JP4776204B2 - Coil parts manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a coil component .

Conventionally, as a coil component, for example, as shown in Patent Document 1, a substantially U-shaped terminal fitting is provided as an electrode on a collar part of a core constituted by a core part and collar parts provided at both ends thereof. A technique is disclosed in which a coil component is configured by connecting an end portion of a conducting wire wound around a winding core portion to an electrode by laser welding or arc welding. Further, as shown in Patent Document 2, a technique is disclosed in which an electrode is formed by plating or the like on a flange portion of a core having substantially the same shape as the core of Patent Document 1, and is connected to the electrode by soldering or spot welding.
JP 2001-93756 A JP 2003-332139 A

  Polyurethane coatings are formed on the surfaces of the conductors used in the coil components shown in Patent Document 1 and Patent Document 2 in order to prevent a short circuit between the conductors. In this polyurethane-coated conductor, the coated portion of the conductor is melted by the heat of soldering or welding at the time of connection and the surface of the conductor is exposed. Therefore, it was possible to carry out the connection suitably without carrying out the peeling treatment of the coated portion in advance by a machine or the like.

  In recent years, environmental pollution by industrial waste has been regarded as a problem. Lead-free solder has been developed because substrates using solder containing lead also cause environmental pollution.

  However, the melting point of the solder that is a conventional lead-tin alloy is about 180 ° C., whereas the melting point of the lead-free solder that is an example of a tin-silver-copper alloy that is an example of a lead-free solder is about 220 ° C. It becomes ℃. The reflow temperature when mounting coil components on a board using such lead-free solder is higher than when mounting on a board using conventional lead-containing solder. Higher heat resistance was required than before.

  In response to this requirement, for example, there is a method of using a conductive wire using a polyamideimide having a high heat resistance as a coating material. However, since the polyamide-imide coating is inferior to the polyurethane coating in terms of flexibility, stress is applied to the coating when winding the conductive wire of the polyamide-imide coating, and wiring to the connection location is difficult.

  In addition, due to the high heat resistance of the polyamideimide coating, when soldering or welding, etc., without stripping the coating at the time of connection, the coating is carbonized, resulting in poor connection, and the carbonized coating is scattered on the circuit. There was a fear. Accordingly, a process of peeling the coating by mechanical peeling or laser irradiation is required, but the workability is deteriorated due to the introduction of a process that is not required in the past, and the productivity of the coil component may be lowered. Further, when peeling is performed by laser irradiation, it is necessary to perform laser irradiation from at least both surfaces of the conducting wire because peeling is possible only on one side where laser irradiation is performed.

  In the case where a thin conductive wire, for example, a conductive wire having an outer diameter of 40 μm or less is peeled off by laser irradiation, it is not easy to suitably peel off the lead wire due to the impact of the laser irradiation. If a special short-wavelength laser is used, it is possible to peel off each side without causing the conductor to break, but it takes a long time to peel off, resulting in poor workability and possibly lowering the productivity of coil components. .

  Then, an object of this invention is to provide the manufacturing method of the coil components provided with high heat resistance, and the coil components with high work efficiency.

In order to achieve the above object, the present invention provides a core having a core part and a pair of flanges at both ends of the core part, a plate-like core disposed across the pair of flanges, Provided is a method of manufacturing a coil component that is constituted by a conductive wire that is wound around a core and is formed by covering a conductor with an insulating resin and an electrode that is electrically connected to both ends of the conductive wire. The coil component manufacturing method includes a first heat treatment step in which a first heat treatment is performed on the lead wire to make the resin coating semi-cured, and a winding step in which the lead wire is wound around the core after the first heat treatment step. In connection with the winding process, the end of the conductor is heated to melt the resin coating, expose the conductor and connect to the electrode, and after the connection process, the conductor is subjected to a second heat treatment process. And a second heat treatment step in which the resin coating is brought into a main-cured state in which heat resistance and hardness are increased compared to the semi-cured state, and the plate-like core is bonded to the pair of flanges by an adhesive. Yes.

According to such a configuration, the first heat treatment step makes the resin coating in a semi-cured state, maintains flexibility as a whole conductor, and protects the conductor by the resin coating. Therefore, when winding a conducting wire around a core part, it can wind well in a core part, suppressing damage to a conducting wire. In addition, after the conducting wire is wound around the core and connected to the electrode, the resin coating is brought into a fully cured state by the second heat treatment step, thereby curing the resin coating and increasing the protection performance of the conducting wire by the resin coating. be able to. In addition, by joining the plate-shaped core across the flange portion, the inductance value as the entire coil component can be increased, and the joining process can be performed in the second heat treatment process. Thus, productivity can be increased while improving performance as a coil component.

  Moreover, as for resin coating, it is desirable that the resin coating after the second heat treatment step has a higher melting point than the resin coating after the first heat treatment step than the second heat treatment step. The resin coating is preferably a modified epoxy resin.

  According to such a configuration, the resin coating is removed by the heat of heat fusion by thermally fusing the lead wire and the electrode without peeling off the semi-cured resin coating after the first heat treatment step. It is possible to make the connection easy by omitting the resin coating peeling step. In addition, the resin coating in the fully cured state after the second heat treatment step has a high melting point and increased heat resistance even if there is scattering of a fusion base material such as solder during mounting. However, it is possible to protect the conductive wire without receiving heat damage due to the scattering of the fusion base material. In addition, by using a modified epoxy resin as a resin coating, a resin having properties according to purposes such as heat resistance and flexibility that cannot be obtained by a single resin can be produced, and a resin coating can be easily formed. .

  According to the coil component and the coil component manufacturing method of the present invention, the coil component can be provided with high heat resistance and the work efficiency at the time of manufacturing can be increased.

  The coil component according to the first embodiment of the present invention will be described with reference to FIGS. The coil component 1 according to the present embodiment is a common mode filter used for a high-speed operation signal interface, and includes a drum-type magnetic core 2 as shown in FIG. And about 1.2 mm in the width direction. The magnetic core 2 is formed by compressing or sintering magnetic powder such as ferrite.

  The magnetic core 2 includes a core portion 3 having a substantially rectangular cross section perpendicular to the longitudinal direction, and a pair of flange portions 4 and 5 having substantially the same shape. Two conductors 6 and 7 are wound around the core 3. These conducting wire 6 and conducting wire 7 are covered conducting wires. As shown in FIG. 2, the conducting wire 6 and the conducting wire 7 are configured by covering a conductor 6A such as a copper wire and a conductor 7A with a coating 6B and a coating 7B of a modified epoxy resin. The conductor 6A and the conductor 7A have a diameter of about 40 μm, and the coating 6B and the coating 7B have a thickness of about 5 μm.

  In the modified epoxy resin constituting the coating 6B and the coating 7B, a different type of resin (for example, epoxy, acrylic, butadiene, polyester, etc.) is mixed or reacted with a standard epoxy resin such as a bisphenol A type epoxy resin. Resin.

  The modified epoxy resin has the property of making a resin having properties according to the purpose, such as heat resistance and flexibility that cannot be obtained with an epoxy resin alone, and this modified epoxy resin is used as the conductor in the first embodiment. 6 and conductor 7 are used as coatings. In the first heat treatment step, the modified epoxy resin is cured to such an extent that the conducting wire 6 and the conducting wire 7 can be handled at least as conducting wires, and is in a temporarily cured state having flexibility and a low melting point. In particular, since it has a low melting point, it is possible to provide insulation wire coating that exposes the conductor part by melting the coating by heat such as thermocompression bonding or welding at the time of connection without stripping the coating during connection. It becomes. Then, the second heat treatment step completely cures the modified epoxy resin to increase the performance as a protective coating, for example, surface strength, moisture resistance, insulation, etc., and a fully cured state with a high melting point and excellent heat resistance. Become.

  As shown in FIG. 3, the core part 3 is a substantially rectangular parallelepiped, and includes a top surface 3A, a bottom surface 3C that is a bottom surface of the top surface 3A, a side surface 3B that is a surface between the top surface 3A and the bottom surface 3C, and It has a side surface 3D.

  The flange portion 4 is a substantially rectangular parallelepiped, and is connected to the top surface 4A, the top surface 4A, the inner side surface 4F that is a connection surface with the core portion 3, the front side surface 4E facing the inner side surface 4F, and the top surface The lower surface 4C is opposed to 4A, and the side surface 4D and the side surface 4B are surrounded by the top surface 4A, the inner side surface 4F, the lower surface 4C, and the front side surface 4E.

  An electrode 8A is formed on the flange portion 4 at the end portion in the vicinity of the connection position between the top surface 4A, the front side surface 4E and the lower surface 4C, and the side surface 4B across the top surface 4A, the front side surface 4E, and the lower surface 4C. Similarly, the electrode 9A is formed in the vicinity of the connection position of the top surface 4A, the front side surface 4E, the lower surface 4C, and the side surface 4D across the top surface 4A, the front side surface 4E, and the lower surface 4C. These electrodes 8A and 9A are formed on the surface of the flange 4 by plating.

  Similarly to the flange portion 4, the flange portion 5 includes a top surface 5A, an inner side surface 5F, a side surface 5D, a front side surface 5E, a side surface 5B, and a lower surface 5C, and includes an electrode 8B and an electrode 9B, respectively.

  As shown in FIG. 4, the conducting wire 6 and the conducting wire 7 are drawn out from the vicinity of the coupling portion between the core portion 3 and the flange portion 4 and wired in the direction of the top surface 4A along the inner side surface 4F. It is bent along the top surface 4A at the intersection of 4A and the inner side surface 4F. As shown in FIG. 1, on the top surface 4A, the conducting wire 6 and the conducting wire 7 are connected to the electrode 8A and the electrode 9A by thermocompression bonding, respectively. Similarly, the lead wire 6 and the lead wire 7 are connected to the electrode 8B and the electrode 9B on the top surface 5A by thermocompression bonding in the flange portion 5 as well.

  Hereinafter, the manufacturing method about the coil component 1 of the said structure is demonstrated. First, as shown in FIG. 3, an electrode 8A, an electrode 9A, an electrode 8B, and an electrode 9B are formed on the flange portion 4 and the flange portion 5 of the magnetic core 2 by plating, respectively.

  Further, the conductor 6 and the conductor 7 are coated with the modified epoxy resin 6B on the conductor 6A, and then heated at about 80 ° C. for about 30 minutes in a heat treatment furnace or the like as the first heat treatment step, so that the coating 6B is temporarily cured. It is in a state. The conductor 6 and the conductor 7 in the temporarily cured state are wound around the outer periphery of the core portion 3.

  At the time of winding, the conducting wire 6 and the conducting wire 7 are made substantially parallel and wound along the top surface 3A, the side surface 3B, the bottom surface 3C, the side surface 3D of the winding core portion 3, and the corners constituted by the respective surfaces. (FIGS. 3 and 4). In this case, especially in the corner portion, the stress concentration portion is not formed in the resin coating due to the flexibility of the coating 6B, and it is difficult to form a defective portion such as peeling due to cracks in the resin coating. It becomes easy to become familiar with the shape of the part. Therefore, when the conducting wire 6 and the conducting wire 7 are wound, no stress is generated on the conducting wire 6 and the conducting wire 7 and the winding can be suitably performed.

  Even when the conductive wire 6 and the conductive wire 7 are adjacent to each other, since the coating 6B and the coating 7B are in a temporarily cured state, they serve as a buffer material between the conductive wire, the conductive wire, and the core body. Damage to the conducting wire 6 and the conducting wire 7 due to direct contact can be suppressed. Even if the coating 6B and the coating 7B rub against each other, the conductor 6A and the conductor 7A are not exposed, and a short circuit or the like can be suppressed.

  After winding the conducting wire 6 and the conducting wire 7 around the core part 3, after wiring the one end side of the conducting wire 6 and the conducting wire 7 along the inner side surface 4F of the flange part 4, the one end of the conducting wire 6 is placed on the top surface 4A. It arrange | positions on the formed electrode 8A, and arrange | positions the end of the conducting wire 7 on the electrode 9A formed on the top surface 4A (FIG. 4). Similarly, the other ends of the conducting wire 6 and the conducting wire 7 are disposed on the electrode 8B and the electrode 9B on the top surface 5A, respectively (FIG. 4). Also in this case, although the conducting wire 6 and the conducting wire 7 are wired along the top surface 4A from the inner side surface 4F, the flexibility of the coating 6B and the coating 7B enables appropriate wiring without stress.

  After the conducting wire 6 and the conducting wire 7 are disposed on the electrode 8A and the electrode 9A, respectively, a crimping element (not shown) is pressed against the electrode 8A and the electrode 9A, and heat is applied at 300 ° C. to 400 ° C. to thermocompress the conducting wire 6 and the conducting wire 7. Process and connect. Since the melting points of the coating 6B and the coating 7B are low in the temporarily cured state, the coating 6B and the coating 7B are melted by the heat of the pressure-bonding element at the time of the connection even if the connecting portion is not particularly peeled off. 7A is exposed and connected to the electrodes 8A and 9A. In this case, since the coating 6B and the coating 7B are melted, carbide or the like is not formed by heating at the time of pressure bonding.

  When the above connecting process is completed, the coil component 1 is temporarily shaped as a complete body (FIG. 1). However, the coating 6B and the coating 7B at the core portion are still in a temporarily cured state. There are parts that are inferior in high temperature durability. Therefore, as a second heat treatment step, the entire coil component 1 including the conductor 6 and the conductor 7 is heated and cured at about 180 ° C. for about 40 minutes. As a result, the coating 6B and the coating 7B are in a fully cured state, the resin is completely cured and exhibits performance as a protective coating, and has a high melting point and excellent heat resistance.

  One of the heat resistance tests is a reflow heat test. In this test, reflow is performed with the solder paste attached to the conductive wire portion. However, the conventional polyurethane-coated conductive wire has been subjected to reflow at most twice, thereby causing defects such as a short circuit from the solder paste attached portion. On the other hand, in the coil component 1 according to the first embodiment, when this reflow heat resistance test was performed, defects such as a short circuit at the solder paste adhesion portion were not obtained even after 10 reflows. By setting the coating 6B and the coating 7B to the fully cured state, the result was that the heat resistance was clearly superior compared to the conventional polyurethane coating.

  As a modified example of the first embodiment, as shown in FIG. 5, a plate-like core 10 may be attached across the flange 4 and the flange 5 at both ends of the coil component 1. By adopting this form, it is possible to increase the inductance value of the entire coil component. The plate-shaped core 10 is joined to the collar part 4 and the collar part 5 with an adhesive. A thermosetting adhesive is used as this adhesive. Specifically, after connecting the conducting wire 6 and the conducting wire 7, the plate-like core 10 is temporarily bonded to the flange portion 4 and the flange portion 5 with an adhesive. The coil component 1 enters the second heat treatment step after the connection. At this time, the plate core 10 is also heated at the same time, and the adhesive between the plate core 10 and the flange portion 4 and the flange portion 5 is cured. The plate core 10 is integrated with the coil component 1. That is, in the modified example of the first embodiment, it is possible to join the plate cores 10 at the same time by the second heat treatment step without particularly providing a step of joining the plate cores 10, and in particular, man-hours. It is possible to increase the performance of the entire coil component without increasing the value.

  In the first embodiment, a ferrite core is used as the magnetic core 2. However, the present invention is not limited to this. For example, a ceramic core may be used as long as it is a coil component that requires high-frequency characteristics.

  Next, as a second embodiment, a coil component using laser welding at the time of connection will be described with reference to FIGS. The coil component 11 shown in FIG. 8 takes substantially the same form as the coil component 1 according to the first embodiment. As shown in FIG. 6, the winding core portion 13 and the flange portions 14 provided at both ends thereof, A metal terminal 18, which is a terminal electrode, is provided on the core 12 composed of the flange portion 15. And as shown in FIG. 9, the conducting wire 16 and the conducting wire 17 which were wound around the core part 13 are welded and connected to the metal terminal 18, respectively. The conducting wire 16 and the conducting wire 17 are coated conducting wires coated with a modified epoxy resin as in the first embodiment.

  As shown in FIG. 6, the flange portion 14 has a top surface 14 </ b> A, a bottom surface 14 </ b> C, an inner side surface 14 </ b> F that is a connection surface with the core portion 13, and a front side surface 14 </ b> E that faces the inner side surface 14 </ b> F. , And the side surface 14B and the side surface 14D, and the flange portion 15 is configured in the same manner. As shown in FIG. 7, a step portion 14f in which the axial thickness of the core portion 13 is thin is formed at the end portions of the inner side surface 14F on the side surface 14B side and the side surface 14D side. Moreover, the recessed part 19 formed with the groove | channel which continues from the top surface 14A of the collar part 14 to the lower surface 14C is formed in the both ends of the front side surface 14E of the collar part 14 as a retaining part which prevents a metal terminal from detaching, respectively (FIG. 7). The recess 19 is also formed on the side surface 15E of the flange portion 15 in the same manner. The coil component 11 has a length of 4.5 mm, a width of 3.2 mm, and a height of 2 mm.

  The metal terminal 18 serving as a terminal electrode is a copper alloy such as phosphor bronze or brass, and is bent into a substantially U shape. As shown in FIG. 7, the side surface portion 18A, the top surface portion 18B, the bottom surface portion 18C, It has upper and lower folded portions 18D. Further, a convex portion 18E that protrudes toward the inner surface side is formed on the inner surface of the side surface portion 18A as a metal fitting-side retaining portion that engages with the core-side retaining portion 19. Further, the upper surface portion 18B is integrally formed with a connecting portion 20 formed of an inverted L-shaped bent portion. The connecting portion 20 is open toward the distal end of the flange portion 14 for the convenience of inserting the conducting wire 16 and the conducting wire 17. The connecting portion 20 may be opened in the direction opposite to the distal end direction. Such a metal terminal 18 is inserted into the flange 14 from the side surface 14B and the side surface 14D, which are the sides thereof, and is fitted and mounted (FIG. 7). In this case, the convex part 18E as the metal part side retaining part fits into the concave part 19 as the core side retaining part, and the folded part 18D presses the stepped part 21, and the metal terminal as shown in FIG. 18 is attached to the collar 14. By forming the step portion 21 on the flange portion 14, the folded portion 18 </ b> D is prevented from projecting to the core portion 13 so that the winding work around the core portion 13 is not hindered.

  Hereinafter, the manufacturing method about the coil component 11 of the said structure is demonstrated. First, as shown in FIGS. 6 and 7, metal terminals 18 that serve as electrodes are attached to the flanges 14 and 15 of the core 12. When the metal terminal 18 is attached, no adhesive is used because the retaining portion is formed on the core side and the metal fitting side, and the metal terminal 18 is fitted to the flange portion 14 and the flange portion by fitting the protrusion 18E and the recess 19 together. 15 is fixed.

  Next, the conducting wire 16 and the conducting wire 17 are wound around the core part 13 of the core 12 (FIG. 8). At this time, the conducting wire 16 and the conducting wire 17 are preliminarily heated at about 80 ° C. for about 30 minutes by a heat treatment furnace or the like as the first heat treatment step as in the first embodiment, and are in a coated or temporarily cured state. Yes. Since the winding process is the same as that of the first embodiment, the details are omitted.

  After the conducting wire 16 and the conducting wire 17 are wound around the winding core portion 13, one end side of the conducting wire 16 and the conducting wire 17 is wired along the inner side surface 14 </ b> F and the top surface 14 </ b> A of the flange portion 14, and one end thereof is connected to the metal terminal 18. The unit 20 is disposed. Then, by caulking the connecting portion 20, the conducting wire 16 and the conducting wire 17 are respectively fixed to the metal terminals 18. Thereafter, the connecting portion 20, the conducting wire 16 and the conducting wire 17 are melted by laser welding or arc welding, and the conducting wire 16, the conducting wire 17 and the metal terminal 18 are integrated electrically and mechanically. At this time, welding with a laser beam is performed, and the conductors 16 and 17 are melted. Since the coating of the conducting wires 16 and 17 is in a temporarily cured state, the melting point is low, and the coating of the conducting wires 16 and 17 can be dissolved without carbonizing the coating by the heat of the laser beam. Furthermore, the conducting wire 16 and the conducting wire 17 are fixed at the connecting portion 20, so that the conducting wire 16 and the conducting wire 17 are not disturbed by the impact of the laser beam at the time of welding and can be suitably welded without causing a positional shift or the like. . Similarly, the lead wire 16 and the lead wire 17 are connected to the metal terminal 18 in the flange portion 15, and the coil component 11 is shaped as shown in FIG. Thereafter, as in the first embodiment, as a second heat treatment step, the entire coil component 11 including the conductor 16 and the conductor 17 is heated and cured at about 180 ° C. for about 40 minutes, and the coating is made into a fully cured state. 11 is completed.

  In the first embodiment, the connection is performed by thermocompression bonding, but as shown in the second embodiment, when performing the connection using a laser, the coating is temporarily cured, It becomes possible to connect suitably without carrying out peeling processing of a coating.

  Next, as a third embodiment, a coil component using a drum core and molded with a mold resin will be described with reference to FIGS. As shown in FIG. 14, the external appearance of the coil component 31 according to the third embodiment is formed in a substantially rectangular parallelepiped shape by a mold resin 43, and lead terminals 42 serving as electrodes at the time of circuit mounting are formed at both ends of the rectangular parallelepiped. Has been placed.

  As shown in FIG. 10, the core 32 constituting the coil component 31 is configured by providing substantially disc-shaped flange portions 34 and flange portions 35 at both ends of a substantially cylindrical core portion 33. An electrode portion 34A is formed by plating or sputtering on the opposite surface of the flange portion 34 to the surface to be joined with the core portion 33, and a similar electrode portion is also formed on the flange portion 35. As shown in FIGS. 11 and 12, the lead terminal 42 electrically connected to the electrode portion 34 </ b> A is formed by extending a part of the lead frame 41 that supports the core 32 and the like when the coil component 31 is manufactured. The tip is bent at a substantially right angle to form the core holding portion 42A. As shown in FIGS. 11 and 12, the conductive wire 36 wound around the core portion 33 is a coated conductive wire coated with a modified epoxy resin, as in the first embodiment. The lead wire 42 is wired along the outer periphery of the flange portion 34 to the position of the electrode portion 34A. Similarly, the lead wire 36 is also wired to the electrode portion of the flange portion 35.

  Hereinafter, the manufacturing method about the coil component 31 of the said structure is demonstrated. First, as shown in FIG. 10, an electrode portion 34 </ b> A is formed on the flange portion 34 of the core 32, and a similar electrode is formed on the flange portion 35. Thereafter, the conductive wire 36 heat-treated in the first heat treatment step is wound around the core. The core portion 33 according to the third embodiment has a cylindrical shape, and the coating of the conductive wire 36 is also preheated by heating at about 80 ° C. for about 30 minutes in advance through a first heat treatment step. Since it is in a state with flexibility, it can be wound without stress when the conducting wire 36 is wound.

  After the conducting wire 36 is wound around the winding core portion 33, one end side of the conducting wire 36 is wired to the electrode portion 34 </ b> A along the flange portion 34, and the other end side is similarly connected to the electrode portion of the flange portion 35 along the flange portion 35. Wired up to. The lead frame 41 is preliminarily cut into a substantially H shape by pressing or the like, and the projecting piece portions at both ends of the lead frame 41 cut into a substantially H shape become lead terminals 42 and 42, and the tips thereof are bent to form the core 32. The core holding portions 42A and 42A to be held are used. The core 32 around which the conducting wire 36 is wound is disposed and held between the core holding portions 42A and 42A. At this time, one end of the conducting wire 36 wired on the flange portion 34 side is disposed between the core holding portion 42A and the electrode portion 34A, and the other end of the conducting wire 36 similarly wired on the flange portion 35 side is the core holding portion. It arrange | positions between 42A and the electrode part by the side of the collar part 35 (FIG. 12).

  Thereafter, the core holding portions 42A and 42A and the conductive wire 36 are soldered (FIG. 13). At this time, the coating of the conductive wire 36 is melted by the heat of soldering, and the conductor portion is exposed, so that it is possible to perform soldering without performing a coating peeling process. Further, at the time of this soldering, the core holding portions 42A, 42A and the conductor 36 are soldered, and the core holding portions 42A, 42A, the electrode portions 34A, and the electrode portions formed on the flange portion 35 are also soldered. Is done.

  After the core 32 and the lead wire 36 are soldered to the lead frame 41, as a second heat treatment step, the lead wire 41 and the core 32 are integrally heated with the lead frame 41 and the core 32 at about 180 ° C. for about 40 minutes to fully coat the lead wire 36. Set to a cured state. Thereafter, the unit including the core 32, the conductive wire 36, and the lead terminals 42, 42 is covered with the mold resin 43 (FIG. 14). Also in this case, the conducting wire 36 is covered with the fully cured coating. The modified epoxy resin constituting the coating exhibits high heat resistance and chemical resistance in the fully cured state, so even if the conductive wire 36 is covered with the mold resin 43, the coating of the conductive wire 36 is damaged by the mold resin 43. The conductor in the conductor 36 is preferably protected. Further, since the core 32 and the like are integrally covered with the mold resin 43, the protection performance against the external causes of the coil component 31 as a whole is increased, and the coil component having a more stable operation can be obtained. After the core 32 is covered with the mold resin 43 and formed into a substantially rectangular shape, the lead terminals 42 and 42 are cut off from the lead frame 41, and the cut off tip portions are processed. As shown in FIG. 31 is completed.

  Next, a coil component having a shape in which a substantially circular toroidal core is built in a resin case will be described as a fourth embodiment with reference to FIGS. As shown in FIG. 15, the coil component 51 shown in FIG. 18 has a substantially annular toroidal core 52 inserted in a resin case 53. The toroidal core 52 is wound by bifilar winding in which two conductors 56 and 57 are wound in parallel at the same time. As shown in FIG. 16, one end and the other end of the conductors 56 and 57 are wound. Are extended substantially radially in the four directions of the toroidal core 52. The conductive wire 56 and the conductive wire 57 are coated conductive wires coated with a modified epoxy resin, as in the first embodiment.

  As shown in FIG. 15, the resin case 53 has a plate-like base 54 having a substantially square shape and a substantially circular opening formed in the center, and extends from the opening edge of the base 54 to one surface in the normal direction of the base 54. It is comprised from the cylindrical part 55 comprised from the substantially cylindrical wall and the cover which covers one of the walls. The toroidal core 52 is inserted and held from the other surface side of the base 54 in a space formed in the cylindrical portion 55.

  At the four corners of the base 54, holes 54a penetrating from the other surface side of the base 54 to the one surface side are formed, and a substantially L-shaped metal terminal 58 serving as an electrode extends from the other surface of the base 54 to the one surface. The inserted tip portion protrudes from one surface of the base 54 to form a connecting portion 58A (FIG. 17). Moreover, the part located in the other surface side of the metal terminal 58 becomes a part joined to the circuit when the coil component 51 is mounted on the circuit.

  In the vicinity of the holes 54a formed at the four corners of the side surface of the base 54, as shown in FIG. In the groove 54 b, one end side and the other end side of the conducting wire 56 and the conducting wire 57 are connected to a connecting portion 58 A provided on one surface side of the base 54 with the toroidal core 52 inserted into the resin case 53. Therefore, it becomes a place for wiring (FIG. 17).

  Hereinafter, the manufacturing method about the coil component 51 of the said structure is demonstrated. First, the conducting wire 56 and the conducting wire 57 are wound around the toroidal core 52 by bifilar winding. At this time, the conductive wire 56 and the conductive wire 57 are preliminarily heat-treated at about 80 ° C. for about 30 minutes by a heat treatment furnace or the like as a first heat treatment step, and the coating is in a temporarily cured state. For this reason, in order to protect the conductor part in a conducting wire, maintaining the flexibility as the whole conducting wire, it is easy to wind the conducting wire 56 and the conducting wire 57 even when it is wound around the toroidal core 52, and the conducting wire 56 and the conducting wire 57 are not easily damaged. . After the conducting wire 56 and the conducting wire 57 are wound around the toroidal core 52, one end side and the other end side thereof are extended toward substantially four directions of the toroidal core 52. In this state, as shown in FIG. 15, the toroidal core 52 is inserted into the cylindrical portion 55 of the resin case 53 through the opening formed in the base 54 of the resin case 53. At this time, the metal terminals 58 are inserted into the holes 54 a formed at the four corners of the base 54.

  After the toroidal core 52 is inserted into the cylindrical portion 55, one end side and the other end side of the conducting wire 56 and the conducting wire 57 are routed through the groove 54b to the other surface side of the base 54 (FIGS. 16 and 17). Then, as shown in FIG. 17, the wire is wound around the connecting portion 58 </ b> A protruding from the base 54. It is not necessary to remove the coating from the portion wound at this time.

  After the conducting wire 56 and the conducting wire 57 are wound around the connecting portion 58A, the connecting is performed by soldering or welding as shown in FIG. At this time, since the coating of the conducting wire 56 and the conducting wire 57 is in a semi-cured state, the melting point is low, and it is melted by the heat at the time of connection. Therefore, the conductor part of the conducting wire 56 and the conducting wire 57 and the connecting part 58A can be connected without stripping the coating. After the connection of the conducting wire 56 and the conducting wire 57 is finished, as a second heat treatment step, the conducting wire 56 and the conducting wire 57 are heated together with the resin case 53 and the toroidal core 52 at about 180 ° C. for about 40 minutes. The coil component 51 is completed by setting the coating of 57 to the fully cured state and improving the heat resistance and strength characteristics of the coating.

  In the first heat treatment process in the first embodiment to the fourth embodiment, the heat treatment is performed at about 80 ° C. for about 30 minutes. However, the heat treatment is not limited to this. Also good. In the second heat treatment step, the heat treatment is performed at about 180 ° C. for about 40 minutes. However, the heat treatment is not limited to this. For example, the heat treatment may be performed at 150 ° C. to 200 ° C. for about 10 minutes to 120 minutes.

The perspective view which shows the completion state of the coil components which concern on 1st embodiment of this invention. The block diagram of the conducting wire of the coil components which concern on 1st embodiment of this invention. The perspective view which shows the core and electrode of a coil component which concern on 1st embodiment of this invention. The perspective view which shows the connecting wire front body of the coil components which concern on 1st embodiment of this invention. The perspective view of the state which provided the plate-shaped core of the coil components which concern on 1st embodiment of this invention. The perspective view of the core and metal terminal of the coil component which concern on 2nd embodiment of this invention. The detailed perspective view which showed the direction which attaches the metal terminal of the coil components which concern on 2nd embodiment of this invention. The perspective view which shows the connecting wire front body of the coil components which concern on 2nd embodiment of this invention. The perspective view which shows the completion state of the coil component which concerns on 2nd embodiment of this invention. The perspective view which shows the core and electrode of a coil component which concern on 3rd embodiment of this invention. The perspective view which shows the state by which winding was performed to the core of the coil components which concern on 3rd embodiment of this invention. The perspective view which shows the state by which the core was hold | maintained at the lead frame of the coil components which concern on 3rd embodiment of this invention. The perspective view which shows the state by which the connection of the coil components which concern on 3rd embodiment of this invention was performed. The perspective view which shows the completion state of the coil component which concerns on 3rd embodiment of this invention. The perspective view which shows the positional relationship of the corner | angular component of the coil components which concern on 4th embodiment of this invention. The lower surface side top view of the coil component which concerns on 4th embodiment of this invention. The perspective view which shows the state before the connection of the coil components which concern on 4th embodiment of this invention. The perspective view which shows the completion state of the coil component which concerns on 4th embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coil component 2 Magnetic core 3 Core part 4 Collar part 5 Collar part 6 Conductor 6B Coating 7 Conductor 7A Conductor 7B Coating 8A Electrode 8B Electrode 9A Electrode 9B Electrode 10 Plate-shaped core 11 Coil part 12 Core 13 Coil part 14 Collar 15 flange 16 conductor 17 conductor 18 metal terminal 18A side 18B top 18C bottom 18D turn 18E convex 19 concave 20 joint 21 step 31 coil part 32 core 33 core 34 flange 34A electrode 35鍔 36 Conductor 36 Cover 41 Lead frame 42 Lead terminal 42A Core holding part 43 Mold resin 51 Coil component 52 Toroidal core 53 Resin case 54 Base 54a Hole 54b Groove 55 Cylindrical part 56 Conductor 57 Conductor 58 Metal terminal 58A Connection part

Claims (3)

A core having a core part and a pair of flanges at both ends of the core part;
A plate-like core disposed across the pair of buttocks,
A conducting wire wound around the winding core and configured by covering the conductor with an insulating resin; and
A method of manufacturing a coil component comprising electrodes electrically connected to both ends of the conducting wire,
A first heat treatment step for applying a first heat treatment to the conducting wire to bring the resin coating into a semi-cured state;
A winding step of winding the conducting wire around the core after the first heat treatment step;
In connection with the winding step, a connecting step of heating an end portion of the conducting wire to melt the resin coating to expose the conductor and to connect to the electrode;
After the connecting step, the conductive wire is subjected to a second heat treatment step so that the resin coating is in a fully cured state in which heat resistance and hardness are increased as compared to the semi-cured state, and the plate-like core is the pair of flanges. And a second heat treatment step to be joined to each other by an adhesive . The resin coating is characterized in that the resin coating after the second heat treatment step has a higher melting point than the resin coating after the first heat treatment step than the second heat treatment step. The manufacturing method of the coil components of Claim 1 . The method for manufacturing a coil component according to claim 1, wherein the resin coating is a modified epoxy resin.

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