Coil component

Abstract

To provide a coil component having a planar coil pattern electrically accessible from a surface and a rear face which enhances strength in a terminal.SOLUTION: A coil component 100 includes a planar coil pattern 10, a first resin layer 21 covering a first main surface 11 of the coil pattern 10, and a magnetic body 30 covering a second main surface 12 of the coil pattern 10. The coil pattern 10 includes a terminal 10A positioned at the end, the first resin layer 21 has a first opening V1 in a part overlapped with the first main surface 11 of the terminal 10A, and the magnetic body 30 has a second opening V2 in a part overlapped with the second main surface 12 of the terminal 10A. The first main surface 11 of the terminal 10A has a first part A1 overlapped with the first opening V1, and a second part A2 covered with the first resin layer 21. The second main surface 12 of the terminal 10A has a third part A3 overlapped with the second opening V2, and a fourth part A4 overlapped with the magnetic body 30.SELECTED DRAWING: Figure 5

Description

[Technical field]

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

[0002] Patent Document 1 discloses a coil component having a planar coil pattern that is electrically accessible from the front and back. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-068841 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the coil component described in Patent Document 1 may have insufficient strength in the terminal portions located at the ends of the coil pattern.

[0005] Therefore, an object of the present disclosure is to increase the strength of terminal portions in a coil component having a planar coil pattern that is electrically accessible from the front and back. [Means for solving the problem]

[0006] A coil component according to one embodiment of the present disclosure comprises a planar coil pattern having a first main surface and a second main surface located opposite the first main surface, a first resin layer covering the first main surface of the coil pattern, and a magnetic body covering the second main surface of the coil pattern, wherein the coil pattern includes a terminal portion located at an end thereof, the first resin layer has a first opening at a portion overlapping with the first main surface of the terminal portion, the magnetic body has a second opening at a portion overlapping with the second main surface of the terminal portion, the first main surface of the terminal portion has a first portion overlapping with the first opening and a second portion covered by the first resin layer, and the second main surface of the terminal portion has a third portion overlapping with the second opening and a fourth portion covered by the magnetic body. Effect of the Invention

[0007] According to the present disclosure, it is possible to increase the strength of the terminal portion in a coil component having a planar coil pattern that is electrically accessible from both sides. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic plan view showing the appearance of a coil device 100 according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a schematic plan view showing the appearance of the coil device 100 as viewed from the opposite side to that in FIG. [Diagram 3] FIG. 3 is a schematic plan view showing the coil device 100 with the magnetic body 30 removed. [Figure 4] FIG. 4 is an enlarged view of area C shown in FIG. [Diagram 5] FIG. 5 is a schematic cross-sectional view taken along the line DD shown in FIG. [Figure 6] FIG. 6 is a schematic cross-sectional view for explaining the structure of each member constituting the coil device 100 in more detail. [Figure 7] FIG. 7 shows a modification of the structure shown in FIG. [Figure 8] FIG. 8 is an enlarged view of the terminal portion 10A of the coil pattern 10 as viewed from the first main surface 11 side. [Figure 9] FIG. 9 is an enlarged view of the terminal portion 10A of the coil pattern 10 as viewed from the second main surface 12 side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0010] 1 and 2 are schematic plan views showing the appearance of a coil device 100 according to an embodiment of the present disclosure, viewed from opposite sides.

[0011] As shown in FIG. 1 and FIG. 2, the coil component 100 according to the present embodiment has a substantially circular planar shape as viewed from the Z direction, with the magnetic body 30 located on one surface and the first resin layer 21 located on the other surface. As shown in FIG. 3, which shows a state in which the magnetic body 30 is removed from the coil component 100, a planar coil pattern 10 is provided between the magnetic body 30 and the first resin layer 21. In the example shown in FIG. 3, the coil pattern 10 turns about four times in a planar spiral shape, and a part of the terminal portion 10A, which is one end (inner peripheral end) of the coil pattern 10, and a part of the terminal portion 10B, which is the other end (outer peripheral end) of the coil pattern 10, are both exposed on both sides of the coil component 100. As a result, the coil component 100 according to the present embodiment is electrically accessible from the front and back, and therefore has a high degree of freedom in mounting and is highly convenient. The planar shape of the coil component 100 as viewed from the Z direction is not limited to a substantially circular shape, and may be a substantially polygonal shape.

[0012] The planar shape of the terminal portions 10A and 10B is substantially circular, and the diameter is larger than the pattern width of the coil pattern 10 in the region other than the terminal portions 10A and 10B. The pattern width of the coil pattern 10 in the region other than the terminal portions 10A and 10B is almost constant at a position away from the terminal portions 10A and 10B, but is locally reduced in the portion going around the terminal portions 10A and 10B. This makes it possible to sufficiently secure the area of ​​the opening region surrounded by the coil pattern 10 while suppressing the planar size of the entire coil component 100. That is, the terminal portion 10A, which is the inner peripheral end, is arranged so as to bite into the innermost peripheral turn, so that the reduction in the area of ​​the opening region due to the terminal portion 10A is suppressed. The terminal portion 10B, which is the outer peripheral end, is arranged so as to bite into the outermost peripheral turn, so that the expansion of the planar size of the entire coil component 100 due to the terminal portion 10B is suppressed. The pattern width of the coil pattern 10 is reduced in the portion where the terminal portions 10A and 10B bite into.

[0013] Fig. 4 is an enlarged view of a region C shown in Fig. 3. Fig. 5 is a schematic cross-sectional view taken along line DD shown in Fig. 4.

[0014] 4, the portion of the coil pattern 10 that winds around the terminal portion 10A is bent more in the turns closer to the inner circumference to avoid the terminal portion 10A that is disposed so as to bite into it, whereas the amount of bending is smaller in the turns closer to the outer circumference. And, the outermost turn is hardly bent at all, and only the pattern width is reduced compared to other portions.

[0015] As shown in FIG. 5, the coil pattern 10 has a first main surface 11 that constitutes an XY plane and is located on the -Z direction side, and a second main surface 12 that constitutes an XY plane opposite to the first main surface 11 and is located on the +Z direction side. The first main surface 11 of the coil pattern 10 is covered with a first resin layer 21 through a third resin layer 40, except for a part of the terminal parts 10A and 10B. The second main surface 12 of the coil pattern 10 is covered with a magnetic body 30 through a second resin layer 22, except for a part of the terminal parts 10A and 10B. Both sides of the first resin layer 21 and the second resin layer 22 may have adhesiveness. The material of the first resin layer 21 is not particularly limited, and examples thereof include an acrylic double-sided tape. The material of the second resin layer 22 is not particularly limited, and examples thereof include an acrylic double-sided tape and an acrylic binder resin. The second resin layer 22 may be made of a material containing a ceramic material or the like in an acrylic binder resin. When both sides of the second resin layer 22 have adhesiveness, the coil pattern 10 and the magnetic body 30 can be firmly bonded via the second resin layer 22. When both sides of the first resin layer 21 have adhesiveness, the coil component 100 according to the present embodiment can be bonded to a mounting object such as a circuit board without using a separate adhesive. The material of the third resin layer 40 is not particularly limited, and examples of the material include binder resins such as polyvinyl chloride resin, polycarbonate resin, polystyrene resin, polymethyl methacrylate resin, polyester resin, polysulfone resin, polyphenylene oxide resin, polybutadiene resin, poly(N-vinylcarbazole) resin, hydrocarbon resin, ketone resin, phenoxy resin, polyamide resin, ethyl cellulose resin, vinyl acetate resin, ABS resin, urethane resin, melamine resin, acrylic resin, unsaturated polyester resin, alkyd resin, epoxy resin, and silicone resin. The third resin layer 40 may be made of a material containing a conductive resin material in the binder resin.

[0016] In the example shown in FIG. 5, the magnetic body 30 is made of a magnetic sheet, and the first resin layer 21 and the second resin layer 22 are both made of an acrylic double-sided tape. In contrast, FIG. 6 shows an example in which the magnetic body 30 is made of a magnetic sheet, the first resin layer 21 is made of an acrylic double-sided tape, and the second resin layer 22 is made of an acrylic binder resin. In the example shown in FIG. 6, the second resin layer 22 made of an acrylic binder resin functions as a filling layer for the space region S located between the coil patterns 10. In this case, the thickness T4 of the second resin layer 22 at the portion overlapping the space region S located between the coil patterns 10 is thicker than the thickness T3 of the portion overlapping the coil pattern 10. The thickness T4 of the second resin layer 22 located in the space region S may be smaller than the thickness T0 of the coil pattern 10. According to this, since at least a part of the side surface 13 connecting the first main surface 11 and the second main surface 12 of the coil pattern 10 is covered with the magnetic body 30, it is possible to obtain higher magnetic properties. Here, the thickness T0 of the coil pattern 10 may be the total thickness of the third resin layer 40 and the coil pattern 10.

[0017] As shown in FIG. 6, the magnetic body 30 includes a first region 31 overlapping the coil pattern 10 and a second region 32 overlapping a space region S located between the coil patterns 10. The thickness T1 of the first region 31 may be substantially the same as the thickness T2 of the second region 32. When the thickness T1 of the first region 31 is substantially the same as the thickness T2 of the second region 32, the height difference T5 between the surface 31a of the first region 31 and the surface 32a of the second region 32 is T4-T3, which is smaller than the thickness T0 of the coil pattern 10. This makes it possible to improve the flatness of the surface of the magnetic body 30. The thicknesses T1 and T2 of the magnetic body 30 may be larger than the thickness T0 of the coil pattern 10. This makes it possible to obtain high magnetic properties. The height of the surface 31a of the first region 31 and the height of the surface 32a of the second region 32 are heights based on the first resin layer 21.

[0018] As yet another embodiment, the second resin layer 22 may be omitted as shown in FIG. 7. The other configurations are the same as those in the example shown in FIG. 6, with the magnetic body 30 being made of a magnetic sheet and the first resin layer 21 being made of an acrylic double-sided tape. In this case, the coil pattern 10 is directly covered with the magnetic body 30. Also, since the entire side surface 13 of the coil pattern 10 is covered with the magnetic body 30, it is possible to obtain even higher magnetic properties. In the example shown in FIG. 7, the thickness T2 of the second region 32 may be thicker than the thickness T1 of the first region 31.

[0019] As shown in FIG. 5, the first resin layer 21 and the third resin layer 40 have a first opening V1 and a fourth opening V4, respectively, at a portion overlapping the first main surface 11 of the terminal portion 10A. The magnetic body 30 and the second resin layer 22 have a second opening V2 and a third opening V3, respectively, at a portion overlapping the second main surface 12 of the terminal portion 10A. As a result, a portion of the first main surface 11 of the terminal portion 10A is exposed through the first opening V1 and the fourth opening V4. Similarly, a portion of the second main surface 12 of the terminal portion 10A is exposed through the second opening V2 and the third opening V3. A surface treatment layer made of Ni / Au plating or the like may be provided on the exposed portion of the terminal portion 10A.

[0020] FIG. 8 is an enlarged view of the terminal portion 10A of the coil pattern 10 as viewed from the first main surface 11 side.

[0021] As shown in FIG. 8, the first main surface 11 of the terminal portion 10A has a first portion A1 overlapping the first opening V1 of the first resin layer 21 and a second portion A2 that is covered by the first resin layer 21 without overlapping the first opening V1. The inner peripheral edge of the first opening V1 overlaps with the first main surface 11 of the terminal portion 10A over the entire circumference. In other words, the outer peripheral edge of the terminal portion 10A on the first main surface 11 side is covered by the first resin layer 21 over the entire circumference. As a result, the outer peripheral edge of the terminal portion 10A on the first main surface 11 side is covered by the first resin layer 21 without being exposed from the first opening V1, so that peeling of the terminal portion 10A is suppressed and the mechanical strength of the terminal portion 10A is ensured.

[0022] Furthermore, the inner peripheral edge of the fourth opening V4 of the third resin layer 40 overlaps with the first portion A1 of the terminal portion 10A over the entire circumference. That is, the third resin layer 40 covers the inner peripheral edge of the first opening V1 over the entire circumference. As a result, the first portion A1 of the terminal portion 10A is divided into a first region A11 exposed from the fourth opening V4 and a second region A12 covered by the third resin layer 40. The first region A11 is a portion where the terminal portion 10A is exposed, and the second region A12 is a portion where the third resin layer 40 is exposed. When a surface treatment layer made of NiAu plating or the like is provided on the terminal portion 10A, the surface treatment layer is formed in the first region A11 without being formed in the second region A12. In this case, the solder does not spread to the second region A12 during mounting, thereby improving the connection reliability.

[0023] Here, assuming a virtual line L extending in the radial direction from the center P of the terminal portion 10A, which is substantially circular, the width W11 of the first region A11 along the virtual line L may be larger than the width W12 of the second region A12 along the virtual line L and the width W2 of the second portion A2 along the virtual line L. This makes it possible to ensure a sufficient exposed area of ​​the terminal portion 10A on the first main surface 11 side. Also, the area of ​​the first region A11 where the terminal portion 10A is exposed may be larger than the area of ​​the second region A12, may be larger than the area of ​​the second portion A2, or may be larger than the combined area of ​​the second region A12 and the second portion A2.

[0024] FIG. 9 is an enlarged view of the terminal portion 10A of the coil pattern 10 as viewed from the second main surface 12 side.

[0025] As shown in FIG. 9, the second main surface 12 of the terminal portion 10A has a third portion A3 that overlaps with the second opening V2 of the magnetic body 30 and the third opening V3 of the second resin layer 22, and a fourth portion A4 that does not overlap with the second opening V2 and the third opening V3 and is covered by the second resin layer 22 and the magnetic body 30. The planar positions of the inner peripheral edge of the second opening V2 and the inner peripheral edge of the third opening V3 may coincide. The inner peripheral edges of the second opening V2 and the third opening V3 overlap with the second main surface 12 of the terminal portion 10A over the entire circumference. In other words, the outer peripheral edge of the terminal portion 10A on the second main surface 12 side is covered with the second resin layer 22 and the magnetic body 30 over the entire circumference. As a result, the outer peripheral edge of the terminal portion 10A on the second main surface 12 side is covered with the second resin layer 22 and the magnetic body 30 without being exposed from the second opening V2 and the third opening V3, thereby suppressing peeling of the terminal portion 10A and ensuring the mechanical strength of the terminal portion 10A.

[0026] Here, assuming an imaginary line L extending radially from a center P of the terminal portion 10A, which is substantially circular, a width W3 of the third portion A3 along the imaginary line L may be larger than a width W4 of the fourth portion A4 along the imaginary line L. This makes it possible to ensure a sufficient exposed area of ​​the terminal portion 10A on the second main surface 12 side. Also, the area of ​​the third portion A3 where the terminal portion 10A is exposed may be larger than the area of ​​the fourth portion A4.

[0027] While the terminal portion 10A of the coil pattern 10 and its surrounding structure have been described in detail above, the terminal portion 10B of the coil pattern 10 and its surrounding structure also have a similar structure.

[0028] As described above, the coil component 100 according to this embodiment has a disk shape with the XY plane as the main surface, and can be connected to the coil pattern 10 from both sides in the Z direction, thereby increasing the degree of freedom in mounting. Moreover, the terminal portions 10A, 10B located at both ends of the coil pattern 10 are sandwiched in the Z direction by the first resin layer 21 and the magnetic body 30 without exposing the outer peripheral edges, so that it is possible to sufficiently ensure the mechanical strength of the terminal portions 10A, 10B even if the thickness of the coil component 100 in the Z direction is thin.

[0029] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present disclosure, and it goes without saying that these modifications are also included within the scope of the present disclosure.

[0030] For example, the first resin layer 32 and the coil pattern 10 do not need to be in direct contact with each other, and a base material such as a PET film may be present between them. In this case, the base material such as a PET film is removed from the portion covering the terminal portion 10A.

[0031] In the examples shown in FIGS. 6 and 7, when the magnetic body 30 is provided, a process for removing steps on the surface of the magnetic body 30 may be performed to further improve the flatness of the surface of the magnetic body 30.

[0032] The technology according to the present disclosure includes the following configuration examples, but is not limited to these.

[0033] A coil component according to an embodiment of the present disclosure includes a planar coil pattern having a first main surface and a second main surface located opposite to the first main surface, a first resin layer covering the first main surface of the coil pattern, and a magnetic body covering the second main surface of the coil pattern, the coil pattern including a terminal portion located at an end, the first resin layer having a first opening at a portion overlapping the first main surface of the terminal portion, the magnetic body having a second opening at a portion overlapping the second main surface of the terminal portion, the first main surface of the terminal portion having a first portion overlapping the first opening and a second portion covered by the first resin layer, and the second main surface of the terminal portion having a third portion overlapping the second opening and a fourth portion covered by the magnetic body. This allows electrical access from the front and back while ensuring the mechanical strength of the terminal portion.

[0034] In the coil component, the coil pattern may further have a side surface connecting the first main surface and the second main surface, and the magnetic body may cover at least a part of the side surface of the coil pattern, thereby making it possible to obtain high magnetic properties.

[0035] In the coil component, the magnetic body includes a first region overlapping the coil pattern and a second region overlapping a space region between the coil patterns, and the difference in height between the surfaces of the first region and the second region may be smaller than the thickness of the coil pattern, thereby making it possible to improve the flatness of the surface of the magnetic body.

[0036] The coil component may further include a second resin layer located between the second main surface of the coil pattern and the magnetic body, and the second resin layer may have a third opening overlapping the second opening, thereby enabling electrical connection to the second main surface of the terminal portion through the second and third openings.

[0037] In the coil component described above, both the first and second resin layers may have adhesive properties on both sides, which allows the coil component to be attached to an object such as a circuit board.

[0038] In the coil component described above, the inner peripheral edge of the first opening may overlap the first main surface of the terminal portion along the entire circumference, and the inner peripheral edge of the second opening may overlap the second main surface of the terminal portion along the entire circumference, thereby making it possible to further increase the mechanical strength of the terminal portion.

[0039] The coil component may further include a third resin layer located between the first main surface of the coil pattern and the first resin layer and covering an inner peripheral edge of the first opening, and the third resin layer may have a fourth opening exposing the first portion, thereby enabling electrical connection to the first main surface of the terminal portion through the first and fourth openings.

[0040] In the coil component described above, the first portion has a first region exposed from the fourth opening and a second region covered by the third resin layer, and the width of the first region along an imaginary line extending radially from the center of the terminal portion may be larger than the width of the second region along the imaginary line, thereby making it possible to ensure a sufficient exposed area on the first main surface side of the terminal portion.

[0041] In the coil component, the coil pattern may be wound multiple times in a planar spiral shape, and the pattern width of the coil pattern may be locally reduced in the portion where it winds around the terminal portion. This makes it possible to obtain a high inductance and to ensure a sufficient area of ​​the opening region surrounded by the coil pattern while suppressing the planar size of the entire coil component. [Explanation of symbols]

[0042] 10 Coil Pattern 10A,10B terminal section 11 First main surface 12 Second main surface 13 Side 21 1st resin layer 22 Second resin layer 30 Magnetic material 31 First area 32 Second area 40 Third resin layer 100 Coil parts A1 Part 1 A2 Part 2 A3 Part 3 A4 Part 4 A11 1st Area A12 Second Area C Field L Fantasy Line P Center S スペース domain V1 1st opening V2 2nd opening V3 3rd opening V4 4th opening

Claims

1. a planar coil pattern having a first main surface and a second main surface located opposite to the first main surface; a first resin layer covering the first main surface of the coil pattern; a magnetic body covering the second main surface of the coil pattern; Equipped with The coil pattern includes a terminal portion located at an end portion, the first resin layer has a first opening at a portion overlapping the first main surface of the terminal portion, the magnetic body has a second opening at a portion overlapping the second main surface of the terminal portion, the first main surface of the terminal portion has a first portion overlapping with the first opening and a second portion covered with the first resin layer, the second main surface of the terminal portion has a third portion overlapping with the second opening and a fourth portion covered with the magnetic material; Coil parts.

2. The coil pattern further has a side surface connecting the first main surface and the second main surface, The magnetic body covers at least a portion of the side surface of the coil pattern. The coil component according to claim 1 .

3. the magnetic body includes a first region overlapping the coil pattern and a second region overlapping a space region located between the coil patterns; a height difference between a surface of the first region and a surface of the second region is smaller than a thickness of the coil pattern; The coil component according to claim 2 .

4. a second resin layer located between the second main surface of the coil pattern and the magnetic body, The second resin layer has a third opening overlapping the second opening. The coil component according to claim 1 .

5. Both of the first and second resin layers have adhesive properties on both sides. The coil component according to claim 4 .

6. an inner peripheral edge of the first opening overlaps with the first main surface of the terminal portion along the entire periphery; An inner peripheral edge of the second opening overlaps with the second main surface of the terminal portion along the entire periphery. The coil component according to claim 1 .

7. a third resin layer located between the first main surface of the coil pattern and the first resin layer and covering an inner peripheral edge of the first opening, the third resin layer has a fourth opening portion exposing the first portion; The coil component according to claim 6.

8. the first portion has a first region exposed from the fourth opening and a second region covered by the third resin layer, a width of the first region along a virtual line extending radially from a center of the terminal portion is greater than a width of the second region along the virtual line; The coil component according to claim 7.

9. The coil pattern is wound multiple times in a planar spiral shape, The pattern width of the coil pattern is locally reduced in a portion where the coil pattern winds around the terminal portion. The coil component according to claim 1 .

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