JP5877300B2 - Coil parts manufacturing method - Google Patents

Description

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

  In recent years, DC / DC converters that drive electronic devices have become larger in current with higher functionality of electronic devices, and rectangular copper wires have been wound vertically as coil components used in these DC / DC converters. 2. Description of the Related Art Coil components that use an edgewise coil to increase the space factor of a copper wire and cope with a large current have been used.

  Furthermore, for in-vehicle electronic devices, an external body in which a coil component body is covered with a resin is formed to meet severe vibration resistance and weather resistance required for in-vehicle devices.

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

  FIG. 10A is a perspective view of a conventional coil component, and FIG. 10B is an exploded perspective view of the coil component main body before the exterior body is formed.

  As shown in FIG. 10 (b), the conventional coil component has an edgewise shape in which a wide surface of a rectangular copper wire is wound about 5 turns perpendicularly to the winding axis and the through hole 1 is provided on the winding axis. The coil component main body 4 is formed by incorporating and abutting a pair of magnetic cores 3 from both sides of the winding axis of the coil electrode 2. When the magnetic core 3 is incorporated, an insulating sleeve 5 made of an insulating material is interposed between the coil electrode 2 and the magnetic core 3 as necessary.

  And the exterior body 7 was formed by molding the coil component main body 4 with resin except for the end portion 6 of the coil electrode by using a molding die (not shown) to constitute the coil component.

  In the process of forming the exterior body 7, molding was performed by inserting the winding axis of the coil component body 4 in the vertical direction into a molding die (not shown) composed of an upper mold and a lower mold. .

  The upper mold and the lower mold of the molding die have a corner portion formed by the side wall surface and the bottom surface of the cavity and rises from the side wall surface between the side wall surface and the magnetic core 3 and a parting line A plurality of positioning projections for positioning the magnetic core 3 having a taper on the surface side are provided, and when the coil component body 4 is inserted into the lower mold cavity, the lower magnetic core 3 is positioned. The upper magnetic core 3 is positioned when the molding die is closed.

  As shown in FIG. 10A, the coil component having the exterior body 7 thus formed has a recess 8 in a portion corresponding to the positioning protrusion of the molding die.

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

JP 2004-128025 A

  In the above-described conventional method for forming the outer package 7 for a coil component, the upper magnetic core 3 is formed by positioning protrusions for positioning the magnetic core 3 formed in the upper cavity when the molding die is closed. Since the horizontal position is positioned, when the lower die of the slide type or turntable type molding machine moves and stops after inserting the coil component body into the lower die cavity, the upper magnetic body The core 3 may be tilted due to vibration, centrifugal force, or inertia, and the corner of the upper magnetic core 3 may protrude onto the parting line surface. After that, when the molding die is closed, the upper magnetic core 3 is molded into the molding die. There are problems that the mold bites and the molding machine stops, or the magnetic core 3 is broken to deteriorate the yield.

  In the present invention, after inserting the coil component body into the lower mold cavity of the molding die, the upper magnetic core is prevented from tilting and protruding from the lower mold cavity to the parting line surface, thereby improving productivity. It aims at providing the manufacturing method of the improved coil components.

In order to solve the above-mentioned problems, the present invention incorporates a pair of magnetic cores from both sides of a winding shaft into a coil electrode having a through hole in the winding shaft by winding a rectangular copper wire edgewise. In the method of manufacturing a coil component in which the coil component body is formed by covering the periphery of the coil component body excluding the end portion of the coil electrode with a resin exterior body, the step of forming the exterior body is performed by winding the coil component body. The rotating die is placed in the molding die in the vertical direction and molded. The molding die is a lower mold cavity that can be inserted from the lower end of the magnetic core of the coil component body to the height of the upper end of the coil electrode part. And the upper mold cavity into which the remainder of the coil component body can be inserted. The lower mold cavity and the upper mold cavity are respectively provided at the corners of the side wall surface and the bottom surface and between the side wall surface and the magnetic core. On the side And raised from the surface and providing a plurality of positioning protrusion for positioning the magnetic core, a further side wall surface of the lower die cavity, between the magnetic core to reduce the protrusion height than the positioning projection A plurality of ridges spaced from each other so that the resin can flow are provided from a position higher than the butt surface of the magnetic core to the bottom surface.

  By the above method, a plurality of ridges having a raised height smaller than the positioning convex portion for positioning the magnetic core are provided on the side wall surface of the lower mold cavity from the position higher than the butt surface of the magnetic core to the bottom surface. When the upper magnetic core is tilted, the ridge at a position higher than the butt surface of the magnetic core is in contact with the upper magnetic core. It is possible to prevent the corner of the magnetic core from protruding to the parting line surface of the molding die.

  Thus, according to the present invention, the magnetic core is prevented from protruding to the parting line surface, and when the molding die closes, the molding die bites the magnetic core and the molding machine stops, It is possible to prevent the magnetic core from being damaged and to improve the productivity.

The bottom side perspective view of the finished product by the manufacturing method of the coil components in one embodiment of the present invention The disassembled perspective view of the coil component main body by the manufacturing method of the coil component in one embodiment of this invention The figure explaining the coil electrode formation process of the manufacturing method of the coil components in one embodiment of this invention The figure explaining the coil component main body assembly process of the manufacturing method of the coil component in one embodiment of this invention Side surface sectional drawing of the shaping | molding die explaining the exterior body formation process of the manufacturing method of the coil components in one embodiment of this invention Plan sectional drawing of the shaping | molding die explaining the exterior body formation process of the manufacturing method of the coil components in one embodiment of this invention The figure explaining the edge part position correction of the coil electrode of the manufacturing method of the coil components in one embodiment of this invention The figure explaining the inclination of the magnetic body core of the manufacturing method of the coil components in one embodiment of this invention The perspective view of the coil component after the exterior body formation of the manufacturing method of the coil component in position embodiment of this invention The figure explaining the conventional coil parts

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

  Initially, the coil component manufactured by the manufacturing method of the coil component in one embodiment of this invention is demonstrated.

  FIG. 1 is a perspective view of a coil component according to an embodiment of the present invention as viewed from the lower surface side, and FIG. 2 is an exploded perspective view before forming an exterior body.

  As shown in FIGS. 1 and 2, the coil component of the present invention penetrates the winding shaft by so-called edgewise winding in which a wide surface of a rectangular copper wire with an insulating film is wound perpendicularly to the winding shaft. A pair of insulating sleeves 15 including a cylindrical portion 13 and a flange portion 14 are inserted into the coil electrode 12 having the hole 11 from both sides of the through hole 11, and the through hole 11 of the coil electrode 12 and the both sides of the through hole 11 and A coil component main body 17 is formed by incorporating and butting a pair of magnetic cores 16 around the periphery.

  Then, the coil component body 17 is molded with a resin such as a liquid crystal polymer except for the end portion 18 of the coil electrode to form an exterior body 19, and the end portion 18 of the coil electrode protruding from the exterior body 19 is bent to be a surface mount type. The terminal electrode 20 is formed to constitute a coil component.

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

  2 to 9 are views for explaining a method of manufacturing a coil component according to an embodiment of the present invention.

  First, as shown in FIG. 3, a coil electrode 12 is formed by winding a rectangular copper wire with an insulating film (coil electrode forming step).

  In this coil electrode forming step, a so-called edgewise coil electrode 12 is formed by winding a wide surface of a rectangular copper wire perpendicularly to the winding axis. The coil electrode 12 is formed with a through hole 11 extending in the direction of the winding axis in the core portion, and the end 18 of the coil electrode is drawn out in the same direction. The insulating film on the end 18 of the coil electrode has a predetermined dimension peeled off before or after the coil electrode 12 is wound.

  In the present embodiment, a 2.4 mm × 0.22 mm rectangular copper wire with an insulating film is wound for 30.5 turns to draw the end 18 of the coil electrode in the same direction.

  Next, as shown in FIG. 2, the magnetic core 16 is attached to the coil electrode 12 to assemble the coil component body 17 (coil component body assembly step).

  In this coil component body assembling step, first, a pair of insulating sleeves 15 including a cylindrical portion 13 that can be inserted into the through-hole 11 of the coil electrode 12 and a flange portion 14 formed at one end of the cylindrical portion 13 are connected to the through-hole 11. The cylindrical portion 13 is inserted from both sides, the flange portion 14 is brought into contact with the coil electrode 12, and the insulating sleeve 15 is attached to the coil electrode 12.

  The intermediate magnetic leg portion 21 that can be inserted into the cylindrical portion 13 of the insulating sleeve 15 and the outer wall disposed in parallel with a space larger than the dimension of the wide portion of the flat copper wire between the intermediate magnetic leg portion 21. A pair of magnetic cores 16 comprising a magnetic leg portion 22 and an articulated magnetic leg portion 23 that is arranged orthogonally to the direction in which the middle magnetic leg portion 21 extends and that connects one end of the outer magnetic leg portion 22 with the middle magnetic leg portion 21. The middle magnetic leg portion 21 is inserted into the inside of the cylindrical portion 13 from both sides of the through-hole 11 of the coil electrode 12 and assembled until the pair of magnetic cores 16 are abutted with each other.

  In this way, the coil component main body 17 in which the magnetic path is formed by incorporating the magnetic core 16 into the coil electrode 12 as shown in FIG. 4 is assembled.

  The insulating sleeve 15 insulates the coil electrode 12 and the magnetic core 16 from each other, and may be used by forming an insulating resin by plastic molding or processing a film-like one.

  The magnetic core 16 may be a ferrite core or a so-called dust core formed by mixing a resin with metal magnetic powder and press-molding. If the specific resistance of the magnetic core 16 is sufficiently large, the insulating sleeve 15 may be used. Can be omitted.

  Next, an exterior body 19 made of resin is formed around the coil component main body 17 excluding the end portions 18 of the coil electrodes (exterior body formation step).

  In this exterior body forming step, the coil component body 17 is inserted into a molding die 24 composed of a lower die 26 and an upper die 28 with the winding axis in the vertical direction as shown in FIG. .

  The exterior body 19 also has a function of fixing the pair of magnetic cores 16. In the case of a coil component that does not form the exterior body 19, the pair of magnetic cores 16 are bonded and fixed at the abutting surfaces or fixed by springs from both sides, but if the periphery of the coil component body 17 is molded with resin Since the magnetic core 16 is also fixed, the step of fixing the pair of magnetic cores 16 before the exterior body forming step can be eliminated.

  Therefore, the coil component main body 17 is put into the molding die 24 in a state where the pair of magnetic cores 16 are not fixed, and molding is performed.

  The resin material for forming the exterior body 19 is not particularly limited, and may be selected from various resins depending on the use conditions, moldability, and the like of the coil component. In this embodiment, a liquid crystal polymer that has a low viscosity at the time of melting and can be used for thin-wall molding is used to reduce the size of the coil component.

  FIG. 5 shows a state in which the coil component main body 17 is inserted into the molding die in a cross section cut by a plane parallel to the winding axis, and the position of the cross section in the perspective view of the finished product in FIG. FIG. 3 is a cross section of the coil part as viewed from the upper surface side (the direction from the top to the bottom in FIG. 1).

  FIG. 6 shows a cross section cut by the parting line surface of the molding die 24. When the position of the cross section is shown in the perspective view of the finished product in FIG. 1, a cross section taken along the line BB is shown. 6A is a cross section of the lower mold 26 side as viewed from the parting line surface, and FIG. 6B is a cross section of the upper mold 28 side as viewed from the parting line surface.

  As shown in FIGS. 5 and 6, the molding die 24 includes a lower die 26 in which a lower die cavity 25 into which the lower end of the magnetic core 16 of the coil component body 17 can be inserted to the upper end of the coil electrode 12 is formed. The upper die 28 is formed with an upper die cavity 27 that can be inserted from the upper end of the remaining coil electrode 12 to the upper end of the magnetic core 16.

  A plurality of holding pins 30 projecting from the bottom surface 29 are provided on the bottom surface 29 of the lower mold cavity 25 and the bottom surface 29 of the upper mold cavity 27, respectively, and when the upper mold 28 and the lower mold 26 are closed, the coil While holding the magnetic body core 16 of the component main body 17, the thickness of the exterior body 19 is ensured.

  The holding pin 30 is desirably provided at a position facing the middle magnetic leg portion 21 and the outer wall magnetic leg portion 22 of the magnetic core 16. Since the strength of the magnetic core 16 is greater at the position facing the middle magnetic leg portion 21 and the outer wall magnetic leg portion 22 of the magnetic core 16 than the portion of the articulated magnetic leg portion 23 alone, the upper die 28 and the lower die 26 are closed. Thus, the magnetic core 16 can be prevented from being damaged when the holding pin 30 comes into contact with the magnetic core 16.

  Further, it is desirable that one of the holding pins 30 of the upper die 28 and the lower die 26 is a movable pin such as a spring type, and the other is a fixed pin. By doing so, even if the dimensions of the magnetic core 16 vary, the movable holding pin 30 can securely hold the magnetic core 16 in response to the dimensional change, and the magnetic core When the dimensions of 16 vary, the abutting surfaces 40 of the pair of magnetic cores 16 are separated by the molding pressure when resin is injected into the molding die 24, and the characteristics such as the inductance of the coil components vary. Can be prevented.

  The upper mold cavity 27 and the lower mold cavity 25 are each formed at a corner formed by the side wall surface 31 and the bottom surface 29 of the cavity and between the side wall surface 31 and the magnetic core 16. A plurality of positioning projections 32 for positioning the magnetic core 16 protruding from the side wall surface 31 are provided, and the positioning of the magnetic core 16 in a direction perpendicular to the winding axis by the plurality of positioning projections 32. In addition, a gap is formed between the magnetic core 16 and the side wall surface 31 to ensure the thickness of the exterior body 19.

  The number and location of the positioning protrusions 32 are not particularly limited, but a plurality of positioning protrusions 32 are arranged so that the magnetic cores 16 do not move and shift or rotate due to the plurality of positioning protrusions 32 acting on each other. In this embodiment, as shown in FIG. 6, six positioning convex portions 32 are provided in the lower mold cavity 25 and the upper mold cavity 27, respectively.

  The parting line surface side of the positioning convex portion 32 is desirably formed in a taper shape. When the coil component body 17 is inserted into the lower mold cavity 25, the lower magnetic core 16 is brought into contact with the taper 33. By inserting them while sliding, the lower magnetic core 16 is guided by the taper 33 and can be fitted between the plurality of positioning projections 32 to be positioned at a predetermined position. Thereafter, when the upper die 28 and the lower die 26 are closed, the magnetic core 16 of the upper die cavity 27 is placed on the upper magnetic core by the taper 33 of the positioning convex portion 32 as in the case of the lower die cavity 25. 16 is guided to a predetermined position, so that the pair of magnetic cores 16 can be easily positioned.

  However, since there is only a clearance of about 0.05 to 0.1 mm between the positioning convex portion 32 and the magnetic core 16 so that the magnetic core 16 can be inserted, the resin does not flow. There is a possibility that the flow of the resin may deteriorate. For this reason, the height from the bottom surface 29 of the positioning convex part 32 should be higher than the protruding height of the holding pin 30 and lower than the height obtained by adding the thickness of the holding pin 30 and the connecting magnetic leg part 23. In this way, it is possible to prevent the resin flow of the entire exterior body 19 from deteriorating and to suppress problems such as short shots.

  Further, on the side wall surface 31 of the lower mold cavity 25, in addition to the positioning convex portion 32, a ridge 34 having a raised height smaller than the positioning convex portion 32 from the side wall surface 31 is abutting surface 40 of the magnetic core 16. A plurality are provided from a higher position to the bottom surface 29 in the vertical direction.

  In this way, even if the upper magnetic core 16 is tilted before the coil part body 17 is inserted into the cavity of the lower mold 26 and the upper mold 28 and the lower mold 26 are closed, The magnetic core 16 can come into contact with the ridge 34 to keep the tilt small, and the upper magnetic core 16 tilts so that a part of the magnetic core 16 protrudes from the parting line surface and the upper die 28 and the lower die. It is possible to prevent the molding machine from being stopped by the biting and to prevent the magnetic core 16 from being damaged.

  In the present embodiment, the gap between the side wall surface 31 of the cavity and the magnetic core 16 (thickness dimension of the exterior body 19) is set to 0.4 mm, and the height of the protruding protrusion 32 from the side wall surface 31 is set to 0. The protrusion height of the protrusion 34 is set to 0.2 mm by 35 mm, and the inclination of the magnetic core 16 in the protrusion 34 portion is restricted to be small, and the interval between the protrusion 34 and the magnetic core 16 is set to 0.2 mm. The liquid crystal polymer forming the body 19 has a dimension that ensures fluidity.

  One reason for the tilting of the upper magnetic core 16 is simply vibration, centrifugal force, inertia, etc. when the lower mold 26 of the turntable type molding machine or the sliding type molding machine moves and stops. Inclination occurs.

  As another cause, in particular, when the positional deviation of the end 18 of the coil electrode generated when the coil electrode 12 is formed is corrected to a predetermined position in the exterior body forming process, the upper magnetic core 16 Tilt occurs.

  This cause will be described in detail.

  In the coil electrode forming step, the rectangular copper wire is wound in an edgewise manner as described above. However, in response to variations in the thickness dimension of the rectangular copper wire and the width dimension of the wide surface, As compared with a predetermined position indicated by a solid line as shown in FIG. 7A, the distance between the end portions 18 of the pair of coil electrodes is widened as shown by a broken line, or conversely as shown in FIG. 7B. May occur.

  While inserting the coil component main body 17 in which the position of the end portion 18 of the coil electrode varies into the lower mold 26 of the molding die 24, the position of the end portion 18 of the coil electrode is a predetermined line indicated by a solid line in FIG. When the position is corrected, the winding portion 35 of the coil electrode 12 is deformed as shown in FIG. 8 along with the correction of the end 18 of the coil electrode. The deformation of the coil electrode 12 causes an inclination in the upper magnetic core 16.

  When the number of windings is as small as about 5 turns and the length of the terminal electrode is short as in the conventional coil parts, the inclination of the magnetic core due to deformation of the winding part when the end of the coil electrode is corrected is Although not increased, the number of windings of the coil electrode 12 is as large as 30.5 turns as in the present embodiment, and the end 18 of the coil electrode is long in order to form the surface mount type terminal electrode 20. In this case, the positional deviation of the tip of the end 18 of the coil electrode becomes large, and the deformation of the winding portion 35 of the coil electrode 12 when this positional deviation is corrected becomes large, and the deformation becomes larger than the number of windings. Thus, the inclination of the magnetic core 16 is increased.

  On the other hand, according to the present invention, the inclination of the magnetic core 16 can be kept small, and a part of the magnetic core 16 protrudes from the parting line surface due to the inclination of the magnetic core 16. It is possible to prevent the mold 28 and the lower mold 26 from being caught when they are closed, and to prevent the molding machine from being stopped or the magnetic core 16 from being damaged to deteriorate the yield.

  In particular, correction of the position of the end 18 of the coil electrode is performed by providing a guide structure (not shown) such as a taper in a portion sandwiching the end 18 of the coil electrode of the upper mold 28 and the lower mold 26. When the position of the end 18 of the coil electrode is automatically corrected while closing the lower die 26 and the lower die 26, the magnetic core 16 protrudes from the parting line surface before the upper die 28 and the lower die 26 are closed. Since it cannot be confirmed, the effect of the present invention is significant.

  Further, it is desirable that the ridge 34 is formed from a position lower than the parting line surface to the bottom surface 29 of the cavity of the lower mold 26. By doing so, when the coil component body 17 is inserted into the cavity of the lower die 26, it is possible to prevent the protrusion 34 from obstructing the insertability of the coil component at the opening portion of the lower die 26. In addition, it is desirable that the parting line surface side of the protrusion 34 is formed in a tapered shape like the positioning protrusion 32 because the insertion workability is improved.

  Furthermore, it is desirable to form the positioning convex part 32 and the convex line 34 on the same line. By doing in this way, compared with the case where the positioning convex part 32 and the protruding item | line 34 are each formed in another place, the fluidity | liquidity of the resin which forms the exterior body 19 is good, and generation | occurrence | production of malfunctions, such as a short shot, is prevented. can do.

  FIG. 9 shows the coil component body 17 in which the exterior body 19 is thus formed.

  As shown in FIG. 9, a plurality of recesses and grooves are formed on the surface of the exterior body 19, in which the magnetic body core 16 is held or positioned by the molding die 24 when the exterior body 19 is molded. A holding pin recess 36 in which a recess is formed by holding the magnetic core 16 with the holding pin 30 is formed on the side surface orthogonal to the winding axis, and the side surface parallel to the winding axis is perpendicular to the winding axis. A positioning concave portion 37 in which a concave portion is formed by the positioning convex portion 32 is formed in a portion adjacent to the side surface to be performed.

  Further, a plurality of grooves 38 having a depth dimension formed by the ridges 34 shallower than the depth dimension of the positioning recess 37 is formed in parallel with the winding axis on the same line as the positioning recess 37.

  Lastly, the end portion 18 of the coil electrode protruding from the exterior body 19 is bent to form a terminal electrode (terminal electrode forming step).

  In this terminal electrode bending step, the end portion 18 of the coil electrode protruding from the exterior body 19 is bent in the side surface direction far from the side surface orthogonal to the winding axis, and the locking portion provided on the side surface of the exterior body 19 The terminal electrode 20 is formed by locking at 39.

  In this way, the coil component shown in FIG. 1 can be manufactured.

  In the method of manufacturing a coil component according to the present invention, in the step of forming the exterior body, after the coil component body is inserted into the lower mold cavity of the molding die, the upper magnetic core is tilted and the party is separated from the lower mold cavity. It is possible to prevent the mold from sticking out to the grinding surface, and the productivity can be improved by preventing the molding die from biting the magnetic core, which is industrially useful.

DESCRIPTION OF SYMBOLS 11 Through-hole 12 Coil electrode 13 Cylindrical part 14 collar part 15 Insulation sleeve 16 Magnetic body core 17 Coil component main body 18 End part of coil electrode 19 Exterior body 20 Terminal electrode 21 Middle magnetic leg part 22 Outer wall magnetic leg part 23 Articulated magnetic leg part 24 Molding die 25 Lower mold cavity 26 Lower mold 27 Upper mold cavity 28 Upper mold 29 Bottom surface 30 Holding pin 31 Side wall surface 32 Positioning convex part 33 Taper 34 Convex strip 35 Winding part 36 Holding pin concave part 37 Positioning concave part 38 Groove 39 Locking part 40 Butting surface

Claims (3)

A coil component body is formed by winding a flat copper wire in an edgewise manner and incorporating a pair of magnetic cores from both sides of the winding shaft into a coil electrode having a through-hole on the winding shaft. In the method of manufacturing a coil component in which the periphery of the coil component body excluding the end portion of the coil component is covered with an exterior body made of resin, the step of forming the exterior body has the winding axis of the coil component body in the vertical direction. The mold is inserted into a molding die, and the molding die is inserted into a lower mold cavity that can be inserted from the lower end of the magnetic core of the coil component body to the height of the upper end of the coil electrode portion, An upper mold cavity into which the remainder of the coil component body can be inserted, and the lower mold cavity and the upper mold cavity have corner portions of a side wall surface and a bottom surface, respectively, and the side wall surface and the A plurality of positioning protrusions are provided on the side wall surface of the lower mold cavity so as to be higher than the positioning protrusions. A plurality of ridges, each having a height from which the resin is allowed to flow, are provided between the magnetic core and the bottom surface from a position higher than the butting surface of the magnetic core. A method for manufacturing a coil component. 2. The method of manufacturing a coil component according to claim 1, wherein the ridges are formed from a position lower than the parting line surface of the molding die to the bottom surface of the lower mold cavity. The method of manufacturing a coil component according to claim 1, wherein the magnetic core positioning convex portion and the ridge are formed on the same line.

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