Common mode noise filter
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
- Filing Date
- 2025-12-15
- Publication Date
- 2026-07-02
Smart Images
Figure JP2025043701_02072026_PF_FP_ABST
Abstract
Description
Common mode noise filter
[0001] The present disclosure generally relates to a common mode noise filter. More specifically, the present disclosure relates to a common mode noise filter including two or more conductor portions.
[0002] Patent Document 1 discloses a common mode noise filter including a spiral-shaped first coil in which a first internal electrode and a second internal electrode are connected, and a spiral-shaped second coil in which a third internal electrode and a fourth internal electrode are connected. The first coil and the second coil overlap in one arc portion and a straight portion, and are offset in the remaining arc portion.
[0003] Specification of Chinese Patent Application Publication No. 111145985
[0004] In the common mode noise filter described in Patent Document 1, the first coil and the second coil overlap in one arc portion and a straight portion in a state where a difference in wiring distance from the internal electrode occurs for one turn. Therefore, there is a problem that the balance state between the first coil and the second coil deteriorates, resulting in deterioration of mode conversion characteristics.
[0005] A common mode noise filter according to an aspect of the present disclosure includes a non-magnetic layer and two or more conductor portions. The two or more conductor portions are provided inside the non-magnetic layer and are arranged in a predetermined direction. At least one of the two or more conductor portions has a first spiral conductor. The first spiral conductor is a conductor wound in a spiral shape and includes a plurality of first circumferential portions that are portions of each turn. At least one of the remaining two or more conductor portions has a second spiral conductor. The second spiral conductor is a conductor wound in a spiral shape and includes a plurality of second circumferential portions that are portions of each turn. When n is a natural number of 1 or more, the n-th first circumferential portion among the plurality of first circumferential portions intersects the n-th second circumferential portion among the plurality of second circumferential portions at two locations when viewed from the predetermined direction.
[0006] According to the present disclosure, there is an advantage that deterioration of mode conversion characteristics can be suppressed.
[0007] Figure 1 is a projection view of the common-mode noise filter according to this embodiment, showing the first conductor portion and the second conductor portion projected onto a single plane. Figure 2 is a schematic cross-sectional view of the common-mode noise filter shown on line A1-A1 in Figure 1. Figure 3 is a schematic cross-sectional view of the common-mode noise filter shown on line A2-A2 in Figure 2. Figure 4 is a schematic cross-sectional view of the main part of the common-mode noise filter shown on line A1-A1 in Figure 1. Figure 5 is a graph showing the mode conversion characteristics of the common-mode noise filter. Figure 6 is a projection view of the common-mode noise filter of the first modified example shown on the same, showing the first conductor portion and the second conductor portion projected onto a single plane. Figure 7 is a schematic cross-sectional view of the common-mode noise filter of the second modified example shown on the same, parallel to the front-to-back and up-and-down directions. Figure 8 is a schematic cross-sectional view of the common-mode noise filter of the second modified example shown on the same, parallel to the left-to-right and up-and-down directions.
[0008] The embodiments and modifications described below are merely examples of the present disclosure. This disclosure is not limited to these embodiments and modifications, and various modifications are possible depending on the design, etc., as long as they do not depart from the technical idea of the present disclosure. The figures described in the embodiments and modifications below are schematic diagrams, and the ratios of the size and thickness of each component in the figures do not necessarily reflect the actual dimensional ratios.
[0009] (Embodiment) (1) Overview Below, an overview of the common-mode noise filter 100 according to this embodiment will be described with reference to Figures 1 to 3.
[0010] The common-mode noise filter 100 according to this embodiment allows the differential mode component of a signal to pass through while attenuating the common-mode noise component. The common-mode noise filter 100 is mounted on a circuit board or electronic component of an electronic device.
[0011] The common-mode noise filter 100 of the embodiment, as shown in Figures 1 to 3, comprises a non-magnetic layer 1 and two or more conductor portions 2. The two or more conductor portions 2 are provided inside the non-magnetic layer 1 and are arranged in a predetermined direction D1. At least one of the two or more conductor portions 2 is a spirally wound conductor and has a first spiral conductor X1 consisting of a plurality of first circumferential portions X11, which are the parts of each turn. On the other hand, the remaining conductor portions 2 of the two or more conductor portions 2 are spirally wound conductors and have a second spiral conductor X2 consisting of a plurality of second circumferential portions X21, which are the parts of each turn. In this disclosure, "spiral conductor" refers to a conductor wound in a spiral shape in a plane (i.e., two dimensions). The plurality of conductor portions 2 are conductors that extend in a spiral shape and are elongated, surrounding a central axis AX1 that extends in a predetermined direction D1. In the common-mode noise filter 100, when p is an integer of 1 or more, the first spiral conductor X1 includes a p-turn spiral conductor consisting of p first peripheral portions X11, and the second spiral conductor X2 includes a p-turn spiral conductor consisting of p second peripheral portions X21. In this embodiment, the first spiral conductor X1 as a whole is a p-turn spiral conductor, and the second spiral conductor X2 as a whole is a p-turn spiral conductor.
[0012] In the common-mode noise filter 100 of this embodiment, as shown in Figure 1, when n is a natural number of 1 or more, the nth turn of the first turn X11 among the multiple first turn X11 intersects with the nth turn of the second turn X21 among the multiple second turn X21 at two locations when viewed from a predetermined direction D1. In this embodiment, n is a plurality of integers of 1 or more and less than or equal to p, and is all integers of 1 or more and less than or equal to p. For example, the first turn X11 among the multiple first turn X11 intersects with the first turn of the second turn X21 among the multiple second turn X21 at two locations when viewed from a predetermined direction D1.
[0013] The first and second spiral conductors are capacitively coupled via stray capacitance, and in common-mode noise filters that handle high-frequency signals of 1 MHz or higher, it is necessary to consider the number of capacitive coupling points per unit length of the conductor. In the comparative example common-mode noise filter, the first and second spiral conductors overlap in one of the arc and straight sections, with a difference in wiring distance from the internal electrodes equivalent to one full turn. This structure, in which the capacitive coupling points of the first and second spiral conductors are relatively different, causes an unbalanced state in the differential transmission line, leading to a problem of deterioration in mode conversion characteristics.
[0014] On the other hand, in the common-mode noise filter 100 of this embodiment, the first turn X11 of the nth turn can be considered to be capacitively coupled with the second turn X21 of the nth turn and the second turn X21 of the (n+1)th turn in one of the two parts located between the two points where it intersects with the second turn X21 of the nth turn (the front part of the first turn X11). Similarly, the first turn X11 of the nth turn can be considered to be capacitively coupled with the second turn X21 of the (n-1)th turn and the second turn X21 of the nth turn in the remaining part of the two parts located between the two points where it intersects with the second turn X21 of the nth turn (the rear part of the first turn X11). When connected in this way, the first turn X11 of the nth turn has points where it capacitively couples with the second turn X21 of the (n-1)th turn, the nth turn, and the n+1th turn in one turn. In other words, when the first turn X11 of the nth turn capacitively couples with the second turn X21, the second turn X21 capacitively couples with the (n-1)th and (n+1)th turns, with respect to the nth turn of the second turn X21. When this is repeated over the entire circumference, it can be considered a balanced circuit for signals of a specific wavelength.
[0015] As a result, the common-mode noise filter 100 of this embodiment has the advantage of being able to suppress the degradation (increase) of the mode conversion characteristics at a specific frequency. In this disclosure, "mode conversion characteristics" refers to the characteristics of converting differential-mode signals into common-mode noise, and also includes the characteristics of converting common-mode noise into differential-mode signals. When these mode conversion characteristics are high, the differential-mode signal waveform is distorted, so suppressing the degradation of the mode conversion characteristics enables high-quality communication.
[0016] (2) Detailed Configuration (2-1) Overall Configuration Below, the detailed configuration of the common-mode noise filter 100 of this embodiment will be described with reference to Figures 1 to 5.
[0017] In the following description, as shown in Figure 2, the direction in which the first conductor section 21 and the second conductor section 22, which will be described later, are aligned is defined as the up and down direction, the side of the first conductor section 21 as viewed from the second conductor section 22 is defined as up, and the side of the second conductor section 22 as viewed from the first conductor section 21 is defined as down. Unless otherwise specified, the front, back, left, and right directions indicated by arrows in Figure 1 are defined as the front, back, left, and right directions of the common mode noise filter 100. Furthermore, "up" and "down" as used in this disclosure merely represent relative directions indicating the relative positional relationship of each component of the common mode noise filter 100, and are not intended to limit the direction in which the common mode noise filter 100 can be used. The common mode noise filter 100 may be used in a direction where "down" as used in this disclosure is, for example, up, front, back, left, or right. Also, although arrows representing up, down, left, right, and front and back are shown in Figures 1 and 2, these arrows are merely for illustrative purposes and do not represent actual dimensions. The vertical, horizontal, and front-to-back directions intersect with each other and, in this embodiment, are perpendicular to each other.
[0018] As shown in Figures 1 to 3, the common-mode noise filter 100 of this embodiment comprises a non-magnetic layer 1, two or more conductor portions 2, a first via B1, a second via B2, a first lead conductor 31, and a second lead conductor 32.
[0019] (2-2) The magnetic layer and non-magnetic layer 1 are the basic components of the common-mode noise filter 100. The non-magnetic layer 1 is a plate member, as shown in Figures 1 to 3. The thickness direction of the non-magnetic layer 1 is aligned with the vertical direction. For example, the non-magnetic layer 1 may include, for example, glass ceramic as a material.
[0020] The non-magnetic layer 1 consists, for example, of a plurality of non-magnetic layers stacked in the vertical direction. In the upper part of the non-magnetic layer 1 (the part above the first conductor portion 21, which will be described later and shown in Figures 2 and 3), a magnetic layer may be stacked between the plurality of non-magnetic layers. Similarly, in the lower part of the non-magnetic layer 1 (the part below the first and second lead conductors 31 and 32, shown in Figures 2 and 3), a magnetic layer may be stacked between the plurality of non-magnetic layers. The magnetic layer referred to here includes, for example, ferrite as a material.
[0021] (2-3) Conductors Two or more conductors 2 are provided inside the non-magnetic layer 1 as shown in Figures 2 and 3, and are arranged in a predetermined direction D1. In this embodiment, there are two conductors 2, and the two conductors 2 are arranged in the predetermined direction D1 in the order of a first conductor 21 and a second conductor 22. The first conductor 21 is located above the second conductor 22. The "predetermined direction D1" here is the vertical direction, that is, the thickness direction of the non-magnetic layer 1. In this embodiment, the first conductor 21 and the second conductor 22 are arranged in this order in the downward direction of the vertical direction.
[0022] In the common-mode noise filter 100 of this embodiment, one of the first pad conductor 211 and the first lead conductor 31 of the first conductor section 21 (described later) is used as the first input terminal, and the other is used as the first output terminal. Similarly, one of the first pad conductor 221 and the second lead conductor 32 of the second conductor section 22 (described later) is used as the second input terminal, and the other is used as the second output terminal. That is, the common-mode noise filter 100 of this embodiment includes a first input terminal, a second input terminal, a first output terminal, and a second output terminal. The common-mode noise filter 100 of this embodiment removes common-mode noise from the differential signal input through the first input terminal and the second input terminal, and outputs the differential signal from the first output terminal and the second output terminal.
[0023] (First Conductor Section) The first conductor section 21 has a first spiral conductor X1, as shown in Figure 1. In this embodiment, the first conductor section 21 further includes, in addition to the first spiral conductor X1, a first pad conductor 211, a second pad conductor 212, and connecting conductors 213 and 214. In Figure 1, the first conductor section 21 is hatched to clearly distinguish it from the second conductor section 22, but the first conductor section 21 shown in Figure 1 is not a cross-section.
[0024] The first spiral conductor X1 is a conductor wound in a spiral shape, that is, a conductor formed in a spiral. More specifically, the first spiral conductor X1 has a shape in which a conductor is wound multiple times along a square with rounded corners. The left-right dimension of the first spiral conductor X1 is longer than the front-back dimension of the first spiral conductor X1. The direction of the spiral of the first spiral conductor X1 is counterclockwise, from the outside to the inside of the spiral when viewed from above. As shown in Figure 1, the first spiral conductor X1 consists of a plurality of first circumferences X11, which are the parts of each turn. In this disclosure, "each turn" refers to the part of the spirally wound conductor that corresponds to each circumference. Note that the left-right dimension of the first spiral conductor X1 may be shorter than the front-back dimension of the first spiral conductor X1, or it may be the same as the front-back dimension of the first spiral conductor X1.
[0025] The number of turns of the first spiral conductor X1 in this embodiment is 5. That is, the first spiral conductor X1 in this embodiment has a first circumference X11 of the first turn, a first circumference X11 of the second turn, a first circumference X11 of the third turn, a first circumference X11 of the fourth turn, and a first circumference X11 of the fifth turn. The first circumference X11 of the first turn is located on the outermost side, and the first circumference X11 of the fifth turn is located on the innermost side. In the illustrated example shown in Figure 1, the first circumference X11 of the fifth turn is shorter than each of the first circumference X11 of the first turn, the first circumference X11 of the second turn, the first circumference X11 of the third turn, and the first circumference X11 of the fourth turn. More specifically, the first turn X11 of the first turn, the first turn X11 of the second turn, the first turn X11 of the third turn, and the first turn X11 of the fourth turn each have a shape in which the conductor is wound around a square with rounded corners for one full turn. On the other hand, the first turn X11 of the fifth turn has a shape in which the conductor is wound around a square with rounded corners for half a turn.
[0026] Each of the multiple first circumferential sections X11 has straight sections X12 and X13 formed in a straight line, as shown in Figure 1. In the illustrated example shown in Figure 1, each of the first circumferential section X11 of the first turn, the first circumferential section X11 of the second turn, the first circumferential section X11 of the third turn, and the first circumferential section X11 of the fourth turn has straight sections X12, X13, X14, and X15. On the other hand, the first circumferential section X11 of the fifth turn has straight sections X12, X13, and X14, but does not have a straight section X15. The straight section X12 is the left portion of each of the multiple first circumferential sections X11, and the straight section X13 is the right portion of each of the multiple first circumferential sections X11. Similarly, the straight section X14 is the upper portion of each of the multiple first circumferential sections X11, and the straight section X15 is the lower portion of each of the multiple first circumferential sections X11. Note that the straight section X12 corresponds to the first straight section Y1 of the present invention. Similarly, the straight section X13 corresponds to the second straight section Y2 of the present invention. Note that in Figures 1 to 3, the reference numerals X12, X13, X14, and X15 are given only to the first circumferential section X11 of the first turn among the multiple first circumferential sections X11, and the reference numerals X12, X13, X14, and X15 are omitted for the first circumferential sections X11 other than the first circumferential section X11 of the first turn.
[0027] The first spiral conductor X1 is electrically connected to the first pad conductor 211 via a connecting conductor 213. The first pad conductor 211 and the connecting conductor 213 are located on the outside of the first spiral conductor X1. The first end (outer end) of the first spiral conductor X1 is connected to the first end of the connecting conductor 213, and the second end of the connecting conductor 213 is connected to the first pad conductor 211. Here, "the first end of the first spiral conductor X1" refers to the end of the first spiral conductor X1 that is different from the end connected to the first circumference X11 of the second turn (i.e., the end not connected to the first circumference X11 of the second turn) from the two ends in the winding direction of the first circumference X11 of the first turn.
[0028] The first pad conductor 211 is rectangular with rounded corners. The first pad conductor 211 is aligned in the front-to-back direction with the first pad conductor 221 of the second conductor section 22, which will be described later. The first pad conductor 211 is positioned towards the rear of the center in the front-to-back direction.
[0029] Similarly, the first spiral conductor X1 is electrically connected to the second pad conductor 212 via a connecting conductor 214. The second pad conductor 212 and the connecting conductor 214 are located inside the first spiral conductor X1. The second end (inner end) of the first spiral conductor X1 is connected to the first end of the connecting conductor 214, and the second end of the connecting conductor 214 is connected to the second pad conductor 212. Here, the "second end of the first spiral conductor X1" refers to the end of the first spiral conductor X1 that is different from the end connected to the first circumference X11 of the fourth turn (i.e., the end not connected to the first circumference X11 of the fourth turn) among the two ends in the winding direction of the first circumference X11 of the fifth turn.
[0030] The second pad conductor 212 is rectangular with rounded corners. The second pad conductor 212 is aligned in the front-to-back direction with the second pad conductor 222 of the second conductor section 22, which will be described later. The second pad conductor 212 is positioned towards the rear of the center in the front-to-back direction.
[0031] As shown in Figures 2 and 3, the second pad conductor 212 is electrically connected to the first lead conductor 31 via the first via B1. In other words, the first via B1 electrically connects the second pad conductor 212 and the first lead conductor 31. The first via B1 has length in the vertical direction. The shape of the first via B1 is cylindrical with the vertical direction as its axial direction. Here, a non-magnetic layer of the non-magnetic layer 1 is arranged between the first conductor portion 21 having the second pad conductor 212 and the first lead conductor 31. The first via B1 electrically connects the second pad conductor 212 and the first lead conductor 31 by penetrating the non-magnetic layer of the non-magnetic layer 1. As shown in Figure 3, the first lead conductor 31 extends to the outer surface of the non-magnetic layer 1. The first lead conductor 31 leads the second pad conductor 212 to the outer surface of the non-magnetic layer 1 via the first via B1.
[0032] (Second Conductor Section) The second conductor section 22 has a second spiral conductor X2, as shown in Figure 1. In this embodiment, the second conductor section 22 further includes, in addition to the second spiral conductor X2, a first pad conductor 221, a second pad conductor 222, and connecting conductors 223 and 224.
[0033] The second spiral conductor X2 is a conductor wound in a spiral shape, that is, a conductor formed in a spiral. More specifically, the second spiral conductor X2 has a shape in which a conductor is wound multiple times along a square with rounded corners. The left-right dimension of the second spiral conductor X2 is longer than the front-back dimension of the second spiral conductor X2. The direction of the spiral of the second spiral conductor X2 is counterclockwise, from the outside to the inside of the spiral when viewed from above. As shown in Figure 1, the second spiral conductor X2 consists of multiple second turns X21, which are the parts of each turn.
[0034] The number of turns of the second spiral conductor X2 in this embodiment is 5. That is, the second spiral conductor X2 in this embodiment has a second circumference X21 of the first turn, a second circumference X21 of the second turn, a second circumference X21 of the third turn, a second circumference X21 of the fourth turn, and a second circumference X21 of the fifth turn. The second circumference X21 of the first turn is located on the outermost side, and the second circumference X21 of the fifth turn is located on the innermost side. In the illustrated example shown in Figure 1, the second circumference X21 of the fifth turn is shorter than each of the second circumference X21 of the first turn, the second circumference X21 of the second turn, the second circumference X21 of the third turn, and the second circumference X21 of the fourth turn. More specifically, the second turn X21 of the first turn, the second turn X21 of the second turn X21 of the second turn X21 of the third turn X21, and the second turn X21 of the fourth turn each have a shape in which the conductor is wound around a square with rounded corners for one full turn. On the other hand, the second turn X21 of the fifth turn has a shape in which the conductor is wound around a square with rounded corners for half a turn.
[0035] Each of the multiple second circumferential sections X21 has straight sections X22 and X23 that are formed in a straight line. In the illustrated example shown in Figure 1, each of the second circumferential section X21 of the first turn, the second circumferential section X21 of the second turn, the second circumferential section X21 of the third turn, and the second circumferential section X21 of the fourth turn has straight sections X22, X23, X24, and X25. On the other hand, the second circumferential section X21 of the fifth turn has straight sections X22, X23, and X24, but does not have a straight section X25. The straight section X22 is the left portion of each of the multiple second circumferential sections X21, and the straight section X23 is the right portion of each of the multiple second circumferential sections X21. Similarly, the straight section X24 is the upper portion of each of the multiple second circumferential sections X21, and the straight section X25 is the lower portion of each of the multiple second circumferential sections X21. Note that the straight section X22 corresponds to the third straight section Y3 of the present invention. Similarly, the straight section X23 corresponds to the fourth straight section Y4 of the present invention. Note that in Figures 1 to 3, the reference numerals X22, X23, X24, and X25 are given only to the second circumferential section X21 of the first turn among the multiple second circumferential sections X21, and the reference numerals X22, X23, X24, and X25 are omitted for the second circumferential sections X21 other than the second circumferential section X21 of the first turn.
[0036] The second spiral conductor X2 is electrically connected to the first pad conductor 221 via a connecting conductor 223. The first pad conductor 221 and the connecting conductor 223 are located outside the second spiral conductor X2. The first end (outer end) of the second spiral conductor X2 is connected to the first end of the connecting conductor 223, and the second end of the connecting conductor 223 is connected to the first pad conductor 221. Here, "the first end of the second spiral conductor X2" refers to the end of the second spiral conductor X2 that is different from the end connected to the second circumference X21 of the second turn (i.e., the end not connected to the second circumference X21 of the second turn) among the two ends in the winding direction of the second circumference X21 of the first turn.
[0037] The first pad conductor 221 is rectangular with rounded corners. The first pad conductor 221 is aligned in the front-to-back direction with the first pad conductor 211 of the first conductor portion 21. The first pad conductor 221 is positioned in front of the center in the front-to-back direction.
[0038] Similarly, the second spiral conductor X2 is electrically connected to the second pad conductor 222 via a connecting conductor 224. The second pad conductor 222 and the connecting conductor 224 are located inside the second spiral conductor X2. The second end (inner end) of the second spiral conductor X2 is connected to the first end of the connecting conductor 224, and the second end of the connecting conductor 224 is connected to the second pad conductor 222. Here, "the second end of the second spiral conductor X2" refers to the end of the second spiral conductor X2 that is different from the end connected to the second circumference X21 of the fourth turn (i.e., the end not connected to the second circumference X21 of the fourth turn) among the two ends in the winding direction of the second circumference X21 of the fifth turn.
[0039] The second pad conductor 222 is rectangular with rounded corners. The second pad conductor 222 is aligned with the second pad conductor 212 of the first conductor section 21 in the front-to-back direction. The second pad conductor 222 is positioned in front of the center in the front-to-back direction.
[0040] As shown in Figure 2, the second pad conductor 222 is electrically connected to the second lead conductor 32 via the second via B2. In other words, the second via B2 electrically connects the second pad conductor 222 and the second lead conductor 32. The second via B2 has length in the vertical direction. The shape of the second via B2 is cylindrical with the vertical direction as its axial direction. Here, a non-magnetic layer of the non-magnetic layer 1 is arranged between the second conductor portion 22 having the second pad conductor 222 and the second lead conductor 32. As shown in Figure 2, the second via B2 electrically connects the second pad conductor 222 and the second lead conductor 32 by penetrating the non-magnetic layer of the non-magnetic layer 1. The second lead conductor 32 extends to the outer surface of the non-magnetic layer 1, similar to the first lead conductor 31. The second lead conductor 32 leads the second pad conductor 222 to the outer surface of the non-magnetic layer 1 via the second via B2.
[0041] (Positional relationship between the first spiral conductor and the second spiral conductor) When n is a natural number greater than or equal to 1, the nth turn of the nth turn of the nth turn of the nth turn of the nth turn of the nth turn of the first spiral conductor X1 intersects at two points when viewed from a predetermined direction D1. For example, the first turn of the nth turn of the nth turn of the nth turn of the nth turn of the nth turn of the nth turn of the first In this embodiment, point P1 is the first straight section Y1 (straight section X12) of the first circumference X11 and the third straight section Y3 (straight section X22) of the second circumference X21. Similarly, in this embodiment, point P2 is the second straight section Y2 (straight section X13) of the first circumference X11 and the fourth straight section Y4 (straight section X23) of the second circumference X21.
[0042] In this embodiment, as shown in Figures 1 and 3, the first straight section Y1 (straight section X12) of the nth turn of the first circumferential section X11 overlaps with the third straight section Y3 (straight section X22) of the nth turn of the second circumferential section X21 over its entire length when viewed from a predetermined direction D1. For example, the first straight section Y1 of the first turn of the first circumferential section X11 overlaps with the third straight section Y3 of the first turn of the second circumferential section X21 over its entire length when viewed from a predetermined direction D1. Here, "overlapping" means that, when viewed from a predetermined direction D1, at least a portion of the short-side (left-right) direction of the first straight section Y1 overlaps with the third straight section Y3 in the longitudinal direction (front-back direction) of the first straight section Y1.
[0043] Similarly, the second straight section Y2 (straight section X13) of the nth turn of the first circumferential section X11 overlaps with the fourth straight section Y4 (straight section X23) of the nth turn of the second circumferential section X21 over its entire length when viewed from a predetermined direction D1. For example, the second straight section Y2 of the first turn of the first circumferential section X11 overlaps with the fourth straight section Y4 of the first turn of the second circumferential section X21 over its entire length when viewed from a predetermined direction D1. Here, "overlapping" means that, when viewed from a predetermined direction D1, at least a portion of the second straight section Y2 in the short direction (left-right direction) overlaps with the fourth straight section Y4 in the longitudinal direction (front-back direction) of the second straight section Y2.
[0044] Further, as shown in FIG. 1, the straight portion X14 of the n-th turn of the plurality of first circumferential portions X11 does not intersect with the straight portion X24 of the n-th turn of the plurality of second circumferential portions X21 when viewed from the predetermined direction D1. That is, as shown in FIG. 2, the straight portion X14 of the n-th turn of the plurality of first circumferential portions X11 is arranged between the straight portion X24 of the n-th turn of the second circumferential portion X21 and the straight portion X24 of the (n + 1)-th turn of the second circumferential portion X21 in the radial direction of the first circumferential portion X11. More specifically, as shown in FIG. 4, the center line L1 of the straight portion X14 of the n-th turn of the first circumferential portion X11 is located in the gap GA1 between the inner surface (right side surface) of the straight portion X24 of the n-th turn of the second circumferential portion X21 and the outer surface (left side surface) of the straight portion X24 of the (n + 1)-th turn of the second circumferential portion X21 in the radial direction of the first circumferential portion X11. Here, the radial direction of the first circumferential portion X11 refers to the width direction of the first circumferential portion X11, which is the left-right direction shown in FIG. 4. In the present embodiment, this radial direction is perpendicular to the central axis AX1 and is a direction away from the central axis AX1, which is the front-rear direction in FIG. 2 and the left-right direction shown in FIG. 3. Also, the center line L1 of the straight portion X14 here is a straight line passing through the center of the straight portion X14 in the radial direction of the first circumferential portion X11 and perpendicular to the radial direction of the first circumferential portion X11.
[0045] Similarly, the straight section X15 of the nth turn first circumferential section X11 among the multiple first circumferential sections X11 does not intersect with the straight section X25 of the nth turn second circumferential section X21 when viewed from a predetermined direction D1. That is, as shown in Figure 2, the straight section X15 of the nth turn first circumferential section X11 is positioned in the radial direction of the first circumferential section X11 between the straight section X25 of the n-1 turn second circumferential section X21 and the straight section X25 of the nth turn second circumferential section X21. More specifically, the straight section X15 of the first circumferential section X11 in the nth turn is positioned such that, similar to the straight section X14, its centerline lies in the gap between the inner surface (left side) of the straight section X24 of the second circumferential section X21 in the (n-1)th turn and the outer surface (right side) of the straight section X24 of the second circumferential section X21 in the nth turn, in the radial direction of the first circumferential section X11. The centerline of the straight section X15 referred to here is a straight line that passes through the center of the straight section X15 in the radial direction of the first circumferential section X11 and is perpendicular to the radial direction of the first circumferential section X11.
[0046] According to the above configuration, the straight section X14 of the nth turn of the first circumference X11 among the multiple first circumference X11s of the first spiral conductor X1 can be considered to be capacitively coupled with the straight section X24 of the nth turn of the second circumference X21 and the straight section X24 of the n+1 turn of the second circumference X21. Similarly, the straight section X15 of the nth turn of the first circumference X11 among the multiple first circumference X11s of the first spiral conductor X1 can be considered to be capacitively coupled with the straight section X25 of the n-1 turn of the second circumference X21 and the straight section X25 of the nth turn of the second circumference X21. When connected in this way, the nth turn of the first circumference X11 will have capacitive coupling points with the n-1 turn, n turn, and n+1 turn of the second circumference X21 during one rotation. In other words, when the first turn X11 of the nth turn capacitively couples with the second turn X21, the second turn X21 capacitively couples with the (n-1)th and (n+1)th turns with respect to the nth turn of the second turn X21. When this is repeated over the entire circumference, it can be considered a balanced circuit for signals of a specific wavelength. As a result, the common-mode noise filter 100 of this embodiment has the advantage of being able to suppress the deterioration (increase) of the mode conversion characteristics at a specific frequency.
[0047] Graph G1 in Figure 5 shows the mode conversion characteristics of the common-mode noise filter 100 of this embodiment. On the other hand, graph G2 in Figure 5 shows the mode conversion characteristics of the common-mode noise filter of the comparative example. The common-mode noise filter of the comparative example shown in Figure 5 is assumed to be a common-mode noise filter in which, when n is a natural number of 1 or more, the first turn of the nth of the multiple first turns of the first spiral conductor X1 completely overlaps with the second turn of the nth of the multiple second turns of the second spiral conductor when viewed from a predetermined direction.
[0048] As shown in FIG. 5, in the frequency band of 0.1 to 2 GHz, the common mode noise filter 100 of the present embodiment has a larger attenuation amount of the mode conversion characteristics as compared with the common mode noise filter of the comparative example. In particular, when the frequency F1 is included between 0.8 and 0.9 GHz, the attenuation amount of the common mode noise filter 100 of the present embodiment is about 30 dB lower than that of the common mode noise filter of the comparative example. Thus, the common mode noise filter 100 of the present embodiment has an advantage that it can suppress the deterioration (increase) of the mode conversion characteristics as compared with the common mode noise filter of the comparative example.
[0049] (3) Effects The common mode noise filter 100 according to the present embodiment includes a non-magnetic layer 1 and two or more conductor portions 2. The two or more conductor portions 2 are provided inside the non-magnetic layer 1 and are arranged in a predetermined direction D1. At least one of the two or more conductor portions 2 is a conductor wound in a spiral shape and has a first spiral conductor X1 composed of a plurality of first circumferential portions X11 that are portions of each turn. On the other hand, the remaining conductor portions 2 of the two or more conductor portions 2 are conductors wound in a spiral shape and have a second spiral conductor X2 composed of a plurality of second circumferential portions X21 that are portions of each turn. When n is a natural number of 1 or more, the n-th first circumferential portion X11 among the plurality of first circumferential portions X11 intersects the n-th second circumferential portion X21 among the plurality of second circumferential portions X21 at two locations when viewed from the predetermined direction D1. Thereby, the common mode noise filter 100 of the present embodiment can be regarded as a balanced circuit for a signal of a specific wavelength. As a result, the common mode noise filter 100 of the present embodiment has an advantage that it can suppress the deterioration (increase) of the mode conversion characteristics at a specific frequency.
[0050] In the common-mode noise filter 100 according to this embodiment, each of the plurality of first circumferential sections X11 has a linear first linear section Y1 and a linear second linear section Y2, and each of the plurality of second circumferential sections X21 has a linear third linear section Y3 and a linear fourth linear section Y4. The first linear section Y1 (linear section X12) of the nth turn of the first circumferential section X11 overlaps with the third linear section Y3 (linear section X22) of the nth turn of the second circumferential section X21 over its entire length when viewed from a predetermined direction D1. Similarly, the second straight section Y2 (straight section X13) of the nth turn of the first turn section X11 among the multiple first turn sections X11 overlaps with the fourth straight section Y4 (straight section X23) of the nth turn of the second turn section X21 among the multiple second turn sections X21 over its entire length when viewed from a predetermined direction D1. This has the effect of suppressing the deterioration of mode conversion characteristics without significantly changing the conventional structure (for example, without reducing the number of turns). In other words, it has the advantage of suppressing a decrease in the inductance value when functioning as an inductor and attenuating common-mode noise components compared to the conventional structure, and suppressing the deterioration of mode conversion characteristics.
[0051] (4) Modifications The embodiments described above are merely one of many embodiments of the present disclosure. The embodiments described above can be modified in various ways depending on the design, etc., as long as the objectives of the present disclosure are achieved. The following modifications may be implemented by combining them as appropriate. Components similar to those in the embodiments described above are denoted by the same reference numerals and their description is omitted.
[0052] (4-1) First Modified Example In the common-mode noise filter 100 of the above embodiment, the first linear portion Y1 of the nth turn first peripheral portion X11 of the plurality of first peripheral portions X11 overlaps with the third linear portion Y3 of the nth turn second peripheral portion X21 of the plurality of second peripheral portions X21 over its entire length when viewed from a predetermined direction D1. Similarly, in the common-mode noise filter 100 of the above embodiment, the second linear portion Y2 of the nth turn first peripheral portion X11 of the plurality of first peripheral portions X11 overlaps with the fourth linear portion Y4 of the nth turn second peripheral portion X21 of the plurality of second peripheral portions X21 over its entire length when viewed from a predetermined direction D1. However, in the common-mode noise filter 100A of the first modified example shown in Figure 6, the first arc portion Z1 of the nth turn of the first circumferential portion X11A intersects with the third arc portion Z3 of the nth turn of the second circumferential portion X21A at a single point when viewed from a predetermined direction D1. Similarly, in the common-mode noise filter 100A of the first modified example, the second arc portion Z2 of the nth turn of the first circumferential portion X11A intersects with the fourth arc portion Z4 of the nth turn of the second circumferential portion X21A at a single point when viewed from a predetermined direction D1. With this configuration, for example, if the first conductor portion 21A is shifted in the left-right direction relative to the second conductor portion 22A due to manufacturing variations, the amount by which the area overlaps between the nth turn of the first circumferential portion X11A and the nth turn of the second circumferential portion X21A, when viewed from a predetermined direction D1, becomes smaller. Therefore, there is an advantage in that the influence of manufacturing variations is reduced.
[0053] The following describes the detailed configuration of the common-mode noise filter 100A in the first modified example.
[0054] The device comprises a non-magnetic layer 1, two or more conductor portions 2A, a first via B1, a second via B2, a first lead conductor 31, and a second lead conductor 32. The number of conductor portions 2A is two, and the two conductor portions 2A are arranged in a predetermined direction D1 in the order of a first conductor portion 21A and a second conductor portion 22A. In the first modified example, the first conductor portion 21A and the second conductor portion 22A are arranged in this order in the downward direction of the vertical direction. The multiple conductor portions 2A are conductors that extend in a spiral shape around a central axis AX1 that extends in a predetermined direction D1.
[0055] The first conductor section 21A includes a first spiral conductor X1A, a first pad conductor 211, a second pad conductor 212, and connecting conductors 213 and 214. The first spiral conductor X1A is a conductor wound in a spiral shape, that is, a conductor formed in a spiral shape. More specifically, the first spiral conductor X1A has a shape in which a conductor is wound multiple times along an ellipse. As shown in Figure 6, the first spiral conductor X1A consists of a plurality of first circumferential sections X11A, which are the parts of each turn.
[0056] Each of the multiple first circumferential portions X11A has a first circular arc portion Z1 and a second circular arc portion Z2 that are curved in an arc shape, and straight portions X14A and X15A that are formed in a straight line. The first circular arc portion Z1 is the left portion of each of the multiple first circumferential portions X11A, and the second circular arc portion Z2 is the right portion of each of the multiple first circumferential portions X11A. Similarly, the straight portion X14A is the upper portion of each of the multiple first circumferential portions X11A, and the straight portion X15A is the lower portion of each of the multiple first circumferential portions X11A. In Figure 6, among the multiple first circumferential sections X11A, only the first circumferential section X11A of the first turn is labeled with the symbols for the first circular arc section Z1, the second circular arc section Z2, and the straight sections X14A and X15A, while the symbols for the first circular arc section Z1, the second circular arc section Z2, and the straight sections X14A and X15A in the first circumferential sections X11A other than the first circumferential section X11A of the first turn are omitted.
[0057] The second conductor section 22A further comprises a second spiral conductor X2A, a first pad conductor 221, a second pad conductor 222, and connecting conductors 223 and 224. The second spiral conductor X2A is a conductor wound in a spiral shape, that is, a conductor formed in a spiral shape. More specifically, the second spiral conductor X2 has a shape in which a conductor is wound multiple times along an ellipse. As shown in Figure 6, the second spiral conductor X2A consists of a plurality of second circumferential sections X21A, which are the parts of each turn.
[0058] Each of the multiple second circumferential portions X21A has a third arc portion Z3 and a fourth arc portion Z4 that are curved in an arc shape, and straight portions X24A and X25A that are formed in a straight line. The third arc portion Z3 is the left portion of each of the multiple second circumferential portions X21A, and the fourth arc portion Z4 is the right portion of each of the multiple second circumferential portions X21A. Similarly, the straight portion X24A is the upper portion of each of the multiple second circumferential portions X21A, and the straight portion X25A is the lower portion of each of the multiple second circumferential portions X21A. In Figure 6, the symbols for the third arc section Z3, the fourth arc section Z4, and the straight sections X24A and X25A are only applied to the second arc section X21A of the first turn among the multiple second arc sections X21, while the symbols for the third arc section Z3, the fourth arc section Z4, and the straight sections X24A and X25A are omitted for the second arc sections X21 other than the second arc section X21 of the first turn. In the common-mode noise filter 100A, when p is an integer of 1 or more, the first spiral conductor X1A includes a p-turn spiral conductor made up of p first arc sections X11A, and the second spiral conductor X2A includes a p-turn spiral conductor made up of p second arc sections X21A. In the modified example 1, the first spiral conductor X1A as a whole is a p-turn spiral conductor, and the second spiral conductor X2A as a whole is a p-turn spiral conductor. In variation 1, n is a plurality of integers greater than or equal to 1 and less than or equal to p, and is all integers greater than or equal to 1 and less than or equal to p.
[0059] When viewed from a predetermined direction D1, the first arc portion Z1 of the nth turn of the first circumferential portion X11A intersects at one point with the third arc portion Z3 of the nth turn of the second circumferential portion X21A among the multiple first circumferential portions X11A. For example, when viewed from a predetermined direction D1, the first arc portion Z1 of the first turn of the first circumferential portion X11A intersects at one point with the third arc portion Z3 of the first turn of the second circumferential portion X21A among the multiple second circumferential portions X21A. Specifically, when viewed from a predetermined direction D1, the first arc portion Z1 of the first turn of the first circumferential portion X11A intersects at P3 with the third arc portion Z3 of the first turn of the second circumferential portion X21A among the multiple second circumferential portions X21A. More specifically, the first arc portion Z1 of the nth turn of the first circumferential portion X11A among the multiple first circumferential portions X11A is aligned in the front-rear direction with the third arc portion Z3 of the nth turn of the second circumferential portion X21A among the multiple second circumferential portions X21A when viewed from a predetermined direction D1. The first arc portion Z1 of the nth turn of the first circumferential portion X11A is positioned behind the third arc portion Z3 of the nth turn of the second circumferential portion X21A when viewed from a predetermined direction D1.
[0060] Similarly, the second arc portion Z2 of the nth turn first circumferential portion X11A among the multiple first circumferential portions X11A intersects at one point with the fourth arc portion Z4 of the nth turn second circumferential portion X21A among the multiple second circumferential portions X21A when viewed from a predetermined direction D1. For example, in the common-mode noise filter 100A of the first modified example, the second arc portion Z2 of the first turn first circumferential portion X11A among the multiple first circumferential portions X11A intersects at one point with the fourth arc portion Z4 of the first turn second circumferential portion X21A among the multiple second circumferential portions X21A when viewed from a predetermined direction D1. Specifically, the second arc portion Z2 of the first turn of the first circumferential portion X11A among the multiple first circumferential portions X11A intersects at point P4 with the fourth arc portion Z4 of the first turn of the second circumferential portion X21A among the multiple second circumferential portions X21A when viewed from a predetermined direction D1. More specifically, the second arc portion Z2 of the nth turn of the first circumferential portion X11A among the multiple first circumferential portions X11A are aligned in the front-rear direction with the fourth arc portion Z4 of the nth turn of the second circumferential portion X21A when viewed from a predetermined direction D1. The second arc portion Z2 of the nth turn of the first circumferential portion X11A is positioned behind the fourth arc portion Z4 of the nth turn of the second circumferential portion X21A when viewed from a predetermined direction D1.
[0061] Furthermore, the straight section X14A of the nth turn first circumferential section X11A among the multiple first circumferential sections X11A does not intersect with the straight section X24A of the nth turn second circumferential section X21A among the multiple second circumferential sections X21A when viewed from a predetermined direction D1, similar to the straight section X14 in the above embodiment. In addition, the straight section X15A of the nth turn first circumferential section X11A among the multiple first circumferential sections X11A does not intersect with the straight section X25A of the nth turn second circumferential section X21A when viewed from a predetermined direction D1, similar to the straight section X15 in the above embodiment.
[0062] (4-2) Second Modified Example In the common-mode noise filter 100 of the above-described embodiment, the number of two or more conductor sections 2 is two, and the two conductor sections 2 are arranged in a predetermined direction D1 in the order of a first conductor section 21 and a second conductor section 22. Furthermore, in the common-mode noise filter 100 of the above-described embodiment, the first conductor section 21 has a first spiral conductor X1, and the second conductor section 22 has a second spiral conductor X2. However, in the common-mode noise filter 100B of the second modified example shown in Figures 7 and 8, the number of two or more conductor sections 2B is four, and the four conductor sections 2B are arranged in a predetermined direction D1 in the order of a first conductor section 21, a second conductor section 22, a third conductor section 23, and a fourth conductor section 24. In the second modified example, the first conductor section 21B, the second conductor section 22B, the third conductor section 23B, and the fourth conductor section 24B are arranged in this order in the downward direction of the vertical direction. The multiple conductor sections 2B are conductors that extend in a spiral shape, surrounding a central axis AX1 that extends in a predetermined direction D1. Furthermore, in the common-mode noise filter 100B of the second modified example, each of the first conductor section 21 and the fourth conductor section 24 has a first spiral conductor X1, and each of the second conductor section 22 and the third conductor section 23 has a second spiral conductor X2. This configuration has the advantage of being able to further attenuate common-mode noise components.
[0063] The following describes the detailed configuration of the common-mode noise filter 100B, which is the second modified example.
[0064] The common-mode noise filter 100B of the second modified example, as shown in Figures 7 and 8, comprises a non-magnetic layer 1, four conductor sections 2B, a third via B3, a fourth via B4, a fifth via B5, a sixth via, a third lead conductor 33, and a fourth lead conductor. The four conductor sections 2B are arranged in a predetermined direction D1 in the order of a first conductor section 21, a second conductor section 22, a third conductor section 23, and a fourth conductor section 24. The first conductor section 21 and the second conductor section 22 in the second modified example are the same as the first conductor section 21 and the second conductor section 22 in the above-described embodiment, so a detailed explanation is omitted.
[0065] The third conductor section 23 has a third spiral conductor X3. As shown in Figures 7 and 8, in addition to the third spiral conductor X3, the third conductor section 23 further has a first pad conductor 231, a second pad conductor 232, and two connecting conductors. The third spiral conductor X3 of the third conductor section 23 corresponds to the second spiral conductor X2 of the second conductor section 22. Note that the first pad conductor 231, the second pad conductor 232, and the two connecting conductors of the third conductor section 23 are the same as the first pad conductor 221, the second pad conductor 222, and the connecting conductors 223 and 224 of the second conductor section 22, so a detailed explanation is omitted.
[0066] The third spiral conductor X3 is a conductor wound in a spiral shape, that is, a conductor formed in a spiral. The third spiral conductor X3 consists of multiple third turns X31, which are the parts of each turn. The number of turns of the third spiral conductor X3 is 5.
[0067] As shown in Figures 7 and 8, the first conductor section 21 and the third conductor section 23 are electrically connected via the third via B3. Therefore, the first spiral conductor X1 of the first conductor section 21 and the third spiral conductor X3 of the third conductor section 23 function as a single coil.
[0068] Each of the third vias B3 has a length in the vertical direction. The shape of the third vias B3 is cylindrical with the vertical direction as its axis. The third vias B3 electrically connect the second pad conductor 212 of the first conductor section 21 and the second pad conductor 232 of the third conductor section 23. Here, a non-magnetic layer of the non-magnetic layer 1 is placed between the second pad conductors 212 and 232. The third vias B3 electrically connect the second pad conductors 212 and 232 by penetrating the non-magnetic layer of the non-magnetic layer 1.
[0069] Similarly, the fourth via B4 has length in the vertical direction, as shown in Figure 8. The shape of the fourth via B4 is cylindrical, with the vertical direction as its axial direction. The fourth via B4 electrically connects the first pad conductor 231 and the third lead conductor 33 of the third conductor portion 23. Here, a non-magnetic layer of the non-magnetic layer 1 is placed between the first pad conductor 231 and the third lead conductor 33. The fourth via B4 electrically connects the first pad conductor 231 and the third lead conductor 33 by penetrating the non-magnetic layer of the non-magnetic layer 1. The third lead conductor 33 extends to the outer surface of the non-magnetic layer 1, as shown in Figure 8. The third lead conductor 33 leads the first pad conductor 231 of the third conductor portion 23 to the outer surface of the non-magnetic layer 1 via the fourth via B4.
[0070] The fourth conductor section 24 has a fourth spiral conductor X4. As shown in Figure 7, in addition to the fourth spiral conductor X4, the fourth conductor section 24 further has a first pad conductor, a second pad conductor 242, and two connecting conductors. The fourth spiral conductor X4 of the fourth conductor section 24 corresponds to the first spiral conductor X1 of the first conductor section 21. Note that the first pad conductor, the second pad conductor 242, and the two connecting conductors of the fourth conductor section 24 are the same as the first pad conductor 211, the second pad conductor 212, and the connecting conductors 213 and 214 of the first conductor section 21, so a detailed explanation is omitted.
[0071] The fourth spiral conductor X4 is a conductor wound in a spiral shape, that is, a conductor formed in a spiral. The fourth spiral conductor X4 consists of a plurality of fourth circumferential portions X41, which are the parts of each turn. The number of turns of the third spiral conductor X3 is 5. In the common-mode noise filter 100B, when p is an integer of 1 or more, the first spiral conductor X1 includes a p-turn spiral conductor made up of p first circumferential portions X11, the second spiral conductor X2 includes a p-turn spiral conductor made up of p second circumferential portions X21, the third spiral conductor X3 includes a p-turn spiral conductor made up of p third circumferential portions X31, and the fourth spiral conductor X4 includes a p-turn spiral conductor made up of p fourth circumferential portions X41. In Modification 2, the first spiral conductor X1 is a spiral conductor with p turns as a whole, the second spiral conductor X2 is a spiral conductor with p turns as a whole, the third spiral conductor X3 is a spiral conductor with p turns as a whole, and the fourth spiral conductor X4 is a spiral conductor with p turns as a whole. In Modification 2, n is a plurality of integers between 1 and p, and all integers between 1 and p.
[0072] As shown in Figure 7, the second conductor section 22 and the fourth conductor section 24 are electrically connected via the fifth via B5. Therefore, the second spiral conductor X2 of the second conductor section 22 and the fourth spiral conductor X4 of the fourth conductor section 24 function as a single coil.
[0073] The fifth via B5 has length in the vertical direction. The shape of the fifth via B5 is cylindrical with the vertical direction as its axial direction. The fifth via B5 electrically connects the second pad conductor 222 of the second conductor section 22 and the second pad conductor 242 of the fourth conductor section 24. Here, a non-magnetic layer of the non-magnetic layer 1 is placed between the second pad conductor 222 and the second pad conductor 242. The fifth via B5 electrically connects the second pad conductor 222 and the second pad conductor 242 by penetrating the non-magnetic layer of the non-magnetic layer 1.
[0074] Similarly, the sixth via has length in the vertical direction. The shape of the sixth via is cylindrical with the vertical direction as its axis. The sixth via electrically connects the first pad conductor and the fourth lead conductor of the fourth conductor portion 24. Here, a non-magnetic layer of the non-magnetic layer 1 is arranged between the first pad conductor and the third lead conductor of the fourth conductor portion 24. The sixth via electrically connects the first pad conductor and the fourth lead conductor of the fourth conductor portion 24 by penetrating the non-magnetic layer of the non-magnetic layer 1. The fourth lead conductor extends to the outer surface of the non-magnetic layer 1. The fourth lead conductor leads the first pad conductor of the fourth conductor portion 24 to the outer surface of the non-magnetic layer 1 via the sixth via.
[0075] When m is a natural number greater than or equal to 1, the fourth circumferential portion X41 of the fourth spiral conductor X4 at the m-th turn intersects with the third circumferential portion X31 of the third spiral conductor X3 at two locations when viewed from a predetermined direction D1. For example, the fourth circumferential portion X41 of the first turn intersects with the third circumferential portion X31 of the third circumferential portion X31 at two locations when viewed from a predetermined direction D1. The positional relationship between the fourth spiral conductor X4 and the third spiral conductor X3 in the second modified example is the same as the positional relationship between the first spiral conductor X1 and the second spiral conductor X2 in the above embodiment, so a detailed explanation is omitted.
[0076] According to the above configuration, the fourth perimeter X41 at turn m can be considered to be capacitively coupled with the third perimeter X31 at turn m and the third perimeter X31 at turn m+1 at one of the two parts (the front part of the fourth perimeter X41) located between the two points where it intersects with the third perimeter X31 at turn m. Similarly, the fourth perimeter X41 at turn m can be considered to be capacitively coupled with the third perimeter X31 at turn m-1 and the third perimeter X31 at turn m at the remaining part (the rear part of the fourth perimeter X41) located between the two points where it intersects with the third perimeter X31 at turn m. When connected in this way, the fourth perimeter X41 at turn m has three points of capacitive coupling with the third perimeter X31 at turn m-1, turn m, and turn m+1 during one rotation. In other words, when the fourth turn X41 of the m-th turn capacitively couples with the third turn X31, it capacitively couples with the m-1th and m+1th turns of the third turn X31 symmetrically with respect to the m-th turn of the third turn X31. When this is repeated over the entire circumference, it can be considered a balanced circuit for signals of a specific wavelength. As a result, the common-mode noise filter 100B of the second modified example has the advantage of being able to further suppress the deterioration (increase) of the mode conversion characteristics at a specific frequency.
[0077] In the second modified common-mode noise filter 100B, one of the first pad conductor 211 and the third lead conductor of the first conductor section 21A is used as the first input terminal, and the other is used as the first output terminal. Similarly, one of the first pad conductor 221 and the fourth lead conductor of the second conductor section 22A is used as the second input terminal, and the other is used as the second output terminal.
[0078] (4-3) Other Modifications The following lists other modifications of the embodiments described above. The following modifications may be implemented in combination as appropriate.
[0079] In the above-described embodiment, the number of turns of the first spiral conductor X1 is 5, but it is sufficient to have one or more turns. In other words, the number of turns of the first spiral conductor X1 is not limited.
[0080] Similarly, the number of turns of the second spiral conductor X2 is 5, but it is sufficient to have one or more turns. In other words, the number of turns of the second spiral conductor X2 is not limited.
[0081] (Summary) The common-mode noise filters (100, 100A, 100B) of the first embodiment include a non-magnetic layer (1) and two or more conductor parts (2, 2A, 2B). The two or more conductor parts (2, 2A, 2B) are provided inside the non-magnetic layer (1) and are arranged in a predetermined direction (D1). At least one of the two or more conductor parts (2, 2A, 2B) has a first spiral conductor (X1, X1A). The first spiral conductor (X1, X1A) is a spirally wound conductor and consists of a plurality of first circumferential parts (X11, X11A) which are the parts of each turn. At least one of the remaining conductor parts (2, 2A, 2B) has a second spiral conductor (X2, X2A). The second spiral conductor (X2, X2A) is a spirally wound conductor and consists of multiple second turns (X21, X21A), which are the parts of each turn. When n is a natural number greater than or equal to 1, the first turn (X11, X11A) of the multiple first turns (X11, X11A) intersects with the second turn (X21, X21A) of the multiple second turns (X21, X21A) at two points when viewed from a predetermined direction (D1).
[0082] This embodiment has the advantage of suppressing the degradation of mode conversion characteristics.
[0083] In the second embodiment of the common-mode noise filter (100, 100B), each of the plurality of first circumferential sections (X11) has a linearly formed first linear section (Y1) and a second linear section (Y2). Each of the plurality of second circumferential sections (X21) has a linearly formed third linear section (Y3) and a fourth linear section (Y4). The first linear section (Y1) of the nth turn of the plurality of first circumferential sections (X11) overlaps with the third linear section (Y3) of the nth turn of the plurality of second circumferential sections (X21) over its entire length when viewed from a predetermined direction (D1). The second straight section (Y2) of the nth turn first circumferential section (X11) among the multiple first circumferential sections (X11) overlaps with the fourth straight section (Y4) of the nth turn second circumferential section (X21) among the multiple second circumferential sections (X21) over its entire length when viewed from a predetermined direction (D1).
[0084] This embodiment has the advantage of suppressing a decrease in inductance value compared to conventional structures, and also suppressing deterioration of mode conversion characteristics.
[0085] In the third embodiment of the common-mode noise filter (100A), each of the plurality of first circumferential sections (X11A) has a first arc portion (Z1) and a second arc portion (Z2) that are curved in an arc shape. Each of the plurality of second circumferential sections (X21A) has a third arc portion (Z3) and a fourth arc portion (Z4) that are curved in an arc shape. The first arc portion (Z1) of the nth turn of the first circumferential section (X11A) intersects at one point with the third arc portion (Z3) of the nth turn of the second circumferential section (X21A) when viewed from a predetermined direction (D1). The second arc portion (Z2) of the nth turn first circumferential portion (X11A) among the multiple first circumferential portions (X11A) intersects at a single point with the fourth arc portion (Z4) of the nth turn second circumferential portion (X21A) among the multiple second circumferential portions (X21A) when viewed from a predetermined direction (D1).
[0086] This embodiment has the advantage of reducing the impact of manufacturing variations.
[0087] The common-mode noise filter (100, 100A) of the fourth embodiment has, in any of the first to third embodiments, two or more conductor sections (2, 2A), which are two: a first conductor section and a second conductor section. The first conductor section (21, 21A) and the second conductor section (22, 22A) are arranged in this order in a predetermined direction (D1). The first conductor section (21, 21A) is the at least one conductor section having a first spiral conductor (X1, X1A). The second conductor section (22, 22A) is the remaining at least one conductor section having a second spiral conductor (X2, X2A).
[0088] The common-mode noise filter (100B) of the fifth embodiment has, in any of the first to third embodiments, two or more conductor sections (2B), numbering four: a first conductor section, a second conductor section, a third conductor section, and a fourth conductor section. The first conductor section (21), the second conductor section (22), the third conductor section (23), and the fourth conductor section (24) are arranged in this order in a predetermined direction (D1). The first conductor section (21) is the above-mentioned at least one conductor section having a first spiral conductor (X1). The second conductor section (22) is the above-mentioned at least one conductor section having a second spiral conductor (X2). The third conductor section (23) is a spirally wound conductor and has a third spiral conductor (X3) consisting of a plurality of third turns (X31) which are portions of each turn. The fourth conductor section (24) is a spirally wound conductor and has a fourth spiral conductor (X4) consisting of a plurality of fourth turns (X41), which are the parts of each turn. When m is a natural number of 1 or more, the fourth turn (X41) of the plurality of fourth turns (X41) intersects with the third turn (X31) of the plurality of third turns (X31) at two locations when viewed from a predetermined direction (D1).
[0089] This embodiment has the advantage of being able to further attenuate common-mode noise components.
[0090] 100, 100A, 100B Common-mode noise filter 1 Non-magnetic layer 2, 2A, 2B Conductor section 21, 21A First conductor section 22, 22A Second conductor section 23 Third conductor section 24 Fourth conductor section D1 Determined direction X1, X1A First spiral conductor X11, X11A First circumference section X2, X2A Second spiral conductor X21, X21A Second circumference section X3 Third spiral conductor X31 Third circumference section X4 Fourth spiral conductor X41 Fourth circumference section Y1 First straight section Y2 Second straight section Y3 Third straight section Y4 Fourth straight section Z1 First arc section Z2 Second arc section Z3 Third arc section Z4 Fourth arc section
Claims
1. A common-mode noise filter comprising: a non-magnetic layer; and two or more conductor portions provided inside the non-magnetic layer and arranged in a predetermined direction, wherein at least one of the two or more conductor portions is a spirally wound conductor and has a first spiral conductor consisting of a plurality of first circumferences which are the parts of each turn; and the remaining at least one of the two or more conductor portions is a spirally wound conductor and has a second spiral conductor consisting of a plurality of second circumferences which are the parts of each turn, and when n is a natural number of 1 or more, the first circumference of the nth turn of the plurality of first circumferences intersects with the second circumference of the nth turn of the plurality of second circumferences at two locations when viewed from the predetermined direction.
2. Each of the plurality of first circumferential portions has a first linear portion and a second linear portion formed in a straight line; Each of the plurality of second circumferential portions has a third linear portion and a fourth linear portion formed in a straight line; The first linear portion of the nth turn of the plurality of first circumferential portions overlaps with the third linear portion of the nth turn of the plurality of second circumferential portions over its entire length when viewed from the predetermined direction; The second linear portion of the nth turn of the plurality of first circumferential portions overlaps with the fourth linear portion of the nth turn of the plurality of second circumferential portions over its entire length when viewed from the predetermined direction; The common mode noise filter according to claim 1.
3. Each of the plurality of first circumferential portions has a first and second arc portion that are curved in an arc shape, each of the plurality of second circumferential portions has a third and a fourth arc portion that are curved in an arc shape, the first arc portion of the nth turn of the plurality of first circumferential portions intersects at one point with the third arc portion of the nth turn of the plurality of second circumferential portions when viewed from the predetermined direction, the second arc portion of the nth turn of the plurality of first circumferential portions intersects at one point with the fourth arc portion of the nth turn of the plurality of second circumferential portions when viewed from the predetermined direction, the common mode noise filter according to claim 1.
4. The number of the two or more conductor parts is two, a first conductor part and a second conductor part, the first conductor part and the second conductor part are arranged in this order in the predetermined direction, the first conductor part is the at least one conductor part having the first spiral conductor, and the second conductor part is the remaining at least one conductor part having the second spiral conductor, the common mode noise filter according to any one of claims 1 to 3.
5. The number of the two or more conductor parts is four: a first conductor part, a second conductor part, a third conductor part, and a fourth conductor part, the first conductor part, the second conductor part, the third conductor part, and the fourth conductor part are arranged in this order in the predetermined direction, the first conductor part is the at least one conductor part having the first spiral conductor, the second conductor part is the remaining at least one conductor part having the second spiral conductor, the third conductor part is a spirally wound conductor and has a third spiral conductor consisting of a plurality of third turns which are the parts of each turn, the fourth conductor part is a spirally wound conductor and has a fourth spiral conductor consisting of a plurality of fourth turns which are the parts of each turn, and when m is a natural number of 1 or more, the fourth turn of the plurality of fourth turns intersects with the third turn of the plurality of third turns at two locations when viewed from the predetermined direction, the common mode noise filter according to any one of claims 1 to 3.