electrode 11 itself is molded with a mixture of resin and magnetic powder. It does not matter if it is

  In the coil component and the manufacturing method thereof according to the present invention, even if the area of the terminal electrode is increased, both end portions thereof, that is, both the locking portion portion and the protruding portion portion are visible from the side surface direction. This heat is easily absorbed at both ends of the terminal electrode, so that the entire terminal electrode can be improved in solderability and vibration resistance can be improved, which is industrially useful.

DESCRIPTION OF SYMBOLS 11 Coil electrode 11a End part of coil electrode 12 Exterior body 12a Bottom surface of exterior body 12b First side surface 12c First bottom part 12d Second bottom part 13 Locking part 14 Terminal electrode 15 Squash part 16 Projection part 17 Mold 18 Insulation Sleeve 19 Magnetic core 20 Protrusion 21 Clearance

Claims (4)

An edgewise coil electrode formed by winding a wide surface of a flat conducting wire perpendicularly to a winding axis, and an exterior body in which the coil electrode is embedded, and an end portion of the coil electrode is a bottom surface of the exterior body From the protruding portion (hereinafter referred to as the protruding portion) and bent toward the first side surface, and the end of the coil electrode is engaged with the locking portion provided on the first side surface. The terminal electrode is formed by stopping, and when the first side surface side is the first bottom portion and the opposite side is the second bottom portion from the projecting portion, A coil component characterized in that one bottom portion is higher than the second bottom portion. The coil component according to claim 1, wherein a shape of a bottom surface of the exterior body at a portion sandwiched between the terminal electrodes is a cylindrical shape. A step of forming an edgewise coil electrode by winding a wide surface of a flat rectangular wire perpendicularly to a winding axis, a step of forming an exterior body by molding the coil electrode with a resin, and the exterior body The end portion of the coil electrode protruding from the bottom surface of the coil is bent toward the first side surface far from the protruding portion (hereinafter referred to as the protruding portion), and the locking portion provided on the first side surface Forming a terminal electrode by locking the end of the coil electrode, and in the step of forming the exterior body, the first side surface side from the protruding portion is a first bottom portion, and the opposite side is formed. A method of manufacturing a coil component, wherein the first bottom portion is higher than the second bottom portion when the second bottom portion is used and the terminal electrode is turned up. The step of forming the outer package is performed using a mold, and a crushing portion is formed by crushing the surface of the protruding portion of the coil electrode on the first bottom side with the mold. Item 4. A method for manufacturing a coil component according to Item 3.

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