Common mode filter

Abstract

To achieve higher common mode attenuation characteristics and lower differential insertion loss characteristics in a common mode filter that has a structure in which a magnetic material is placed in the inner diameter area surrounded by a coil pattern.SOLUTION: A common mode filter 1 includes coil patterns 110 and 210 and a magnetic body 3 arranged in an inner diameter region A. The inner diameter region A includes regions A1 and A2 located on the +X and -X sides, respectively, of an imaginary line Ly extending in the Y direction, which is the short side direction. The coil patterns 110 and 210 have sections 111 and 211 and sections 112 and 212 located on the +X and -X sides, respectively, of the imaginary line Ly. The number of coil conductors constituting the sections 111 and 211 is one more than the number of coil conductors constituting the sections 112 and 212. The magnetic body 3 is arranged offset toward the region A2.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a common mode filter, and more particularly to a common mode filter having a plurality of coil patterns stacked with an insulating layer interposed therebetween. [Background technology]

[0002] Patent Document 1 discloses a chip-type common mode filter having two coil patterns stacked with an insulating layer between them. In the common mode filter described in Patent Document 1, a magnetic body is arranged in an inner diameter region surrounded by the coil patterns in a plan view seen from the stacking direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4683071 Summary of the Invention [Problem to be solved by the invention]

[0004] This type of common mode filter is required to have higher common mode attenuation characteristics and lower differential insertion loss characteristics within a limited planar size.

[0005] This disclosure describes a technology for achieving higher common-mode attenuation characteristics and lower differential insertion loss characteristics in a common-mode filter having a structure in which a magnetic material is arranged in an inner diameter region surrounded by a coil pattern. [Means for solving the problem]

[0006] A common mode filter according to one aspect of the present disclosure includes a first coil pattern that wraps around in a spiral shape over multiple turns, a second coil pattern that is stacked on the first coil pattern via an insulating layer and that wraps around in a spiral shape over multiple turns, and a magnetic body that is arranged in an inner diameter region that is surrounded by the first and second coil patterns in a plan view seen from the stacking direction, wherein the inner diameter region has a shape that is larger in size in a first direction than in a second direction that is orthogonal to the first direction, and the inner diameter region includes a first region that is located on one side in the first direction as seen from an imaginary line that passes through the center of the inner diameter region and extends in the second direction, and a second region that is located on the other side in the first direction as seen from the imaginary line, and the first coil pattern is The second coil pattern includes a first section located on one side in the first direction as viewed from the imaginary line, and a second section located on the other side in the first direction as viewed from the imaginary line, and a third section located on the other side in the first direction as viewed from the imaginary line, and a fourth section located on the other side in the first direction as viewed from the imaginary line, and the number of coil conductors constituting the first section is one more at at least some circumferential positions than the number of coil conductors constituting the second section at at least some circumferential positions, and the number of coil conductors constituting the third section is one more at at least some circumferential positions than the number of coil conductors constituting the fourth section at at least some circumferential positions, and the magnetic body is arranged offset toward the second region. [Effects of the Invention]

[0007] According to the present disclosure, a technology is provided for achieving higher common-mode attenuation characteristics and lower differential insertion loss characteristics in a common-mode filter having a structure in which a magnetic material is arranged in an inner diameter region surrounded by a coil pattern. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic perspective view showing the appearance of a common mode filter 1 according to an embodiment of the technology disclosed herein. [Figure 2]FIG. 2 is a schematic plan view for explaining the pattern shape of the conductor layer 100. As shown in FIG. [Figure 3] FIG. 3 is a schematic plan view of the insulating layer 10. As shown in FIG. [Figure 4] FIG. 4 is a schematic plan view for explaining the pattern shape of the conductor layer 200. As shown in FIG. [Figure 5] FIG. 5 is a schematic plan view of the insulating layer 20. As shown in FIG. [Figure 6] FIG. 6 is a schematic plan view for explaining the pattern shape of the conductor layer 300. As shown in FIG. [Figure 7] FIG. 7 is a schematic plan view of the insulating layer 30. As shown in FIG. [Figure 8] FIG. 8 is an equivalent circuit diagram of the common mode filter 1. As shown in FIG. [Figure 9] FIG. 9 is a schematic plan view illustrating the pattern shape of a conductor layer 100A according to a modified example. [Figure 10] FIG. 10 is a schematic plan view of an insulating layer 10A according to a modified example. [Figure 11] FIG. 11 is a schematic plan view illustrating the pattern shape of a conductor layer 200A according to a modified example. [Figure 12] FIG. 12 is a schematic plan view of an insulating layer 20A according to a modified example. [Figure 13] FIG. 13 is a schematic plan view illustrating the pattern shape of a conductor layer 300A according to a modified example. [Figure 14] FIG. 14 is a schematic plan view of an insulating layer 30A according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

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

[0010] FIG. 1 is a schematic perspective view showing the appearance of a common mode filter 1 according to an embodiment of the technology disclosed herein.

[0011] 1, the common mode filter 1 according to the first embodiment is a surface-mounted chip component, and includes an element body 2 and four terminal electrodes E1 to E4 embedded in the element body 2. As will be described later, three conductor layers 100, 200, and 300 are embedded in the element body 2, stacked with insulating layers interposed between them.

[0012] FIG. 2 is a schematic plan view for explaining the pattern shape of the conductor layer 100. As shown in FIG.

[0013] The conductor layer 100 is the bottommost conductor layer and has a spiral coil pattern 110 and connection patterns 121 to 125. An outer peripheral end 110A of the coil pattern 110 is connected to the connection pattern 121 via an extension portion 113. An inner peripheral end 110B of the coil pattern 110 is connected to the connection pattern 125. The connection pattern 125 can be considered as part of the coil pattern 110, and in this case, the tip of the connection pattern 125 forms the inner peripheral end of the coil pattern 110. The coil pattern 110 winds around in a right-handed (clockwise) direction from the outer peripheral end 110A to the inner peripheral end 110B, whereas the extension portion 113 does not wind around in a right-handed (clockwise) direction but extends linearly in the -X direction from the outer peripheral end 110A to the inner peripheral end 110B. The connection patterns 122 to 124 are provided independently within the conductor layer 100 without being connected to other conductor patterns.

[0014] The coil pattern 110 has a substantially elliptical shape in a plan view from the Z direction, which is the stacking direction, with the X direction as the major axis and the Y direction as the minor axis. Therefore, the inner diameter region A surrounded by the coil pattern 110 has a shape in which the size in the X direction is larger than the size in the Y direction. Here, assuming a virtual line Ly passing through the center of the inner diameter region A of the coil pattern 110 and extending in the Y direction, the coil pattern 110 is divided into a section 111 located on the +X direction side from the virtual line Ly and a section 112 located on the -X direction side from the virtual line Ly. As shown in FIG. 2 , in this embodiment, both the outer peripheral end 110A and the inner peripheral end 110B of the coil pattern 110 belong to the section 111. That is, both the outer peripheral end 110A and the inner peripheral end 110B of the coil pattern 110 are located on the +X direction side from the virtual line Ly. Furthermore, the circumferential position of inner circumferential end 110B of coil pattern 110 is located further in the circumferential direction from outer circumferential end 110A to inner circumferential end 110B than the circumferential position of outer circumferential end 110A of coil pattern 110. As a result, the number N of coil conductors constituting section 112 is 12 (N=12), while the number N of coil conductors constituting section 111 is 13 (N=13), which is one more than the number of coil conductors constituting section 112.

[0015] In the example shown in Fig. 2, in section 112, the number N of coil conductors is 12 (N = 12) at any circumferential position. In contrast, in section 111, the number N of coil conductors in the rightward (clockwise) direction is 13 (N = 13) in the region from circumferential position R1 to circumferential position R2, and the number N of coil conductors in the other regions is 12 (N = 12). Circumferential position R1 is the position of the outer peripheral end 110A of coil pattern 110. Circumferential position R2 is the position of the end of connection pattern 125 in the rightward (clockwise) direction, and corresponds to the inner peripheral end when connection pattern 125 is considered to be part of coil pattern 110.

[0016] The inner diameter region A of the coil pattern 110 is divided into a region A1 located on the +X direction side as viewed from the imaginary line Ly, and a region A2 located on the −X direction side as viewed from the imaginary line Ly. The entire connection pattern 125 is located in region A1.

[0017] As shown in FIG. 2, a magnetic body 3, which is a part of the base body 2, is disposed in the inner diameter region A of the coil pattern 110. The magnetic body 3 is disposed so as to axially penetrate the inner diameter region A of the coil patterns 110 and 210. The magnetic body 3 is made of a material having a higher magnetic permeability than an insulating material such as resin that constitutes other parts of the base body 2, for example, a mixture of magnetic fillers such as ferrite powder and metallic magnetic powder and a resin binder. The magnetic body 3 is not located at the center of the inner diameter region A of the coil pattern 110, but is offset and disposed on the region A2 side. In the example shown in FIG. 2, the virtual line Ly crosses the magnetic body 3, a part (most part) of the magnetic body 3 is located in the region A2, and the remaining part of the magnetic body 3 is located in the region A1. Thus, since the magnetic body 3 is offset and disposed on the region A2 side, the section 112 of the coil pattern 110 is closer to the magnetic body 3 than the section 111 of the coil pattern 110.

[0018] More specifically, when the area of the part located in the region A1 of the XY cross section of the magnetic body 3 is defined as Sa and the area of the part located in the region A2 is defined as Sb, Sa < Sb. The area Sb is preferably at least twice the area Sa, and may be at least 2.3 times. Also, when the maximum size of the part located in the region A1 of the size of the magnetic body 3 in the Y direction is defined as La and the maximum size of the part located in the region A is defined as Lb, La < Lb. The size Lb is preferably at least 1.2 times the size La. Further, when a virtual line Lx passing through the center of the inner diameter region A of the coil pattern 110 and extending in the X direction is assumed, when the distance along the virtual line Lx between the part of the magnetic body 3 located in the region A1 and the innermost turn of the coil pattern 110 is defined as Wa, and the distance along the virtual line Lx between the part of the magnetic body located in the region A2 and the innermost turn of the coil pattern 110 is defined as Wb, Wa > Wb. The distance Wa is preferably at least 1.5 times the distance Wb, and may be at least 1.9 times. The distance Wa is defined by the distance between a part that is a part of the connection pattern 125 and is located on the extension line of the innermost turn of the coil pattern 110 and the magnetic body 3, as shown by the broken line in FIG. 2.

[0019] FIG. 3 is a schematic plan view of the insulating layer 10. As shown in FIG.

[0020] The insulating layer 10 is located between the conductor layer 100 and the conductor layer 200, and has openings 11 to 15 and 17. The openings 11 to 15 are provided at positions that expose the connection patterns 121 to 125, respectively. A magnetic body 3 is embedded in the opening 17.

[0021] FIG. 4 is a schematic plan view for explaining the pattern shape of the conductor layer 200. As shown in FIG.

[0022] The conductor layer 200 has a spiral coil pattern 210 and connection patterns 221 to 226. An outer peripheral end 210A of the coil pattern 210 is connected to the connection pattern 222 via an extension portion 213. An inner peripheral end 210B of the coil pattern 210 is connected to the connection pattern 226. The connection pattern 226 can be considered as part of the coil pattern 210, and in this case, the tip of the connection pattern 226 forms the inner peripheral end of the coil pattern 210. The coil pattern 210 winds around in a right-handed (clockwise) direction from the outer peripheral end 210A toward the inner peripheral end 210B, while the extension portion 213 extends linearly in the +X direction from the connection pattern 222 toward the outer peripheral end 210A. The connection patterns 221, 223, 224, and 225 are provided independently without being connected to other conductor patterns within the conductor layer 200. The connection patterns 221 to 225 are connected to the connection patterns 121 to 125 via openings 11 to 15 provided in the insulating layer 10, respectively.

[0023] The number of turns in coil pattern 210 is approximately the same as the number of turns in coil pattern 110, and each turn of coil pattern 210 overlaps in the Z direction with the corresponding turn of coil pattern 110. Even if there is a difference in the number of turns between coil pattern 110 and coil pattern 210 due to the position of the lead-out portion or the like, it is preferable that the difference in the number of turns between coil pattern 110 and coil pattern 210 be ½ turn or less in order to ensure the function as a common mode filter.

[0024] Here, assuming an imaginary line Ly that passes through the center of the inner diameter region of the coil pattern 210 and extends in the Y direction, the coil pattern 210 is divided into a section 211 located on the +X direction side as viewed from the imaginary line Ly and a section 212 located on the −X direction side as viewed from the imaginary line Ly. As shown in FIG. 4 , in this embodiment, the outer circumferential end 210A of the coil pattern 210 is located on the imaginary line Ly, and the inner circumferential end 210B of the coil pattern 210 belongs to the section 211. That is, the inner circumferential end 210B of the coil pattern 210 is located on the +X direction side as viewed from the imaginary line Ly. Furthermore, the circumferential position of the inner circumferential end 210B of the coil pattern 210 is located further ahead than the circumferential position of the outer circumferential end 210A of the coil pattern 210 in the winding direction from the outer circumferential end 210A to the inner circumferential end 210B. As a result, the number N of coil conductors constituting section 212 is 12 (N=12), while the number N of coil conductors constituting section 211 is 13 (N=13), which is one more than the number of coil conductors constituting section 212.

[0025] 4, the number N of coil conductors in section 211 is 13 (N=13) at any circumferential position, and the number N of coil conductors in section 212 is 12 (N=12) at any circumferential position. The right-handed (clockwise) end of connection pattern 226 is located on imaginary line Ly, and this part corresponds to the inner circumferential end when connection pattern 226 is considered to be part of coil pattern 210. Connection patterns 225 and 226 are entirely located in area A1.

[0026] The position of the magnetic body 3 in the inner diameter region of the coil pattern 210 is the same as in Fig. 2. That is, the magnetic body 3 is disposed offset toward the region A2 side. As a result, the section 212 of the coil pattern 210 is closer to the magnetic body 3 than the section 211 of the coil pattern 210.

[0027] 4, the outer peripheral edge of the magnetic body 3 in plan view from the Z direction, which is the stacking direction, is located in region A2 and includes a convex edge 3a that follows the innermost turn of the coil pattern 210 and a concave edge 3b that is cut out to avoid the connection pattern 226 that forms the inner peripheral end of the coil pattern 210. The concave edge 3b intersects with the imaginary line Ly.

[0028] FIG. 5 is a schematic plan view of the insulating layer 20. As shown in FIG.

[0029] The insulating layer 20 is located between the conductor layer 200 and the conductor layer 300, and has openings 21 to 27. The openings 21 to 26 are provided at positions that expose the connection patterns 221 to 226, respectively. A magnetic body 3 is embedded in the opening 27.

[0030] FIG. 6 is a schematic plan view for explaining the pattern shape of the conductor layer 300. As shown in FIG.

[0031] The conductor layer 300 has connection patterns 321 to 326. The connection patterns 321 to 326 are connected to the connection patterns 221 to 226 via openings 21 to 26 provided in the insulating layer 20, respectively. The connection pattern 325 is connected to the connection pattern 323 via an extension portion 325a. The connection pattern 326 is connected to the connection pattern 324 via an extension portion 326a.

[0032] FIG. 7 is a schematic plan view of the insulating layer 30. As shown in FIG.

[0033] The insulating layer 30 is the uppermost insulating layer and has openings 31 to 34, 37. The openings 31 to 34 are provided at positions that expose the connection patterns 321 to 324, respectively. A magnetic substance 3 is embedded in the opening 37. The terminal electrodes E1 to E4 shown in FIG. 1 are connected to the connection patterns 321 to 324 via the openings 31 to 34, respectively.

[0034] With this configuration, the outer peripheral end of coil pattern 110 is connected to terminal electrode E1, the outer peripheral end of coil pattern 210 is connected to terminal electrode E2, the inner peripheral end of coil pattern 110 is connected to terminal electrode E3, and the inner peripheral end of coil pattern 210 is connected to terminal electrode E4. As a result, as shown in Fig. 8, coil pattern 110 connected between terminal electrode E1 and terminal electrode E3 and coil pattern 210 connected between terminal electrode E2 and terminal electrode E4 are coupled.

[0035] In the common mode filter 1 according to this embodiment, the magnetic body 3 is not disposed in the center of the inner diameter region of the coil patterns 110, 210 but is disposed offset toward region A2, thereby increasing the inductance in the sections 112, 212 with a small number of coil conductors. In other words, the difference between the inductance generated in the sections 112, 212 with a small number of coil conductors and the inductance generated in the sections 111, 211 with a large number of coil conductors is reduced. As a result, it is possible to obtain higher common-mode attenuation characteristics and lower differential insertion loss characteristics.

[0036] Furthermore, since the connection patterns 125, 225, and 226 are arranged on the region A1 side, the inner diameter region A of the coil patterns 110 and 210 is effectively utilized. That is, the inner diameter region A of the coil patterns 110 and 210 has a shape whose longitudinal direction is in the X direction, and by arranging the connection patterns 125, 225, and 226 in the space on the +X direction side that is generated by arranging the magnetic body 3 offset to the -X direction side, it is possible to accommodate the magnetic body 3 and the connection patterns 125, 225, and 226 in the inner diameter region A of the coil patterns 110 and 210 without increasing the size of the coil patterns 110 and 210.

[0037] Furthermore, the planar shape of the magnetic body 3 is not a simple circle or rectangle, but has a convex edge 3a in region A2 and a concave edge 3b in the portion close to the connection pattern 226, which makes it possible to further expand the volume of the magnetic body 3 while ensuring a planar distance from the connection patterns 125, 225, and 226. Moreover, by positioning the tip of the connection pattern 226 substantially on the imaginary line Ly, the number of turns of the coil pattern 210 is maximized. As a result, the concave edge 3b of the magnetic body 3 intersects with the imaginary line Ly.

[0038] 9, 11, and 13 are schematic plan views illustrating the pattern shapes of conductor layers 100A, 200A, and 300A according to modifications, respectively, and FIGS. 10, 12, and 14 are schematic plan views of insulating layers 10A, 20A, and 30A according to modifications, respectively.

[0039] 9 to 14 differ from the configuration shown in FIGS. 2 to 7 in that the modified examples further include magnetic bodies 4 and 5 located in the outer regions of the coil patterns 110 and 210. The magnetic bodies 4 and 5 are separate parts of the element body 2 and may be made of the same magnetic material as the magnetic body 3. The other basic configuration is the same as the configuration shown in FIGS. 2 to 7, so the same elements are given the same reference numerals and redundant explanations will be omitted.

[0040] The magnetic body 4 is located in the outer region of the coil patterns 110, 210, on the +X-direction side of the coil patterns 110, 210. The magnetic body 5 is located in the outer region of the coil patterns 110, 210, on the -X-direction side of the coil patterns 110, 210. Adding such magnetic bodies 4, 5 further increases the inductance of the coil patterns 110, 210. In this embodiment, the planar shape of the element body 2 is a rectangle with the X-direction as the longitudinal direction and the Y-direction as the lateral direction, so that there is more space on the X-direction side than on the Y-direction side in the outer region of the coil patterns 110, 210, and by arranging the magnetic bodies 4, 5 in this space, it is possible to increase the inductance.

[0041] The above describes embodiments of the technology according to the present disclosure, but the technology according to the present disclosure is not limited to the above embodiments, and various modifications are possible within the scope of the gist of the technology, and it goes without saying that these modifications are also included within the scope of the technology according to the present disclosure.

[0042] The technology according to the present disclosure includes, but is not limited to, the following configuration examples.

[0043] A common mode filter according to one aspect of the present disclosure includes a first coil pattern that wraps around in a spiral shape over multiple turns, a second coil pattern that is stacked on the first coil pattern via an insulating layer and that wraps around in a spiral shape over multiple turns, and a magnetic body that is arranged in an inner diameter region that is surrounded by the first and second coil patterns in a plan view seen from the stacking direction, wherein the inner diameter region has a shape that is larger in size in a first direction than in a second direction that is orthogonal to the first direction, and the inner diameter region includes a first region that is located on one side in the first direction as seen from an imaginary line that passes through the center of the inner diameter region and extends in the second direction, and a second region that is located on the other side in the first direction as seen from the imaginary line, and the first coil pattern is The second coil pattern includes a first section located on one side in the first direction as viewed from the imaginary line, and a second section located on the other side in the first direction as viewed from the imaginary line, and a third section located on the other side in the first direction as viewed from the imaginary line, and a fourth section located on the other side in the first direction as viewed from the imaginary line, and the number of coil conductors constituting the first section is one more at at least some circumferential positions than the number of coil conductors constituting the second section at at least some circumferential positions, and the number of coil conductors constituting the third section is one more at at least some circumferential positions than the number of coil conductors constituting the fourth section at at least some circumferential positions, and the magnetic body is arranged offset toward the second region.

[0044] In the above common mode filter, the inner circumferential ends of the first and second coil patterns may both be located in the first region, which makes it possible to further increase the volume of the magnetic body while ensuring a planar distance between the inner circumferential ends of the first and second coil patterns and the magnetic body.

[0045] In the above common mode filter, the outer peripheral edge of the magnetic body in plan view from the stacking direction may be located in the second region and may include a convex edge along the innermost turns of the first and second coil patterns and a concave edge cut out to avoid the inner peripheral edge of the second coil pattern. This allows the volume of the magnetic body to be further increased while maintaining a planar distance between the inner peripheral edge of the second coil pattern and the magnetic body. In this case, the concave edge may intersect with a virtual line. This allows the number of turns of the second coil pattern to be increased. [Explanation of symbols]

[0046] 1 Common mode filter 2 Base 3~5 Magnetic material 3a Convex edge 3b Concave Edge 10,10A,20,20A,30,30A Insulation layer 11~15,17,21~27,31~34,37 Openings 100,100A,200,200A,300,300A Conductor layer 110,210 coil pattern 110A, 210A outer edge 110B,210B Inner edge 111,112,211,212 sections 113,213,325a,326a Drawer section 121~125, 221~226, 321~326 connection patterns A Inner diameter area A1,A2 area E1~E4 terminal electrode Lx,Ly virtual lines R1, R2 circumferential position

Claims

1. a first coil pattern that is spirally wound over a plurality of turns; a second coil pattern that is laminated on the first coil pattern via an insulating layer and that winds around in a spiral shape over a plurality of turns; a magnetic body disposed in an inner diameter region surrounded by the first and second coil patterns in a plan view seen from the stacking direction; Equipped with the inner diameter region has a shape in which a size in a first direction is larger than a size in a second direction perpendicular to the first direction, the inner diameter region includes a first region located on one side in the first direction as viewed from a virtual line that passes through a center of the inner diameter region and extends in the second direction, and a second region located on the other side in the first direction as viewed from the virtual line, the first coil pattern includes a first section located on one side in the first direction as viewed from the imaginary line, and a second section located on the other side in the first direction as viewed from the imaginary line, the second coil pattern includes a third section located on the one side in the first direction as viewed from the imaginary line, and a fourth section located on the other side in the first direction as viewed from the imaginary line, the number of coil conductors constituting the first section is one more at at least some circumferential positions than the number of coil conductors constituting the second section at at least some circumferential positions, the number of coil conductors constituting the third section is one more at at least some circumferential positions than the number of coil conductors constituting the fourth section at at least some circumferential positions, the magnetic body is disposed offset toward the second region, Common mode filter.

2. Inner circumferential ends of the first and second coil patterns are both located in the first region.

2. The common mode filter according to claim 1.

3. an outer peripheral edge of the magnetic body in a plan view seen from the stacking direction is located in the second region and includes a convex edge along the innermost circumferential turns of the first and second coil patterns and a concave edge cut out so as to avoid the inner peripheral end of the second coil pattern; 3. The common mode filter according to claim 2.

4. the concave edge intersects with the imaginary line; 4. The common mode filter according to claim 3.

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