JP6561973B2 - Method of resin coil molding of coil parts - Google Patents

Description

  The present invention relates to a method of molding a coil component used in a transformer device or the like with an insulating resin.

  Patent Document 1 discloses a transformer device (mold) in which a coil component (vertically wound coil) having a structure formed by winding a plurality of conductor plates such as a flat copper wire is molded with an insulating thermoplastic resin or the like. Coil) is disclosed.

Japanese Patent Laid-Open No. 10-303036

  For example, a coil having a structure in which a first coil 121 formed by winding a conductive plate once as shown in FIG. 5A and a second coil 122 formed by winding the conductive plate once is connected. When the component 125 is resin-molded by providing a predetermined space for sandwiching the substrate between the first coil 121 and the second coil 122, the first coil is prevented from being deformed by the molding pressure. It is necessary to ensure the positional accuracy between 121 and the second coil 122.

  As a countermeasure, for example, a press pin for holding the first coil 121 from both sides and a press pin for holding the second coil 122 from both sides are installed in a mold for resin molding, and each coil is held by the press pin. A method of preventing the position accuracy of the first coil 121 and the second coil 122 from being deteriorated by deforming the coil component 125 due to the molding pressure by performing the molding in the held state can be considered.

  However, in the case of the above-described method, the coil component 125 after resin molding that has been removed from the mold after molding is placed in the position where the presser pin has been installed, as shown in FIGS. The pinhole 124p from which the first coil 121 and the second coil 122 are exposed remains. By leaving this pinhole 124p, the insulation between the coil component 125 and other components, for example, the insulation between the first coil 121 and the second coil 122 and the substrate 110 inserted into the space 124g of these coils can be achieved. , Difficult to secure.

  Here, a countermeasure for filling the pinhole 124p with another part such as a lid may be considered. However, in this case, an increase in the number of parts due to different parts and a new process (adhesive bonding, vibration welding, ultrasonic welding, laser welding, etc.) different from the resin molding process for filling the pinhole 124p with other parts. Process) is added. For this reason, there exists a problem that the manufacturing cost for resin mold forming of coil components rises.

  This invention is made | formed in view of the said subject, Resin-molding the coil component which can ensure the insulation between a coil component and another component, suppressing the raise in manufacturing cost. It aims to provide a method.

  In order to solve the above-described problem, according to one embodiment of the present invention, a first coil formed by winding a conductive plate once or more and a second coil formed by winding the conductive plate one or more times are connected. In this method, the coil component is resin-molded into a shape that is mounted on the substrate with the substrate sandwiched between the first coil and the second coil, with at least a part of the outer edge exposed. A substantially annular first resin portion in which the coil is covered with an insulating resin is molded, and a substantially annular second resin portion in which the second coil is covered with an insulating resin in a state where at least a part of the outer edge portion is exposed. Forming a primary molding step, forming a substantially annular third resin portion joined to the first resin portion while covering the exposed outer edge portion of the first coil with an insulating resin, and exposing the second coil The outer edge portion is covered with an insulating resin and joined to the second resin portion A secondary molding step of molding an annular fourth resin portion, and in the primary molding step, a convex first welding rib is molded on the outer periphery of a portion of the first resin portion on the side sandwiching the substrate. At the same time, a convex second weld rib is formed on the outer periphery of the portion of the second resin portion that is on the side sandwiching the substrate, and in the secondary molding step, the first resin portion and the third resin portion are melted by melting the first weld rib. The interface with the resin part is welded, and the second welding rib is melted to weld the interface between the second resin part and the fourth resin part.

  In this aspect of the present invention, in the primary molding step, the convex first welding rib is formed on the outer periphery of the portion of the first resin portion on the side of sandwiching the substrate, and the substrate is sandwiched of the second resin portion. Convex-shaped second welding ribs are formed on the outer periphery of the side portion. Then, in the secondary molding step, the first weld rib molded in the primary molding step is melted to weld the resin portions at the interface between the first resin portion and the third resin portion, and in the primary molding step, the first molding is performed. The two weld ribs are melted to weld the resin parts at the interface between the second resin part and the fourth resin part.

  Thereby, in the coil component after molding, the first resin portion and the third resin portion of the first coil can be brought into close contact with each other, and the second resin portion and the fourth resin portion of the second coil are bonded together. It can be adhered without gaps. Therefore, insulation between the coil component and other components can be ensured. Specifically, it is possible to ensure insulation between the first coil and the second coil and the substrate sandwiched between the first coil and the second coil.

  Further, in one aspect of the present invention, the weld rib formed in the primary molding process is melted in the secondary molding process and the resin parts are welded at the interface between the resin parts. Separate parts for filling are not required. Therefore, it is possible to suppress an increase in manufacturing cost for molding the coil component by resin molding.

  Furthermore, in one aspect of the present invention, the secondary molding step is a step of molding the coil component by inserting the same insulating resin as in the primary molding step, so a new step (adhesive) different from the primary molding step The addition of processes such as bonding, vibration welding, ultrasonic welding, and laser welding is not necessary. Therefore, it is possible to suppress an increase in manufacturing cost for molding the coil component by resin molding.

  As described above, according to the method of resin-molding a coil component according to the present invention, it is possible to ensure insulation between the coil component and other components while suppressing an increase in the manufacturing cost of the coil component. it can.

The figure which shows an example of the transformer apparatus which comprises the coil components which can apply the method of resin molding which concerns on one Embodiment of this invention to a structure. The figure explaining the detailed structure of the 2nd coil part shown in FIG. The figure explaining the method of resin-molding the coil components which concern on one Embodiment of this invention A direction arrow view in the coil component of FIG. BB sectional view in the coil component of FIG. The figure explaining an example of the method of resin-molding the conventional coil components CC sectional view in the coil component of FIG.

[Overview]
In the method of resin-molding a coil component according to the present invention, a welding rib is provided in a primary molding step of molding a part of the coil component in order to ensure positional accuracy. Then, in the secondary molding step, the entire coil component is molded and the welding rib is melted, and the interface between the molding resin portion in the primary molding step and the molding resin portion in the secondary molding step is welded without a gap. Thereby, insulation at the interface of the molded product is ensured.

[Transformer structure]
First, with reference to FIG. 1 and FIG. 2, the structure of the transformer apparatus 1 which can apply the method of resin-molding the coil component of this invention is demonstrated.

  FIG. 1 is a diagram for explaining the structure of a transformer device 1 including a coil component to which a resin molding method according to an embodiment of the present invention can be applied by developing the component parts of the device. The transformer device 1 illustrated in FIG. 1 includes components of a substrate 10 on which a first coil portion 11 is formed, a second coil portion 20, an upper core portion 30, and a lower core portion 40. FIG. 2 is a diagram illustrating a more detailed structure of the second coil unit 20 in FIG.

  The coil component to which the resin molding method according to the embodiment of the present invention can be applied corresponds to “coil component 25” described in the present embodiment and the drawings.

  In the transformer device 1 according to the present embodiment, the component parts of the second coil unit 20, the upper core unit 30, and the lower core unit 40 are respectively arranged in the order of the arrow numbers from the direction of the arrows shown in FIG. It is formed by being assembled and mounted on the (first coil portion 11).

  The transformer device 1 assembled in this way is an element having a structure in which the first coil portion 11 and the second coil portion 20 are magnetically coupled via the upper core portion 30 and the lower core portion 40.

-Substrate 10 and first coil part 11
The substrate 10 is a printed circuit board on which a conductor pattern that circulates electricity is printed, and a predetermined electrical circuit is configured by wiring-connecting mounted components and the like with the conductor pattern. The substrate 10 may have a multilayer structure or a single layer structure.

  The board 10 has an insertion hole 12a through which a middle leg portion 40a, which will be described later, is inserted, an insertion hole 12b through which the outer leg portion 40b of the lower core portion 40 is inserted, and an outer leg of the lower core portion 40. Insertion holes 12c through which the portion 40c is inserted are provided.

  In addition, a spiral conductor pattern is formed around the insertion hole 12a of the substrate 10 by being wound one or more times in a planar shape. When the substrate 10 has a multilayer structure, a spiral conductor pattern may be formed in each layer. The first coil portion 11 having the spiral conductor pattern constitutes a high-voltage coil in the transformer device 1.

  Further, the substrate 10 is provided with a slit 13 into which a connecting portion 24c of the second coil portion 20 described later is inserted. The slit 13 is positioned so that the winding core of the first coil portion 11 and the winding core of the second coil portion 20 coincide with each other by inserting and fitting the connecting portion 24c until it comes into contact with the back end portion 13w. It is formed so that it can be easily realized.

Second coil unit 20
The second coil unit 20 constitutes a low voltage side coil in the transformer device 1. As shown in FIG. 2, the second coil portion 20 includes a coil component 25 in which two first coils 21 and second coils 22 are connected at a connecting portion 23, and an insulating thermoplastic resin (hereinafter referred to as “insulation”). It is a structure (resin mold structure) covered with 24).

  Each of the first coil 21 and the second coil 22 is an air-core coil formed by winding a conductor plate such as a flat copper wire once (edgewise winding). The first coil 21 and the second coil 22 are formed with the same coil inner diameter and coil outer shape. The first coil 21 and the second coil 22 are electrically connected to each other at a connecting portion 23 with their winding cores coincided with each other and at a predetermined interval and substantially in parallel. The predetermined interval is designed to have an arbitrary dimension capable of providing a predetermined space 24g between an upper ring 24u and a lower ring 24d covered with an insulating resin 24 described later.

  A first connection terminal 21 t extending to the outside of the insulating resin 24 is connected to the first coil 21. The second coil 22 is connected to a second connection terminal 22t that extends outside the insulating resin 24.

  The periphery of the first coil 21 is covered with an insulating resin 24 with a predetermined thickness, thereby forming an annular upper ring 24u having a through hole on the inner diameter side of the coil. The periphery of the second coil 22 is covered with an insulating resin 24 with a predetermined thickness, thereby forming an annular lower ring 24d having a through hole on the inner diameter side of the coil. Moreover, the connection part 23 which connects the 1st coil 21 and the 2nd coil 22 also forms the connection part 24c by covering the circumference | surroundings with the insulating resin 24 by giving predetermined | prescribed thickness.

  The first coil 21 and the second coil 22 are resin-molded so that a predetermined space 24g is formed between the upper ring 24u and the lower ring 24d. For example, the predetermined space 24g can be designed to have a dimension (more than the thickness of the substrate 10) in which the substrate 10 can be inserted and sandwiched. Further, the connecting portion 23 is resin-molded so that the connecting portion 24 c has a thickness equal to or less than the width of the slit 13 provided in the substrate 10.

  On the surface of the upper ring 24u opposite to the space 24g, a pair of V-shaped upper guide portions 24ur that are positioned by fitting the upper core portion 30 are provided upright. The upper guide portion 24ur is shaped like the outer shape of the upper core portion 30, and is formed in a shape in which the opposite inner side surfaces abut on the side surfaces of the upper core portion 30.

  In addition, a pair of V-shaped lower guide portions 24dr are provided upright on the surface of the lower ring 24d opposite to the space 24g so that the lower core portion 40 is fitted and positioned. The lower guide portion 24dr is shaped like the outer shape of the lower core portion 40, and is formed in a shape in which the opposite inner side surfaces are in contact with the side surfaces of the lower core portion 40. More specifically, the lower guide portion 24dr includes an insertion hole provided in the substrate 10 with the middle leg portion 40a, the outer leg portion 40b, and the outer leg portion 40c of the lower core portion 40 fitted along the side surface. 12a, the insertion hole 12b, and the insertion hole 12c are erected at positions where they can be guided.

  The upper guide portion 24ur described above is erected at a location where the horizontal positions of the upper core portion 30 and the lower core portion 40 fitted into the second coil portion 20 can be aligned. More specifically, the upper guide portion 24ur is erected at a position that coincides with the lower guide portion 24dr in the axial direction of the second coil portion 20.

  In the example of FIG. 2, the example in which the first coil 21 and the second coil 22 of the coil component 25 are formed by winding the conductor plate once has been described. However, the first coil 21 and the second coil 22 may be formed by winding the conductor plate twice or more, or the first coil 21 and the second coil 22 may have different numbers of windings.

-Upper core part 30 and lower core part 40
The upper core portion 30 is a so-called I-shaped plate having a butterfly shape in plan view, which is formed of a magnetic material such as a ferrite material. The upper core portion 30 is formed such that the center portion of one side pair is recessed so as to be fitted into a pair of upper guide portions 24ur provided upright on the surface of the upper ring 24u of the second coil portion 20.

  The lower core portion 40 is formed of a magnetic material such as a ferrite material, for example, and has a flat plate-like main body portion 40p having a butterfly shape in plan view, a middle leg portion 40a, an outer leg portion 40b, and an outer leg portion 40c. A so-called E-type core. The main body portion 40p is formed such that the center portion of one side pair is recessed so as to be fitted into a pair of lower guide portions 24dr provided upright on the surface of the lower ring 24d of the second coil portion 20. The outer leg portion 40b is erected so that it can be inserted into the insertion hole 12b of the substrate 10 at one end portion in the longitudinal direction of the main body portion 40p. The outer leg portion 40c is erected on the other end portion in the longitudinal direction of the main body portion 40p so as to be inserted into the insertion hole 12c of the substrate 10. The middle leg portion 40a is erected between the outer leg portion 40b and the outer leg portion 40c so as to be inserted into the insertion hole 12a of the substrate 10. The middle leg portion 40a, the outer leg portion 40b, and the outer leg portion 40c have the same height from the main body portion 40p and have end faces formed in parallel with the main body portion 40p.

  The pair of the upper core portion 30 and the lower core portion 40 are formed by joining the end surfaces of the respective leg portions of the lower core portion 40 to one plane of the upper core portion 30 so that the middle leg portion 40a and the outer leg portion 40b are joined. The middle leg portion 40a and the outer leg portion 40c form a closed magnetic circuit (closed magnetic path) through which the magnetic flux penetrating the winding of the second coil portion 20 and the winding of the first coil portion 11 passes.

[Resin molding method]
Next, with reference to FIG. 3, FIG. 4A, and FIG. 4B, the method to resin mold the coil component which concerns on this embodiment is demonstrated. In the method of the present invention, the coil component 25 is divided into a primary molding step and a secondary molding step, and the substrate 10 is sandwiched between the first coil 21 and the second coil 22 so as to be mounted on the substrate 10. Resin mold forming.

  FIG. 3 is a view for explaining a method of resin-molding the coil component 25 according to one embodiment of the present invention. FIG. 4A is an arrow view seen from the A direction of the coil component 25 after the completion of the primary forming step shown in FIG. 4B is a cross-sectional view taken along line BB of the coil component 25 (that is, the second coil portion 20) after the secondary forming step shown in FIG.

(Primary molding process)
In the primary molding step, first, the coil component 25 is deformed by the molding pressure generated during the molding using the insulating resin 24 and the positional accuracy between the first coil 21 and the second coil 22 is deteriorated. In order to prevent this, one of the first coil 21 and the second coil 22 can be formed so that resin molding can be performed with the first coil 21 held from both sides and the second coil 22 held from both sides. A resin part having a shape in which the part is covered with the insulating resin 24 is molded.

  In the present embodiment, for example, the outer edge portion 21e of the first coil 21 is held on both sides, and the outer edge portion 22e of the second coil 22 is held on both sides (see arrows in FIG. 4A). In order to achieve this, in the primary molding step, the first coil 21 is covered with an insulating resin 24 in a state where at least a part of the outer edge portion 21e holding the first coil 21 is exposed. While the resin portion 24u1 is molded and at least a part of the outer edge portion 22e holding the second coil 22 is exposed, the substantially annular second resin portion 24d1 in which the second coil 22 is covered with the insulating resin 24 is formed. Molding is performed (see FIG. 3B and FIG. 4A).

  Accordingly, since the resin molding can be performed in a state where both surfaces of the first coil 21 and both surfaces of the second coil 22 are held, the primary molding process is completed and the first resin portion 24u1 and the second resin portion 24d1 are In the molded coil component 25, the positional accuracy between the first coil 21 and the second coil 22 does not deteriorate.

  In this primary molding step, the resin portion (first resin portion 24u1 and second resin portion 24d1) molded in the primary molding step and the resin portion (third to be described later) molded in the subsequent secondary molding step are then used. In order to closely adhere the interface between the resin portion 24u2 and the fourth resin portion 24d2) without gap, a means capable of welding the resin portions at the interface is formed.

  In the present embodiment, for example, in order to realize the welding of the resin portions at the interface, in the primary molding step, the portion of the first resin portion 24u1 that is the side sandwiching the substrate 10 (that is, the second coil 22 side). A first convex welding rib 24 urib having a convex shape is formed on the outer periphery, and a second convex second is formed on the outer periphery of a portion of the second resin portion 24 d 1 that sandwiches the substrate 10 (that is, the first coil 21 side). The welding rib 24drib is formed (see FIG. 4A). The first welding rib 24 urib and the second welding rib 24 drib are the interface between the resin part (first resin part 24 u 1 and second resin part 24 d 1) molded in the primary molding process and the resin part molded in the subsequent secondary molding process. In any of the above, the first coil 21 and the second coil 22 molded by resin molding are provided to be shielded from the outside (such as the atmosphere).

  More specifically, the first welding rib 24 urib and the second welding rib 24 drib may be provided in a direction that requires at least insulation. Therefore, when the board | substrate 10 is pinched | interposed (inserted) between the 1st coil 21 (upper ring 24u) and the 2nd coil 22 (lower ring 24d) like the 2nd coil part 20 illustrated in this embodiment. The first welding rib 24 urib and the second welding rib 24 drib are provided between the first coil 21 (upper ring 24 u) and the substrate 10 and between the second coil 22 (lower ring 24 d) and the substrate 10, respectively. It is done. In FIG. 4A, the first welding rib 24urib extends vertically toward the first coil 21 of the second resin portion 24d1 on the wall portion extending vertically toward the second coil 22 of the first resin portion 24u1. The second welding rib 24drib is provided in each part.

(Secondary molding process)
In the secondary molding step, a resin portion having a shape in which the exposed portions of the first coil 21 and the second coil 22 are completely resin-molded in the coil component 25 after the primary molding step is formed.

  In the present embodiment, in the secondary molding step, the substantially annular third resin portion 24u2 joined to the first resin portion 24u1 is formed while covering the exposed outer edge portion 21e of the first coil 21 with the insulating resin 24. While molding, covering the outer edge portion 22e of the second coil 22 with the insulating resin 24, the substantially annular fourth resin portion 24d2 joined to the second resin portion 24d1 is molded (FIG. 3C). ) And FIG. 4B).

  In the secondary molding step, the first welding rib 24 urib provided in the first resin portion 24 u 1 is melted during molding using the insulating resin 24, and the first resin portion 24 u 1 and the third resin portion 24 u 2 are melted. While welding the interface, the second welding rib 24drib provided in the second resin portion 24d1 is melted to weld the interface between the second resin portion 24d1 and the fourth resin portion 24d2. As a result, the first resin portion 24u1 and the third resin portion 24u2 of the first coil 21 can be brought into close contact with each other without any gap, and the second resin portion 24d1 and the fourth resin portion 24d2 of the second coil 22 are spaced from each other. It can be closely attached.

  The first coil 21 resin-molded in a state where the first resin portion 24u1 and the third resin portion 24u2 are in close contact with each other without a gap constitutes the upper ring 24u. Further, the second coil 22 resin-molded in a state where the second resin portion 24d1 and the fourth resin portion 24d2 are in close contact with each other without a gap constitutes the lower ring 24d.

[Operations and effects of the embodiment]
As described above, according to the method of resin molding the coil component 25 according to the embodiment of the present invention, in the primary molding process, the first coil 21 is insulated with at least a part of the outer edge portion 21e exposed. The substantially annular first resin portion 24u1 covered with the conductive resin 24 is molded, and the second coil 22 is covered with the insulating resin 24 in a state where at least a part of the outer edge portion 22e is exposed. The part 24d1 is formed.

  Therefore, in the primary molding step, the resin component molding of the coil component 25 can be performed while holding both surfaces of the first coil 21 and both surfaces of the second coil 22 at the exposed outer edge portion 21e and outer edge portion 22e. it can. Thereby, it can prevent that the coil components 25 deform | transform with a molding pressure, and the positional accuracy of a 1st coil and a 2nd coil will deteriorate.

  Further, in one aspect of the present invention, in the primary molding step, the convex first minute welding rib 24 urib is molded on the outer periphery of the portion of the first resin portion 24 u 1 on the side sandwiching the substrate 10, and the second resin A small convex second welding rib 24drib is formed on the outer periphery of a portion of the portion 24d1 on the side sandwiching the substrate 10. In the secondary molding step, the first welding rib 24 urib molded in the primary molding step is melted to weld the resin portions at the interface between the first resin portion 24 u 1 and the third resin portion 24 u 2, and in the primary molding step. The molded second welding rib 24drib is melted to weld the resin parts at the interface between the second resin part 24d1 and the fourth resin part 24d2.

  Thereby, in the coil component 25 after resin molding (that is, the second coil portion 20), the first resin portion 24u1 and the third resin portion 24u2 of the first coil 21 can be closely adhered without any gaps, and The second resin portion 24d1 and the fourth resin portion 24d2 of the second coil 22 can be brought into close contact with each other without a gap.

  Therefore, it is possible to ensure insulation between the coil component 25 and other components. More specifically, it is possible to ensure insulation between the first coil 21 and the second coil 22 and the wiring of the substrate 10 sandwiched between the spaces 24 g between the first coil 21 and the second coil 22. Further, even if water droplets or the like adhere to the interface between the first resin part 24u1 and the third resin part 24u2 or the vicinity of the interface between the second resin part 24d1 and the fourth resin part 24d2 due to condensation or moisture (water spillage). In addition, since it is possible to prevent water from entering the interface between the resin parts due to the capillary phenomenon, there is no possibility that the creepage distance becomes short and insulation cannot be secured. Therefore, it is possible to stably ensure insulation.

  Further, in one aspect of the present invention, the first welding rib 24 urib and the second welding rib 24 drib molded in the primary molding process are melted in the secondary molding process, and the resin parts are welded at the interface between the resin parts. Therefore, there is no need for a separate part for filling the pinhole as in the prior art. Therefore, an increase in manufacturing cost for forming the coil component 25 by resin molding can be suppressed.

  Furthermore, in one aspect of the present invention, the secondary molding step is a step of molding the coil component 25 by inserting the same insulating resin 24 as that in the primary molding step, so that a new step different from the primary molding step ( Additional steps such as adhesive bonding, vibration welding, ultrasonic welding, and laser welding are not required. Therefore, an increase in manufacturing cost for forming the coil component 25 by resin molding can be suppressed.

  The resin molding method of the present invention can be used for coil parts used in transformer devices and the like, and in particular, it is desirable to ensure insulation between the coil parts and other parts while suppressing an increase in manufacturing cost. This is useful in some cases.

DESCRIPTION OF SYMBOLS 1 Transformer apparatus 10 Board | substrate 11 1st coil part 20 2nd coil part 21, 121 1st coil 22, 122 2nd coil 21e, 22e Outer edge part 24 Insulating resin 24u Upper ring 24d Lower ring 24u1 1st resin part 24d1 1st resin part 24d1 2 resin part 24u2 3rd resin part 24d2 4th resin part 24urib 1st welding rib 24drib 2nd welding rib 25 Coil component 30 Upper core part 40 Lower core part

Claims (1)

A coil component in which a first coil formed by winding a conductor plate at least once and a second coil formed by winding the conductor plate at least once is connected to the first coil and the second coil. Is a method of resin molding into a shape to be mounted on a substrate with a substrate sandwiched between,
A substantially annular first resin portion in which the first coil is covered with an insulating resin is formed with at least a portion of the outer edge portion exposed, and at least a portion of the outer edge portion is exposed. Forming a substantially annular second resin portion in which the coil is covered with an insulating resin;
While forming the substantially annular third resin portion to be joined to the first resin portion while covering the exposed outer edge portion of the first coil with an insulating resin, the exposed outer edge portion of the second coil Forming a substantially annular fourth resin portion joined to the second resin portion while covering the substrate with an insulating resin, and a secondary molding step,
In the primary molding step, a convex first welding rib is formed on an outer periphery of a portion of the first resin portion which is a side sandwiching the substrate, and at the side of the second resin portion sandwiching the substrate. A convex second weld rib is formed on the outer periphery of the part,
In the secondary molding step, the first welding rib is melted to weld an interface between the first resin portion and the third resin portion, and the second welding rib is melted to form the second resin portion. Welding the interface with the fourth resin portion;
A method of resin-molding a coil component, characterized in that

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