JP6561902B2 - AIR-COIL COIL, ITS MANUFACTURING METHOD, AND COIL COMPONENT USING AIR-CORE COIL - Google Patents

Description

  The present invention relates to an air core coil and a manufacturing method thereof, and more particularly to an air core coil in which a winding portion is self-held by an adhesive member and a manufacturing method thereof. The present invention also relates to a coil component using such an air-core coil.

  As a coil component in which an air-core coil is embedded in a magnetic core made of a composite magnetic material, one described in Patent Document 1 is known. Since the air core coil does not have a winding core, the shape is not stable as compared with a general coil having a winding core, and in particular, the posture of the lead portion may become unstable. For this reason, various devices for stabilizing the posture of the lead portion are sometimes applied. In Patent Document 2, the lead portion is bent at a right angle to suppress the spring back of the lead portion.

JP 2009-170488 A JP 2007-227779 A

  However, if the lead part is strongly bent as in Patent Document 2, there is a risk of damaging the insulating film covering the core material, which may reduce the reliability of the coil component.

  Therefore, the present invention provides an air core coil capable of stabilizing the posture of the lead portion without reducing reliability, a method for manufacturing the air core coil, and a coil component using such an air core coil. With the goal.

  An air-core coil according to the present invention includes a winding portion wound in an air-core shape, a first lead portion derived from one end of the winding portion, and a first lead portion derived from the other end of the winding portion. A coil conductor including two lead portions, a first adhesive member for mutually fixing the coil conductors constituting the winding portion, and a boundary portion between the winding portion and the first and second lead portions And a second adhesive member different from the first adhesive member.

  According to the present invention, in addition to the first adhesive member for self-holding the winding portion, the second adhesive member for fixing the boundary portion between the winding portion and the first and second lead portions is used. Therefore, the posture of the lead portion can be stabilized without strongly bending the lead portion.

  In the present invention, the first and second lead portions are led out in a tangential direction from the winding portion, and the second portion is disposed at a boundary portion between the winding portion and the first and second lead portions. It is preferable that a fillet made of an adhesive member is formed. According to this, since the roots of the first and second lead portions are firmly fixed, the posture of the lead portion can be further stabilized.

  In the present invention, it is preferable that the first adhesive member is made of a thermoplastic resin having a melting point lower than that of the second adhesive member. According to this, it is possible to use the coil conductor coated with the fusion layer constituting the first adhesive member, and in this case, it is possible to self-hold the winding part only by heating the winding part. Become.

  In the present invention, the second adhesive member is preferably made of a thermosetting resin or an ultraviolet curable resin. According to this, it is possible to firmly fix the roots of the first and second lead portions.

  The air-core coil according to the present invention may include a plurality of the coil conductors, and the plurality of coil conductors may be wound concentrically. According to this, it becomes possible to use it for coil parts with four terminals or more.

  A coil component according to the present invention includes a magnetic core including a magnetic material and a binder, the air core coil embedded in the magnetic core, and a first terminal electrode connected to the first lead portion of the air core coil. And a second terminal electrode connected to the second lead portion of the air-core coil.

  According to the present invention, it is possible to provide a surface mount type coil component suitable as a power supply coil.

  In the present invention, it is preferable that the first lead portion and the first terminal electrode, and the second lead portion and the second terminal electrode are all connected inside the magnetic core. In the coil component having such a structure, the lead portion is not led out of the magnetic core, so the lead portion cannot be held outside the magnetic core, and the stability of the lead portion is particularly important. is there.

  An air core coil manufacturing method according to the present invention includes an air core winding portion, a first lead portion led out from one end of the winding portion, and the winding portion by winding a coil conductor. A first step of forming a second lead portion led out from the other end of the coil, a second step of fixing the coil conductors constituting the winding portion to each other by a first adhesive member, and the winding And a third step of fixing the boundary portion by selectively supplying a second adhesive member to the boundary portion between the turning portion and the first and second lead portions.

  According to the present invention, it is possible to stabilize the posture of the lead portion without strongly bending the lead portion. In addition, since the second adhesive member is selectively supplied, the second adhesive member does not become excessive.

  In the present invention, the coil conductor is covered with a fusion layer constituting the first adhesive member, and the second step is to melt the fusion layer by heating the winding portion. Is preferably performed. According to this, it is not necessary to separately supply the first adhesive member to the winding part, and the process can be simplified.

  Thus, according to the present invention, an air core coil capable of stabilizing the attitude of the lead portion without reducing reliability, a method for manufacturing the air core coil, and a coil component using such an air core coil Can be provided.

FIG. 1 is a schematic perspective view showing an appearance of a coil component 10 according to a preferred embodiment of the present invention. FIG. 2 is a cross-sectional view of the coil component 10. FIG. 3 is a schematic perspective view for explaining the shape of the first terminal electrode 41. FIG. 4 is a schematic perspective view for explaining the internal structure of the coil component 10. FIG. 5 is a schematic external view for explaining the structure of the air-core coil 30. FIG. 6 is an enlarged view of the air-core coil 30. FIG. 7 is a cross-sectional view of the coil conductor 50. FIG. 8 is a schematic diagram for explaining a method for manufacturing the air-core coil 30. FIG. 9 is a schematic diagram for explaining a method for manufacturing the air-core coil 30. FIG. 10 is a schematic external view for explaining the structure of the air-core coil 31 according to a modification.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic perspective view showing an appearance of a coil component 10 according to a preferred embodiment of the present invention. FIG. 2 is a cross-sectional view of the coil component 10.

  As shown in FIGS. 1 and 2, the coil component 10 according to the present embodiment is provided on a magnetic core 20 having a substantially rectangular parallelepiped shape, an air core coil 30 embedded in the magnetic core 20, and a mounting surface 23 of the magnetic core 20. Two terminal electrodes 41 and 42 connected to the air-core coil 30 are provided. Although not particularly limited, the coil component 10 according to the present embodiment is a surface mount type coil component suitable as a power supply coil.

  The magnetic core 20 is made of a composite magnetic material including a magnetic material and a binder, and includes a lower magnetic core 21 and an upper magnetic core 22. As the magnetic material contained in the composite magnetic material, it is particularly preferable to use a soft magnetic metal powder having a high magnetic permeability. Specific examples include ferrites such as Ni—Zn, Mn—Zn, and Ni—Cu—Zn, permalloy (Fe—Ni alloy), super permalloy (Fe—Ni—Mo alloy), sendust (Fe—Si—Al). Alloy), Fe—Si alloy, Fe—Co alloy, Fe—Cr alloy, Fe—Cr—Si alloy, Fe, amorphous (Fe-based), nanocrystal (nanocrystal), and the like. In addition, as the binder, thermosetting resin materials such as epoxy resin, phenol resin, silicone resin, diallyl phthalate resin, polyimide resin, and urethane resin can be used.

  The lower magnetic core 21 has a flat plate portion 21 a and a convex portion 21 b, and the air core coil 30 is placed on the flat plate portion 21 a so that the convex portion 21 b is inserted into the inner diameter portion of the air core coil 30. The upper magnetic core 22 is a portion in which the air-core coil 30 placed on the lower magnetic core 21 is embedded. Although not particularly limited, in the present embodiment, the convex portion 21b has a tapered shape, and thus, when the lower magnetic core 21 is formed using a mold, the convex portion 21b is formed from the mold. It is easy to come off.

  The air-core coil 30 is constituted by a coated conductor in which a core material such as copper is coated with an insulating coating. Although details will be described later, the air-core coil 30 according to the present embodiment includes a coil conductor 50 and first and second adhesive members 51 and 52 (see FIG. 5). The first lead 61 that is one end of the coil conductor 50 is connected to the first terminal electrode 41, and the second lead 62 that is the other end of the coil conductor 50 is connected to the second terminal electrode 42. (See FIG. 4).

  As shown in FIG. 3, the first terminal electrode 41 has a mounting portion 43 located on the mounting surface 23 of the magnetic core 20 and a connecting portion 44 connected to the first lead portion 61. 44 penetrates the flat plate portion 21 a of the lower magnetic core 21. The second terminal electrode 42 has a similar structure. Then, as shown in FIG. 4, after placing the air core coil 30 on the lower magnetic core 21, the lead portions 61 and 62 of the air core coil 30 are welded to the connection portions 44 of the terminal electrodes 41 and 42, and finally, If the air-core coil 30 is embedded by the upper magnetic core 22, the coil component 10 according to the present embodiment is completed.

  FIG. 5 is a schematic external view for explaining the structure of the air-core coil 30.

  As shown in FIG. 5, the air-core coil 30 according to the present embodiment includes a winding part 60 wound in an air-core shape, a first lead part 61 led out from one end of the winding part 60, and a winding. The coil conductor 50 includes a second lead portion 62 led out from the other end of the turning portion 60. The coil conductor 50 is a coated conductor in which a core material such as copper is coated with an insulating coating. The lead portions 61 and 62 are led out from the winding portion 60 in the tangential direction, and are portions of the coil conductor 50 that are not wound. In the example shown in FIG. 5, the coil conductor 50 has a single-wire structure, but a coil conductor having a structure in which a plurality of covered conductors are integrated, such as a pair wire, may be used. In this case, the plurality of covered conductors may have a stranded wire structure.

  The coil conductors 50 constituting the winding part 60 are fixed to each other by the first adhesive member 51 and are thus self-held. The type of the first adhesive member 51 is not particularly limited, but it is preferable to use a thermoplastic resin having a low melting point such as polyester. The first adhesive member 51 serves as a temporary fastening for holding the coil conductor 50 integrally in the step of embedding the air-core coil 30 in the magnetic core 20. Therefore, it is sufficient that the first adhesive member 51 has a characteristic and an amount capable of holding the winding portion 60 by itself, and the adhesive force does not need to be excessively strong, and the amount of use may be minimized. Rather, if the amount of the first adhesive member 51 used is too large, the proportion of the non-magnetic material embedded in the magnetic core 20 increases, which is not preferable.

  Further, the boundary portion between the winding portion 60 and the lead portions 61 and 62 is fixed by a second adhesive member 52 different from the first adhesive member 51. The type of the second adhesive member 52 is not particularly limited, but it is preferable to use a thermosetting resin or an ultraviolet curable resin having a melting point higher than that of the first adhesive member 51. Since the second adhesive member 52 plays a role of preventing spring back of the lead portions 61 and 62, it is preferable to use a member having a stronger adhesive force than the first adhesive member 51. Further, the second adhesive member 52 is selectively provided not at the entire winding part 60 but at a boundary portion between the winding part 60 and the lead parts 61 and 62. As a result, it is possible to stabilize the posture of the lead portions 61 and 62 while minimizing an increase in the nonmagnetic material embedded in the magnetic core 20.

  In particular, as shown in FIG. 6 which is an enlarged view of the boundary portion, a fillet made of the second adhesive member 52 is preferably formed at the boundary portion between the winding portion 60 and the lead portions 61 and 62. According to this, since the lead parts 61 and 62 are firmly supported by the winding part 60, the postures of the lead parts 61 and 62 can be more reliably stabilized.

  Next, a method for manufacturing the air-core coil 30 will be described.

  First, the coil conductor 50 is prepared, and the winding part 60 is formed by winding this. As shown in FIG. 7, the coil conductor 50 is a coated conductor having a three-layer structure including a core material 71, a coating film 72, and a fusion layer 73. The core material 71 is made of a good conductor such as copper (Cu), and the surface thereof is covered with a coating film 72. The covering film 72 is made of an insulating material made of imide-modified polyurethane or the like, and its surface is covered with a thin fusion layer 73. The fusion layer 73 is a material of the first adhesive member 51 and is made of an insulating resin material such as polyester. The melting point of the fusion layer 73 is preferably sufficiently lower than that of the coating film 72. As an example, the melting point of the imide-modified polyurethane is about 260 ° C., whereas the melting point of the polyester is about 70 ° C.

  Next, as shown in FIG. 8, the coil conductor 50 is set in a winding jig having a rotating shaft 80 and guide shafts 81 and 82, and the rotating shaft is fixed with the coil conductor 50 on one guide shaft 82 side fixed. Rotate 80. Thereby, the coil conductor 50 is sent out from the guide shaft 81 side, and the coil conductor 50 is wound around the rotation shaft 80. And if the rotation of the rotating shaft 80 is stopped at the timing of winding the required number of turns, the winding part 60 is formed around the rotating shaft 80. The coil conductor 50 extending in the tangential direction from the winding part 60 becomes the lead parts 61 and 62.

  Next, the fusing layer 73 is melted by heating the winding part 60. The winding part 60 can be heated using an air heater or the like. As a result, the space between the coil conductors 50 in the winding part 60 is filled with the first adhesive member 51, so that the coil conductors 50 constituting the winding part 60 are fixed to each other by the first adhesive member 51 when cooled to room temperature. Will be.

  Next, as shown in FIG. 9, the second adhesive member 52 is locally supplied to the boundary portion between the winding portion 60 and the lead portions 61 and 62 using the nozzle 90. As described above, it is preferable to use a thermosetting resin or an ultraviolet curable resin as the second adhesive member 52. Then, if the second adhesive member 52 is heat-cured or ultraviolet-cured, the root portions of the lead portions 61 and 62 are firmly fixed to the winding portion 60.

  Here, as a method of applying the second adhesive member 52, a method of immersing the air-core coil 30 in a container filled with the second adhesive member 52 is also conceivable. However, in this method, since the second adhesive member 52 adheres to the coil conductor 50 in a large amount, the magnetic characteristics of the coil component 10 may be deteriorated. Further, depending on the viscosity or the like of the second adhesive member 52, the second adhesive member 52 may stretch a film on the inner diameter portion of the winding portion 60. On the other hand, as described above, if the second adhesive member 52 is selectively supplied to the boundary portion between the winding portion 60 and the lead portions 61 and 62, such a problem does not occur.

  Then, if the unnecessary part of the coil conductor 50 is cut | disconnected, the air-core coil 30 shown in FIG. 5 will be completed.

  In the air core coil 30 thus created, the coil conductors 50 constituting the winding part 60 are bonded together by the first adhesive member 51, so that the winding part 60 is self-held and the shape is stable. To do. In addition, since the boundary portion between the winding portion 60 and the lead portions 61 and 62 is fixed by the second adhesive member 52, the posture of the lead portions 61 and 62 is stabilized. For example, the lead portions 61 and 62 are not opened by the spring back and are not separated from the winding portion 60.

  When the coil component 10 is created using such an air core coil 30, the air core coil 30 is placed on the lower magnetic core 21 as shown in FIG. The lead portions 61 and 62 of the air-core coil 30 are welded. At this time, in the conventional air-core coil, the posture of the lead portions 61 and 62 is not stable, and there is a case where welding to the terminal electrodes 41 and 42 becomes difficult. Since the posture is stable, welding to the terminal electrodes 41 and 42 can be easily performed. Thereafter, when the air core coil 30 is embedded by the upper magnetic core 22, the coil component 10 according to the present embodiment is completed.

  Here, as in Patent Document 1, in the case of a coil component that embeds an air-core coil in a state where the lead portion is led out of the magnetic core, the lead portion led out of the magnetic core is held by some jig. Therefore, even if the posture of the lead portion is not particularly stable, no major trouble occurs in the work. However, such a jig cannot be used in a product in which the lead portions 61 and 62 and the terminal electrodes 41 and 42 are connected inside the magnetic core 20 as in the coil component 10 according to the present embodiment. In order to improve workability, it is very important that the postures of the lead portions 61 and 62 are stable. In this embodiment, since the postures of the lead portions 61 and 62 are greatly stabilized by using the second adhesive member 52, the lead portions 61 and 62 and the terminal electrodes 41 and 42 are connected to the magnetic core 20. It is possible to manufacture the coil component 10 of the type connected inside with good workability.

  FIG. 10 is a schematic external view for explaining the structure of the air-core coil 31 according to a modification.

  The air-core coil 31 shown in FIG. 10 is different from the air-core coil 30 shown in FIG. 5 in that two coil conductors 50 and 53 are wound concentrically. Both of these two coil conductors 50 and 53 constitute a winding part 60 wound in an air-core shape, and one coil conductor 50 has first and second leads derived from the winding part 60. The other coil conductor 53 includes third and fourth lead portions 63 and 64 led out from the winding portion 60.

  The coil conductors 50 and 53 constituting the winding part 60 are fixed to each other by the first adhesive member 51 and are self-held. Further, the boundary part between the winding part 60 and the lead parts 61 and 62 and the boundary part between the winding part 60 and the lead parts 63 and 64 are all fixed by the second adhesive member 52. Thereby, it becomes possible to stabilize the attitude | position of the lead parts 61-64.

  In the example shown in FIG. 10, the root portions of the lead portions 61 and 62 are fixed by the second adhesive member 52, and the root portions of the lead portions 63 and 64 are fixed by the second adhesive member 52. The combination of the lead portions fixed by the second adhesive 52 is arbitrary. For example, the root portions of the lead portions 61 and 63 may be fixed by the second adhesive member 52, and the root portions of the lead portions 62 and 64 may be fixed by the second adhesive member 52. Alternatively, the lead portions 61 to 64 may be fixed at different positions using the second adhesive 52.

  The air-core coil 31 having such a configuration can be used for a coil component having a four-terminal configuration.

  Thus, the air-core coil in the present invention may be formed by concentrically winding a plurality of coil conductors. In this case, the number of coil conductors is not limited to two and may be three or more.

  The preferred embodiments of the present invention have been described above, but 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. Needless to say, it is included in the range.

DESCRIPTION OF SYMBOLS 10 Coil component 20 Magnetic core 21 Lower magnetic core 21a Flat plate part 21b Convex part 22 Upper magnetic core 23 Mounting surface 30, 31 Air-core coil 41, 42 Terminal electrode 43 Mounting part 44 Connection part 50, 53 Coil conductor 51 1st adhesion member 52 1st Two adhesive members 60 Winding portions 61 to 64 Lead portion 71 Core material 72 Coating film 73 Fusion layer 80 Rotating shafts 81 and 82 Guide shaft 90 Nozzle

Claims (9)

A coil including a winding part wound in an air-core shape, a first lead part derived from one end of the winding part, and a second lead part derived from the other end of the winding part Conductors,
A first adhesive member for mutually fixing the coil conductors constituting the winding part;
An air-core coil, comprising: a second adhesive member different from the first adhesive member that fixes a boundary portion between the winding portion and the first and second lead portions.   The first and second lead portions are led out from the winding portion in a tangential direction, and a boundary portion between the winding portion and the first and second lead portions is composed of the second adhesive member. The air-core coil according to claim 1, wherein a fillet is formed.   The air core coil according to claim 1 or 2, wherein the first adhesive member is made of a thermoplastic resin having a melting point lower than that of the second adhesive member.   The air core coil according to any one of claims 1 to 3, wherein the second adhesive member is made of a thermosetting resin or an ultraviolet curable resin.   5. The air-core coil according to claim 1, comprising a plurality of the coil conductors, wherein the plurality of coil conductors are wound concentrically.   A magnetic core including a magnetic material and a binder, an air core coil according to any one of claims 1 to 5 embedded in the magnetic core, and a first core connected to the first lead portion of the air core coil. A coil component comprising: one terminal electrode; and a second terminal electrode connected to the second lead portion of the air-core coil.   The first lead portion and the first terminal electrode, and the second lead portion and the second terminal electrode are all connected inside the magnetic core. Coil parts as described in. By winding the coil conductor, an air-core-shaped winding portion, a first lead portion derived from one end of the winding portion, and a second lead derived from the other end of the winding portion A first step of forming a portion;
A second step of fixing the coil conductors constituting the winding part to each other by a first adhesive member;
And a third step of fixing the boundary portion by selectively supplying a second adhesive member to the boundary portion between the winding portion and the first and second lead portions. Manufacturing method of air-core coil. The coil conductor is covered with a fusion layer constituting the first adhesive member,
The method of manufacturing an air-core coil according to claim 8, wherein the second step is performed by melting the fusion layer by heating the winding part.

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