Coil parts

Abstract

To provide a coil component capable of reducing a line capacitance between a first wire and a second wire in an overlapping winding region.SOLUTION: A coil component 10 comprises a core 20, a first wire 31, and a second wire 41. The core 20 includes a rectangular column-shaped winding core part 21. The first wire 31 and the second wire 41 are wound around the winding core part 21. In the coil component 10, an overlapping winding region 50 is provided in which the first wire 31 is wound around the winding core part 21 and the second wire 41 is wound around the winding core part 21 on the first wire. The overlapping winding region 50 has a predetermined part 51 that is a part where the first wire 31 and the second wire 41 are wound around the winding core part 21 so that a gap SP is interposed between a part wound around a side surface 211 of the winding core part 21 of the first wire 31 and a part wound around the side surface 211 of the second wire 41.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a coil component in which a plurality of wires are wound around a winding core portion of a core. [Background technology]

[0002] Patent Document 1 describes an example of a common mode choke coil. The common mode choke coil includes a core, a first wire, and a second wire. The core has a winding core part around which the first wire and the second wire are wound, a first flange part connected to a first end of the winding core part, and a second flange part connected to a second end of the winding core part. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-183444 A Summary of the Invention [Problem to be solved by the invention]

[0004] The common mode choke coil has an overlap winding region in which the first wire and the second wire are wound around the winding core by overlap winding. The overlap winding region has a multi-winding structure in which the first wire is wound around the winding core, and the second wire is wound around the first wire. In such a multi-winding structure, the wire density is high, and therefore the inter-wire capacitance between the first wire and the second wire is likely to be large. [Means for solving the problem]

[0005] A coil component for solving the above problem includes a core having a rectangular columnar winding core, a first flange connected to a first end of the winding core in the axial direction of the winding core, and a second flange connected to a second end of the winding core in the axial direction, and a first wire and a second wire wound around the winding core. The winding core has a first side surface, a second side surface connected to the first side surface via a first corner, and a third side surface connected to the first side surface via a second corner. The coil component includes an overlap winding region in which the first wire is wound around the winding core and the second wire is wound around the winding core. The overlap winding region includes a predetermined portion in which the first wire and the second wire are wound around the winding core such that a gap is provided between a portion of the first wire wound around the first side surface and a portion of the second wire wound around the first side surface.

[0006] According to the above configuration, in a predetermined portion of the overlap winding region, the first wire and the second wire are wound around the winding core such that a gap is provided between the portion of the first wire wound around the first side surface and the portion of the second wire wound around the first side surface. This allows a portion where the distance between the first wire and the second wire is long to be provided. In other words, a portion where the wire density is low can be formed. As a result, the inter-wire capacitance between the first wire and the second wire can be reduced. Effect of the Invention

[0007] According to the coil component described above, it is possible to reduce the inter-wire capacitance between the first wire and the second wire in the lap winding region. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a perspective view showing a coil component according to the first embodiment. [Diagram 2] FIG. [Diagram 3] FIG. 2 is a diagram showing a cross-sectional shape of the coil component. [Figure 4]FIG. 4 is a diagram showing a schematic cross-sectional shape of a portion of the coil component. [Diagram 5] An enlarged view of a portion of Figure 4. [Figure 6] FIG. 4 is a schematic diagram illustrating the positional relationship between a first wire and a second wire. [Figure 7] FIG. 4 is a diagram showing an equivalent circuit of the coil component. [Figure 8] 5A and 5B are schematic diagrams illustrating how inter-wire capacitance occurs between a first wire and a second wire. [Figure 9] 11 is a graph showing the relationship between the frequency of a signal input to a coil component and the intensity ratio of an output signal to an input signal to the coil component. [Figure 10] FIG. 11 is a schematic diagram showing a cross-sectional shape of a portion of a coil component according to a second embodiment. [Figure 11] An enlarged view of a portion of Figure 10. [Figure 12] FIG. 11 is a schematic diagram showing a cross-sectional shape of a portion of a coil component according to a modified example. [Figure 13] FIG. 11 is a schematic diagram showing a cross-sectional shape of a portion of a coil component according to a modified example. [Figure 14] FIG. 11 is a schematic diagram showing a cross-sectional shape of a portion of a coil component according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (First embodiment) Hereinafter, an embodiment of a coil component will be described with reference to Figs. 1 to 9. In the drawings, components may be shown enlarged to facilitate understanding. The dimensional ratios of components may differ from the actual ones or from those in other drawings. In addition, although hatching is applied in the cross-sectional views, hatching of some components may be omitted to facilitate understanding.

[0010] 1 and 2, the coil component 10 includes a core 20 and a plurality of wires 31, 41 wound around the core 20. The coil component 10 is, for example, a common mode choke coil.

[0011] The core 20 contains, for example, an electrically insulating material. Specifically, the core 20 contains a non-magnetic material such as alumina or resin, or a magnetic material such as ferrite or resin containing magnetic powder. Preferably, the core 20 is made of a sintered material such as alumina or ferrite.

[0012] The core 20 has a polygonal winding core portion 21, a first flange portion 22 connected to a first end 21a of the winding core portion 21 in the axial direction Z1, and a second flange portion 23 connected to a second end 21b of the winding core portion 21 in the axial direction Z1. The axial direction Z1 is the extension direction of the central axis F of the winding core portion 21.

[0013] Fig. 3 is a schematic diagram of a cross section of the coil device 10 cut along a line LN1 shown in Fig. 2. The line LN1 is an imaginary straight line that extends in a direction perpendicular to the axial direction Z1 and passes through the center of the core 20 in the axial direction Z1. That is, the cross section of the winding core 21 shown in Fig. 3 is a cross section of the winding core 21 cut along a direction perpendicular to the axial direction Z1. As shown in Fig. 3, the winding core 21 may be a rectangular prism. Of course, the winding core 21 does not have to be a rectangular prism as long as it has a rectangular prism shape.

[0014] When the winding core 21 is a rectangular prism as shown in FIG. 3, the winding core 21 has four side surfaces 211, 212, 213, and 214. In a circumferential direction Z3 centered on the central axis F of the winding core 21, a first end of the side surface 211 is connected to a second end of the side surface 212 via a corner C1. The second end of the side surface 211 is connected to a first end of the side surface 213 via a corner C2. The first end of the side surface 212 is connected to a second end of the side surface 214 via a corner C3. The second end of the side surface 213 is connected to a first end of the side surface 214 via a corner C4. The "first end of the side surface" here refers to the end in the counterclockwise direction in FIG. 3, and the "second end of the side surface" refers to the end in the clockwise direction in FIG. 3.

[0015] In FIG. 3, for ease of understanding, the wires 31, 41 are illustrated as being annular, but in reality, the wires 31, 41 are not annular. The length of the side surface 211, which is the shortest distance from the corner C1 to the corner C2, is defined as the first distance L1. That is, the first distance L1 is a straight line extending from the corner C1 to the corner C2 in a direction perpendicular to the axial direction Z1. More specifically, the length of the line indicating the side surface 211 in the cross section of the winding core 21 shown in FIG. 3 corresponds to the first distance L1. The length of the side surface 212, which is the shortest distance from the corner C1 to the corner C3, is defined as the second distance L2. That is, the second distance L2 is a straight line extending from the corner C1 to the corner C3 in a direction perpendicular to the axial direction Z1. More specifically, the length of the line indicating the side surface 212 in the cross section of the winding core 21 shown in FIG. 3 corresponds to the second distance L2. The length of the side surface 213, which is the shortest distance from the corner C2 to the corner C4, is defined as the third distance L3. That is, the third distance L3 is a straight line extending from the corner C2 to the corner C4 in a direction perpendicular to the axial direction Z1. More specifically, in the cross section of the winding core 21 shown in FIG. 3, the length of the line indicating the side surface 213 corresponds to the third distance L3. The length of the side surface 214, which is the shortest distance from the corner C3 to the corner C4, is set as the fourth distance L4. That is, the fourth distance L4 is a straight line extending from the corner C3 to the corner C4 in a direction perpendicular to the axial direction Z1. More specifically, in the cross section of the winding core 21 shown in FIG. 3, the length of the line indicating the side surface 214 corresponds to the fourth distance L4. For example, in the example shown in FIG. 3, the first distance L1 is longer than the second distance L2 and longer than the third distance L3. Also, for example, the fourth distance L4 is longer than the second distance L2 and longer than the third distance L3.

[0016] As described above, Fig. 3 is a diagram of the coil device 10 cut at the center of the winding core 21 in the axial direction Z1. Therefore, the first distance L1 can be said to be the linear distance from the corner C1 to the corner C2 at the center of the winding core 21 in the axial direction Z1. The second distance L2 can be said to be the linear distance from the corner C1 to the corner C3 at the center of the winding core 21 in the axial direction Z1. The third distance L3 can be said to be the linear distance from the corner C2 to the corner C4 at the center of the winding core 21 in the axial direction Z1. The fourth distance L4 can be said to be the linear distance from the corner C3 to the corner C4 at the center of the winding core 21 in the axial direction Z1.

[0017] 1 and 2, a first wire 31 and a second wire 41 are wound around the winding core 21. That is, each of the first wire 31 and the second wire 41 is wound in a spiral shape around the winding core 21. Moreover, the direction in which the first wire 31 is wound around the winding core 21 is the same as the direction in which the second wire 41 is wound around the winding core 21. Furthermore, the number of turns of the first wire 31 around the winding core 21 is substantially the same as the number of turns of the second wire 41 around the winding core 21.

[0018] In this embodiment, the first wire 31 is directly wound around the winding core 21. Then, the second wire 41 is wound around the winding core 21 around which the first wire 31 is wound. If the region where the first wire 31 is wound around the winding core 21 and where the second wire 41 is wound around the winding core 21 from above is defined as the "lap winding region 50," it can be said that the coil device 10 has the lap winding region 50.

[0019] A first terminal electrode 11a and a second terminal electrode 11b are provided on the first flange portion 22. That is, the second terminal electrode 11b is disposed at the same position as the first terminal electrode 11a in the axial direction Z1. The second terminal electrode 11b is also disposed on the opposite side to the first terminal electrode 11a across the central axis F of the winding core portion 21 in a direction perpendicular to the axial direction Z1.

[0020] The second flange 23 is provided with a third terminal electrode 12a and a fourth terminal electrode 12b. That is, the fourth terminal electrode 12b is disposed at the same position as the third terminal electrode 12a in the axial direction Z1. The fourth terminal electrode 12b is also disposed on the opposite side of the third terminal electrode 12a across the central axis F in a direction perpendicular to the axial direction Z1.

[0021] The first terminal electrode 11a and the third terminal electrode 12a are located on a first side (the right side in FIG. 2) in a direction perpendicular to the axial direction Z1, and the second terminal electrode 11b and the fourth terminal electrode 12b are located on a second side (the left side in FIG. 2) in a direction perpendicular to the axial direction Z1.

[0022] A first end 31a of the first wire 31 is electrically connected to the first terminal electrode 11a, and a second end 31b of the first wire 31 is electrically connected to the third terminal electrode 12a. Meanwhile, a first end 41a of the second wire 41 is electrically connected to the second terminal electrode 11b, and a second end 41b of the second wire 41 is electrically connected to the fourth terminal electrode 12b. That is, the first end 31a and the second end 31b of the first wire 31 are electrically connected to a terminal electrode located on a first side (right side in FIG. 2) in a direction perpendicular to the axial direction Z1. The first end 41a and the second end 41b of the second wire 41 are electrically connected to a terminal electrode located on a second side (left side in FIG. 2) in a direction perpendicular to the axial direction Z1.

[0023] Next, the overlap winding region 50 will be described in detail with reference to Fig. 3 to Fig. 6. Fig. 4 shows a schematic diagram of a part of a cross section of the coil device 10 cut along the line LN2 shown in Fig. 2. If a direction along the side surface 211 that is perpendicular to the axial direction Z1 is defined as the "width direction Z2", the line LN2 is an imaginary straight line that extends in the axial direction Z1 and passes through a middle position of the side surface 211 in the width direction Z2. That is, the cross section of the winding core portion 21 shown in Fig. 4 is a part of a cross section of the winding core portion 21 cut along the direction perpendicular to the width direction Z2.

[0024] As shown in Figs. 3, 4, and 5, the overlap winding region 50 has a predetermined portion 51. In this embodiment, the predetermined portion 51 is a portion of the overlap winding region 50 where the first wire 31 and the second wire 41 are wound around the winding core portion 21 so as to satisfy any one of the following conditions (B1), (B2), (B3), and (B4): (B1) A gap SP is provided between a portion of the first wire 31 wound around the side surface 211 and a portion of the second wire 41 wound around the side surface 211. (B2) A gap SP is provided between a portion of the first wire 31 wound around the side surface 212 and a portion of the second wire 41 wound around the side surface 212. (B3) A gap SP is provided between a portion of the first wire 31 wound around the side surface 213 and a portion of the second wire 41 wound around the side surface 213. (B4) A gap SP is present between the portion of the first wire 31 wound around the side surface 214 and the portion of the second wire 41 wound around the side surface 214 .

[0025] In this embodiment, the predetermined portion 51 satisfies all of the above conditions (B1) to (B4). However, this is not limited thereto. For example, the predetermined portion may be a portion where the first wire 31 and the second wire 41 are wound around the winding core 21 so as to satisfy any one of the above conditions (B1) to (A4). That is, in the predetermined portion, it is sufficient that a gap SP is interposed between the first wire 31 and the second wire 41 wound around at least one side surface among the side surfaces 211 to 214 of the winding core 21. More preferably, in the predetermined portion 51, a gap SP is interposed between the first wire 31 and the second wire 41 on the side surface at the longest distance among the distances L1 to L4.

[0026] The interval H1 between the first wire 31 and the second wire 41 wound around the side surface 211 will be described. At the corner C1, the interval H1 is "0". That is, the first wire 31 and the second wire 41 are in contact with each other. The interval H1 becomes wider from the corner C1 toward the corner C2. The interval H1 is maximum at the midpoint between the corners C1 and C2. The maximum value of the interval H1 is called the "maximum interval H1max". The interval H1 becomes narrower from the midpoint toward the corner C2. The interval H1 is "0" at the corner C2. That is, the first wire 31 and the second wire 41 are in contact with each other.

[0027] The interval H4 between the first wire 31 and the second wire 41 wound around the side surface 214 will be described. At the corner C3, the interval H4 is "0". That is, the first wire 31 and the second wire 41 are in contact with each other. The interval H4 becomes wider from the corner C3 to the corner C4. The interval H4 is maximum at the intermediate position between the corners C3 and C4. The maximum value of the interval H4 is called the "maximum interval H4max". The interval H4 becomes narrower from the intermediate position toward the corner C4. The interval H4 is "0" at the corner C4. That is, the first wire 31 and the second wire 41 are in contact with each other.

[0028] The spacing H2 between the first wire 31 and the second wire 41 wound around the side surface 212 will be described. At the corner C1, the spacing H2 is "0". That is, the first wire 31 and the second wire 41 are in contact with each other. The spacing H2 becomes wider from the corner C1 toward the corner C3. The spacing H2 is maximum at the midpoint between the corners C1 and C3. The maximum value of the spacing H2 is called the "maximum spacing H2max". The spacing H2 becomes narrower from the midpoint toward the corner C3. The spacing H2 is "0" at the corner C3. That is, the first wire 31 and the second wire 41 are in contact with each other.

[0029] The interval H3 between the first wire 31 and the second wire 41 wound around the side surface 213 will be described. At the corner C2, the interval H3 is "0". That is, the first wire 31 and the second wire 41 are in contact with each other. The interval H3 becomes wider from the corner C2 toward the corner C4. The interval H3 is maximum at the midpoint between the corners C2 and C4. The maximum value of the interval H3 is called the "maximum interval H3max". The interval H3 becomes narrower from the midpoint toward the corner C4. And the interval H2 is "0" at the corner C4. That is, the first wire 31 and the second wire 41 are in contact with each other.

[0030] In this embodiment, each of the first distance L1 and the fourth distance L4 is longer than the second distance L2 and longer than the third distance L3. Therefore, as shown in Fig. 3, the maximum interval H1max is wider than both the maximum interval H2max and the maximum interval H3max. Similarly, the maximum interval H4max is wider than both the maximum interval H2max and the maximum interval H3max.

[0031] As shown in Fig. 6, the maximum intervals H1max, H2max, H3max, and H4max are set so as to satisfy the following (A1) and (A2). The upper limit radial position below refers to a position that is spaced outward from the outermost end 311 of the first wire 31 by the diameter D2 of the second wire 41 in the radial direction Z4 centered on the central axis F of the winding core portion 21. (A1) In the radial direction Z4, the innermost end 411 of the second wire 41 is located outward (upper in Fig. 6) than the outermost end 311 of the first wire 31. (A2) In the radial direction Z4, the innermost end 411 of the second wire 41 is located inside (inside in Fig. 6) the upper limit radial position.

[0032] That is, among the portion of the first wire 31 wound around the side surface 211, the portion located furthest outward in the radial direction Z4 is defined as the outermost end 311, and among the portion of the second wire 41 wound around the side surface 211, the portion located furthest inward in the radial direction Z4 is defined as the innermost end 411. In this case, the maximum interval H1max is set so as to satisfy the following: the innermost end 411 of the portion of the second wire 41 wound around the side surface 211 is located radially outward from the outermost end 311 of the portion of the first wire 31 wound around the side surface 211, and the innermost end 411 of the second wire 41 is located inside a position separated by a diameter D2 from the outermost end 311 of the first wire 31.

[0033] Of the first wire 31, the portion wound around the side surface 212 that is located most outside in the radial direction Z4 is defined as the outermost end 311, and of the second wire 41, the portion wound around the side surface 212 that is located most inside in the radial direction Z4 is defined as the innermost end 411. In this case, the maximum interval H1max is set so as to satisfy the following: the innermost end 411 of the portion of the second wire 41 wound around the side surface 212 is located radially outside the outermost end 311 of the portion of the first wire 31 wound around the side surface 212, and the innermost end 411 of the second wire 41 is located inside a position that is separated by a diameter D2 from the outermost end 311 of the first wire 31.

[0034] Of the first wire 31, the portion wound around the side surface 213 that is located most outside in the radial direction Z4 is defined as the outermost end 311, and of the second wire 41, the portion wound around the side surface 213 that is located most inside in the radial direction Z4 is defined as the innermost end 411. In this case, the maximum interval H1max is set so as to satisfy the following: the innermost end 411 of the portion of the second wire 41 wound around the side surface 213 is located radially outside the outermost end 311 of the portion of the first wire 31 wound around the side surface 213, and the innermost end 411 of the second wire 41 is located inside a position that is separated by a diameter D2 from the outermost end 311 of the first wire 31.

[0035] Of the first wire 31, the portion wound around the side surface 214 that is located most outside in the radial direction Z4 is defined as the outermost end 311, and of the second wire 41, the portion wound around the side surface 214 that is located most inside in the radial direction Z4 is defined as the innermost end 411. In this case, the maximum interval H1max is set so as to satisfy the following: the innermost end 411 of the portion of the second wire 41 wound around the side surface 214 is located radially outside the outermost end 311 of the portion of the first wire 31 wound around the side surface 214, and the innermost end 411 of the second wire 41 is located inside a position that is separated by a diameter D2 from the outermost end 311 of the first wire 31.

[0036] By satisfying the above (A1), the second wire 41 is positioned outward of the outermost end 311 of the first wire 31 in the radial direction Z4 at the intermediate position between the two corners located at both ends of the side surface. Moreover, by satisfying the above (A2), the distance between the outermost end 311 of the first wire 31 and the innermost end 411 of the second wire 41 is narrower than the diameter D2 of the second wire 41 at the intermediate position between the two corners located at both ends of the side surface.

[0037] However, at the corners C1 to C4, the second wire 41 is in contact with the first wire 31. Therefore, in the vicinity of the corners C1 to C4, the above condition (A1) may not be satisfied. Incidentally, among the four side surfaces 211 to 214 of the winding core portion 21, if the side surface 211 is regarded as the "first side surface", the side surface 212 corresponds to the "second side surface", the side surface 213 corresponds to the "third side surface", and the side surface 214 corresponds to the "fourth side surface". Furthermore, the corner C1 connecting the side surface 211 and the side surface 212 corresponds to the "first corner", and the corner C2 connecting the side surface 211 and the side surface 213 corresponds to the "second corner". Furthermore, the corner C3 connecting the side surface 212 and the side surface 214 corresponds to the "third corner", and the corner C4 connecting the side surface 213 and the side surface 214 corresponds to the "fourth corner".

[0038] Next, the operation of this embodiment will be described. FIG. 7 shows an equivalent circuit of a coil component in which both the first wire 31 and the second wire 41 are wound around one winding core 21. In this case, the first wire 31 and the second wire 41 form a pseudo capacitor 100. That is, a line capacitance LC, which is the capacitance of the capacitor 100, is generated between the first wire 31 and a portion of the second wire 41 located near the first wire 31. For example, as shown in FIG. 8, a line capacitance LC is generated between the first turn of the second wire 41 and the first turn of the second wire 41. A line capacitance LC is generated between the first turn of the second wire 41 and the second turn of the first wire 31. The magnitude of the line capacitance LC is proportional to the physical distance between the wires 31 and 41. Therefore, the line capacitance LC increases as the distance between the first wire 31 and the second wire 41 decreases. If the line capacitance LC is large, the high-frequency characteristics of the coil component may deteriorate.

[0039] In the lap winding region 50 of the coil device 10 in this embodiment, a region is formed in which a gap SP is interposed between the first wire 31 and the second wire 41. That is, the lap winding region 50 has a predetermined portion 51. In the predetermined portion 51, it is possible to reduce the number of locations where the gap between the first wire 31 and the second wire 41 is narrow.

[0040] The inter-line capacitance LCA of the coil component of the comparative example in which no gap is present between the first wire 31 and the second wire 41 in the lap winding region 50 is larger than the inter-line capacitance LC of the coil component 10 of the present embodiment. This is because, while there is a portion in which the gap between the first wire 31 and the second wire 41 is wide in the lap winding region 50 of the coil component 10 of the present embodiment, there is no portion in which the gap between the first wire and the second wire is wide in the lap winding region of the coil component of the comparative example. FIG. 9 shows the relationship between the frequency of the signal input to the coil component and the intensity ratio of the output signal to the input signal to the coil component for the mode conversion characteristics. In FIG. 9, the dashed line shows the relationship in the coil component of the comparative example, and the solid line shows the relationship in the coil component 10 of the present embodiment. When the frequency of the signal input to the coil component is relatively low, the magnitude of the intensity ratio in the coil component 10 of the present embodiment is approximately the same as the magnitude of the intensity ratio in the coil component of the comparative example. However, because the line capacitance LC is small, when the frequency of the input signal increases, a difference occurs between the magnitude of the intensity ratio in the coil component 10 of the present embodiment and the magnitude of the intensity ratio in the coil component of the comparative example. Specifically, the magnitude of the intensity ratio in the coil component 10 of the present embodiment is smaller than that in the coil component of the comparative example. Therefore, the mode conversion characteristics at high frequencies of the coil component 10 of the present embodiment are better than those of the coil component of the comparative example. In other words, the high frequency characteristics of the coil component 10 of the present embodiment are better than those of the coil component of the comparative example.

[0041] In addition, in this embodiment, the following effects can be further obtained. (1-1) In the specified portion 51, a region is formed in which a gap SP is interposed between the first wire 31 wound around the winding core portion 21 and the second wire 41 wound around the winding core portion 21 from above the first wire 31. By providing a portion in which the distance between the first wire 31 and the second wire 41 is long in this manner, a portion with low wire density can be formed, and accordingly the line capacitance LC generated between the first wire 31 and the second wire 41 can be reduced. Furthermore, by reducing the line capacitance LC, the high-frequency characteristics of the coil device 10 can be improved.

[0042] (1-2) In the present embodiment, the entire lap winding region 50 in the axial direction Z1 is the specified portion 51. As such, the higher the proportion of the specified portion 51 in the lap winding region 50, the greater the effect of reducing the inter-wire capacitance LC generated between the first wire 31 and the second wire 41.

[0043] Note that "the entire overlap winding region 50" here does not have to include the winding start portion of the first wire 31 and the second wire 41 and the winding end portion of the first wire 31 and the second wire 41. This is because the tension of the wire is not stable at the winding start and end portion depending on the winding method. If the tension of the wire is not stable, it is difficult to appropriately adjust the relative position of the second wire 41 with respect to the first wire 31. Of course, if the tension of the wire can be stabilized at the winding start and end portion, the specified portion 51 may include the winding start portion of the wire, or the specified portion 51 may include the winding end portion of the wire.

[0044] (1-3) The interval between the first wire 31 and the second wire 41 wound around the side where the linear distance from the first end to the second end in the circumferential direction Z3 is long is wider than the interval between the first wire 31 and the second wire 41 wound around the side where the linear distance from the first end to the second end in the circumferential direction Z3 is short. By widening the interval between the first wire 31 and the second wire 41 wound around the side where the linear distance from the first end to the second end is long in this manner, the effect of reducing the line capacitance LC generated between the first wire 31 and the second wire 41 can be increased.

[0045] (1-4) In this embodiment, in the specified portion 51, the first wire 31 and the second wire 41 are wound around the winding core portion 21 so as to satisfy the above (A1). This makes it possible to widen the interval between the first wire 31 and the second wire 41, and thus to reduce the line capacitance LC.

[0046] (1-5) In this embodiment, in the specified portion 51, the first wire 31 and the second wire 41 are wound around the winding core portion 21 so as to satisfy the above (A2). This makes it possible to maintain the state in which the second wire 41 is wound around the winding core portion 21 without causing any irregular winding of the second wire 41.

[0047] Second embodiment Next, a second embodiment of the coil device will be described with reference to Figures 10 and 11. In the following description, differences from the first embodiment will be mainly described, and the same reference numerals will be used to designate the same or corresponding members as those in the first embodiment, and duplicated description will be omitted.

[0048] As shown in Fig. 10, the coil device 10A has an overlap winding region 50. The overlap winding region 50 has a specified portion 51. However, as shown in Fig. 10 and Fig. 11, although a part of the overlap winding region 50 in the axial direction Z1 is the specified portion 51, the remaining portion is not the specified portion 51. The portion of the overlap winding region 50 that is not the specified portion 51 is referred to as a "non-specified portion 52."

[0049] 10, in the axial direction Z1, a region of the lap winding region 50 that is closer to the first flange 22 is a specified portion 51. A region of the lap winding region 50 that is closer to the second flange 23 than the specified portion 51 is a non-specified portion 52. In the non-specified portion 52, the first wire 31 and the second wire 41 are not separated from each other between the two corners located on both sides of the side surface. That is, the first wire 31 and the second wire 41 are in contact with each other.

[0050] In this embodiment, the lap winding region 50 has both the specified portion 51 and the non-specified portion 52. Even in this case, the inter-wire capacitance LC generated between the first wire 31 and the second wire 41 can be made smaller than in a case where the lap winding region 50 does not have the specified portion 51. Therefore, the high-frequency characteristics of the coil device 10A can be improved.

[0051] The tension applied to the second wire 41 when winding the second wire 41 around the winding core 21 to form the non-predetermined portion 52 is set as the reference tension. When forming the predetermined portion 51, it is preferable to set the tension applied to the second wire 41 when winding the second wire 41 around the winding core 21 to be smaller than the reference tension. This allows the first wire 31 to be separated from the second wire 41 between the two corners located on both sides of the side surface. In other words, the predetermined portion 51 can be formed.

[0052] (Example of change) The above-described embodiments may be modified as follows: The above-described embodiments and the following modifications may be combined with each other to the extent that no technical contradiction occurs.

[0053] In the second embodiment, the portion of the lap winding region 50 closer to the second flange portion 23 in the axial direction Z1 may be the specified portion 51, and the portion closer to the first flange portion 22 in the axial direction Z1 may be the non-specified portion 52.

[0054] In addition to the lap winding region 50, the coil component may have a bifilar region, which is a region where the first wire 31 and the second wire 41 are wound around the winding core portion 21 by bifilar winding.

[0055] For example, as shown in FIG. 12, the coil device 10B may have a configuration in which a lap winding region 50 is provided near the first flange portion 22 in the axial direction Z1, and a bifilar region 60 is disposed on the opposite side of the first flange portion 22 with the lap winding region 50 in between.

[0056] For example, as shown in FIG. 13, the coil device 10B may be configured such that a first bifilar region 61 is arranged near the first flange portion 22 in the axial direction Z1, a second bifilar region 62 is arranged near the second flange portion 23 in the axial direction Z1, and a lap winding region 50 is arranged between the first bifilar region 61 and the second bifilar region 62.

[0057] For example, as shown in FIG. 14, the coil device 10B may have a configuration in which a lap winding region 50 is provided near the second flange portion 23 in the axial direction Z1, and a bifilar region 60 is disposed on the opposite side of the second flange portion 23 with the lap winding region 50 in between.

[0058] For example, the coil device 10B may be configured such that a first overlap winding region is disposed near the first flange portion 22 in the axial direction Z1, a second overlap winding region is disposed near the second flange portion 23 in the axial direction Z1, and a bifilar region 60 is disposed between the first overlap winding region and the second overlap winding region.

[0059] The overlap winding region may be configured such that the specified portions 51 and the non-specified portions 52 are alternately arranged in the axial direction Z1. The dimension of the specified portion 51 in the axial direction Z1 may be a length equivalent to one turn of the first wire 31. That is, in the lap winding region, it is sufficient that a gap SP is provided between the portion of the first wire 31 wound around the first side surface and the portion of the second wire 41 wound around the first side surface at only one location.

[0060] In the specified portion 51, so long as the portion of the second wire 41 wound around the side surface 211 is separated from the portion of the first wire 31 wound around the side surface 211, the above (A1) does not have to be satisfied. In other words, in the specified portion 51, so long as there is a portion on the side surface 211 where the second wire 41 is separated from the first wire 31, there may be a portion on the side surface 211 where the second wire 41 is in contact with the first wire 31.

[0061] The predetermined portion 51 does not have to satisfy (A2) above. The above-mentioned maximum interval H2max may be the same as the above-mentioned maximum interval H1max, or may be wider than the maximum interval H1max.

[0062] The above maximum interval H3max may be the same as the above maximum interval H1max, or may be wider than the maximum interval H1max. In the specified portion 51, the first wire 31 and the second wire 41 may be wound around the winding core portion 21 so that the interval H1 is maximum at a position other than the midpoint between the corners C1 and C2.

[0063] In the specified portion 51, the first wire 31 and the second wire 41 may be wound around the winding core portion 21 so that the interval H2 is maximum at a position other than the midpoint between the corners C1 and C3.

[0064] In the specified portion 51, the first wire 31 and the second wire 41 may be wound around the winding core portion 21 so that the interval H3 is maximum at a position other than the midpoint between the corners C2 and C4.

[0065] In the specified portion 51, the first wire 31 and the second wire 41 may be wound around the winding core portion 21 so that the interval H4 is maximum at a position other than the midpoint between the corners C3 and C4.

[0066] In the specified portion 51, as long as the spacing H1 is maximum at a part in the axial direction Z1, that is, at a midpoint between the corners C1 and C2, the spacing H1 may be maximum at a position other than the midpoint between the corners C1 and C2 in other parts of the specified portion 51.

[0067] In the specified portion 51, as long as the spacing H2 is maximum at a part in the axial direction Z1, midway between the corners C1 and C3, the spacing H2 may be maximum at a position other than the midway between the corners C1 and C3 in other parts of the specified portion 51.

[0068] In the specified portion 51, as long as the spacing H3 is maximum at a part in the axial direction Z1, that is, midway between the corners C2 and C4, the spacing H3 may be maximum at a position other than the midway between the corners C2 and C4 in other parts of the specified portion 51.

[0069] In the specified portion 51, as long as the spacing H4 is maximum at a position midway between the corners C3 and C4 in a part of the axial direction Z1, the spacing H4 may be maximum at a position other than the midway between the corners C3 and C4 in other parts of the specified portion 51.

[0070] In each of the above embodiments, the cross section of the winding core 21 cut in a direction perpendicular to the axial direction Z1 is rectangular, but this is not limited to this. For example, the winding core 21 may be a winding core having a square cross section when cut.

[0071] The winding core 21 does not have to be a rectangular prism as long as it has a rectangular prism shape. For example, the winding core may be a triangular prism or a hexagonal prism. In each of the above embodiments, the winding core 21 is configured such that the side surfaces 211-214 have a linear shape when the winding core 21 is cut in a direction perpendicular to the axial direction Z1, but this is not limited to this. That is, it is sufficient that the winding core 21 has a ridgeline on the cross section when the winding core 21 is cut in a direction perpendicular to the axial direction Z1.

[0072] The coil components 10, 10A, 10B may include a third wire in addition to the first wire 31 and the second wire 41. In this case, in the lap winding region 50, the first wire 31 is wound around the winding core portion 21, the second wire 41 is wound around the winding core portion 21 from above, and the third wire is further wound around the winding core portion 21 from above. In this case, by widening the gap between the second wire 41 and the third wire, the line capacitance LC generated between the second wire 41 and the third wire can be reduced.

[0073] The coil component does not have to be a common mode choke coil as long as it has a plurality of wires wound around the winding core portion 21. [Explanation of symbols]

[0074] 10, 10A, 10B... Coil parts 20…Core 21...Core 21a...first end 21b…Second end 211~214…Side 22…First flange 23…Second flange 31…First wire 311…Outermost end 41…Second wire 411…Innermost end 50…Overlap winding area 51...Predetermined part C1~C4…Corner F…Center axis SP…Gap

Claims

1. a core having a rectangular columnar winding core portion, a first flange portion connected to a first end of the winding core portion in an axial direction of the winding core portion, and a second flange portion connected to a second end of the winding core portion in the axial direction; A first wire and a second wire are wound around the winding core, the winding core portion has a first side surface, a second side surface connected to the first side surface via a first corner, and a third side surface connected to the first side surface via a second corner, the first wire is wound around the winding core, and an overlap winding region is provided in which the second wire is wound around the winding core without any other member interposed therebetween; the overlap winding region has a predetermined portion where the first wire and the second wire are wound around the winding core such that a gap is interposed between a portion of the first wire that is wound around the first side surface and a portion of the second wire that is wound around the first side surface, the first wire and the second wire contact each other on the first corner; The first wire and the second wire contact each other on the second corner. Coil parts.

2. Only a portion of the lap winding region in the axial direction is the predetermined portion. The coil component according to claim 1 .

3. The entire area of ​​the lap winding region in the axial direction is the predetermined portion. The coil component according to claim 1 .

4. At a middle position between a pair of the corners located at both ends of the side surface in the predetermined portion, the second wire is located outside an outermost end of the first wire in a radial direction centered on a central axis of the winding core. The coil component according to any one of claims 1 to 3.

5. At a middle position between a pair of the corners located at both ends of the side surface in the predetermined portion, a distance between an outermost end of the first wire and an innermost end of the second wire in a radial direction centered on a central axis of the winding core is narrower than a diameter of the second wire. The coil component according to any one of claims 1 to 4.

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