Coil parts

Abstract

To provide a coil component with improved insulation between external terminals provided on the same surface of a base body.SOLUTION: In a coil component 1, when a voltage is applied via external terminal electrodes 60A, 60B, 60C, and 60D, a potential difference may occur, for example, between outer ends 41a and 42a. In the coil component 1, the insulation between the outer ends 41a and 42a is enhanced by an upper insulator 50A exposed on an end face 10a of an element body 10, so that even when a potential difference occurs between the outer ends 41a and 42a, short-circuiting between the outer ends 41a and 42a on the end surface 10a is suppressed.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a coil component. [Background technology]

[0002] 2. Description of the Related Art Conventionally, coil components in which a plurality of coils are provided within an element body are known. Patent Document 1 listed below discloses a four-terminal coil component in which two coils are provided within an element body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-130472 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the coil components as described above, a plurality of external terminals may be provided on the same surface of the element body, and it is necessary to provide sufficient insulation between these external terminals.

[0005] The inventors have conducted extensive research into insulation between external terminals and have discovered a new technique that can further improve the insulation between external terminals.

[0006] An object of the present invention is to provide a coil component having improved insulation between external terminals provided on the same surface of an element body. [Means for solving the problem]

[0007] A coil component according to one aspect of the present invention comprises: a base body made of a resin containing metal magnetic powder and having a first end face and a second end face that are parallel to each other; an insulating substrate provided within the base body, perpendicular to the first end face and the second end face, and extending between the first end face and the second end face; a pair of coil sections provided on the insulating substrate, each having a first end exposed at the first end face; a pair of first external terminals provided on the first end face and respectively connected to the first ends of the pair of coil sections; and a first insulating section exposed at the first end face from inside the base body and located between the first ends of the pair of coil sections at the first end face.

[0008] In the coil component described above, the first insulating portion exposed on the first end surface of the element body prevents the first ends of the pair of coil portions from shorting each other on the first end surface.

[0009] In a coil component according to another aspect of the present invention, the first insulating portion is present over the entire area of ​​the first end face that is sandwiched between the first ends of the pair of coil portions.

[0010] In a coil component according to another aspect of the present invention, a first insulating portion and a resin containing metal magnetic powder are exposed in a region on a first end face sandwiched between first ends of a pair of coil portions, and the first insulating portion is sandwiched by the resin containing metal magnetic powder in the direction in which the first ends of the pair of coil portions are aligned.

[0011] In a coil component according to another aspect of the present invention, a first insulating portion extends across between first ends of a pair of coil portions.

[0012] A coil component according to another aspect of the present invention further includes an insulating layer that covers at least a part of a region of the first end face that is sandwiched between the first ends of the pair of coil portions.

[0013] In a coil component according to another aspect of the present invention, the first external terminal directly covers a portion of the first insulating portion on the first end face.

[0014] A coil component according to another aspect of the present invention includes a pair of coil portions each having a second end exposed at a second end face, and further includes a pair of second external terminals provided on the second end face and respectively connected to the second ends of the pair of coil portions, and a second insulating portion exposed at the second end face from inside the body and positioned between the second ends of the pair of coil portions at the second end face. Effect of the Invention

[0015] According to the present invention, there is provided a coil component in which the insulation between external terminals provided on the same surface of the element body is improved. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic perspective view of a coil component according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing the inside of the coil component of FIG. [Diagram 3] FIG. 3 is an exploded view of the coil shown in FIG. [Figure 4] FIG. 4 is a cross-sectional view of the coil device shown in FIG. 2 taken along line IV-IV. [Diagram 5] FIG. 5 is a cross-sectional view of the coil device shown in FIG. 2 taken along line VV. [Figure 6] FIG. 6 is a plan view of the coil shown in FIG. [Figure 7] FIG. 7 is a diagram showing one end surface of the element body of the coil device shown in FIG. [Figure 8] FIG. 8 is a view showing the other end face of the element body of the coil device shown in FIG. [Figure 9] FIG. 9 shows an embodiment different from that of FIG. [Figure 10] FIG. 10 shows an embodiment different from that of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same elements or elements having the same functions will be designated by the same reference numerals, and duplicated descriptions will be omitted.

[0018] The coil component 1 according to the embodiment is a balun coil. The balun coil is used, for example, when a near field communication circuit (NFC circuit) is installed in a cellular terminal. The balun coil converts between an unbalanced signal of an antenna and a balanced signal of the NFC circuit, thereby realizing a connection between an unbalanced circuit and a balanced circuit.

[0019] As shown in FIG. 1, the coil component 1 is composed of an element body 10, a coil structure 20 embedded in the element body 10, and two pairs of external terminal electrodes 60A, 60B, 60C, 60D provided on the surface of the element body 10.

[0020] The element body 10 has a rectangular parallelepiped outer shape and six faces 10a to 10f. As an example, the element body 10 is designed to have dimensions of a long side of 2.0 mm, a short side of 1.25 mm, and a height of 0.65 mm. Of the faces 10a to 10f of the element body 10, the end face 10a (first end face) and the end face 10b (second end face) are parallel to each other, the top face 10c and the bottom face 10d are parallel to each other, and the side face 10e and the side face 10f are parallel to each other. The top face 10c of the element body 10 is a face that faces and is parallel to the mounting surface of a mounting board on which the coil component 1 is mounted.

[0021] The element 10 is made of a resin 12 containing a magnetic metal powder, which is a type of magnetic material. The resin 12 containing a magnetic metal powder is a binder powder in which a magnetic metal powder is bound by a binder resin. The magnetic metal powder of the resin 12 containing a magnetic metal powder is made of, for example, an iron-nickel alloy (permalloy alloy), carbonyl iron, an amorphous, non-crystalline or crystalline FeSiCr-based alloy, sendust, or the like. The binder resin is, for example, a thermosetting epoxy resin. In this embodiment, the content of the magnetic metal powder in the binder powder is 80 to 92 vol% in volume percent and 95 to 99 wt% in mass percent. From the viewpoint of magnetic properties, the content of the magnetic metal powder in the binder powder may be 85 to 92 vol% in volume percent and 97 to 99 wt% in mass percent. The magnetic powder of the resin 12 containing a magnetic metal powder may be a powder having one type of average particle size, or may be a mixed powder having a plurality of types of average particle sizes.

[0022] The metal magnetic powder-containing resin 12 of the element body 10 integrally covers the coil structure 20 described below. Specifically, the metal magnetic powder-containing resin 12 covers the coil structure 20 from above and below, and also covers the outer periphery of the coil structure 20. In addition, the metal magnetic powder-containing resin 12 fills the inner periphery of the coil structure 20.

[0023] The coil structure 20 is configured to include an insulating substrate 30, an upper coil structure 40A provided on the upper side of the insulating substrate 30, and a lower coil structure 40B provided on the lower side of the insulating substrate 30.

[0024] The insulating substrate 30 has a flat plate shape, extends between the end faces 10a, 10b of the element body 10, and is designed to be perpendicular to the end faces 10a, 10b. The insulating substrate 30 also extends parallel to the upper face 10c and the lower face 10d of the element body 10. As shown in Fig. 3, the insulating substrate 30 has an elliptical ring-shaped coil forming portion 31 extending along the long side direction of the element body 10, and a pair of frame portions 34A, 34B extending along the short side direction of the element body 10 and sandwiching the coil forming portion 31 from both sides. An elliptical opening 32 extending along the long side direction of the element body 10 is provided in the center of the coil forming portion 31.

[0025] The insulating substrate 30 is made of a non-magnetic insulating material. The thickness of the insulating substrate 30 can be designed to be in the range of, for example, 10 to 60 μm. In this embodiment, the insulating substrate 30 has a structure in which a glass cloth is impregnated with an epoxy resin. The resin constituting the insulating substrate 30 is not limited to an epoxy resin, and may be BT resin, polyimide, aramid, or the like. The material constituting the insulating substrate 30 may be ceramic or glass. The material constituting the insulating substrate 30 may be a mass-produced printed circuit board material. The material constituting the insulating substrate 30 may be a resin material used for a BT printed circuit board, an FR4 printed circuit board, or an FR5 printed circuit board.

[0026] Upper coil structure 40A is provided on substrate upper surface 30a in coil formation portion 31 of insulating substrate 30. Upper coil structure 40A includes first planar coil 41, second planar coil 42, and upper insulator 50A, as shown in Figures 2 and 3. First planar coil 41 and second planar coil 42 are wound adjacent to each other in parallel on upper surface 30a of insulating substrate 30.

[0027] The first planar coil 41 is a substantially oval spiral air-core coil wound around the opening 32 of the coil forming section 31 in the same layer on the upper surface 30a of the insulating substrate 30. The number of turns of the first planar coil 41 may be one turn or multiple turns. In this embodiment, the number of turns of the first planar coil 41 is 3 to 4. The first planar coil 41 has an outer end 41a and an inner end 41b. The outer end 41a is provided on the frame section 34A and exposed from the end surface 10a of the element body 10. The inner end 41b is provided on the edge of the opening 32. The insulating substrate 30 is provided with a first through conductor 41c extending in the thickness direction of the insulating substrate 30 at a position overlapping with the inner end 41b of the first planar coil 41. The first planar coil 41 is made of, for example, Cu, and can be formed by electrolytic plating.

[0028] The second planar coil 42, like the first planar coil 41, is a substantially oval spiral air-core coil wound around the opening 32 of the coil forming portion 31 in the same layer on the upper surface 30a of the insulating substrate 30. The second planar coil 42 is wound so as to be adjacent to the first planar coil 41 on the inner circumferential side of the first planar coil 41. The number of turns of the second planar coil 42 may be one turn or multiple turns. In this embodiment, the number of turns of the second planar coil 42 is the same as the number of turns of the first planar coil 41. The second planar coil 42 has an outer end 42a and an inner end 42b. The outer end 42a of the second planar coil 42, like the outer end 41a of the first planar coil 41, is provided on the frame portion 34A and exposed from the end surface 10a of the element body 10. An inner end 42b of the second planar coil 42 is provided on the edge of the opening 32 and is adjacent to an inner end 41b of the first planar coil 41. A second through conductor 42c extending in the thickness direction of the insulating substrate 30 is provided in the insulating substrate 30 at a position overlapping with the inner end 42b of the second planar coil 42. The second planar coil 42, like the first planar coil 41, is made of, for example, Cu, and can be formed by electrolytic plating.

[0029] The upper insulator 50A (first insulating portion) is provided on the upper surface 30a of the insulating substrate 30, and is a thick-film resist patterned by known photolithography. The upper insulator 50A defines plating growth regions of the first planar coil 41 and the second planar coil 42. In this embodiment, as shown in FIG. 4, the upper insulator 50A integrally covers the first planar coil 41 and the second planar coil 42, and more specifically, covers the side and upper surfaces of the first planar coil 41 and the second planar coil 42. As shown in FIGS. 5 and 6, a part of the upper insulator 50A extends from the inside of the element body 10 through between the outer end 41a and the outer end 42a to the end surface 10a of the element body 10, and is exposed at the end surface 10a. 5 and 6, a portion of upper insulator 50A extends from the inside of element body 10 along substrate upper surface 30a to end surface 10b and is exposed at end surface 10b. Upper insulator 50A is thicker than first planar coil 41 and second planar coil 42. Upper insulator 50A is made of, for example, epoxy resin.

[0030] Lower coil structure 40B is provided on substrate lower surface 30b in coil forming portion 31 of insulating substrate 30. Lower coil structure 40B includes first planar coil 41, second planar coil 42, and lower insulator 50B, as shown in Figures 2 and 3. First planar coil 41 and second planar coil 42 are wound adjacent to each other in parallel on lower surface 30b of insulating substrate 30.

[0031] The first planar coil 41 and the second planar coil 42 of the lower coil structure 40B are symmetrical to the first planar coil 41 and the second planar coil 42 of the upper coil structure 40A. More specifically, the first planar coil 41 and the second planar coil 42 of the lower coil structure 40B have a shape obtained by inverting the first planar coil 41 and the second planar coil 42 of the upper coil structure 40A around an axis parallel to the short side of the base body 10.

[0032] The outer end 41a of the first planar coil 41 of the lower coil structure 40B is provided on the frame portion 34B and exposed from the end surface 10b of the element body 10. The inner end 41b of the first planar coil 41 of the lower coil structure 40B overlaps with a first through conductor 41c provided on the insulating substrate 30. Therefore, the inner end 41b of the first planar coil 41 of the lower coil structure 40B is electrically connected to the inner end 41b of the first planar coil 41 of the upper coil structure 40A via the first through conductor 41c. The first planar coil 41 of the lower coil structure 40B is made of, for example, Cu, and can be formed by electrolytic plating.

[0033] The outer end 42a of the second planar coil 42 of the lower coil structure 40B is provided on the frame portion 34B and exposed from the end surface 10b of the element body 10. The inner end 42b of the second planar coil 42 of the lower coil structure 40B overlaps with a second through conductor 42c provided on the insulating substrate 30. Therefore, the inner end 42b of the second planar coil 42 of the lower coil structure 40B is electrically connected to the inner end 42b of the second planar coil 42 of the upper coil structure 40A via the second through conductor 42c. The second planar coil 42 of the lower coil structure 40B is made of, for example, Cu, and can be formed by electrolytic plating.

[0034] The lower insulator 50B (second insulating portion) is provided on the lower surface 30b of the insulating substrate 30, and is a thick-film resist patterned by known photolithography. The lower insulator 50B defines the plating growth regions of the first planar coil 41 and the second planar coil 42, similar to the upper insulator 50A. In this embodiment, as shown in FIG. 4, the lower insulator 50B integrally covers the first planar coil 41 and the second planar coil 42, and more specifically covers the side and upper surfaces of the first planar coil 41 and the second planar coil 42. A part of the lower insulator 50B extends from the inside of the element body 10 through between the outer end 41a and the outer end 42a to the end surface 10b of the element body 10, similar to the upper insulator 50A, and is exposed at the end surface 10b. A portion of lower insulator 50B extends from inside element body 10 along substrate lower surface 30b to end surface 10a and is exposed at end surface 10a. Lower insulator 50B has a thickness greater than that of first planar coil 41 and second planar coil 42. Lower insulator 50B may have the same thickness as upper insulator 50A. Lower insulator 50B is made of, for example, epoxy resin.

[0035] The element body 10 includes a pair of coil sections C1 and C2 that form a double coil structure. The first coil section C1 is composed of a first planar coil 41 of an upper coil structure 40A provided on the upper surface 30a of the insulating substrate 30, a first planar coil 41 of a lower coil structure 40B provided on the lower surface 30b of the insulating substrate 30, and a first through conductor 41c that connects the first planar coils 41 on both sides. In the first coil section C1, the outer end 41a of the first planar coil 41 of the upper coil structure 40A forms a first end, and the outer end 41a of the first planar coil 41 of the lower coil structure 40B forms a second end. The second coil portion C2 is composed of a second planar coil 42 of an upper coil structure 40A provided on the upper surface 30a of the insulating substrate 30, a second planar coil 42 of a lower coil structure 40B provided on the lower surface 30b of the insulating substrate 30, and a second through conductor 42c connecting the second planar coils 42 on both sides. In the second coil portion C2, the outer end 42a of the second planar coil 42 of the upper coil structure 40A constitutes a first end, and the outer end 42a of the second planar coil 42 of the lower coil structure 40B constitutes a second end.

[0036] Two pairs of external terminal electrodes 60A, 60B, 60C, and 60D are provided on end faces 10a, 10b of the element body 10, each of which is parallel to each other.

[0037] Of the pair of external terminal electrodes 60A, 60B (first external terminals) provided on the end face 10a, the external terminal electrode 60A is connected to the outer end 41a of the first planar coil 41 of the upper coil structure 40A, and the external terminal electrode 60B is connected to the outer end 42a of the second planar coil 42 of the upper coil structure 40A. As shown in FIG. 6, when viewed from the end face 10a side, the external terminal electrode 60A is biased toward the side face 10f and covers the end face 10a up to the vicinity of the side face 10f. Moreover, the external terminal electrode 60B is biased toward the side face 10e and covers the end face 10a up to the vicinity of the side face 10e. When viewed from the end face 10a side, the external terminal electrode 60A and the external terminal electrode 60B are spaced apart by a predetermined uniform width.

[0038] Of the pair of external terminal electrodes 60C, 60D (second external terminals) provided on the end face 10b, the external terminal electrode 60C is connected to the outer end 41a of the first planar coil 41 of the lower coil structure 40B, and the external terminal electrode 60D is connected to the outer end 42a of the second planar coil 42 of the lower coil structure 40B. The external terminal electrode 60C is biased toward the side face 10f and covers the end face 10b up to the vicinity of the side face 10f. The external terminal electrode 60D is biased toward the side face 10e and covers the end face 10b up to the vicinity of the side face 10e. When viewed from the end face 10b side, the external terminal electrodes 60C and 60D are spaced apart by a predetermined uniform width.

[0039] The external terminal electrode 60A on the end face 10a and the external terminal electrode 60C on the end face 10b are provided at positions corresponding to each other in the long side direction of the element body 10. Similarly, the external terminal electrode 60B on the end face 10a and the external terminal electrode 60D on the end face 10b are provided at positions corresponding to each other in the long side direction of the element body 10.

[0040] Each of the external terminal electrodes 60A, 60B, 60C, and 60D is bent into an L shape and continuously covers the end faces 10a, 10b and the upper face 10c. In this embodiment, the external terminal electrodes 60A, 60B, 60C, and 60D are made of resin electrodes, for example, made of a resin containing Ag powder.

[0041] Next, the configuration of the end surface 10a of the element body 10 will be described with reference to FIG.

[0042] On the end face 10a of the element body 10, the outer end 41a of the first planar coil 41 and the outer end 42a of the second planar coil 42 are arranged side by side on the upper surface 30a of the insulating substrate 30. An upper insulator 50A is located in a region R between the outer end 41a of the first planar coil 41 and the outer end 42a of the second planar coil 42 on the end face 10a of the element body 10. In this embodiment, the upper insulator 50A exists over the entire region R and extends across the outer ends 41a, 42a on the end face 10a of the element body 10. A lower insulator 50B is located on the end face 10a of the element body 10 so as to face the upper insulator 50A with the insulating substrate 30 in between.

[0043] In the coil component 1, when a voltage is applied via the external terminal electrodes 60A, 60B, 60C, and 60D, a potential difference may occur between the outer ends 41a and 42a. In the coil component 1, the upper insulator 50A exposed at the end face 10a of the element body 10 enhances the insulation between the outer ends 41a and 42a, so that even if a potential difference occurs between the outer ends 41a and 42a, the outer ends 41a and 42a are prevented from shorting each other on the end face 10a. In this embodiment, the lower insulator 50B exposed at the end face 10a of the element body 10 further enhances the insulation between the outer ends 41a and 42a, so that the outer ends 41a and 42a are further prevented from shorting each other on the end face 10a.

[0044] Similarly, on the end face 10b of the element body 10, as shown in FIG. 8, the lower insulator 50B exposed on the end face 10b is located in the region R between the outer end 41a of the first planar coil 41 and the outer end 42a of the second planar coil 42. Since the lower insulator 50B enhances the insulation between the outer ends 41a and 42a, even if a potential difference occurs between the outer ends 41a and 42a, the outer ends 41a and 42a are prevented from shorting each other on the end face 10b. In this embodiment, the upper insulator 50A exposed on the end face 10b of the element body 10 further enhances the insulation between the outer ends 41a and 42a, and the outer ends 41a and 42a are further prevented from shorting each other on the end face 10b.

[0045] In this embodiment, the external terminal electrode 60A directly covers a portion of the upper insulator 50A exposed in region R (more specifically, a portion on the outer end 41a side), and the external terminal electrode 60B directly covers a portion of the upper insulator 50A exposed in region R (more specifically, a portion on the outer end 42a side). By having the external terminal electrodes 60A, 60B cover a portion of the upper insulator 50A in this manner, the contact area between the external terminal electrodes 60A, 60B and the element body 10 can be reduced, and even if a potential difference occurs between the outer ends 41a, 42a, the risk of a short circuit can be reduced.

[0046] The upper insulator 50A and the lower insulator 50B do not necessarily need to be present over the entire region R, and may be present in only a part of the region R. In this case, the external terminal electrodes 60A, 60B, 60C, 60D may cover only a part of the upper insulator 50A and the lower insulator 50B, or may not cover the upper insulator 50A and the lower insulator 50B at all.

[0047] For example, as shown in Fig. 9, the metal magnetic powder-containing resin 12 of the element body 10 may be located in region R. In the embodiment shown in Fig. 9, a part 12a of the metal magnetic powder-containing resin 12 is exposed from inside the element body 10 in region R, and the upper insulator 50A is sandwiched between the metal magnetic powder-containing resin 12 in the arrangement direction of the outer ends 41a, 42a (the left-right direction in Fig. 9). In this case as well, the external terminal electrode 60A can directly cover the part of the upper insulator 50A exposed in region R, and the external terminal electrode 60B can directly cover the part of the upper insulator 50A exposed in region R.

[0048] 10, an insulating layer 70 may be provided to cover the end face 10a exposed between the external terminal electrodes 60A, 60B. The insulating layer 70 extends across the end face 10a of the element body 10 between the external terminal electrodes 60A, 60B. The insulating layer 70 may be provided to cover at least a portion of the region R. The insulating layer 70 may also be provided to cover the end face 10b exposed between the external terminal electrodes 60C, 60D. The insulating layer 70 may be made of an epoxy resin. [Explanation of symbols]

[0049] 1...coil component, 10...element body, 12...resin containing metal magnetic powder, 30...insulating substrate, 41...first planar coil, 42...second planar coil, 41a, 42a...outer end portion, 50A...upper insulator, 50B...lower insulator, 60A to 60D...external terminal electrodes, 70...insulating layer, C1...first coil portion, C2...second coil portion, R...region.

Claims

1. an element body made of a resin containing metal magnetic powder and having a first end face and a second end face parallel to each other; an insulating substrate provided within the element body, perpendicular to the first end face and the second end face, and extending between the first end face and the second end face; a pair of coil portions provided on the insulating substrate, each having a first end portion exposed on the first end surface; a pair of first external terminals provided on the first end surface and connected to first ends of the pair of coil portions, respectively; a first insulating portion exposed from inside the element body to the first end surface and positioned between first ends of the pair of coil portions on the first end surface; Equipped with the first insulating portion and the resin containing metal magnetic powder are exposed in a region sandwiched between first ends of the pair of coil portions on the first end surface, A coil component, wherein the first insulating portion is sandwiched between the resin containing metal magnetic powder in a direction in which the first ends of the pair of coil portions are aligned.

2. The coil component according to claim 1 , wherein the first insulating portion extends across between first ends of the pair of coil portions.

3. The coil component according to claim 1 , further comprising an insulating layer covering at least a part of a region of the first end surface sandwiched between the first ends of the pair of coil portions.

4. The coil component according to claim 1 , wherein the first external terminal directly covers a portion of the first insulating portion at the first end face.

5. The pair of coil portions each have a second end portion exposed on the second end surface, a pair of second external terminals provided on the second end surface and connected to second ends of the pair of coil portions, respectively; a second insulating portion exposed from inside the element body to the second end surface and positioned between second ends of the pair of coil portions at the second end surface; The coil component according to any one of claims 1 to 4, further comprising:

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