Coil component and filter circuit comprising the same

Abstract

To provide a coil component which is usable for a filter circuit for attenuating noise in a high-frequency band and a filter circuit comprising the same.SOLUTION: The present invention relates to a coil component which has a coil L1 and a coil L2 magnetically coupled together. The coil component comprises an insulator 3, wiring patterns 12, 14, via conductors 11, 13 and 15, wiring patterns 22, 24, and via conductors 21, 23 and 25. Length directions of the via conductors 11, 13 and 15 and via conductors 21, 23 and 25 are perpendicular to winding axis directions of the coils L1 and L2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a coil component and a filter circuit including the same. [Background technology]

[0002] Filter circuits are used in electronic devices to combat noise. Multilayer coil components (multilayer inductors) are sometimes used in filter circuits used to combat noise. Multilayer coil components are formed by stacking multiple wiring patterns, as described in, for example, Japanese Patent Laid-Open Publication No. 2000-138120 (Patent Document 1). Therefore, multilayer coil components allow for a high degree of freedom in the coil shape, and a coil with high inductance can be formed by forming the shape of each wiring pattern to match the shape of the coil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-138120 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a coil is formed by stacking multiple wiring patterns, as in the coil component described in JP 2000-138120 A (Patent Document 1), stray capacitance occurs in the area where the multiple wiring patterns overlap when viewed from the stacking direction. For example, when forming a coil component including a transformer coil in which two coils are magnetically coupled, if a large stray capacitance occurs in the transformer coil, the self-resonant frequency of the coil component will be low. If a coil component with a low self-resonant frequency is used in a filter circuit, the filter circuit will not be able to attenuate high-frequency band noise.

[0005] Therefore, an object of the present disclosure is to provide a coil component that can be used in a filter circuit that attenuates noise in the high frequency band, and a filter circuit that includes the coil component. [Means for solving the problem]

[0006] A coil component according to one embodiment of the present disclosure is a coil component in which a first coil and a second coil are magnetically coupled. The coil component includes an insulator, a plurality of first wiring patterns, a plurality of first via conductors, a plurality of second wiring patterns, and a plurality of second via conductors. The insulator has a pair of opposing main surfaces and a side surface connecting the main surfaces. The plurality of first wiring patterns constitute at least a portion of the first coil. The plurality of first via conductors constitute at least a portion of the first coil. The plurality of second wiring patterns constitute at least a portion of the second coil. The length directions of the plurality of first via conductors and the plurality of second via conductors are perpendicular to the winding axis directions of the first coil and the second coil.

[0007] A filter circuit according to an embodiment of the present disclosure includes the above coil component and a capacitor connected to an electrode between the first coil and the second coil of the coil component. [Effects of the Invention]

[0008] According to one embodiment of the present disclosure, the length directions of the plurality of first via conductors and the plurality of second via conductors are perpendicular to the winding axis direction of the first coil and the second coil, which reduces the overlapping portion of the plurality of wiring patterns when viewed from the stacking direction, thereby reducing the stray capacitance of the coil component. As a result, a filter circuit using this coil component can attenuate noise in the high frequency band because the self-resonant frequency of the coil component is high. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a coil component according to a first embodiment. [Figure 2] 1 is a schematic diagram of a coil component according to a first embodiment. [Figure 3] 1 is a circuit diagram of a filter circuit including a coil component according to a first embodiment. [Figure 4] 4 is a graph showing impedance characteristics of the coil component according to the first embodiment. [Figure 5] 4 is a graph showing the transmission characteristics of the coil device according to the first embodiment. [Figure 6] FIG. 10 is a perspective view of a coil component according to a second embodiment. [Figure 7] FIG. 10 is a schematic diagram of a coil component according to a second embodiment. [Figure 8] FIG. 11 is a perspective view of a coil component according to a third embodiment. [Figure 9] 10 is a schematic diagram of a coil component according to a third embodiment. FIG. [Figure 10] FIG. 10 is a perspective view of a coil component according to a fourth embodiment. [Figure 11] FIG. 10 is a schematic diagram of a coil component according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] A coil component according to the present disclosure and a filter circuit including the coil component will be described below. <First Embodiment> First, a coil component according to a first embodiment will be described with reference to the drawings. Fig. 1 is a perspective view of the coil component 1 according to the first embodiment. Fig. 2 is a schematic diagram of the coil component 1 according to the first embodiment. Fig. 2(a) is a transparent side view from the long side of the insulator 3, Fig. 2(b) is a transparent plan view from the top surface 31 side of the insulator 3, and Fig. 2(c) is a transparent side view from the short side of the insulator 3. Here, in Figs. 1 and 2, the short side direction of the coil component 1 is the X direction, the long side direction is the Y direction, and the height direction is the Z direction.

[0011] Unlike conventional coil components in which the shape of each wiring pattern is formed to match the shape of the coil and multiple wiring pattern layers are connected by via conductors, coil component 1 arranges via conductors to match the shape of the coil and connects multiple via conductors with wiring patterns, as shown in Fig. 1. Therefore, in coil component 1, the lamination direction of the insulating substrates on which the wiring patterns are formed is the Y direction in Fig. 1, and the direction of the arrow indicates the upward layer direction.

[0012] FIG. 3 is a circuit diagram of a filter circuit 100 including a coil component 1 according to a first embodiment. The filter circuit 100 is, for example, an EMI suppression filter, and is a third-order T-type LC filter circuit. The coil component 1 is used in this filter circuit 100. In the following first embodiment, the filter circuit 100 will be described using a third-order T-type LC filter circuit as its configuration, but coil components with a similar configuration can also be applied to fifth-order T-type LC filter circuits or higher-order T-type LC filter circuits. First, as shown in FIG. 3, the filter circuit 100 includes a coil component 1 including a coil L1 (first coil) and a coil L2 (second coil), and a capacitor C1 electrically connected to an outer electrode 4c of the coil component 1.

[0013] 3, one end of the capacitor C1 is connected to the external electrode 4c and the other end is connected to the GND electrode. Note that the capacitor C1 is not limited to a multilayer ceramic capacitor whose main component is BaTiO3 (barium titanate), but may also be a multilayer ceramic capacitor whose main component is another material, or may be another type of capacitor other than a multilayer ceramic capacitor, such as an aluminum electrolytic capacitor.

[0014] Capacitor C1 has inductor L3 as a parasitic inductance (equivalent series inductance (ESL)), and is equivalent to a circuit configuration in which inductor L3 is connected in series with capacitor C1a. Note that capacitor C1 may also be equivalent to a circuit configuration in which parasitic resistance (equivalent series resistance (ESR)) is connected in series with inductor L3 and capacitor C1a.

[0015] In addition to the capacitor C1, coils L1 and L2 are connected to the external electrode 4c. Coils L1 and L2 are magnetically coupled, generating a negative inductance component. This negative inductance component is used to cancel out the parasitic inductance of capacitor C1 (inductor L3), thereby making the inductance component of capacitor C1 appear smaller. In this way, in the filter circuit 100, the negative inductance component due to the mutual inductance between coils L1 and L2 cancels out the parasitic inductance of capacitor C1, thereby improving the effect of attenuating high-frequency band noise.

[0016] However, in conventional coil components in which coils L1 and L2 are formed by stacking multiple wiring patterns, there are many overlapping portions of the multiple wiring patterns when viewed from the stacking direction, resulting in a large stray capacitance C2. When a large stray capacitance C2 occurs in coils L1 and L2, as shown in Figure 3, even if the inductance of coils L1 and L2 is secured as designed, the frequency will be lower than the desired self-resonant frequency. Therefore, filter circuits using conventional coil components are unable to attenuate noise in the required high-frequency band.

[0017] Therefore, the coil component 1 according to the first embodiment employs a structure in which via conductors are arranged to match the shape of the coils in order to reduce the stray capacitance C2 of the coils L1 and L2. The coil component 1 includes an insulator 3 formed by stacking multiple insulating substrates on which wiring patterns are formed. The insulator 3 has a pair of surfaces facing each other in the Z direction perpendicular to the Y direction, rather than a pair of surfaces facing each other in the Y direction in which the insulating substrates are stacked. The surfaces connecting the main surfaces of the insulator 3 serve as side surfaces. The insulating substrates may be made of an insulating material primarily composed of borosilicate glass, or an insulating resin such as alumina, zirconia, or polyimide resin. Furthermore, the interfaces between the multiple insulating substrates in the insulator 3 may be unclear due to processes such as baking and curing.

[0018] An external electrode 4a (first external electrode) is formed on a side surface 41 (first surface) of the insulator 3, and an external electrode 4b (second external electrode) is formed on a side surface 42 (second surface) opposite the side surface 41. Furthermore, an external electrode 4c (third external electrode) is formed on a side surface 43 (third surface) of the insulator 3, and an external electrode 4d (fourth external electrode) is formed on a side surface 44 (fourth surface) opposite the side surface 43. Of a pair of opposing main surfaces (XY planes), the insulator 3 has a lower main surface (second main surface) in FIG. 1 as a mounting surface, which faces a circuit board. In this disclosure, the upper main surface (first main surface) in FIG. 1 is referred to as a top surface 31, and the lower main surface in FIG. 1 is referred to as a bottom surface 32. Portions of the external electrodes 4a to 4d are also formed on the top surface 31 and the bottom surface 32 of the insulator 3.

[0019] The coil component 1 includes a coil L1 and a coil L2 that are parallel to the top surface 31 of the insulator 3. The coils L1 and L2 are formed by wiring patterns and via conductors that are formed in the insulator 3.

[0020] The coil L1 includes a via conductor 11 having one end electrically connected to the external electrode 4a, a wiring pattern 12 electrically connected to the other end of the via conductor 11, a via conductor 13 having one end electrically connected to the wiring pattern 12, a wiring pattern 14 electrically connected to the other end of the via conductor 13, and a via conductor 15 having one end electrically connected to the wiring pattern 14. Each of the wiring pattern 12 and the wiring pattern 14 (plurality of first wiring patterns) is configured with three layers as shown in FIG.

[0021] The coil L2 includes a via conductor 21 having one end electrically connected to the external electrode 4b, a wiring pattern 22 electrically connected to the other end of the via conductor 21, a via conductor 23 having one end electrically connected to the wiring pattern 22, a wiring pattern 24 electrically connected to the other end of the via conductor 23, and a via conductor 25 having one end electrically connected to the wiring pattern 24. Each of the wiring pattern 22 and the wiring pattern 24 (plurality of second wiring patterns) is configured with three layers as shown in FIG.

[0022] In the coil component 1, the coil L2 is disposed on top of the coil L1, and the via conductors 15 of the coil L1 are electrically connected to the via conductors 25 of the coil L2. Furthermore, the via conductors 15 of the coil L1 and the via conductors 25 of the coil L2 are electrically connected to the wiring pattern 30, which is electrically connected to the external electrode 4c. Therefore, an intermediate terminal connecting the coils L1 and L2 is drawn from a position between the coils L1 and L2 to the external electrode 4c.

[0023] 2(b), the insulator 3 has a rectangular shape when viewed from the top surface 31 side, with the short sides facing the side surfaces 41 and 42 and the long sides facing the side surfaces 43 and 44. The via conductors 11 and 15 and the via conductors 21 and 25 are arranged on the side surface 43 side (long side) of the line E passing through the center of the short sides of the insulator 3. The via conductors 13 and 23 are arranged on the side surface 44 side (long side) of the line E passing through the center of the short sides of the insulator 3.

[0024] 2(b), coil L1 has an opening surrounded by via conductors 11 and 15, wiring pattern 12, via conductor 13, and wiring pattern 14 when viewed from the top surface 31. Coil L1 is a coil wound in the order of via conductor 11, wiring pattern 12, via conductor 13, wiring pattern 14, and via conductor 15, with the winding axis direction being the Z direction. Therefore, the length directions of via conductors 11, 13, and 15 (plurality of first via conductors) are all perpendicular to the winding axis direction, that is, the Z direction.

[0025] 2(b), coil L2 has an opening surrounded by via conductors 21 and 25, wiring pattern 22, via conductor 23, and wiring pattern 24 when viewed from the top surface 31. Coil L2 is a coil wound in the order of via conductor 21, wiring pattern 22, via conductor 23, wiring pattern 24, and via conductor 25, with the winding axis direction being the Z direction. Therefore, the length directions of via conductors 21, 23, and 25 (plurality of second via conductors) are all perpendicular to the winding axis direction, that is, the Z direction.

[0026] In the case of a conventional coil component in which multiple wiring patterns are stacked, the length direction of the via conductors is parallel to the winding axis direction, that is, the Z direction, which is the opposite of coils L1 and L2 of the present disclosure. Therefore, in a conventional coil component in which multiple wiring patterns are stacked, there are many overlapping portions of the multiple wiring patterns when viewed from the stacking direction, which generates a large stray capacitance.

[0027] On the other hand, in coil L1 of the present disclosure, the overlapping portion of wiring patterns 12 and 14 is small when viewed from the stacking direction, and they are far apart with via conductors 11 and 13 in between, as shown in Figure 2(a), so the stray capacitance is small. Similarly, in coil L2 of the present disclosure, the overlapping portion of wiring patterns 22 and 24 is small when viewed from the stacking direction, and they are far apart with via conductors 21 and 23 in between, as shown in Figure 2(a), so the stray capacitance is small.

[0028] 2(b) and 2(c), the opening surfaces of coil L1 and coil L2 are formed parallel to each other in the XY plane, and the openings overlap when viewed from above from the top surface 31. Therefore, coil L1 and coil L2 are magnetically coupled to form a transformer coil.

[0029] As shown in FIGS. 1 and 2 , the length directions of the via conductors 11, 13, 15, 21, 23, and 25 are all perpendicular to the Z direction, which is the winding axis direction, so that the via conductors 11, 21, 15, and 25 overlap, and the via conductors 13 and 23 overlap, when viewed in a plan view from the top surface 31. That is, in the coil component 1, the overlapping portions of the via conductors are greater than the overlapping portions of the wiring patterns. Because the via conductors 11, 13, 15, 21, 23, and 25 are cylindrical as shown in FIGS. 1 and 2 , the portions where the via conductors face each other are arc-shaped, and the distance between the conductors where the via conductors face each other is not uniform. On the other hand, because the wiring patterns are flat, the distance between the conductors where the wiring patterns face each other is uniform. Therefore, by increasing the overlapping portions of the via conductors, the coil component 1 can reduce the stray capacitance C2 ( FIG. 3 ) compared to coil components with more overlapping portions of the wiring patterns. Reducing the stray capacitance C2 can increase the self-resonant frequency of the coil device 1. Fig. 4 is a graph showing the impedance characteristics of the coil device 1 according to embodiment 1. In Fig. 4, the horizontal axis represents frequency, and the vertical axis represents impedance characteristics.

[0030] Graph A shows the results of a simulation of impedance characteristics performed on the configuration of coil device 1, where stray capacitance C2 is 0.13 pF and the self-resonant frequency indicated by mark M1 is 2.54 GHz. Graph B shows the results of a simulation of impedance characteristics performed on a conventional coil device having multiple stacked wiring patterns, where stray capacitance C2 is 0.23 pF and the self-resonant frequency indicated by mark M2 is 1.47 GHz. Therefore, by employing the configuration of coil device 1 according to embodiment 1, the self-resonant frequency can be increased from 1.47 GHz to 2.54 GHz.

[0031] By using the coil device 1 according to the first embodiment in the filter circuit 100 shown in Fig. 3, it is possible to attenuate noise in the high frequency band. Fig. 5 is a graph showing the pass characteristics of the coil device 1 according to the first embodiment. In Fig. 5, the horizontal axis represents frequency and the vertical axis represents the pass characteristics, with the amount of attenuation increasing downward in the diagram.

[0032] Graph C shows the results of a simulation of the pass characteristics of a filter circuit 100 using coil component 1, with a large amount of attenuation being obtained around 1.5 GHz, as indicated by mark M3. On the other hand, graph D shows the results of a simulation of the pass characteristics of a filter circuit using a conventional coil component in which multiple wiring patterns are stacked, with no large amount of attenuation being obtained around 1.5 GHz, as indicated by mark M4. Because the frequency around 1.5 GHz is the frequency band used by GPS (Global Positioning System), filter circuit 100 using coil component 1 has noise removal performance in this frequency band.

[0033] Furthermore, as shown in Figure 1, in coil component 1, the length of via conductors 11, 13, 15, 21, 23, and 25 accounts for a high proportion of the line length of coil L1 and coil L2. On the other hand, in the case of conventional coil components in which multiple wiring patterns are stacked, the via conductors are only used to connect adjacent layers, so the proportion of the via conductors in the line length of coil L1 and coil L2 is low. Specifically, when comparing the proportion of the via conductor length in the line length of coil L1 and coil L2 between coil component 1 and conventional coil components that have the same mutual inductance, the proportion is approximately 67% for coil component 1 and approximately 1% for the conventional coil component.

[0034] That is, in the coil component 1, the total length of the via conductors 11, 13, 15, 21, 23, and 25 is longer than the total length of the wiring patterns 12, 14, 22, and 24. When forming a coil using a typical lamination method, the cross-sectional area of ​​the via conductors is larger than the cross-sectional area of ​​the wiring patterns. Therefore, by making the total length of the via conductors 11, 13, 15, 21, 23, and 25 longer than the total length of the wiring patterns 12, 14, 22, and 24, the DC resistance of the coils L1 and L2 can be reduced. By reducing the DC resistance of the coils L1 and L2, the amount of heat generated by the coils L1 and L2 when a current is applied can be reduced. Here, the current value at which the temperature rise when a current is applied is below a certain standard is defined as the rated current value. Therefore, by reducing the amount of heat generated by the coils L1 and L2, the rated current value of the coil component 1 can be set higher.

[0035] <Embodiment 2> In the coil device 1 according to the first embodiment, the coil L1 and the coil L2 are stacked in the Z direction, and the intermediate terminal connecting the coils L1 and L2 is located between the coils L1 and L2 and is electrically connected to the external electrode 4c at that position. A positive inductance is generated according to the length of the external electrode 4c from the intermediate terminal connecting the coils L1 and L2 to the bottom surface 32 mounted on the insulating substrate.

[0036] As described above, the coil device 1 generates a negative inductance component by magnetically coupling the coils L1 and L2, but this negative inductance component is reduced by a positive inductance that occurs in accordance with the length of the external electrode 4c from the intermediate terminal connecting the coils L1 and L2 to the bottom surface 32. Therefore, the coil device according to the second embodiment employs a configuration that can shorten the length of the external electrode 4c from the intermediate terminal connecting the coils L1 and L2 to the bottom surface 32.

[0037] FIG. 6 is a perspective view of a coil component 1A according to a second embodiment. FIG. 7 is a schematic diagram of the coil component 1A according to the second embodiment. FIG. 7(a) is a transparent side view from the long side of the insulator 3, FIG. 7(b) is a transparent plan view from the top surface 31 of the insulator 3, and FIG. 7(c) is a transparent side view from the short side of the insulator 3. Here, in FIGS. 6 to 7, the short side direction of the coil component 1A is the X direction, the long side direction is the Y direction, and the height direction is the Z direction. The lamination direction of the insulating substrates is the Y direction, and the arrow indicates the upward layer direction. In the coil component 1A shown in FIGS. 6 and 7, the same components as those in the coil component 1 shown in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will not be repeated.

[0038] The coil component 1A includes a coil L1 and a coil L2 that are parallel to the top surface 31 of the insulator 3. The coils L1 and L2 are formed by wiring patterns and via conductors that are formed in the insulator 3.

[0039] The coil L1 includes a via conductor 11a, a wiring pattern 11b, a via conductor 11c, a wiring pattern 12, a via conductor 13, a wiring pattern 14, and a via conductor 15. One end of the via conductor 11a is electrically connected to the external electrode 4a. Furthermore, as shown in FIG. 7(b), the via conductor 11a is arranged on a line E passing through the center of the short side of the insulator 3. Therefore, the external electrode 4a does not need to be provided on the entire surface of the side surface 41 as shown in FIG. 6, and it is sufficient to provide it only in the central portion.

[0040] Since the via conductor 11a connected to the external electrode 4a is arranged on the line E, the via conductor 11a is electrically connected through the wiring pattern 11b to the via conductor 11c arranged closer to the side face 43 (longer side) than the line E. The wiring pattern 12 is electrically connected to the other end of the via conductor 11c. One end of the via conductor 13 is electrically connected to the wiring pattern 12. The wiring pattern 14 is electrically connected to the other end of the via conductor 13.

[0041] Wiring pattern 14 is electrically connected to via conductor 15, which is arranged closer to bottom surface 32 than via conductor 11c, and therefore has an L-shape when viewed in plan from side surface 41. On the other hand, in coil component 1 according to embodiment 1, via conductor 15 is arranged closer to top surface 31 than via conductor 11, as shown in FIG. 1, and therefore wiring pattern 14 has an S-shape when viewed in plan from side surface 41. Each of wiring pattern 11b, wiring pattern 12, and wiring pattern 14 is configured with three layers as shown in FIG. 1.

[0042] The coil L2 includes a via conductor 21a, a wiring pattern 21b, a via conductor 21c, a wiring pattern 22, a via conductor 23a, wiring patterns 23b and 23c, a via conductor 23d, a wiring pattern 24, and a via conductor 25. One end of the via conductor 21a is electrically connected to the external electrode 4b. Furthermore, as shown in FIG. 7(b), the via conductor 21a is disposed on a line E passing through the center of the short side of the insulator 3. Therefore, the external electrode 4b does not need to be disposed over the entire surface of the side surface 42 as shown in FIG. 6, and need only be disposed in the central portion.

[0043] Since the via conductor 21a connected to the external electrode 4b is arranged on the line E, the via conductor 21a is electrically connected through the wiring pattern 21b to the via conductor 21c arranged closer to the side face 43 (longer side) than the line E. The wiring pattern 22 is electrically connected to the other end of the via conductor 21c.

[0044] Coil L2 is disposed closer to the top surface 31 than coil L1. However, in coil component 1A, an intermediate terminal connecting coils L1 and L2 is provided closer to the bottom surface 32, and a portion of coil L2 is disposed closer to the bottom surface 32 than coil L1 in order to extend from that position to external electrode 4c. Therefore, in order to electrically connect via conductor 23a, which is disposed closer to the top surface 31 than coil L1, and via conductor 23d, which is disposed closer to the bottom surface 32 than coil L1, they are electrically connected to external electrode 4d via wiring patterns 23b and 23c. In other words, a portion of coil L2 is configured as external electrode 4d.

[0045] One end of via conductor 23d is electrically connected to wiring pattern 24. Wiring pattern 24 is electrically connected to one end of via conductor 25. Each of wiring patterns 21b and 22, wiring patterns 23b and 23c, and wiring pattern 24 is configured with three layers as shown in FIG.

[0046] 6, coil component 1A is arranged such that coil L1 is sandwiched between coils L2, and via conductors 15 on the bottom surface 32 side of coil L1 are electrically connected to via conductors 25 on the bottom surface 32 side of coil L2. Furthermore, via conductors 15 of coil L1 and via conductors 25 of coil L2 are electrically connected to wiring pattern 30, which is electrically connected to external electrode 4c. Therefore, an intermediate terminal connecting coils L1 and L2 is provided at a position of coils L1 and L2 closest to the bottom surface 32, and is drawn out from that position to external electrode 4c.

[0047] In the coil component 1A, a negative inductance component is generated by magnetically coupling the coils L1 and L2, but the offset positive inductance is reduced by shortening the length of the external electrode 4c from the intermediate terminal connecting the coils L1 and L2 to the bottom surface 32. This allows the filter circuit 100 using the coil component 1A to increase the negative inductance component that cancels out the parasitic inductance of the capacitor C1.

[0048] <Third Embodiment> In the coil component 1A according to the second embodiment, a configuration in which a part of the coil L2 is formed by the external electrode 4d has been described. In the coil component according to the third embodiment, a configuration in which another external electrode is used as a part of the coil will be described.

[0049] FIG. 8 is a perspective view of a coil component 1B according to a third embodiment. FIG. 9 is a schematic diagram of the coil component 1B according to the third embodiment. FIG. 9(a) is a transparent side view from the long side of the insulator 3, FIG. 9(b) is a transparent plan view from the top surface 31 of the insulator 3, and FIG. 9(c) is a transparent side view from the short side of the insulator 3. Here, in FIGS. 8 to 9, the short side direction of the coil component 1B is the X direction, the long side direction is the Y direction, and the height direction is the Z direction. The lamination direction of the insulating substrates is the Y direction, and the arrows indicate the upper layer direction. In the coil component 1B shown in FIGS. 8 and 9, the same components as those in the coil component 1 shown in FIGS. 1 and 2 and the coil component 1A shown in FIGS. 6 and 7 are designated by the same reference numerals, and detailed description thereof will not be repeated.

[0050] Coil component 1B includes coils L1 and L2 that are parallel to top surface 31 of insulator 3. Coils L1 and L2 are formed by wiring patterns and via conductors formed within insulator 3.

[0051] The coil L1 includes a via conductor 11a, a wiring pattern 11b, a via conductor 11c, a wiring pattern 12, and a via conductor 13a. One end of the via conductor 11a is electrically connected to the external electrode 4a. Furthermore, the via conductor 11a is arranged on a line E passing through the center of the short side of the insulator 3, as shown in FIG. 9(b). Therefore, the external electrode 4a does not need to be provided on the entire surface of the side surface 41 as shown in FIG. 8, and only needs to be provided in the central portion.

[0052] Because the via conductor 11a connected to the external electrode 4a is arranged on the line E, the via conductor 11a is electrically connected through the wiring pattern 11b to the via conductor 11c arranged closer to the side surface 44 (longer side) than the line E. The wiring pattern 12 is electrically connected to the other end of the via conductor 11c. One end of the via conductor 13a is electrically connected to the wiring pattern 12. The via conductor 13a is electrically connected to the wiring pattern 30a in order to be electrically connected to the external electrode 4c at a position close to the side surface 42.

[0053] Coil L2 is arranged closer to the top surface 31 than coil L1. Coil L2 includes via conductor 21a, wiring pattern 21b, via conductor 21c, wiring pattern 22, and via conductor 23a. One end of via conductor 21a is electrically connected to external electrode 4b. Furthermore, via conductor 21a is arranged on line E passing through the center of the short side of insulator 3, as shown in FIG. 9(b). Therefore, external electrode 4b does not need to be provided on the entire surface of side surface 42 as shown in FIG. 8, and it is sufficient to provide it only in the central portion.

[0054] Because the via conductor 21a connected to the external electrode 4b is arranged on the line E, the via conductor 21a is electrically connected through the wiring pattern 21b to the via conductor 21c arranged closer to the side face 44 (longer side) than the line E. The wiring pattern 22 is electrically connected to the other end of the via conductor 21c. One end of the via conductor 23a is electrically connected to the wiring pattern 22. The via conductor 23a is electrically connected to the wiring pattern 30b in order to be electrically connected to the external electrode 4c at a position close to the side face 41.

[0055] The via conductor 13a is electrically connected to the external electrode 4c at a position close to the side surface 42, so that the external electrode 4c constitutes a part of the coil L1, and the via conductor 23a is electrically connected to the external electrode 4c at a position close to the side surface 41, so that the external electrode 4c constitutes a part of the coil L2. The intermediate terminal connecting the coils L1 and L2 is also the external electrode 4c.

[0056] In coil component 1B, portions of coil L1 and coil L2 are configured with external electrodes 4c, thereby reducing the number of via conductors that form portions of coil L1 and coil L2. By configuring portions of at least one of coil L1 and coil L2 with external electrodes as in coil component 1B, the portions where via conductors are formed can be reduced, thereby reducing manufacturing costs.

[0057] <Fourth Embodiment> In the coil component 1 according to the first embodiment, of the pair of opposing principal surfaces (XY planes), the upper principal surface in FIG. 1 is the top surface 31, and the lower principal surface in FIG. 1 is the bottom surface 32, and it has been described that the bottom surface 32 is the mounting surface that faces the circuit board. However, the mounting surface is not limited to the bottom surface 32, and another surface may be used as the mounting surface. In the coil component according to the fourth embodiment, a surface other than the bottom surface is used as the mounting surface.

[0058] FIG. 10 is a perspective view of a coil device 1C according to a fourth embodiment. FIG. 11 is a schematic diagram of the coil device 1C according to the fourth embodiment. FIG. 11(a) is a transparent side view from the long side of the insulator 3, FIG. 11(b) is a transparent plan view from the top surface 31 of the insulator 3, and FIG. 11(c) is a transparent side view from the short side of the insulator 3. Here, in FIGS. 10 to 11, the short side direction of the coil device 1C is the Z direction, the long side direction is the X direction, and the height direction is the Y direction. The lamination direction of the insulating substrates is the Y direction, and the opposite direction of the arrow indicates the upper layer direction. In the coil device 1C shown in FIGS. 10 and 11, the same components as those in the coil device 1 shown in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will not be repeated.

[0059] The insulator 3 has a pair of opposing main surfaces in the Z direction, and a surface connecting the main surfaces is a side surface. Of the pair of opposing main surfaces (XY planes), the insulator 3 has a right-hand main surface (first main surface) in FIG. 10 referred to as a top surface 31a, and a lower main surface (second main surface) in FIG. 10 referred to as a bottom surface 32a. An external electrode 4a (first external electrode) is formed on the bottom surface 32a of the insulator 3, and an external electrode 4b (second external electrode) is formed on the top surface 31a. Furthermore, an external electrode 4c (third external electrode) is formed on a side surface 43a of the insulator 3, and an external electrode 4d (fourth external electrode) is formed on a side surface 44a opposite the side surface 43a. In the coil component 1C, portions of the external electrodes 4a to 4d are also formed on the side surfaces 41a and 42a of the insulator 3. Furthermore, in the coil component 1C, the side surface 41a is the mounting surface, and this surface faces the circuit board.

[0060] The coil component 1C includes a coil L1 and a coil L2 that are parallel to the top surface 31a of the insulator 3. The coils L1 and L2 are formed by wiring patterns and via conductors that are formed in the insulator 3.

[0061] The coil L1 includes a via conductor 11 electrically connected to the external electrode 4a at one end, a wiring pattern 12 electrically connected to the other end of the via conductor 11, a via conductor 13 electrically connected to one end of the wiring pattern 12, a wiring pattern 14 electrically connected to the other end of the via conductor 13, a via conductor 15 electrically connected to one end of the wiring pattern 14, a wiring pattern 16 electrically connected to the other end of the via conductor 15, and a via conductor 17 electrically connected to one end of the wiring pattern 16. Each of the wiring pattern 12, the wiring pattern 14, and the wiring pattern 16 is configured with three layers as shown in FIG.

[0062] The coil L2 includes a via conductor 21 electrically connected to the external electrode 4b at one end, a wiring pattern 22 electrically connected to the other end of the via conductor 21, a via conductor 23 electrically connected to one end of the wiring pattern 22, a wiring pattern 24 electrically connected to the other end of the via conductor 23, a via conductor 25 electrically connected to one end of the wiring pattern 24, a wiring pattern 26 electrically connected to the other end of the via conductor 25, and a via conductor 27 electrically connected to one end of the wiring pattern 26. Each of the wiring pattern 22, the wiring pattern 24, and the wiring pattern 26 is configured with three layers as shown in FIG.

[0063] In the coil component 1C, the coil L2 is disposed above the coil L1 in the Z direction, and the via conductors 17 of the coil L1 are electrically connected to the via conductors 27 of the coil L2. Furthermore, the via conductors 17 of the coil L1 and the via conductors 27 of the coil L2 are electrically connected to the wiring pattern 30, which is electrically connected to the external electrode 4c. Therefore, an intermediate terminal connecting the coils L1 and L2 is drawn from a position between the coils L1 and L2 to the external electrode 4c.

[0064] 11(b), the insulator 3 has a rectangular shape when viewed from the top surface 31a, with the short sides facing the side surfaces 41a and 42a and the long sides facing the side surfaces 43a and 44a. The via conductors 11 and 15 and the via conductors 21 and 25 are arranged on the side surface 44a side (long side) of the line E passing through the centers of the short sides of the insulator 3. The via conductors 13 and 17 and the via conductors 23 and 27 are arranged on the side surface 43a side (long side) of the line E passing through the centers of the short sides of the insulator 3.

[0065] 11(b), when viewed from the top surface 31a, the coil L1 has an opening surrounded by the via conductors 11 and 15, the wiring patterns 12 and 16, the via conductors 13 and 17, and the wiring pattern 14. The coil L1 is wound in the order of the via conductor 11, the wiring pattern 12, the via conductor 13, the wiring pattern 14, the via conductor 15, the wiring pattern 16, and the via conductor 17, with the winding axis direction being the Z direction. Therefore, the length directions of the via conductors 11, 13, 15, and 17 are all perpendicular to the winding axis direction, the Z direction.

[0066] 11(b), coil L2 has an opening surrounded by via conductors 21 and 25, wiring patterns 22 and 26, via conductors 23 and 27, and wiring pattern 24 when viewed from the top surface 31a. Coil L2 is a coil wound in the order of via conductor 21, wiring pattern 22, via conductor 23, wiring pattern 24, via conductor 25, wiring pattern 26, and via conductor 27, with the winding axis direction being the Z direction. Therefore, the length directions of via conductors 21, 23, 25, and 27 are all perpendicular to the winding axis direction, that is, the Z direction.

[0067] In coil component 1C, the length directions of via conductors 11, 13, 15, 17, 21, 23, 25, and 17 are all perpendicular to the Z direction, which is the winding axis direction, thereby reducing stray capacitance C2 (FIG. 3). Reducing stray capacitance C2 increases the self-resonant frequency of coil component 1C. Furthermore, filter circuit 100 using coil component 1C can attenuate noise in the high-frequency band.

[0068] <Aspect> (1) A coil component according to the present disclosure is a coil component in which a first coil and a second coil are magnetically coupled, an insulator having a pair of opposing main surfaces and a side surface connecting the main surfaces; a plurality of first wiring patterns that form at least a part of the first coil; a plurality of first via conductors that form at least a portion of the first coil; a plurality of second wiring patterns that form at least a part of the second coil; a plurality of second via conductors that form at least a portion of the second coil; The length direction of the plurality of first via conductors and the plurality of second via conductors is perpendicular to the winding axis direction of the first coil and the second coil.

[0069] (2) In the coil component according to (1), the insulator is a rectangular parallelepiped, The length direction of the plurality of first via conductors and the plurality of second via conductors is parallel to the long side direction of the insulator.

[0070] (3) In the coil component described in (1) or (2), the total length of the plurality of first via conductors and the plurality of second via conductors is longer than the total length of the plurality of first wiring patterns and the plurality of second wiring patterns.

[0071] (4) The coil component according to any one of (1) to (3), a first external electrode provided on a first surface of the side surface and electrically connected to one end of the first coil; a second external electrode provided on a second surface of the side surface opposite to the first surface and electrically connected to one end of the second coil; The coil further includes a third external electrode provided on a third surface of the side surface not facing the first surface, the third external electrode being electrically connected to the other end of the first coil and the other end of the second coil.

[0072] (5) The coil component according to (4) is The third external electrode forms a part of the first coil or the second coil.

[0073] (6) The coil component according to (4) or (5), The coil further includes a fourth external electrode provided on a fourth surface of the side surface opposite to the third surface and constituting a part of the first coil or the second coil.

[0074] (7) The coil component according to any one of (4) to (6), the main surface has a first main surface and a second main surface opposite to the first main surface, the second main surface being a mounting surface opposite to a circuit board, The third external electrode is provided on the second main surface at a position where it is electrically connected to the other end of the first coil and the other end of the second coil.

[0075] (8) The coil component according to (2) is The plurality of first via conductors and the plurality of second via conductors are arranged on the longer side of a line passing through the center of a shorter side of the insulator when viewed in plan from one of the principal surfaces.

[0076] (9) The coil component according to (2) is Some of the first via conductors and the second via conductors are arranged on a line passing through the center of a short side of the insulator when viewed in plan from one of the main surfaces.

[0077] (10) A filter circuit according to the present disclosure includes: The coil component according to any one of (1) to (9), a capacitor connected to an electrode between the first coil and the second coil of the coil component.

[0078] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0079] 1, 1A to 1C coil components, 3 insulator, 4a to 4d external electrodes, 11, 11a, 11c, 13, 13a, 15, 17, 21, 21a, 21c, 23, 23a, 25, 27 via conductors, 11b, 12, 14, 16, 21b, 22, 24, 26, 30, 30a, 30b wiring patterns, 100 filter circuit, C1 capacitor, C2 stray capacitance.

Claims

1. A coil component in which a first coil and a second coil are magnetically coupled, an insulator having a pair of opposing main surfaces and a side surface connecting the main surfaces; a plurality of first wiring patterns constituting at least a part of the first coil; a plurality of first via conductors constituting at least a portion of the first coil; a plurality of second wiring patterns constituting at least a part of the second coil; a plurality of second via conductors constituting at least a portion of the second coil; A coil component, wherein the length direction of the plurality of first via conductors and the plurality of second via conductors is perpendicular to the winding axis direction of the first coil and the second coil.

2. The insulator is a rectangular parallelepiped, The coil component according to claim 1 , wherein the length directions of the first via conductors and the second via conductors are parallel to a long side direction of the insulator.

3. The coil component according to claim 2 , wherein a total length of the plurality of first via conductors and the plurality of second via conductors is longer than a total length of the plurality of first wiring patterns and the plurality of second wiring patterns.

4. a first external electrode provided on a first surface of the side surface and electrically connected to one end of the first coil; a second external electrode provided on a second surface of the side surface opposite to the first surface and electrically connected to one end of the second coil; The coil component according to any one of claims 1 to 3, further comprising: a third external electrode provided on a third surface of the side surface that does not face the first surface, the third external electrode being electrically connected to the other end of the first coil and the other end of the second coil.

5. The coil component according to claim 4 , wherein the third external electrode constitutes a part of the first coil or the second coil.

6. The coil component according to claim 4 , further comprising: a fourth external electrode provided on a fourth surface of the side surface opposite to the third surface, the fourth external electrode constituting a part of the first coil or the second coil.

7. the main surface has a first main surface and a second main surface opposite to the first main surface, the second main surface being a mounting surface opposite to a circuit board, The coil component according to claim 4 , wherein the third external electrode has an intermediate terminal positioned on the second main surface side for electrically connecting to the other end of the first coil and the other end of the second coil.

8. The coil component according to claim 2, wherein the plurality of first via conductors and the plurality of second via conductors are arranged on the longer side of a line passing through the center of a short side of the insulator when viewed in a plane from one of the main surfaces.

9. The coil component according to claim 2, wherein a portion of the plurality of first via conductors and the plurality of second via conductors are arranged on a line passing through the center of a short side of the insulator when viewed in a plane from one of the main surfaces.

10. The coil component according to any one of claims 1 to 3; a capacitor connected to an electrode between the first coil and the second coil of the coil component.

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