JP5874134B2 - Inductance element - Google Patents

Description

  The present invention relates to an inductance element in which a coil is embedded in a magnetic core, and more particularly to a withstand voltage between a terminal portion and a magnetic core.

  Patent Document 1 discloses an invention related to an inductor in which a low dielectric constant resin film is disposed between an external electrode and a coil conductor to suppress stray capacitance generated between the external electrode and the coil conductor. Yes.

  In Patent Document 2, a composite member made of ferromagnetic metal powder and resin is formed in a rectangular parallelepiped, the surface of the composite member is impregnated with resin, a through hole is formed inside the composite member, and a signal line is formed in the through hole. A conductor is formed. A terminal conductor is formed from the surface of the composite member impregnated with resin to the surface of the signal conductor exposed.

  Patent Document 3 discloses an invention relating to a coil component in which a terminal from a coil is drawn to the back surface of a core and an insulating sheet is interposed between the core and the terminal.

  Patent Document 4 discloses an invention relating to an inductor in which a terminal from a coil is drawn out to the back surface of a core and an insulating layer of the terminal is removed.

Japanese Patent Laid-Open No. 9-246046 JP-A-9-82528 JP-A-10-223450 JP 2006-13066 A

  By the way, the tip of the terminal portion extending from the coil to the back surface of the magnetic core is a cut surface, and the conductor is exposed without an insulating coating. Therefore, there has been a problem that the withstand voltage between the tip of the terminal portion and the magnetic core facing the tip is lowered.

  In each of the above patent documents, nothing is described about the withstand voltage between the tip of the terminal portion and the magnetic core.

  Therefore, the present invention solves the above-described conventional problems, and in particular, an object of the present invention is to provide an inductance element capable of improving the withstand voltage between the tip of the terminal portion and the magnetic core as compared with the conventional technique. .

The present invention relates to an inductance element in which a coil wound with a conductive band covered with a first insulating layer is embedded inside a magnetic core that is a powder compact.
End portions of the pair of conductive strips extending from the coil are bent, and terminal portions of the tip portions of the end portions are opposed in parallel to the plate surfaces of the conductive strip members constituting the coil. The terminal portion is embedded in a recess formed on the surface of the magnetic core, and the surface of the terminal portion and the surface of the magnetic core are substantially flush with each other ,
The magnetic core of the surface and the surface of the terminal portion is covered with the second insulating layer, the terminal conductive portion is formed on the second insulating layer, said first insulating layer and the second The terminal portion and the terminal conducting portion are in contact with each other through a through hole penetrating the insulating layer in the thickness direction ,
The first insulating layer is not formed at the tip of the terminal portion, and a gap is provided between the tip and the magnetic core facing the tip, and the second insulating layer is formed in the gap. It is characterized by being filled.
Thereby, the withstand voltage between the front-end | tip of a terminal part and a magnetic core can be improved effectively compared with the past.

  In the present invention, the first insulating layer is an electrically insulating coating resin layer that covers the surface of the conductive band, and the second insulating layer is an insulating coating material for the outer surface of the magnetic core. An electrically insulating protective resin layer is preferable. As a result, manufacturing is not complicated, and a high withstand voltage can be stably obtained at a low cost.

  In the present invention, the first insulating layer is not provided at least on the tip surface of the terminal portion, and the gap is provided between at least the tip surface and the side wall of the magnetic core facing the tip surface. Preferably it is formed. Since the tip surface of the terminal portion is a cut surface of the coated conductor, the conductive band is exposed at the tip surface. Therefore, by providing a gap between the end surface of the terminal portion and the side wall of the magnetic core and burying the second insulating layer in the gap, it is possible to appropriately improve the withstand voltage.

  According to the inductance element of the present invention, the withstand voltage between the tip of the terminal portion and the magnetic core can be effectively improved as compared with the conventional case.

The perspective view which shows the state immediately after the coil used for the inductance element of embodiment of this invention was wound-molded, The perspective view which shows the state by which the terminal part was bending-formed by the coil, Back view of the inductance element, 4 is a cross-sectional view of the inductance element, and is a cross-sectional view taken along line IV-IV in FIG. The partial expanded sectional view which expanded a part of FIG. FIG. 5 is a partially enlarged longitudinal sectional view partially different from FIG. FIG. 5 is a partially enlarged longitudinal sectional view partially different from FIG. Partially enlarged longitudinal sectional view showing a comparative example, A back view of the inductance element showing a state in which the terminal conductive portion is not formed, FIG. 9 is a rear view of an inductance element partially different from FIG. Side view showing the process of compacting the magnetic core, FIG. 11 is a partially enlarged longitudinal sectional view showing the vicinity of the terminal portion when the magnetic core shown in FIG. 11 is compacted;

  In the inductance element 1 according to the embodiment of the present invention, a coil 10 is embedded in a magnetic core 20 that is a powder compact. In FIG. 2, the coil 10 embedded in the magnetic core 20 is indicated by a solid line, and the outer surface of the magnetic core 20 is indicated by a dotted line.

  As shown in FIGS. 1 and 2, the coil 10 is formed by winding a conductive band 11. As shown in FIGS. 1 and 2, etc., the conductive band 11 is a band-shaped body having plate surfaces 11a and 11a facing each other and side end surfaces 11b and 11b facing each other and having a rectangular cross section. As shown in FIG. 2, the dimension A in the width direction is sufficiently larger than the dimension B in the thickness direction, and the dimension A is twice or more than the dimension B, and preferably six times or more.

  The conductive band 11 is made of copper, and a coating resin layer 12 is formed on the surface of the conductive band 11 as shown in FIG.

  The winding centerline O of the coil 10 is shown in FIGS. In the coil 10, the plate surface 11a of the conductive band 11 is substantially perpendicular to the winding center line O, the side end surface 11b that determines the thickness direction is parallel to the winding center line O, and the plate surfaces 11a are in contact with each other. It is wound so as to overlap along the winding center line O. As shown in FIGS. 1, 2, and 3, the coil 10 is wound such that the conductive band 11 is elliptical. In FIG. 1 to FIG. 3, the coil 10 has an oval shape, but may be a perfect circle and can be appropriately selected by those skilled in the art.

  As shown in FIG. 1, the first end 13 and the second end 16 of the conductive band 11 protrude from the coil 10 in a state where the coil 10 is wound in an elliptical shape. Here, the end portions 13 and 16 mean both end portions of the conductive band 11 that are not wound as the coil 10.

  As shown in FIG. 2, the first end portion 13 is bent at a substantially right angle in the valley fold direction by the first fold line 14 a, bent at a substantially right angle in the mountain fold direction by the second fold line 14 b, Each of the bent line 14c and the fourth bent line 14d is bent at a substantially right angle in the valley folding direction. The second end portion 16 is bent substantially perpendicularly to the mountain fold direction at the first fold line 17a, and substantially perpendicular to the valley fold direction at the second fold line 17b, the third fold line 17c, and the fourth fold line 17d. It is bent.

  The first end portion 13 has a first terminal portion 15 ahead of the fourth broken line 14d, and the second end portion 16 has a second portion ahead of the fourth bent line 17d. This is a terminal portion 18.

  As shown in FIGS. 2 and 4, the first terminal portion 15 is located slightly away from the plate surface 11 a of the conductive strip 11 wound as the coil 10, and forms the first terminal portion 15. The plate surface 11a of the conductive band 11 and the plate surface 11a of the conductive band 11 constituting the coil 10 face each other substantially in parallel.

  As shown in FIG. 2, the second terminal portion 18 is also located slightly away from the plate surface 11 a of the conductive band 11 wound as the coil 10, and forms the second terminal portion 18. The plate surface 11a of the conductive band 11 and the plate surface 11a of the conductive band 11 constituting the coil 10 are opposed substantially in parallel.

  The plate surface 11a of the first terminal portion 15 facing upward in FIG. 2 and the plate surface 11a of the second terminal portion 18 facing upward in FIG. 2 are located on substantially the same plane. The surface is a surface perpendicular to the winding center line O.

  When the inductance element 1 is installed on a printed circuit board (not shown), the terminals 15 and 18 are directed downward, so the surface facing the upper side of each of FIGS. 2, 4, and 5 to 8 is the printed circuit board. In the installation state above, the surface corresponds to the lower surface (back surface).

  As shown in FIGS. 2 and 3, the magnetic core 20, which is a compacted body, has a cubic shape having an upper surface 21 and a lower surface (back surface) 22 and four side surfaces. As shown in FIGS. 2, 3, and 4, the first terminal portion 15 and the second terminal portion 18 formed by the end portions 13 and 16 of the conductive band 11 extending from the coil 10 are The plate surface 11 a (the plate surface 11 a facing upward in FIGS. 2 and 4) is exposed on the lower surface 22 of the magnetic core 20, and the plate surface 11 a on the surface side of each terminal portion 15, 18 is the lower surface 22 of the magnetic core 20. And almost the same surface.

  In addition, as shown in FIG. 2, the plate surface 11 a of the portion between the fold line 14 c and the fold line 14 d of the first end 13 of the conductive band 11 appears on one side surface 23 of the magnetic core 20. Further, the plate surface 11 a of the portion between the fold line 17 c and the fold line 17 d of the second end portion 16 also appears on the side surface 23 of the magnetic core 20. Each plate surface 11a and the side surface 23 are substantially the same surface.

  As shown in FIGS. 4 and 9 (FIG. 9 is a rear view in which the terminal conducting portion 42 is removed from FIG. 3), each terminal portion 15, 18 has a terminal portion shape formed on the lower surface 22 of the magnetic core 20. It arrange | positions in the recessed part 20a which consists of a substantially identical shape. As shown in FIG. 11, which will be described later, the concave portion 20a applies a pressure F to the magnetic core material supplied into the cavity 34 in a state where the coil 10 and the terminal portions 15 and 18 are disposed inside the cavity 34. It is formed when the pressure is applied. That is, the concave portion 20a is formed by surrounding the terminal portions 15 and 18 with the magnetic core material except for the plate surface 11a located on the surface side of the terminal portions 15 and 18 when the molded body is formed. Is. Alternatively, before forming the terminal portions 15 and 18, the recess 20 a is formed in advance on the lower surface 22 of the magnetic core 20, and the end portions 13 and 16 extending from the coil 10 are bent to arrange the terminal portions 15 and 18 in the recess 20 a. You can also

  As shown in FIG. 5, a pair of terminal portions 15 and 18 (the second terminal portion 18 is not shown in FIG. 5 but has the same cross-sectional structure as the first terminal portion 15; 15 and 18) includes a conductive band 11 and a coating resin layer (first insulating layer) 12 formed on the surface of the conductive band 11. The covering resin layer 12 has a two-layer structure in which, for example, a fusion layer such as nylon is overlaid on the surface of the insulating resin layer.

  The covering resin layer 12 is formed on the plate surface 11a and the side end surface 11b (see FIG. 9 and the like) which are the upper surface and the lower surface of the conductive band 11 shown in FIG. Although not shown in the drawing, the coating resin layer 12 is also formed on the surface of each conductive band 11 of the coil 10 shown in FIGS. 1, 2, and 4. A covering resin layer 12 is interposed between the sex belts 11.

  As shown in FIG. 5, the coating resin layer 12 is not formed on the tip surfaces 24 of the terminal portions 15 and 18. This is because the tip surface 24 corresponds to a cut surface when the coated conductor is cut. Further, a region slightly retracted from the tip surface 24 is defined as a tip 26 of each terminal portion 15, 18, and the coating resin layer 12 is formed on the plate surface 11 a and the side end surface 11 b constituting the tip 26 of each terminal portion 15, 18. It can also be set as the structure which is not formed. In the present specification, the distal end 26 of the terminal portions 15 and 18 may refer only to the distal end surface 24 or may be a region including a position slightly retracted from the distal end surface 24. The tips 26 of the terminal portions 15 and 18 have, for example, a region of 1/4 or less, preferably 1/10 of the extension length of the terminal portions 15 and 18 extending on the back surface 22 of the magnetic core 20 shown in FIG. The following areas are set.

  As shown in FIGS. 5 and 9, the tip surface 24 of each terminal portion 15, 18, and the side wall of the magnetic core 20 facing the tip surface 24 in the plane direction (plane direction orthogonal to the tip surface 24). A gap 25 is formed between 20b. The gap 25 is a space area continuous with the recess 20a. Alternatively, as illustrated in FIG. 10, the gap 25 is formed between the side wall surface 11 b of each terminal portion 15, 18 and the side wall surface 11 b from between the front end surface 24 of each terminal portion 15, 18 and the side wall 20 b of the magnetic core 20. And the side wall 20c of the magnetic core 20 facing each other. The structure in FIG. 10 is suitable for a configuration in which the coating resin layer 12 is not formed at the tip 26 from the tip surface 24 of each terminal portion 15, 18 to a slightly retracted region. The gap 25 may be formed continuously from the tip 26 to the rear end as well as the position of the tip 26 of each terminal portion 15, 18.

  As shown in FIGS. 4 and 5, the gap 25 is filled with a protective resin layer 41 (second insulating layer). The protective resin layer 41 is coated on the entire outer surface of the magnetic core 20. The protective resin layer 41 is an electrically insulating resin layer like the covering resin layer 12. The material of the protective resin layer 41 is not particularly limited, and examples thereof include polyimide and epoxy resin. The protective resin layer 41 is preferably a resin that can be impregnated into the outer surface of the magnetic core 20.

  As shown in FIGS. 3, 4, and 5, a pair of terminal conducting portions 42 are formed on the lower surface 22 (the lower surface) of the magnetic core 20. As shown in FIG. 5, the terminal conducting portion 42 faces the magnetic core 20 with the protective resin layer 41 interposed therebetween. Further, as shown in FIG. 5, the terminal conductive portion 42 and the conductive band 11 constituting the terminal portions 15 and 18 are opposed to each other through a laminated structure of the covering resin layer 12 and the protective resin layer 41 except for a part. doing.

  As shown in FIGS. 3 and 5, the coating resin layer 12 and the protective resin layer 41 are disposed in the thickness direction (height) between the terminal conducting portion 42 and the conductive strip 11 constituting the terminal portions 15 and 18. A through-hole 43 penetrating in the direction) is formed. As described above, in FIG. 5, the protective resin layer 41 is formed on the surface of the magnetic core 20 and the surface of the coating resin layer 12 together with the gap 25, and a part of the coating resin layer 12 and the protective resin layer 41 is laminated. A through hole 43 penetrating the portion is formed, and the surface (plate surface 11 a) of the conductive band 11 is exposed from the through hole 43. The terminal conducting portion 42 enters the through hole 43, and the terminal conducting portion 42 is in contact with the conductive band 11. As a result, the terminal conductive portion 42 and the conductive band 11 constituting the terminal portions 15 and 18 are electrically connected.

  FIG. 8 is a comparative example. In FIG. 8, no gap is formed between the tip surface 24 of each terminal portion 15, 18 and the side wall 20 b of the magnetic core 20 facing the tip surface 24. The conductive band 11 and the magnetic core 20 are in contact with each other at the position 24.

  The magnetic core 20 is, for example, a compacted body made of magnetic powder and a binder resin. In the comparative example of FIG. 8, high insulation is maintained between the tip surfaces 24 of the terminal portions 15 and 18 and the magnetic core 20. It is in a state that does not strike. That is, the withstand voltage is lowered. On the other hand, in the embodiment shown in FIG. 5, a gap 25 is formed between the front end surface 24 of the terminal portions 15 and 18 and the side wall 20 b of the magnetic core 20, and an electrically insulating protective resin layer 41 is formed in the gap 25. Therefore, the withstand voltage between the tip surface 24 where the conductive band 11 is exposed and the side wall 20b of the magnetic core 20 can be effectively improved as compared with the comparative example shown in FIG. 10, the gap 25 is also formed between the side wall surface 11b located at the tip 26 of the terminal portions 15 and 18 and the side wall 20c of the magnetic core 20, and a protective resin layer is formed in the gap 25. Since 41 is filled, the withstand voltage can be effectively improved even when the coating resin layer 12 is not formed at the tip 26 from the tip surface 24 to a region slightly retracted.

  Further, by impregnating the protective resin layer 41 into the outer surface of the magnetic core 20 and the gap 25, the resin penetrates into the gap 25 by capillary action, and the gap 25 can be appropriately filled with the protective resin layer 41. Further, by filling the gap 25 with the same resin as the insulating coating material for the outer surface of the magnetic core 20, the gap 25 can be filled with the resin by a low-cost and simple manufacturing method.

  Further, as shown in FIG. 5, the withstand voltage between the magnetic core 20 and the terminal conducting portion 42 can be improved by interposing the protective resin layer 41 between the magnetic core 20 and the terminal conducting portion 42. . As shown in FIG. 5, the protective resin layer 41 is also formed on the surface of each of the terminal portions 15 and 18, but the conductive portion between the terminal portions 15 and 18 and the terminal conductive portion 42 is covered. A through-hole 43 that penetrates the laminated structure of the resin layer 12 and the protective resin layer 41 is formed, and the conductive band 11 and the terminal conductive portion 42 that constitute the terminal portions 15 and 18 are appropriately connected via the through-hole 43. Can be electrically connected. The through hole 43 is formed in a predetermined size at a position retracted rearward from the distal end surface 24 of each terminal portion 15, 18. Therefore, the laminated structure of the coating resin layer 12 and the protective resin layer 41 remains between the through hole 43 and the front end surface 24 of each terminal portion 15 and 18 and at a position behind the through hole 43. As shown in FIG. 3, the through-hole 43 is smaller than the width dimension of the terminal portions 15 and 18, and the through-hole 43 is formed in a size that fits within the region of the terminal portions 15 and 18 as viewed in the direction of the arrow in FIG. ing. Accordingly, the terminal portions 15 and 18 and the terminal conducting portion 42 can be appropriately connected to each other through the through hole 43, and the insulation between the terminal conducting portion 42 and the magnetic core 20 can be achieved by the insulating resin layer spreading around the through hole 43. Sex can be secured appropriately.

  Although this embodiment does not limit the formation method of the clearance gap 25, the clearance gap 25 can be formed using a springback, for example. The spring back will be described below with reference to FIG.

FIG. 11 shows a process of forming the magnetic core 20 as a green compact.
A press machine 30 shown in FIG. 11 has a lower mold 32 provided inside a mold body 31 and a cavity 34 formed above the lower mold 32. The coil 10 shown in FIG. 2 is inserted into the cavity 34, and the plate surface 11 a on the surface of the first terminal portion 15 and the plate surface 11 a on the surface of the second terminal portion 18 are in contact with the upper surface of the lower mold 32. Are positioned as follows.

  Thereafter, a core material made of magnetic powder and binder resin is supplied into the cavity 34. The magnetic powder is a magnetic alloy powder, for example, an Fe-based amorphous alloy powder mainly composed of Fe and containing various metals such as Ni, Sn, Cr, P, C, B, Si, and water atomization. Powdered by the method. The binder resin is a silicone resin or an epoxy resin.

  The core material is a mixed powder in which the magnetic powder is coated with the binder resin. Alternatively, the magnetic powder and powdered binder resin may be simply mixed. Further, the core material can be preliminarily formed and combined with the coil 10 and then inserted into the cavity.

  When the core material is filled in the cavity 34, the upper mold 33 is inserted from above the cavity 34, the cavity 34 is heated, and the core material is pressurized with the applied pressure F by the lower mold 32 and the upper mold 33. The magnetic core 20 which is a compacting body is formed. In this compacting, the binder resin functions as a binder for binding the magnetic powders. In this pressurization, heating is not necessarily required, and pressurization may be performed at room temperature.

  As shown in FIG. 11, in the cavity 34, the core material composed of the magnetic powder and the binder resin is pressurized between the lower mold 32 and the upper mold 33 with the applied pressure F, and at the same time, the coil 10 and the first mold The first terminal portion 15 and the second terminal portion 18 are also pressurized by receiving the applied pressure F.

  As shown in FIGS. 3 and 4, the first terminal portion 15 and the second terminal portion 18 face each other in a facing region D where a part thereof faces the plate surface 11 a of the conductive band 11 forming the coil 10. have. As shown in FIG. 4, in the facing region D, the gap δ between the terminal portions 15 and 18 and the coil 10 is narrowed, and the springback force that the terminal portions 15 and 18 are about to leave the coil 10 after pressure molding, Internal stress is likely to occur in the magnetic core 20 located in a narrow region of the gap δ. Accordingly, as shown in FIG. 9, the tip 26 of each terminal portion 15 and 18 and the side wall 20b of the magnetic core 20 or the tip 26 of each terminal portion 15 and 18 and the magnetic side as shown in FIG. A gap 25 based on the springback is easily formed between the core 20 and the side wall 20c.

  By appropriately generating the springback force by adjusting the pressure F or adjusting the heating temperature (annealing temperature), the gap 25 having an appropriate size can be formed. Here, the size of the gap 25 is not particularly limited as long as the insulation between the tips 26 of the terminal portions 15 and 18 and the side walls of the magnetic core 20 is ensured by the interposition of the protective resin layer 41, but too much. If the gap 25 is formed large, the strength of the magnetic core 20 is reduced. Therefore, the width of the gap 25 is preferably about 100 μm or less (the vertical and horizontal width dimensions of the inductance element 1 are several tens of mm). For example, a mixed material of Fe-based amorphous alloy powder and binder resin is used as the core material, the applied pressure F is set to about 780 to 1180 MPa, and the heating temperature is set to about 350 ° C. to 450 ° C.

  Also, as shown in FIG. 12, for example, a lower mold 32 having a protrusion 40 on the surface may be used. As shown in FIG. 12, the protrusion 40 is located just in front of the tip surface 24 of the terminal portions 15 and 18, so that the position of the protrusion 40 is not filled with the core material, A gap 25 can be formed between the tip surface 24 and the magnetic core 20. Further, as shown in FIG. 10, a gap 25 surrounding the periphery of the distal end 26 of the terminal portion 15, 18 may be formed as the shape of the protruding portion 40 surrounding the distal end 26 of the terminal portion 15, 18.

  Alternatively, after the magnetic core 20 is compacted, the gap 25 is formed by scraping the magnetic core 20 in front of the tip surfaces 24 of the terminal portions 15 and 18 or around the tips 26 of the terminal portions 15 and 18 with a laser or the like. May be.

  6 and 7 are partially enlarged sectional views different from FIG. 5 in part. In FIG. 6, the tips 26 of the terminal portions 15 and 81 are in a state of floating in a direction away from the concave portion 20 a of the magnetic core 20. Compared to FIG. 5, since the tip 26 of each terminal portion 15, 18 is separated from the magnetic core 20, the dielectric strength between the tip 26 of each terminal portion 15, 18 and the magnetic core 20 can be more effectively reduced. Can be improved.

  Also in the form of FIG. 6, the tip end face 24 of the terminal portions 15 and 18 and the side wall 20 b of the magnetic core 20 are in a positional relationship facing each other as viewed from the direction C perpendicular to the plane.

  Further, as shown in FIG. 6, in the case where the coating resin layer 12 is not formed on the tip 26 facing backward from the tip surface 24 of the terminal portions 15 and 18, the tip 26 is bent as shown in FIG. Thus, the coating resin layer 41 can be interposed between the opposing surfaces E in the height direction (thickness direction) between the tip 26 and the recess 20a. Therefore, the withstand voltage between the tip 26 and the magnetic core 20 can be improved more effectively.

  Further, as shown in FIG. 7, the side wall 20 b is formed so that the distance between the end face 24 of each terminal portion 15, 18 and the side wall 20 b of the magnetic core 20 gradually increases in the height direction approaching the terminal conducting portion 42. An inclined gap 45 may be formed. A gap 45 similar to that in FIG. 7 can also be formed between the side end face 11b located at the tip 26 of each terminal portion 15 and 18 and the side wall 20c of the magnetic core 20 (see FIG. 10). If the gap 45 shown in FIG. 7 is formed in the same volume as the gap 25 shown in FIG. 5, the gap 45 in FIG. The resin layer 41 can be embedded.

  In the inductance element 1 shown in FIGS. 2, 3, etc., the pair of terminal portions 15, 18 are provided on the lower surface (back surface) 22 of the magnetic core 20, but the terminal portions 15, 18 are arranged on the outer surface of the magnetic core 20. It does not specifically limit about whether to arrange | position to a surface.

  Further, as shown in FIGS. 3 and 4 and the like, a pair of terminal conducting portions 42 that are electrically connected to the pair of terminal portions 15 and 18 are provided, but the formation of the terminal conducting portions 42 is not essential. However, by providing the terminal conducting portion 42, the electrical connectivity between the inductance element 1 and the printed board can be made stable and satisfactory.

  In the above description, the first insulating layer formed on the surface of the conductive band 11 is the electrically insulating coating resin layer 12, and the second insulating layer filling the gap 25 is the electrically insulating protective resin. Although the layer 41 is used, the material of each insulating layer is not limited to resin. However, when the coated conductor is used, the first insulating layer is preferably the coated resin layer 12. As the second insulating layer, an insulating material other than resin can be embedded in the gap 25 by sputtering or vapor deposition. However, the protective resin layer 41 that is an insulating coating material on the outer surface of the magnetic core 20 is used for the second insulating layer, and the gap 25 is filled by impregnation, so that the gap 25 can be appropriately filled and the manufacturing process is complicated. The manufacturing cost can be suppressed without conversion.

DESCRIPTION OF SYMBOLS 1 Inductance element 10 Coil 11 Conductive strip 11a Plate surface 11b Side end surface 12 Covering resin layer (1st insulating layer)
13 First end portion 15 First terminal portion 16 Second end portion 18 Second terminal portion 20 Magnetic core 24 Tip surface 25, 45 Clearance 26 Tip 30 Press 32 Lower die 33 Upper die 34 Cavity 40 Projection 41 Protective resin layer (second insulating layer)
42 Terminal conduction part 43 Through-hole D Facing area F Pressurizing force O Winding center line

Claims (3)

In an inductance element in which a coil wound with a conductive band covered with a first insulating layer is embedded inside a magnetic core that is a green compact,
End portions of the pair of conductive strips extending from the coil are bent, and terminal portions of the tip portions of the end portions are opposed in parallel to the plate surfaces of the conductive strip members constituting the coil. The terminal portion is embedded in a recess formed on the surface of the magnetic core, and the surface of the terminal portion and the surface of the magnetic core are substantially flush with each other ,
The magnetic core of the surface and the surface of the terminal portion is covered with the second insulating layer, the terminal conductive portion is formed on the second insulating layer, said first insulating layer and the second The terminal portion and the terminal conducting portion are in contact with each other through a through hole penetrating the insulating layer in the thickness direction ,
The first insulating layer is not formed at the tip of the terminal portion, and a gap is provided between the tip and the magnetic core facing the tip, and the second insulating layer is formed in the gap. An inductance element that is filled.   The first insulating layer is an electrically insulating coating resin layer that covers the surface of the conductive band, and the second insulating layer is an electrical coating material for the outer surface of the magnetic core. The inductance element according to claim 1, wherein the inductance element is an insulating protective resin layer.   The inductance element according to claim 1, wherein the gap is formed between a distal end of the terminal portion and a side wall in the recess facing the distal end.

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