Common mode filter

Abstract

To improve high frequency characteristics of a common mode filter by reducing inter-wire capacity in a section close to a terminal electrode.SOLUTION: A common mode filter 1 comprises conductor layers 100 and 200, which are laminated via an insulation layer, and terminal electrodes E1-E4. The conductor layer 100 includes a spiral coil pattern 110 of which the outer peripheral end is connected to the terminal electrode E1 and the inner peripheral end is connected to the terminal electrode E3. The conductor layer 200 includes a coil pattern 210 of which the outer peripheral end is connected to the terminal electrode E2 and the inner peripheral end is connected to the terminal electrode E4. An outermost peripheral turn 111 of the coil pattern 110 has a non-overlapped section S1 which circulates without overlapping an outermost peripheral turn 211 of the coil pattern 210, or an innermost peripheral turn 112 of the coil pattern 110 has a non-overlapped section S2 which circulates without overlapping an innermost peripheral turn 212 of the coil pattern 210.SELECTED DRAWING: Figure 9

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 a plurality of coil patterns stacked with insulating layers interposed therebetween. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-139368 Summary of the Invention [Problem to be solved by the invention]

[0004] In this type of common mode filter, the line capacitance between the coil patterns affects the high frequency characteristics.

[0005] This disclosure describes a technique for improving high-frequency characteristics in a common mode filter having multiple coil patterns stacked with insulating layers interposed therebetween by reducing the line capacitance in sections close to terminal electrodes. [Means for solving the problem]

[0006] A common mode filter according to one aspect of the present disclosure comprises a plurality of conductor layers stacked via insulating layers, including at least first and second conductor layers, and first, second, third, and fourth terminal electrodes, wherein the first conductor layer has a first spiral coil pattern whose outer peripheral end is connected to the first terminal electrode and whose inner peripheral end is connected to the third terminal electrode, and the second conductor layer has a second spiral coil pattern whose outer peripheral end is connected to the second terminal electrode and whose inner peripheral end is connected to the fourth terminal electrode, and the outermost turn of the first coil pattern has a first non-overlapping section that does not overlap with the outermost turn of the second coil pattern for at least 1 / 4 of a turn, or the innermost turn of the first coil pattern has a second non-overlapping section that does not overlap with the innermost turn of the second coil pattern for at least 1 / 4 of a turn. [Effects of the Invention]

[0007] According to the present disclosure, a technique is provided for improving high-frequency characteristics in a common mode filter having multiple coil patterns stacked via insulating layers by reducing the line-to-line capacitance in sections close to terminal electrodes. [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 a first embodiment of the technique 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 cross-sectional view of the common mode filter 1. As shown in FIG. [Figure 10] FIG. 10 is a graph for explaining the effects of the first embodiment. [Figure 11] FIG. 11 is a schematic plan view illustrating the pattern shape of a conductor layer 100A used in a common mode filter according to a second embodiment of the technique disclosed herein. [Figure 12] FIG. 12 is a schematic cross-sectional view of a common mode filter according to the second embodiment. [Figure 13] FIG. 13 is a schematic plan view illustrating the pattern shape of a conductor layer 100B used in a common mode filter according to a third embodiment of the technique disclosed herein. [Figure 14] FIG. 14 is a schematic plan view illustrating the pattern shape of a conductor layer 100C used in a common mode filter according to a fourth embodiment of the technique disclosed herein. [Figure 15] FIG. 15 is a schematic plan view illustrating the pattern shape of a conductor layer 300A used in the common mode filter according to the fifth embodiment. [Figure 16] FIG. 16 is a schematic plan view of an insulating layer 30 used in the common mode filter according to the fifth embodiment. [Figure 17] FIG. 17 is a schematic plan view for explaining the pattern shape of the conductor layer 400. As shown in FIG. [Figure 18] FIG. 18 is a schematic plan view of the insulating layer 40. As shown in FIG. [Figure 19] FIG. 19 is a schematic cross-sectional view of a common mode filter according to the fifth embodiment. 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] First Embodiment FIG. 1 is a schematic perspective view showing the appearance of a common mode filter 1 according to a first embodiment of the technique 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. In the example shown in FIG. 2, the coil pattern 110 has approximately 12 turns, including an outermost turn 111, an innermost turn 112, and an intermediate turn 113 located between the second turn 113a counting from the outermost periphery and the second turn 113b counting from the innermost periphery. The intermediate turn 113 has approximately 10 turns. The outer circumferential end of the coil pattern 110 is connected to the connection pattern 121 via a lead-out portion 114. The inner circumferential end of the coil pattern 110 is connected to the connection pattern 125. The coil pattern 110 winds clockwise from the outer circumferential end to the inner circumferential end, whereas the lead-out portion 114 extends linearly in the −X direction from the outer circumferential end to the inner circumferential end without winding clockwise. The connection patterns 122 to 124 are provided independently within the conductor layer 100 without being connected to other conductor patterns.

[0014] FIG. 3 is a schematic plan view of the insulating layer 10. As shown in FIG.

[0015] The insulating layer 10 is located between the conductor layer 100 and the conductor layer 200, and has openings 11 to 15. The openings 11 to 15 are provided at positions that expose the connection patterns 121 to 125, respectively.

[0016] FIG. 4 is a schematic plan view for explaining the pattern shape of the conductor layer 200. As shown in FIG.

[0017] The conductor layer 200 has a spiral coil pattern 210 and connection patterns 221 to 226. In the example shown in FIG. 4 , the coil pattern 210 has approximately 12 turns, including an outermost turn 211, an innermost turn 212, and an intermediate turn 213 located between the second turn 213a counting from the outermost circumference and the second turn 213b counting from the innermost circumference. The intermediate turn 213 has approximately 10 turns. That is, the number of turns of the coil pattern 110 and the number of turns of the coil pattern 210 are approximately the same. Even if there is a difference in the number of turns between the coil pattern 110 and the coil pattern 210 due to the position of the lead-out portion or the like, the difference in the number of turns between the coil pattern 110 and the coil pattern 210 needs to be ½ turn or less to ensure the function as a common mode filter.

[0018] The outer peripheral end of coil pattern 210 is connected to connection pattern 222 via lead-out portion 214. The inner peripheral end of coil pattern 210 is connected to connection pattern 226. Coil pattern 210 winds clockwise from the outer peripheral end to the inner peripheral end, while lead-out portion 214 extends linearly in the +X direction from the outer peripheral end to the inner peripheral end. Connection patterns 221, 223, 224, and 225 are provided independently without being connected to other conductor patterns within conductor layer 200. Connection patterns 221 to 225 are connected to connection patterns 121 to 125 via openings 11 to 15 provided in insulating layer 10, respectively.

[0019] FIG. 5 is a schematic plan view of the insulating layer 20. As shown in FIG.

[0020] The insulating layer 20 is located between the conductor layer 200 and the conductor layer 300, and has openings 21 to 26. The openings 21 to 26 are provided at positions that expose the connection patterns 221 to 226, respectively.

[0021] FIG. 6 is a schematic plan view for explaining the pattern shape of the conductor layer 300. As shown in FIG.

[0022] 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.

[0023] FIG. 7 is a schematic plan view of the insulating layer 30. As shown in FIG.

[0024] The insulating layer 30 is the uppermost insulating layer and has openings 31 to 34. The openings 31 to 34 are provided at positions that expose the connection patterns 321 to 324, respectively. 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.

[0025] 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.

[0026] In this embodiment, as shown in Fig. 2, the radial spacing between adjacent turns of the coil pattern 110 is not constant. Instead, a space 115 between the outermost turn 111 and the second turn 113a counting from the outermost circumference, and a space 116 between the innermost turn 112 and the second turn 113b counting from the innermost circumference, are larger than the spacing between the turns constituting the intermediate turn 113. The spaces 115 and 116 are larger than the pattern width of the coil pattern 210. The radial spacing between the turns constituting the intermediate turn 113 is approximately constant. On the other hand, as shown in Fig. 4, the radial spacing between adjacent turns of the coil pattern 210 is approximately constant.

[0027] 9, the outermost turn 111 of the coil pattern 110 and the outermost turn 211 of the coil pattern 210 do not overlap each other at least partially, and the innermost turn 112 of the coil pattern 110 and the innermost turn 212 of the coil pattern 210 do not overlap each other at least partially. The section of the outermost turn 111 of the coil pattern 110 that does not overlap with the outermost turn 211 of the coil pattern 210 constitutes a non-overlapping section S1. The section of the innermost turn 112 of the coil pattern 110 that does not overlap with the innermost turn 212 of the coil pattern 210 constitutes a non-overlapping section S2. The section of the outermost turn 211 of the coil pattern 210 that does not overlap with the outermost turn 111 of the coil pattern 110 constitutes a non-overlapping section S4. The section of the innermost turn 212 of the coil pattern 210 that does not overlap with the innermost turn 112 of the coil pattern 110 constitutes a non-overlapping section S5.

[0028] In this way, since the outermost turns 111, 211 of the coil patterns 110, 210 have non-overlapping sections S1, S4, respectively, the inter-line capacitance generated between the outermost turns 111, 211 is reduced, resulting in a reduction in the capacitance component C1 near the terminal electrodes E1 and E2. Similarly, since the innermost turns 112, 212 of the coil patterns 110, 210 have non-overlapping sections S2, S5, respectively, the inter-line capacitance generated between the innermost turns 112, 212 is reduced, resulting in a reduction in the capacitance component C2 near the terminal electrodes E3 and E4.

[0029] Each turn constituting the intermediate turn 113 of the coil pattern 110 overlaps with each turn constituting the intermediate turn 213 of the coil pattern 210. This enhances the coupling between the coil pattern 110 and the coil pattern 210.

[0030] The non-overlapping section S1 of the coil pattern 110 may be constituted by the entire outermost turn 111, or may be constituted by a part of the outermost turn 111, but to obtain the effect of reducing the capacitance component C1, at least ¼ turn of the outermost turn 111 needs to be the non-overlapping section S1, and it is preferable that the non-overlapping section S1 is ½ turn or more of the outermost turn 111. In other words, the non-overlapping section S1 of the coil pattern 110 does not refer to a section such as the lead-out portion 114, but rather is a section that winds around in the same direction along the second turn 113a counting from the outermost periphery, and that includes at least a portion extending in the X direction and a portion extending in the Y direction.

[0031] The same is true for the non-overlapping section S2 of the coil pattern 110; it may be constituted by the entire innermost turn 112 or by part of the innermost turn 112, but in order to obtain the effect of reducing the capacitance component C2, at least ¼ of the turn of the innermost turn 112 needs to be the non-overlapping section S2, and it is preferable that at least ½ or more of the turn of the innermost turn 112 is the non-overlapping section S2. In other words, the non-overlapping section S2 of the coil pattern 110 is a section that goes around in the same direction along the second turn 113b counting from the innermost circumference, and is a going-around section that includes at least a portion extending in the X direction and a portion extending in the Y direction.

[0032] The lengths of the non-overlapping sections S1 and S2 can be adjusted based on the capacitance components C1 and C2 that are sought. However, if the non-overlapping sections S1 and S2 each exceed one turn, the coupling between the coil pattern 110 and the coil pattern 210 decreases, so it is preferable that the lengths of the non-overlapping sections S1 and S2 be one turn or less.

[0033] Fig. 10 is a graph illustrating the effects of the first embodiment, showing simulation results indicating the insertion loss (Sdd21) of a differential mode signal. In Fig. 10, the solid line indicates the characteristics of the common mode filter 1 according to this embodiment, and the dashed line indicates the characteristics of a common mode filter according to a comparative example that has no non-overlapping section except for the lead-out portions 114, 214 and their vicinity, and the vicinity of the inner circumferential end. In other words, in the common mode filter according to the comparative example, the radial spacing between adjacent turns of the coil pattern 110 is approximately constant.

[0034] 10, it can be seen that the common mode filter 1 according to this embodiment has a reduced insertion loss of differential mode signals compared to the common mode filter according to the comparative example. This is thought to be due to the effect of reducing the capacitance components C1 and C2 in the vicinity of the terminal electrodes E1 to E4 by providing the non-overlapping sections.

[0035] In order to further reduce the capacitance components C1 and C2, the pattern width of the non-overlapping sections S1, S2, S4, and S5 may be made smaller than the pattern width of each turn that constitutes the intermediate turns 113 and 213.

[0036] <Second embodiment> Fig. 11 is a schematic plan view illustrating the pattern shape of a conductor layer 100A used in a common mode filter according to a second embodiment of the technology disclosed herein, and Fig. 12 is a schematic cross-sectional view of the common mode filter according to the second embodiment.

[0037] 11 and 12, the conductor layer 100A used in the common mode filter according to the second embodiment differs from the above-described conductor layer 100 in that it includes additional dummy patterns 117 and 118. The other basic configuration is the same as that of the common mode filter 1 according to the first embodiment, and therefore the same elements are denoted by the same reference numerals and redundant explanations will be omitted.

[0038] The dummy pattern 117 is a pattern disposed between the non-overlapping section S1 of the outermost turn 111 and the second turn 113a counting from the outermost periphery, and is in a floating state without being connected to the coil pattern 110. The dummy pattern 117 overlaps with the non-overlapping section S4 of the outermost turn 211 of the coil pattern 210.

[0039] The dummy pattern 118 is a pattern disposed between the non-overlapping section S2 of the innermost turn 112 and the second turn 113b counting from the innermost circumference, and is in a floating state without being connected to the coil pattern 110. The dummy pattern 118 overlaps with the non-overlapping section S5 of the innermost turn 212 of the coil pattern 210.

[0040] The dummy patterns 117 and 118 function as a base when forming the outermost turn 211 and the innermost turn 212 of the coil pattern 210. Providing such dummy patterns 117 and 118 can ease the process difficulty when forming the coil pattern 210. In order to provide the dummy patterns 117 and 118, it is sufficient to design the pattern pitch of the non-overlapping section S1 of the outermost turn 111 and the second turn 113a counting from the outermost circumference, as well as the pattern pitch of the non-overlapping section S2 of the innermost turn 112 and the second turn 113b counting from the innermost circumference, to be at least twice the pattern pitch of each turn constituting the intermediate turn 113.

[0041] <Third embodiment> FIG. 13 is a schematic plan view illustrating the pattern shape of a conductor layer 100B used in a common mode filter according to a third embodiment of the technique disclosed herein.

[0042] 13, the conductor layer 100B used in the common mode filter according to the third embodiment differs from the conductor layer 100 shown in FIG. 2 in that the innermost turn 112 of the coil pattern 110 does not include the non-overlapping section S2. In other words, the spaces between the turns of the coil pattern 110, except for the outermost turn 111, are substantially constant. The other basic configuration is the same as that of the common mode filter 1 according to the first embodiment, so the same elements are designated by the same reference numerals and redundant explanations will be omitted.

[0043] As illustrated in the third embodiment, the innermost turn 112 of the coil pattern 110 may not include the non-overlapping section S2, and the outermost turn 111 of the coil pattern 110 may include the non-overlapping section S1.

[0044] <Fourth embodiment> FIG. 14 is a schematic plan view illustrating the pattern shape of a conductor layer 100C used in a common mode filter according to a fourth embodiment of the technique disclosed herein.

[0045] 14, the conductor layer 100C used in the common mode filter according to the fourth embodiment differs from the conductor layer 100 shown in FIG. 2 in that the outermost turn 111 of the coil pattern 110 does not include the non-overlapping section S1. In other words, the spaces between the turns of the coil pattern 110 except for the innermost turn 112 are substantially constant. The other basic configuration is the same as that of the common mode filter 1 according to the first embodiment, so the same elements are designated by the same reference numerals and redundant explanations will be omitted.

[0046] As illustrated in the fourth embodiment, the outermost turn 111 of the coil pattern 110 may not include the non-overlapping section S1, and the innermost turn 112 of the coil pattern 110 may include the non-overlapping section S2.

[0047] <Fifth embodiment> The common mode filter according to the fifth embodiment of the technology disclosed herein has a structure in which four conductor layers 100B, 200, 300A, and 400 are stacked with insulating layers interposed between them and embedded in an element body 2. The pattern shape of conductor layer 100B is as shown in Fig. 13, and the pattern shape of conductor layer 200 is as shown in Fig. 4. The shape of insulating layer 10 located between conductor layer 100B and conductor layer 200 is as shown in Fig. 3, and the shape of insulating layer 20 located between conductor layer 200 and conductor layer 300A is as shown in Fig. 5.

[0048] FIG. 15 is a schematic plan view illustrating the pattern shape of a conductor layer 300A used in the common mode filter according to the fifth embodiment.

[0049] As shown in Fig. 15, the conductor layer 300A used in the common mode filter according to the fifth embodiment includes a coil pattern 310, a connection pattern 323 is connected to the outer circumferential edge of the coil pattern 310, a connection pattern 325 is connected to the inner circumferential edge of the coil pattern 310, and a connection pattern 326 is provided independently without being connected to other conductor patterns within the conductor layer 300A, which differs from the conductor layer 300 shown in Fig. 6. Since the other basic configuration is the same as that of the conductor layer 300 shown in Fig. 6, the same elements are denoted by the same reference numerals and redundant description will be omitted.

[0050] 15, the number of turns in the coil pattern 310 is approximately 12. The outer peripheral end of the coil pattern 310 is connected to the connection pattern 323 via the lead-out portion 314. The coil pattern 310 winds counterclockwise from the outer peripheral end to the inner peripheral end, whereas the lead-out portion 314 extends linearly in the −X direction from the outer peripheral end to the inner peripheral end without winding counterclockwise. The connection patterns 321, 322, 324, and 326 are provided independently without being connected to other conductor patterns within the conductor layer 300A.

[0051] FIG. 16 is a schematic plan view of an insulating layer 30 used in the common mode filter according to the fifth embodiment.

[0052] 7 in that the insulating layer 30 is located between the conductor layer 300A and the conductor layer 400 and has an opening 36. The opening 36 is provided at a position that exposes the connection pattern 326. The other basic configuration is the same as that of the insulating layer 30 shown in FIG. 7, so the same elements are given the same reference numerals and redundant explanations will be omitted.

[0053] FIG. 17 is a schematic plan view for explaining the pattern shape of the conductor layer 400. As shown in FIG.

[0054] The conductor layer 400 has a spiral coil pattern 410 and connection patterns 421 to 424 and 426. In the example shown in FIG. 17, the number of turns in the coil pattern 410 is approximately 12. That is, the number of turns in the coil pattern 410 is approximately the same as that in the coil pattern 310. The outer circumferential end of the coil pattern 410 is connected to the connection pattern 424 via an extension portion 414. The inner circumferential end of the coil pattern 410 is connected to the connection pattern 426. The coil pattern 410 winds counterclockwise from the outer circumferential end to the inner circumferential end, whereas the extension portion 414 extends linearly in the +X direction from the outer circumferential end to the inner circumferential end. The connection patterns 421 to 423 are provided independently without being connected to other conductor patterns within the conductor layer 400. The connection patterns 421 to 424 and 426 are connected to the connection patterns 321 to 324 and 326 via openings 31 to 36 provided in the insulating layer 30, respectively.

[0055] FIG. 18 is a schematic plan view of the insulating layer 40. As shown in FIG.

[0056] The insulating layer 40 is the uppermost insulating layer and has openings 41 to 44. The openings 41 to 44 are provided at positions that expose the connection patterns 421 to 424, respectively. The terminal electrodes E1 to E4 shown in FIG. 1 are connected to the connection patterns 421 to 424 via the openings 41 to 44, respectively.

[0057] 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 outer peripheral end of coil pattern 310 is connected to terminal electrode E3, and the outer peripheral end of coil pattern 410 is connected to terminal electrode E4. Furthermore, the inner peripheral ends of coil patterns 110 and 310 are connected to each other, and the inner peripheral ends of coil patterns 210 and 410 are connected to each other. As a result, coil patterns 110 and 310 connected between terminal electrodes E1 and E3 and coil patterns 210 and 410 connected between terminal electrodes E2 and E4 are coupled.

[0058] 15, the radial spacing between adjacent turns of the coil pattern 310 is not constant, and the space 315 between the outermost turn 311 and the second turn 313a counting from the outermost periphery is wider than the spacing between the other turns. The space 315 is larger than the pattern width of the coil pattern 410. The space 315 may be larger than the pattern width of the coil pattern 210. The radial spacing between each turn of the coil pattern 310 other than the outermost turn 311 is approximately constant.

[0059] 19, the outermost turn 311 of the coil pattern 310 and the outermost turn 411 of the coil pattern 410 do not overlap with each other in at least a portion of the section. The section of the outermost turn 311 of the coil pattern 310 that does not overlap with the outermost turn 411 of the coil pattern 410 constitutes a non-overlapping section S3. The non-overlapping section S3 does not have to overlap with the outermost turn 211 of the coil pattern 210. The section of the outermost turn 411 of the coil pattern 410 that does not overlap with the outermost turn 311 of the coil pattern 310 constitutes a non-overlapping section S6.

[0060] In this way, the outermost turns 111, 211, 311, and 411 of the coil patterns 110, 210, 310, and 410 have non-overlapping sections S1, S4, S3, and S6, respectively, which reduces the inter-line capacitance between the outermost turns 111 and 211 and the inter-line capacitance between the outermost turns 311 and 411. As a result, the capacitance component C1 near the terminal electrodes E1 and E2 is reduced, and the capacitance component C2 near the terminal electrodes E3 and E4 is reduced. Furthermore, when the non-overlapping section S3 does not overlap with the outermost turn 211 of the coil pattern 210, the inter-line capacitance between the outermost turns 211 and 311 is also reduced.

[0061] On the other hand, the turns of the coil patterns 110, 210, 310, and 410 other than the outermost turns 111, 211, 311, and 411 overlap each other, thereby enhancing the coupling between the coil patterns 110, 310 and the coil patterns 210, 410.

[0062] As illustrated in the fifth embodiment, four coil patterns 110, 210, 310, and 410 may be laminated in this order, with the inner circumferential end of coil pattern 110 and the inner circumferential end of coil pattern 310 connected to each other, and the inner circumferential end of coil pattern 210 and the inner circumferential end of coil pattern 410 connected to each other. In this way, terminal electrodes E1 to E4 are connected to the outermost turns 111, 211, 311, and 411 of coil patterns 110, 210, 310, and 410, respectively, thereby reducing the difference in characteristics between when terminal electrodes E1 and E2 are used as the input side and terminal electrodes E3 and E4 are used as the output side and when terminal electrodes E1 and E2 are used as the output side and terminal electrodes E3 and E4 are used as the input side.

[0063] 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.

[0064] The technology according to the present disclosure includes, but is not limited to, the following configuration examples.

[0065] A common mode filter according to one aspect of the present disclosure comprises a plurality of conductor layers stacked via insulating layers, including at least first and second conductor layers, and first, second, third, and fourth terminal electrodes, wherein the first conductor layer has a first spiral coil pattern whose outer peripheral end is connected to the first terminal electrode and whose inner peripheral end is connected to the third terminal electrode, and the second conductor layer has a second spiral coil pattern whose outer peripheral end is connected to the second terminal electrode and whose inner peripheral end is connected to the fourth terminal electrode, and the outermost turn of the first coil pattern has a first non-overlapping section that does not overlap with the outermost turn of the second coil pattern for at least 1 / 4 of a turn, or the innermost turn of the first coil pattern has a second non-overlapping section that does not overlap with the innermost turn of the second coil pattern for at least 1 / 4 of a turn. This makes it possible to reduce the line capacitance in the vicinity of the first and second terminal electrodes or the line capacitance in the vicinity of the third and fourth terminal electrodes.

[0066] In the above common mode filter, the first coil pattern may have both a first non-overlapping section and a second non-overlapping section, which makes it possible to reduce the line capacitance in the vicinity of both the first and second terminal electrodes and the third and fourth terminal electrodes.

[0067] In the above common mode filter, the plurality of conductor layers may further include third and fourth conductor layers, the first, second, third and fourth conductor layers being stacked in this order with insulating layers interposed therebetween, the third conductor layer having a third spiral coil pattern whose outer peripheral end is connected to the third terminal electrode and whose inner peripheral end is connected to the inner peripheral end of the first coil pattern, the fourth conductor layer having a fourth spiral coil pattern whose outer peripheral end is connected to the fourth terminal electrode and whose inner peripheral end is connected to the inner peripheral end of the second coil pattern, the outermost turn of the first coil pattern having a first non-overlapping section, and the outermost turn of the third coil pattern having a third non-overlapping section that goes around without overlapping with the outermost turn of the fourth coil pattern over at least a quarter turn. This reduces the difference in characteristics between when the first and second terminal electrodes are the input side and the third and fourth terminal electrodes are the output side and when the first and second terminal electrodes are the output side and the third and fourth terminal electrodes are the input side.

[0068] In the above common mode filter, the first radial space between the first non-overlapping section and the second outermost turn of the first coil pattern, or the second radial space between the second non-overlapping section and the second innermost turn of the first coil pattern, may be wider than the radial space between each intermediate turn of the first coil pattern located between the second outermost turn and the second innermost turn of the first coil pattern, thereby enabling the radial size of the first coil pattern to be reduced.

[0069] In the above common mode filter, at least one of the first and second spaces may be larger than the pattern width of the second coil pattern, which allows the second coil pattern to be arranged at a position overlapping at least one of the first and second spaces.

[0070] In the above common mode filter, the pattern pitch between the first non-overlapping section and the intermediate turn, or the pattern pitch between the second non-overlapping section and the intermediate turn, may be at least twice the pattern pitch of each turn constituting the intermediate turn, which makes it possible to place a dummy pattern in at least one of the first and second spaces.

[0071] In the above common mode filter, the first conductor layer may further include a first dummy pattern disposed in the first space or a second dummy pattern disposed in the second space, which facilitates the formation of the second coil pattern.

[0072] In the above common mode filter, the pattern width of the first or second non-overlapping section may be smaller than the pattern width of each turn constituting the intermediate turn, thereby making it possible to further reduce the line capacitance near the first and second terminal electrodes or the line capacitance near the third and fourth terminal electrodes.

[0073] In the above common mode filter, each of the turns constituting the intermediate turn may overlap the second coil pattern, thereby enhancing the coupling between the first coil pattern and the second coil pattern. [Explanation of symbols]

[0074] 1 Common mode filter 2 Base 10, 20, 30, 40 insulating layers 11~15, 21~26, 31~34, 36, 41~44 Openings 100, 100A, 100B, 100C, 200, 300, 300A, 400 Conductor layer 110,210,310,410 coil patterns 111,211,311,411 Outermost turn 112,212,312,412 Innermost turn 113,213 Middle Turn 113a, 213a, 313a: The second turn from the outermost perimeter 113b, 213b The second turn from the innermost perimeter 114,214,314,325a,326a,414 Drawer section 115,116,315 spaces 117,118 Dummy Pattern 121~125, 221~226, 321~326, 421~424, 426 connection patterns C1,C2 Capacitance component E1~E4 terminal electrode S1~S6 Non-overlapping section

Claims

1. a plurality of conductor layers including at least first and second conductor layers stacked with insulating layers interposed therebetween; first, second, third and fourth terminal electrodes; Equipped with the first conductor layer has a spiral first coil pattern whose outer circumferential end is connected to the first terminal electrode and whose inner circumferential end is connected to the third terminal electrode; the second conductor layer has a spiral second coil pattern whose outer circumferential end is connected to the second terminal electrode and whose inner circumferential end is connected to the fourth terminal electrode, the outermost turn of the first coil pattern has a first non-overlapping section in which it goes around without overlapping with the outermost turn of the second coil pattern over at least ¼ turn, or the innermost turn of the first coil pattern has a second non-overlapping section in which it goes around without overlapping with the innermost turn of the second coil pattern over at least ¼ turn; Common mode filter.

2. the first coil pattern has both the first non-overlapping section and the second non-overlapping section; 2. The common mode filter according to claim 1.

3. the plurality of conductor layers further include third and fourth conductor layers; the first, second, third, and fourth conductor layers are stacked in this order with the insulating layer interposed therebetween; the third conductor layer has a third spiral coil pattern whose outer circumferential end is connected to the third terminal electrode and whose inner circumferential end is connected to the inner circumferential end of the first coil pattern, the fourth conductor layer has a fourth spiral coil pattern whose outer circumferential end is connected to the fourth terminal electrode and whose inner circumferential end is connected to the inner circumferential end of the second coil pattern, the outermost turn of the first coil pattern has the first non-overlapping section, the outermost turn of the third coil pattern has a third non-overlapping section that goes around without overlapping with the outermost turn of the fourth coil pattern over at least a quarter turn; 2. The common mode filter according to claim 1.

4. a first space in the radial direction between the first non-overlapping section and the second turn counting from the outermost circumference of the first coil pattern, or a second space in the radial direction between the second non-overlapping section and the second turn counting from the innermost circumference of the first coil pattern, is wider than a space in the radial direction between each turn constituting an intermediate turn located between the second turn counting from the outermost circumference and the second turn counting from the innermost circumference of the first coil pattern; 2. The common mode filter according to claim 1.

5. At least one of the first and second spaces is larger than a pattern width of the second coil pattern.

5. The common mode filter according to claim 4.

6. a pattern pitch between the first non-overlapping section and the intermediate turn, or a pattern pitch between the second non-overlapping section and the intermediate turn, is at least twice the pattern pitch of each turn constituting the intermediate turn.

6. The common mode filter according to claim 5.

7. the first conductor layer further includes a first dummy pattern disposed in the first space or a second dummy pattern disposed in the second space; 7. The common mode filter according to claim 6.

8. a pattern width of the first or second non-overlapping section is smaller than a pattern width of each turn constituting the intermediate turn; 5. The common mode filter according to claim 4.

9. Each turn constituting the intermediate turn overlaps with the second coil pattern.

9. The common mode filter according to claim 4, wherein the common mode filter is a common mode filter having a first end and a second end.

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