Coil component

Abstract

Provided is a coil component capable of adjusting a coupling coefficient using a magnetic sheet and an insulator interposed between a pair of coils. For example, by increasing the permeability of the magnetic sheet, magnetic flux generated in the coils easily passes through the magnetic sheet, whereby the coupling coefficient is reduced. In the coil component, the thickness of the magnetic body can be suppressed, and the coupling coefficient can be adjusted.

Description

Technical Field

[0001] This invention relates to coil components. Background Technology

[0002] Currently, coil components with a pair of coils overlapping each other in the coil axis are known. Japanese Patent Application Publication No. 2018-137421 discloses a coil component in which a PCB substrate is located between the pair of coils, and a high coupling coefficient is obtained through the PCB substrate, which is a non-magnetic body. Summary of the Invention

[0003] [The technical problem that the invention aims to solve]

[0004] The aforementioned coil components are sometimes required to have a coupling coefficient within a specified range, depending on their application. When a PCB substrate is positioned between a pair of coils, increasing the thickness of the PCB substrate can reduce the coupling coefficient; however, this increases the substrate thickness, leading to a larger component size. The inventors have repeatedly studied techniques for adjusting the coupling coefficient and have discovered a new technique that can suppress the substrate thickness while adjusting the coupling coefficient.

[0005] According to the present invention, a coil component capable of suppressing the thickness of the substrate and adjusting the coupling coefficient is provided.

[0006] [Technical solutions used to solve technical problems]

[0007] One aspect of the present invention provides a coil component comprising: a body made of resin containing metal powder; a pair of coils disposed within the body, each having a pair of ends that overlap each other in the coil axial direction and extend to a surface of the body; two pairs of external terminals disposed on the surface of the body and respectively connected to the ends of the pair of coils; a magnetic sheet disposed within the body and disposed between the pair of coils in the coil axial direction; and an insulator disposed between at least one of the pair of coils and the magnetic sheet.

[0008] In the coil assembly, the coupling coefficient is adjusted using a magnetic sheet and an insulator located between a pair of coils. For example, increasing the permeability of the magnetic sheet makes it easier for the magnetic flux generated by the coil to pass through the magnetic sheet, thereby reducing the coupling coefficient. Therefore, it is possible to suppress the thickness of the substrate and adjust the coupling coefficient in the coil assembly.

[0009] In another coil component, the magnetic sheet is made of a magnetic material containing magnetic powder and resin.

[0010] In another coil component, the magnetic powder of the magnetic sheet has a flat shape.

[0011] In another coil component, the thickness of the magnetic sheet is greater than the thickness of the insulator between the magnetic sheet and the coil.

[0012] In another coil component, the magnetic permeability of the magnetic sheet is higher than that of the solid.

[0013] In another coil component, in the magnetic sheet, at least one of the portion corresponding to the inner peripheral region of the coil and the portion corresponding to the outer peripheral region of the coil is removed. Attached Figure Description

[0014] Figure 1 This is a schematic perspective view of the coil component in the embodiment.

[0015] Figure 2 It means Figure 1 A diagram of the interior of the coil component.

[0016] Figure 3 yes Figure 2 An exploded perspective view of the coil structure shown.

[0017] Figure 4 It means Figure 3 A top view of the magnetic sheet shown.

[0018] Figure 5 yes Figure 2 The figure shown is a cross-sectional view of the V-V line.

[0019] Figure 6 yes Figure 2 The figure shown is a cross-sectional view along line VI-VI.

[0020] Figure 7 It is Figure 6 The main part of the cross-sectional view shown is enlarged. Detailed Implementation

[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and repeated descriptions are omitted.

[0022] The coil component 1 in this embodiment is a so-called coupled coil. The coupled coil contains two coils in a single component, enabling a reduction in the number of components and a smaller mounting area. The coupled coil can be used as a smoothing coil in switching power supplies, such as DC / DC converters in various electronic devices.

[0023] like Figure 1 , Figure 2As shown, the coil component 1 is composed of a body 10, a coil structure 20 embedded in the body 10, and two pairs of external terminal electrodes 60A, 60B, 60C, and 60D disposed on the surface of the body 10.

[0024] The body 10 has a rectangular parallelepiped shape and six faces 10a to 10f. As an example, the body 10 is designed with a long side of 2.0 mm, a short side of 1.25 mm, and a height of 0.45 mm. Of the faces 10a to 10f of the body 10, end faces 10a and 10b are parallel to each other, the upper surface 10c and the lower surface 10d are parallel to each other, and the side surfaces 10e and 10f are parallel to each other. The upper surface 10c of the body 10 is parallel to the mounting surface of the mounting substrate of the coil component 1.

[0025] The base material 10 is composed of resin 12 containing metallic magnetic powder, which is a type of magnetic material. The resin 12 containing metallic magnetic powder comprises metal powder and resin; more specifically, the metallic magnetic powder is a binder powder bonded by a binder resin. The metallic magnetic powder in the resin 12 can be, for example, an iron-nickel alloy (permalloy), carbonyl iron, amorphous, amorphous, or crystalline FeSiCr alloys, aluminum-silicon-iron powder, etc. The binder resin is, for example, a thermosetting epoxy resin. In this embodiment, the content of metallic magnetic powder in the binder powder is 80–92 vol% by volume and 95–99 wt% by mass. From the viewpoint of magnetic properties, the content of metallic magnetic powder in the binder powder can also be 85–92 vol% by volume and 97–99 wt% by mass. The magnetic powder in the resin 12 containing metallic magnetic powder can be a powder having a single average particle size or a mixture of powders having multiple average particle sizes.

[0026] The resin 12 containing metallic magnetic powder of the base body 10 integrally covers the coil structure 20 described later. Specifically, the resin 12 containing metallic magnetic powder covers the coil structure 20 from top to bottom and covers the outer periphery of the coil structure 20. In addition, the resin 12 containing metallic magnetic powder fills the inner periphery region of the coil structure 20.

[0027] like Figure 2 , Figure 3 As shown, the coil structure 20 comprises a magnetic sheet 30, an upper coil structure 40A disposed on the upper side of the magnetic sheet 30, and a lower coil structure 40B disposed on the lower side of the magnetic sheet 30. The coil structure 20 is a laminate formed by sequentially stacking the upper coil structure 40A, the magnetic sheet 30, and the lower coil structure 40B. In the stacking direction, the magnetic sheet 30 is disposed between the upper coil structure 40A and the lower coil structure 40B.

[0028] The magnetic sheet 30 has a flat, plate-like shape (e.g., sheet-like or layered) and extends between the end faces 10a and 10b of the body 10, designed to be orthogonal to the end faces 10a and 10b. Furthermore, the magnetic sheet 30 extends parallel to the upper surface 10c and lower surface 10d of the body 10. Figure 4 As shown, the magnetic sheet 30 has: an elliptical annular coil overlap portion 31 extending along the long side of the body 10; and a pair of frame portions 34A, 34B extending along the short side of the body 10 and sandwiching the coil overlap portion 31 from both sides. An elliptical opening 32 extending along the long side of the body 10 is provided in the central portion of the coil overlap portion 31. The thickness t of the magnetic sheet 30 can be designed, for example, within 10 to 100 μm (30 μm as an example).

[0029] The magnetic sheet 30 is made of a magnetic material. In this embodiment, the magnetic sheet 30 comprises resin and magnetic powder (magnetic material powder), and has a structure in which the magnetic powder is dispersed in the resin. The resin of the magnetic sheet 30 is, for example, an epoxy resin. The magnetic powder of the magnetic sheet 30 may be, for example, composed of ferrite, permalloy, aluminum-silicon-iron powder, Fe-based magnetic materials, etc. The magnetic powder of the magnetic sheet 30 may be in the form of flat or needle-like shapes, or in the form of spheres. For example, when the magnetic powder of the magnetic sheet 30 is flat, the magnetic powder may also extend in a direction intersecting the thickness direction of the magnetic sheet 30 (for example, a direction orthogonal to the thickness direction of the magnetic sheet 30). The magnetic sheet 30 may also be an amorphous foil, amorphous ribbon, or amorphous layer made of a magnetic material.

[0030] The magnetic sheet 30 of this embodiment has a structure in which ferrite flat powder is dispersed substantially uniformly in epoxy resin, and the ferrite flat powder extends in a direction orthogonal to the thickness direction of the magnetic sheet 30. Therefore, for the magnetic sheet 30, the magnetic permeability in the direction orthogonal to the thickness direction is higher than that in the thickness direction. In addition, the ferrite flat powder extends substantially parallel to the extension direction of the magnetic sheet 30, thus suppressing the thickening of the magnetic sheet 30 and improving the magnetic permeability.

[0031] like Figure 3 As shown, the upper coil structure 40A is disposed on the upper surface 30a of the coil overlap portion 31 of the magnetic sheet 30. The upper coil structure 40A is composed of an insulating layer 30A, a first upper planar coil 41, a second upper planar coil 42, a first upper insulator 51, and a second upper insulator 52.

[0032] The insulating layer 30A has a flat, plate-like shape (e.g., sheet-like or layered) and extends parallel to the magnetic sheet 30. Viewed in the thickness direction, the insulating layer 30A has substantially the same shape as the magnetic sheet 30. That is, like the magnetic sheet 30, the insulating layer 30A has: an elliptical annular coil overlap portion 31 extending along the long side of the body 10; and a pair of frame portions 34A, 34B extending along the short side of the body 10 and sandwiching the coil overlap portion 31 from both sides. An elliptical opening 32 extending along the long side of the body 10 is provided in the central portion of the coil overlap portion 31. The thickness t1 of the insulating layer 30A can be designed within, for example, a range of 10 to 50 μm (15 μm as an example). The insulating layer 30A is made of an insulating material, such as a resin material like BT resin.

[0033] The first upper planar coil 41 is a generally elliptical spiral-shaped hollow coil wound around the opening 32 of the coil overlap portion 31 within the same layer on the upper surface 30a of the insulating layer 30A. The first upper planar coil 41 has a coil axis Z along the thickness direction of the body 10. The number of turns of the first upper planar coil 41 can be one turn or multiple turns. In this embodiment, the number of turns of the first upper planar coil 41 is 2 to 3. The first upper planar coil 41 has an outer end portion 41a and an inner end portion 41b. The outer end portion 41a is provided on the frame portion 34A, extends to the end face 10a of the body 10, and is exposed from the end face 10a. The inner end portion 41b is provided at the edge of the opening 32. On the insulating layer 30A, a through conductor 47 extending along the thickness direction of the insulating layer 30A is provided at a position overlapping the inner end portion 41b of the first upper planar coil 41 in a manner that penetrates the insulating layer 30A. The first upper planar coil 41 is made of Cu, for example, and can be formed by electroplating. In this embodiment, the first upper planar coil 41 has an auxiliary outer end 41c, which overlaps with the outer end 42a of the second upper planar coil 42 (described later) by sandwiching an insulating layer 30A. The auxiliary outer end 41c is electrically connected to the outer end 42a via a through conductor (not shown) penetrating the insulating layer 30A. By providing the auxiliary outer end 41c and making the outer end a double-layer structure, the contact area between the outer end and the external terminal electrode is increased, and the connectivity is improved.

[0034] The second upper planar coil 42 is symmetrical to the first upper planar coil 41. More specifically, the second upper planar coil 42 has a shape that reverses the shape of the first upper planar coil 41 about an axis parallel to the short side of the body 10. The second upper planar coil 42 and the first upper planar coil 41 share a coil axis Z. The outer end portion 42a of the second upper planar coil 42 is provided in the frame portion 34B, extends to the end face 10b of the body 10, and protrudes from the end face 10b. The inner end portion 42b of the second upper planar coil 42 overlaps with the through conductor 47 provided in the insulating layer 30A. Therefore, the inner end portion 42b of the second upper planar coil 42 is electrically connected to the inner end portion 41b of the first upper planar coil 41 via the through conductor 47. The second upper planar coil 42 is made of Cu, for example, and can be formed by electroplating. In this embodiment, the second upper planar coil 42 has an auxiliary outer end portion 42c, which overlaps with the outer end portion 41a of the first upper planar coil 41, sandwiching an insulating layer 30A. The auxiliary outer end portion 42c is electrically connected to the outer end portion 41a via a through conductor (not shown) penetrating the insulating layer 30A. By providing the auxiliary outer end portion 42c, the outer end portion is made into a double-layer structure, increasing the contact area between the outer end portion and the external terminal electrode, thus improving connectivity.

[0035] The thickness T of the first upper planar coil 41 41 and the thickness T of the second upper planar coil 42 42 It can be designed within a range of, for example, 20–40 μm (30 μm as an example). The thickness T of the first upper planar coil 41 41 and the thickness T of the second upper planar coil 42 42 They can be the same or different. In the upper coil structure 40A, a first coil C1 with a coil axis Z is formed by using a first upper planar coil 41, a second upper planar coil 42, and a through conductor 47 disposed on the insulating layer 30A.

[0036] The first upper insulator 51 and the second upper insulator 52 are covered by an insulating layer 30A, a first upper planar coil 41, and a second upper planar coil 42 sandwiched in the thickness direction of the substrate 10. Both the first upper insulator 51 and the second upper insulator 52 are made of insulating resin. For example, they may be made of PP resin or BT resin. The first upper insulator 51 and the second upper insulator 52 may also be composite components containing resin and glass fiber (so-called prepreg). The first upper insulator 51 and the second upper insulator 52 can be formed, for example, by vacuum-pressing an insulating resin sheet from the thickness direction of the substrate 10. Thus, the wires of the first upper planar coil 41 and the second upper planar coil 42 are buried between resin materials, and the inner and outer surfaces of the first upper planar coil 41 and the second upper planar coil 42 are covered by resin materials.

[0037] The thickness T of the first upper insulator 51 51 and the thickness T of the second upper insulator 52 52 It can be designed within a range of, for example, 40–50 μm (45 μm as an example). The thickness T of the first upper insulator 51... 51 The thickness T of the second upper insulator 52 52 They can be the same or different.

[0038] like Figure 3 As shown, the lower coil structure 40B is disposed on the lower surface 30b of the coil overlap portion 31 of the magnetic sheet 30. The lower coil structure 40B is composed of an insulating layer 30B, a first lower planar coil 43, a second lower planar coil 44, a first lower insulator 53, and a second lower insulator 54.

[0039] Similar to the insulating layer 30A of the upper coil structure 40A, the insulating layer 30B of the lower coil structure 40B has a flat plate shape (e.g., sheet or layer) and extends parallel to the magnetic sheet 30. Viewed in the thickness direction, the insulating layer 30B has substantially the same shape as the magnetic sheet 30. Like the magnetic sheet 30 and the insulating layer 30A, the insulating layer 30B has: an elliptical annular coil overlap portion 31 extending along the long side of the body 10; and a pair of frame portions 34A, 34B extending along the short side of the body 10 and sandwiching the coil overlap portion 31 from both sides. An elliptical opening 32 extending along the long side of the body 10 is provided in the central portion of the coil overlap portion 31. The thickness t2 of the insulating layer 30B can be designed within, for example, a range of 10 to 50 μm (15 μm as an example). The thickness t2 of the insulating layer 30B can be the same as or different from the thickness t1 of the insulating layer 30A. Similar to insulating layer 30A, insulating layer 30B is made of insulating material, for example, it may be made of resin material such as BT resin.

[0040] The first lower planar coil 43 is a generally elliptical spiral-shaped hollow coil wound around the opening 32 of the coil overlap portion 31 within the same layer on the upper surface 30a of the insulating layer 30B. The first lower planar coil 43 shares a coil axis Z with the upper planar coils 41 and 42. The number of turns of the first lower planar coil 43 can be one or more turns. In this embodiment, the number of turns of the first lower planar coil 43 is 2 to 3. The first lower planar coil 43 has an outer end portion 43a and an inner end portion 43b. The outer end portion 43a is provided on the frame portion 34A, extends to the end face 10a of the body 10, and is exposed from the end face 10a. The inner end portion 43b is provided at the edge of the opening 32. A through conductor 48 extending along the thickness direction of the insulating layer 30B is provided on the insulating layer 30B in such a way that it penetrates the insulating layer 30B at a position overlapping with the inner end portion 43b of the first lower planar coil 43. The first lower planar coil 43 is made of Cu, for example, and can be formed by electroplating. In this embodiment, the first lower planar coil 43 has an auxiliary outer end 43c, which overlaps with the outer end 44a of the second lower planar coil 44 (described later) by sandwiching an insulating layer 30B. The auxiliary outer end 43c is electrically connected to the outer end 44a via a through conductor (not shown) penetrating the insulating layer 30B. By providing the auxiliary outer end 43c, the outer end is made into a double-layer structure, increasing the contact area between the outer end and the external terminal electrode and improving connectivity.

[0041] The second lower planar coil 44 is symmetrical to the first lower planar coil 43. More specifically, the second lower planar coil 44 has a shape that reverses the first lower planar coil 43 about an axis parallel to the short side of the body 10. The second lower planar coil 44 shares a coil axis Z with the upper planar coils 41 and 42 and the first lower planar coil 43. The outer end portion 44a of the second lower planar coil 44 is provided in the frame portion 34B, extends to the end face 10b of the body 10, and is exposed from the end face 10b. The inner end portion 44b of the second lower planar coil 44 overlaps with a through conductor 48 provided in the insulating layer 30B. Therefore, the inner end portion 44b of the second lower planar coil 44 is electrically connected to the inner end portion 43b of the first lower planar coil 43 via the through conductor 48. The second lower planar coil 44 is made of Cu, for example, and can be formed by electroplating. In this embodiment, the second lower planar coil 44 has an auxiliary outer end portion 44c, which overlaps with the outer end portion 43a of the first lower planar coil 43, sandwiched by an insulating layer 30B. The auxiliary outer end portion 44c is electrically connected to the outer end portion 43a via a through conductor (not shown) penetrating the insulating layer 30B. By providing the auxiliary outer end portion 44c, the outer end portion is made into a double-layer structure, increasing the contact area between the outer end portion and the external terminal electrode, thus improving connectivity.

[0042] The thickness T of the first lower plane coil 43 43 and the thickness T of the second lower planar coil 44 44 It can be designed within a range of, for example, 20–40 μm (30 μm as an example). The thickness T of the first lower planar coil 43... 43 and the thickness T of the second lower planar coil 44 44 They can be the same or different. In the lower coil structure 40B, a second coil C2 with a coil axis Z is formed by using a first lower planar coil 43, a second lower planar coil 44, and a through conductor 48 disposed on the insulating layer 30B.

[0043] The first lower insulator 53 and the second lower insulator 54 are covered by an insulating layer 30B, a first lower planar coil 43, and a second lower planar coil 44 sandwiched in the thickness direction of the substrate 10. Both the first lower insulator 53 and the second lower insulator 54 are made of insulating resin. For example, they may be made of PP resin or BT resin. The first lower insulator 53 and the second lower insulator 54 may also be composite components containing resin and glass fiber (so-called prepreg). The first lower insulator 53 and the second lower insulator 54 can be formed, for example, by vacuum-pressing an insulating resin sheet from the thickness direction of the substrate 10. Thus, the wires of the first lower planar coil 43 and the second lower planar coil 44 are buried between resin materials, and the inner and outer surfaces of the first lower planar coil 43 and the second lower planar coil 44 are covered by resin materials.

[0044] The thickness T of the first lower insulator 53 53 and the thickness T of the second lower insulator 54 54 It can be designed within a range of, for example, 40–50 μm (450 μm, for example). The thickness T of the first lower insulator 53... 53 The thickness T of the second lower insulator 54 54 They can be the same or different.

[0045] Two pairs of external terminal electrodes 60A, 60B, 60C, and 60D are each provided on the parallel end faces 10a and 10b of the body 10.

[0046] Of the pair of external terminal electrodes 60A and 60B disposed on end face 10a, external terminal electrode 60A is connected to the outer end 43a of the first lower planar coil 43 of the lower coil structure 40B, and external terminal electrode 60B is connected to the outer end 41a of the first upper planar coil 41 of the upper coil structure 40A. When viewed from end face 10a, external terminal electrode 60A is biased towards side 10f and covers the vicinity of side 10f on end face 10a. External terminal electrode 60B is biased towards side 10e and covers the vicinity of side 10e on end face 10a. When viewed from end face 10a, external terminal electrodes 60A and 60B are separated by a predetermined uniform width.

[0047] Of the pair of external terminal electrodes 60C and 60D disposed on end face 10b, external terminal electrode 60C is connected to the outer end 44a of the second lower planar coil 44 of the lower coil structure 40B, and external terminal electrode 60D is connected to the outer end 42a of the second upper planar coil 42 of the upper coil structure 40A. External terminal electrode 60C is biased toward side 10f and covers the vicinity of side 10f on end face 10b. External terminal electrode 60D is biased toward side 10e and covers the vicinity of side 10e on end face 10b. When viewed from end face 10b, external terminal electrode 60C and external terminal electrode 60D are separated by a predetermined uniform width.

[0048] External terminal electrodes 60A on end face 10a and 60C on end face 10b are positioned at corresponding locations along the long side of the body 10. Similarly, external terminal electrodes 60B on end face 10a and 60D on end face 10b are positioned at corresponding locations along the long side of the body 10.

[0049] External terminal electrodes 60A, 60B, 60C, and 60D are all bent into an L-shape, continuously covering end faces 10a and 10b and the upper surface 10c. In this embodiment, external terminal electrodes 60A, 60B, 60C, and 60D are made of resin electrodes, for example, of resin containing Ag powder.

[0050] In coil component 1, when a voltage is applied between external terminal electrodes 60B and 60D, current flows through the first coil C1 of the upper coil structure 40A, generating magnetic flux around the first coil C1. Similarly, when a voltage is applied between external terminal electrodes 60A and 60C, current flows through the second coil C2 of the lower coil structure 40B, generating magnetic flux around the second coil C2. At this time, magnetic coupling can be generated between the first coil C1 and the second coil C2, which share the same coil axis Z.

[0051] like Figure 4 As shown, in the magnetic sheet 30 of the coil component 1, the coil overlap portion 31 that overlaps with coils C1 and C2 is an elliptical ring, and both the portion corresponding to the inner circumferential region of coils C1 and C2 and the portion corresponding to the outer circumferential region of coils C1 and C2 are removed. Therefore, by filling both portions with the magnetic material constituting the body 10, the inner core and outer core of coils C1 and C2 are formed. Alternatively, the magnetic sheet 30 may also be in a form where only one of the portion corresponding to the inner circumferential region of coils C1 and C2 or the portion corresponding to the outer circumferential region of coils C1 and C2 is removed.

[0052] In coil component 1, leakage flux (i.e., flux passing only through the first coil C1 and flux passing only through the second coil C2) is easily generated due to the magnetic sheet 30 located between the first coil C1 and the second coil C2. The coupling coefficient can be adjusted by increasing or decreasing the leakage flux using the magnetic sheet 30. For example, by increasing the permeability of the magnetic sheet 30, the leakage flux can be increased, and the coupling coefficient can be decreased. Furthermore, by increasing the thickness of the magnetic sheet 30, the permeability of the magnetic sheet 30 can be increased. In this embodiment, the thickness t of the magnetic sheet 30 is designed to be greater than the portion between the magnetic sheet 30 and the coils C1 and C2 (…). Figure 7 Part S shown A S B The thickness T of insulators 52 and 53 A T B Thickness. Furthermore, in this embodiment, the permeability of the magnetic sheet 30 is designed to be higher than that of the substrate material constituting the substrate 10 (i.e., the resin 12 containing metallic magnetic powder), and also higher than the permeability of the insulators 52 and 53 adjacent to the magnetic sheet 30 in the thickness direction. In particular, by increasing the permeability of the magnetic sheet 30 in the planar direction (the direction orthogonal to the coil axis Z), the leakage flux is effectively increased. The permeability of the magnetic sheet 30 can be adjusted according to, for example, the thickness of the magnetic sheet 30, the form of the magnetic powder, the type of magnetic powder, and the content ratio of the magnetic powder.

[0053] In this embodiment, such as Figure 7 As shown, the magnetic powder p contained in the magnetic sheet 30 is flat, and each magnetic powder extends along the surface direction of the magnetic sheet 30. In this magnetic sheet 30, the permeability in the surface direction is higher than the permeability in the thickness direction.

[0054] As described above, the coil component 1 includes: a pair of coils C1 and C2 disposed within the body 10 and overlapping each other in the Z-direction of the coil axis; a magnetic sheet 30 disposed between the pair of coils C1 and C2 in the Z-direction of the coil axis; and insulators 52 and 53 disposed between the pair of coils C1 and C2 and the magnetic sheet 30, respectively. Alternatively, it may be possible to have only either insulator 52 or 53.

[0055] In coil component 1, the coupling coefficient can be adjusted using a magnetic sheet 30 and insulators 52 and 53 located between a pair of coils C1 and C2. For example, by increasing the permeability of the magnetic sheet 30, the magnetic flux generated in coils C1 and C2 can more easily pass through the magnetic sheet 30, thereby reducing the coupling coefficient.

[0056] Even in structures where a non-magnetic substrate, such as a PCB substrate, is located between coils C1 and C2, the coupling coefficient can be reduced by increasing the substrate thickness. However, in this case, the body 10 becomes thicker, resulting in a larger body 10.

[0057] In the coil component 1 described above, the thickness of the body 10 can be suppressed, and the coupling coefficient can be adjusted.

[0058] Furthermore, the present invention is not limited to the embodiments described above, and various methods can be employed. For example, the number of turns of the planar coil constituting the coil can be appropriately increased or decreased. Alternatively, it may be possible to include three or more coils within the body.

Claims

1. A coil component, wherein, have: The base body is made of resin containing metal powder; A pair of coils disposed within the body, each having a pair of ends that overlap each other in the coil axial direction and extend to the surface of the body; Two pairs of external terminals are disposed on the surface of the body and are respectively connected to the ends of the pair of coils; A magnetic sheet is disposed within the body of the core and is positioned between the pair of coils along the axial direction of the coil. as well as An insulator, which is located between at least one of the pair of coils and the magnetic sheet, The magnetic sheet is composed of a magnetic material containing magnetic powder and resin. The magnetic powder of the magnetic sheet has a flat shape and extends along the surface direction of the magnetic sheet.

2. The coil component according to claim 1, wherein, The thickness of the magnetic sheet is greater than the thickness of the insulator in the portion between the magnetic sheet and the coil.

3. The coil component according to claim 1 or 2, wherein, The magnetic permeability of the magnetic sheet is higher than that of the substrate.

4. The coil component according to any one of claims 1 to 3, wherein, In the magnetic sheet, at least one of the portion corresponding to the inner peripheral region of the coil and the portion corresponding to the outer peripheral region of the coil is removed.

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