Coil component and electronic device including same

Abstract

The present disclosure provides a coil component having a structure capable of reducing DC resistance and floating capacity, and an electronic device including the same. A coil component (1) according to the present disclosure comprises: a first coil formed into a cylindrical shape by bending a rectangular first conductor in the long-side direction; a second coil formed into a cylindrical shape by bending a rectangular second conductor in the long-side direction; a first lead wire and a second lead wire; and a third lead wire and a fourth lead wire. The first lead wire is electrically connected to an input electrode. The second lead wire and third lead wire are electrically connected to an intermediate electrode. The fourth lead wire is electrically connected to an output electrode. The first coil and the second coil are disposed on a substrate so that a first winding axis of the first coil and a second winding axis of the second coil are substantially parallel to the substrate.

Description

Coil components and electronic devices containing them

[0001] The present disclosure relates to a coil component and an electronic device including the same.

[0002] In electronic devices, noise suppression is often achieved by using a filter circuit, which uses a coil component. For example, a coil component used in a filter circuit has a structure in which two coils formed by bending a metal plate are stacked vertically (for example, see JP 2004-296630 A: Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2004-296630

[0004] However, in the coil component structure described in JP 2004-296630 A (Patent Document 1), multiple coils are stacked parallel to the main surface, so the coil lead wires are pulled out from the side and run along the side to the main surface that is mounted on the circuit board. This results in longer coil lead wires, increasing the direct current resistance (DCR) of the coil component. Furthermore, because multiple coils are stacked on the main surface, the area where the coils overlap is large when viewed from the main surface, increasing the stray capacitance formed between the stacked coils.

[0005] Therefore, an object of the present disclosure is to provide a coil component having a structure that can reduce DC resistance and stray capacitance, and an electronic device that includes the coil component.

[0006] A coil component according to one embodiment of the present disclosure includes: a first coil formed by bending a rectangular first conductor in the long-side direction to form a cylindrical shape; a second coil formed by bending a rectangular second conductor in the long-side direction to form a cylindrical shape; first and second lead wires electrically connected to the first coil; and third and fourth lead wires electrically connected to the second coil. The first lead wire constitutes an input terminal electrically connected to an input electrode formed on a substrate. The second and third lead wires constitute intermediate terminals electrically connected to intermediate electrodes formed on the substrate. The fourth lead wire constitutes an output terminal electrically connected to an output electrode formed on the substrate. The first coil and the second coil are arranged on the substrate such that a first winding axis of the first coil and a second winding axis of the second coil are substantially parallel to the substrate.

[0007] An electronic device according to an embodiment of the present disclosure includes the coil component described above.

[0008] According to one embodiment of the present disclosure, the first coil and the second coil are arranged on the substrate so that the first winding axis of the first coil and the second winding axis of the second coil are approximately parallel to the substrate, thereby providing a structure that can reduce DC resistance and stray capacitance.

[0009] 1 is a perspective view of a coil component according to an embodiment; FIG. 2 is a plan view and a side view of a coil component according to an embodiment; FIG. 3 is a front view and a rear view of a coil component according to an embodiment; FIG. 4 is a circuit diagram of a filter circuit including a coil component according to an embodiment; FIG. 5 is a graph showing impedance characteristics of a coil component according to an embodiment; FIG. 6 is a graph showing pass characteristics of a coil component according to an embodiment; FIG. 7 is a perspective view of a coil component for comparison; FIG. 8 is a perspective view of a coil component according to a modified example; FIG. 9 is a side view and a bottom view of a coil component according to a modified example.

[0010] Hereinafter, a coil component according to the present disclosure and an electronic device including the coil component will be described with reference to the drawings.

[0011] <Embodiments> First, a coil component according to an embodiment will be described with reference to the drawings. Fig. 1 is a perspective view of a coil component 1 according to an embodiment. Fig. 2 is a plan view and a side view of the coil component 1 according to an embodiment. Fig. 3 is a front view and a rear view of the coil component 1 according to an embodiment. Fig. 4 is a circuit diagram of a filter circuit including a coil component according to an embodiment. Note that with respect to the X-axis, Y-axis, and Z-axis defined in Figs. 1 to 3, the X-axis direction represents the front-rear direction of the coil component 1, the Y-axis direction represents the left-right direction of the coil component 1, and the Z-axis direction represents the up-down direction of the coil component 1, respectively.

[0012] The coil component 1 is, for example, a transformer coil mounted in a filter circuit 100 used to reduce noise in a power line, and is used in electronic devices such as power supply devices. The coil component 1 is not limited to power supply devices, and may also be used in electronic devices other than power supply devices. As will be described later, the coil component 1 magnetically couples two coils to cancel the parasitic inductance of a capacitor mounted in the filter circuit 100.

[0013] The coil component 1 includes a housing 4, a coil 2 (first coil), and a coil 3 (second coil). The coils 2 and 3 are arranged side by side in the X direction, rather than stacked in the Z direction. That is, in the coil component 1, as shown in FIG. 2( b), the coils 2 and 3 are arranged so that the coil winding axes (the winding axis (first winding axis) of the coil 2 and the winding axis (second winding axis) of the coil 3) are substantially parallel to the intermediate electrode 30. Note that although the substrate on which the coil component 1 is mounted is not shown in FIGS. 1 to 3, the input electrode 10, the output electrode 20, and the intermediate electrode 30 provided on the substrate are shown. Therefore, the coil winding axes (the winding axis (first winding axis) of the coil 2 and the winding axis (second winding axis) of the coil 3) are substantially parallel to the substrate.

[0014] The coil 2 has a lead wire 2a (first lead wire) connected to one end and a lead wire 2f (second lead wire) connected to the other end. The coil 2 is formed by bending a rectangular conductor (first conductor) in the long-side direction to form a cylindrical shape. Specifically, the coil 2 has a rectangular cylindrical shape and includes a portion 2b parallel to the side surface 41 of the housing 4, a portion 2c parallel to the main surface 40A of the housing 4, a portion 2d parallel to the side surface 42 of the housing 4, and a portion 2e parallel to the main surface 40B of the housing 4. The coil 2 and the lead wires 2a and 2f are formed from a single conductor, for example, a metal plate or metal wire made of copper or an alloy of copper and other metals. Furthermore, the coil 2 and the lead wires 2a and 2f may be subjected to surface treatment such as Ni-Sn plating or gold plating. When the coil 2 and the lead wires 2a, 2f are formed from a metal plate, the width W1 of the metal plate is, for example, 1.6 mm, and the thickness T is, for example, 0.4 mm, so that the width W1 is greater than the thickness T.

[0015] The coil 3 has a lead wire 3a (fourth lead wire) connected to one end and a lead wire 3f (third lead wire) connected to the other end. The coil 3 is formed into a cylindrical shape by bending a rectangular conductor (second conductor) in the long-side direction. Specifically, the coil 3 has a rectangular cylindrical shape and includes a portion 3b parallel to the side surface 42 of the housing 4, a portion 3c parallel to the main surface 40A of the housing 4, a portion 3d parallel to the side surface 41 of the housing 4, and a portion 3e parallel to the main surface 40B of the housing 4. The coil 3 and the lead wires 3a and 3f are formed from a single conductor, such as a metal plate or metal wire made of copper or an alloy of copper and other metals. Furthermore, the coil 3 and the lead wires 3a and 3f may be subjected to surface treatment such as Ni-Sn plating or gold plating. When the coil 3 and the leads 3a, 3f are formed from a metal plate, the width W1 of the metal plate is, for example, 1.6 mm, and the thickness T is, for example, 0.4 mm, so that the width W1 is greater than the thickness T.

[0016] When the coil component 1 is mounted on a substrate, the lead wire 2a (first lead wire) is electrically connected to the input electrode 10 on the substrate, and the lead wire 3a (fourth lead wire) is electrically connected to the output electrode 20 on the substrate. In other words, the lead wire 2a constitutes the input terminal of the coil component 1, and the lead wire 3a constitutes the output terminal of the coil component 1. The lead wire 2f (second lead wire) and the lead wire 3f (third lead wire) are electrically connected to the intermediate electrode 30 on the substrate. By connecting the lead wire 2f and the lead wire 3f with the intermediate electrode 30, the coil 2 and the coil 3 are connected in series, and the lead wires 2f and 3f constitute the intermediate terminal t of the coil component 1.

[0017] Coil 2 and coil 3 are configured as a transformer coil by arranging the surfaces constituting their respective openings (hereinafter also referred to as opening surfaces) in the X direction, aligned with the YZ plane. Therefore, coil component 1 is arranged inside housing 4 so that the opening surfaces of coil 2 and coil 3 are substantially parallel to side surfaces 43 and 44 of housing 4, and the openings of coil 2 and coil 3 overlap when viewed from side surface 43 of housing 4. The overlapping portion of coil 2 and coil 3 as viewed from side surface 43 of housing 4 is the portion where the plate thickness T of coil 2 overlaps the plate thickness T of coil 3, and the area is narrower than when the plate width W1 of coil 2 overlaps the plate width W1 of coil 3. The narrowing of the opposing area between coil 2 and coil 3 reduces the stray capacitance of coil component 1 and increases the self-resonant frequency.

[0018] Furthermore, portions 2b and 2e of coil 2 extend to main surface 40B, and lead wires 2a and 2f are drawn out from side surfaces 41 and 44 near main surface 40B. Similarly, portions 3b and 3e of coil 3 extend to main surface 40B, and lead wires 3a and 3f are drawn out from side surfaces 43 and 44 near main surface 40B. Therefore, coils 2 and 3 do not have a structure in which lead wires 2a, 2f, 3a, and 3f are provided along the side surfaces of housing 4 to main surface 40B, and the direct current resistance (DCR) of coil component 1 can be reduced, and the rated current of coil component 1 can be increased.

[0019] The lead wire 2a is electrically connected to the coil 2 on the side (side surface 41) opposite to the side (side surface 42) where the lead wire 3a is electrically connected to the coil 3. That is, in the coil component 1, the input terminal (lead wire 2a) and the output terminal (lead wire 3a) are arranged symmetrically in the drawings, as shown in FIGS. 3(a) and 3(b). The intermediate terminal t has a lead wire 2f (first terminal) provided on the coil 2 side (side surface 44) and a lead wire 3f (second terminal) provided on the coil 3 side (side surface 43). That is, in the coil component 1, the lead wires 2f and 3f are arranged symmetrically in the drawings, as shown in FIG. 2(b).

[0020] The intermediate terminal t may be provided only on the coil 2 side (side surface 44) or only on the coil 3 side (side surface 43). Specifically, when the intermediate terminal t is provided only on the coil 2 side (side surface 44), the intermediate terminal t is formed by electrically connecting the lead wire 2f and the portion 3e of the coil 3 with the intermediate electrode 30 without providing the lead wire 3f. When the intermediate terminal t is provided only on the coil 3 side (side surface 43), the intermediate terminal t is formed by electrically connecting the lead wire 3f and the portion 2e of the coil 2 with the intermediate electrode 30 without providing the lead wire 2f.

[0021] When lead wire 2a is connected to a power source, current flows counterclockwise from portion 2b of coil 2 through portions 2c, 2d, 2e, and lead wire 2f in this order. In coil 3, current flows from lead wire 2f to lead wire 3f via intermediate electrode 30, and current flows counterclockwise from portion 3e of coil 3 through portions 3d, 3c, 3b, and lead wire 3a in this order. Therefore, a magnetic field is generated in coils 2 and 3 in the direction from side surface 44 to side surface 43 (-X direction).

[0022] The housing 4 fixes the relative positions of the coil 2 and the coil 3 and is made of, for example, molded resin. Specifically, the molded resin is made of various resins, such as epoxy resin with silica filler, silicone resin, liquid crystal polymer, or a mixed metal magnetic material. The housing 4 has a side 41 (first side) and a side 42 (second side) that face each other, with the side closer to the coil 3 being side 43 (third side), and the side closer to the coil 2 being side 44 (fourth side). While FIG. 1 shows a rectangular parallelepiped shape, the side may be inclined as long as the main surface 40B (second main surface), which serves as the mounting surface for the substrate, and the main surface 40A (first main surface) are substantially parallel. For example, the housing 4 may be a truncated pyramid in which the area of ​​the main surface 40B is larger than that of the main surface 40A.

[0023] The filter circuit 100 is, for example, an EMI filter, as shown in FIG. 4, and is a third-order T-type LC filter circuit. This filter circuit 100 has a lead wire 2a (input terminal) connected to a power supply (not shown) and a lead wire 3a (output terminal) connected to a circuit (not shown), such as a DC / DC converter or a power supply module. The filter circuit 100 passes necessary components of the current flowing from the power supply to the circuit and removes unnecessary components. Specifically, a direct current is passed through the filter circuit 100, and high-frequency noise contained in the direct current is dropped to GND via a capacitor 50. The capacitor 50, which is a capacitance element, has an inductor 50B as a parasitic inductance (equivalent series inductance (ESL)) in addition to a capacitor 50A. This prevents high-frequency noise from passing through, degrading noise removal performance. The filter circuit 100 uses the negative inductance generated by the magnetic coupling between the two coils to cancel the parasitic inductance (inductor 50B) of the capacitor 50, thereby maintaining high noise removal performance. In this disclosure, the negative inductance generated in series with the capacitor 50 is referred to as the mutual inductance (−M) of the coil component 1.

[0024] In the following embodiments, a third-order T-type LC filter circuit will be used as the configuration of the filter circuit 100, but coil components of a similar configuration can also be applied to fifth-order T-type LC filter circuits or higher-order T-type LC filter circuits. As shown in FIG. 2, the filter circuit 100 includes a capacitor 50, lead wires 2 a, 3 a, an intermediate terminal t, a coil 2, and a coil 3.

[0025] As shown in FIG. 2 , one end of the capacitor 50 is connected to the intermediate terminal t, and the other end is connected to the GND wiring. The capacitor 50 may be a multilayer ceramic capacitor primarily composed of BaTiO3 (barium titanate), a multilayer ceramic capacitor primarily composed of other materials, or another type of capacitor, such as an aluminum electrolytic capacitor. The capacitor 50 has an inductor 50B as a parasitic inductance, and is equivalent to a circuit configuration in which the inductor 50B is connected in series with the capacitor 50A. The capacitor 50 may also have a parasitic resistance (equivalent series resistance (ESR)) equivalent to a circuit configuration in which the inductor 50B and the capacitor 50A are connected in series.

[0026] In addition to capacitor 50, coil 2 and coil 3 are also connected to intermediate terminal t. Coil 2 and coil 3 are magnetically coupled and have a mutual inductance (-M). A negative inductance component equal in magnitude to the mutual inductance M is generated between intermediate terminal t and capacitor 50. This negative inductance component can be used to cancel out the parasitic inductance of capacitor 50 (inductor 50B), thereby making the parasitic inductance component of capacitor 50 appear smaller. In other words, filter circuit 100, which is composed of capacitor 50, coil 2, and coil 3, cancels out the parasitic inductance of capacitor 50 with the negative inductance component due to the mutual inductance between coil 2 and coil 3, thereby suppressing a decrease in the noise suppression effect in the high frequency band due to the parasitic inductance of capacitor 50 and improving the noise suppression effect of filter circuit 100.

[0027] A simulation was performed on coil component 1 to evaluate the self-resonant frequency and pass characteristics. Specifically, the height H of coil 2 and coil 3 was 3.1 mm, the width W2 was 5.0 mm, the plate width W1 was 1.6 mm, and the plate thickness T was 0.4 mm. The height a of the openings of coil 2 and coil 3 was 2.3 mm, and the width b of the openings was 2.9 mm. Furthermore, the gap G between coil 2 and coil 3 was 0.15 mm, and the length L from the end of lead wire 2f to the end of lead wire 3f was 5.7 mm.

[0028] Fig. 5 is a graph showing the impedance characteristics of the coil component 1 according to the embodiment. In Fig. 5, the horizontal axis represents frequency, and the vertical axis represents impedance characteristics. Fig. 6 is a graph showing the pass characteristics of the coil component according to the embodiment. In Fig. 6, the horizontal axis represents frequency, and the vertical axis represents pass characteristics, with the amount of attenuation increasing downward in the graph.

[0029] Graph F1 shows the results of a simulation of the impedance characteristics performed on coil component 1, which shows the impedance characteristics of coil component 1 with a mutual inductance (-M) of -0.978 nH and a direct current resistance (DCR) of 0.7 mΩ. The self-resonant frequency of coil component 1 is 3.148 GHz, as indicated by mark M1 on graph F1. Meanwhile, graph F2 shows the results of a simulation of the impedance characteristics performed on a comparative coil component.

[0030] Fig. 7 is a perspective view of a comparative coil component 1A. The coil component 1A shown in Fig. 1 includes a coil 200 and a coil 300 in a housing 400. The coils 200 and 300 are arranged stacked in the Z direction. That is, in the coil component 1A, the coil 200 is arranged above the coil 300 inside the housing 400, approximately parallel to the main surface 400A of the housing 400. Since the coils 200 and 300 are arranged so as to overlap when viewed from the main surface 400A, the coils 200 and 300 are magnetically coupled.

[0031] Coil 200 has lead wire 200a connected to one end and lead wire 200b connected to the other end. Coil 300 has lead wire 300a connected to one end and lead wire 300b connected to the other end. When coil component 1A is mounted on a substrate, lead wire 200a is electrically connected to input electrode 10 on the substrate, and lead wire 300a is electrically connected to output electrode 20 on the substrate. In other words, lead wire 200a constitutes the input terminal of coil component 1A, and lead wire 300a constitutes the output terminal of coil component 1A. Lead wire 200b and lead wire 300b are electrically connected to intermediate electrode 30 on the substrate. Coil 200 and coil 300 are connected in series by connecting lead wire 200b and lead wire 300b with intermediate electrode 30, and lead wires 200b and 300b constitute intermediate terminal t of coil component 1A.

[0032] The overlapping portion of coil 200 and coil 300 as viewed from main surface 400A of housing 400 is the portion where the plate width of coil 200 and the plate width of coil 300 overlap, and the area is larger than the overlapping area between coil 2 and coil 3 of coil component 1 shown in Fig. 1. The wider area where coil 200 and coil 300 face each other increases the stray capacitance of coil component 1A and decreases the self-resonant frequency.

[0033] Returning to FIG. 5 , graph F2 shows the impedance characteristics of coil component 1A, which has a mutual inductance (-M) of -0.912 nH and a direct current resistance (DCR) of 1.5 mΩ. The self-resonant frequency of coil component 1 is 1.29 GHz, as indicated by mark M2 in graph F2. Therefore, by adopting the structure shown in FIG. 1 and other figures, coil component 1 according to this embodiment can increase the self-resonant frequency from 1.29 GHz to 3.148 GHz. As a result, filter circuit 100 using coil component 1 can reduce noise in the high frequency band more effectively than when coil component 1A is used.

[0034] 7, lead wires 200a, 200b, 300a, and 300b are provided along the side surface of housing 400 to main surface 400B. Therefore, the direct current resistance (DCR) of coil component 1A is 1.5 mΩ, which is higher than the direct current resistance (DCR) of coil component 1, which is 0.7 mΩ. Because coil component 1 can have a lower direct current resistance (DCR) than coil component 1A, the rated current of coil component 1 can be made higher than that of coil component 1A.

[0035] The graph shown in FIG. 6 illustrates how the use of the coil component 1 according to this embodiment in the filter circuit 100 can attenuate noise in the high frequency band.

[0036] Graph F3 shows the results of a simulation of the pass characteristics of the filter circuit 100 using the coil component 1, with a large amount of attenuation being obtained around 1.0 GHz, as indicated by mark M3. On the other hand, graph F4 shows the results of a simulation of the pass characteristics of the filter circuit using the comparative coil component 1A, with insufficient attenuation being obtained around 1.0 GHz, as indicated by mark M4. Therefore, the filter circuit 100 using the coil component 1 has noise removal performance in the frequency band around 1.0 GHz.

[0037] 2B, coil 2 and coil 3 are arranged on the substrate so that the winding axis (first winding axis) of coil 2 and the winding axis (second winding axis) of coil 3 are on the same straight line. However, in coil component 1, coil 2 and coil 3 may be arranged on the substrate so that the winding axis (first winding axis) of coil 2 and the winding axis (second winding axis) of coil 3 are shifted from the same straight line. In coil component 1, the magnetic coupling between coil 2 and coil 3 is weakened, but it is sufficient that the opening of coil 2 and the opening of coil 3 at least partially overlap when viewed from side surface 43 of housing 4.

[0038] 1, the housing 4 is provided so that the surfaces of the openings of the coils 2 and 3 are approximately parallel to the side surfaces 43 and 44. However, the positional relationship between the housing 4 and the coils 2 and 3 is not limited to this, and for example, the housing 4 may be arranged so that the side surfaces 43 and 44 are inclined relative to the surfaces of the openings of the coils 2 and 3. Furthermore, although the housing 4 is provided to fix the relative positions of the coils 2 and 3, the housing 4 may not be provided if the relative positions of the coils 2 and 3 can be fixed.

[0039] 1, the shape of the coil component 1 including the coil 2, the lead wires 2a, and the lead wires 2f is substantially the same as the shape of the coil 3, the lead wires 3a, and the lead wires 3f. Therefore, by designing a single shape including the coil 2, the lead wires 2a, and the lead wires 2f, it is possible to manufacture the coil component 1, thereby reducing manufacturing costs. Of course, as long as the coil component 1 has the above-described technical features, the shape including the coil 2, the lead wires 2a, and the lead wires 2f may be different from the shape including the coil 3, the lead wires 3a, and the lead wires 3f.

[0040] In the coil component 1, the coil 2 and the lead wires 2a and 2f are formed from a single conductor, and the coil 3 and the lead wires 3a and 3f are formed from a single conductor. However, the configuration of the coil component 1 is not limited to this, and at least one of the coil 2 and the lead wires 2a and 2f may be formed from a different conductor, and at least one of the coil 3 and the lead wires 3a and 3f may be formed from a different conductor. Conversely, the coil 2, the coil 3, and the lead wires 2a, 2f, 3a, and 3f may be formed from a single conductor.

[0041] Although the coil 2 has been described as having a rectangular cylindrical shape and including a portion 2b parallel to the side surface 41 of the housing 4, a portion 2c parallel to the main surface 40A of the housing 4, a portion 2d parallel to the side surface 42 of the housing 4, and a portion 2e parallel to the main surface 40B of the housing 4, the cross section excluding portion 2e may be an n-shaped cylindrical shape. Similarly, the coil 3 has been described as having a rectangular cylindrical shape and including a portion 3d parallel to the side surface 41 of the housing 4, a portion 3c parallel to the main surface 40A of the housing 4, a portion 3b parallel to the side surface 42 of the housing 4, and a portion 3e parallel to the main surface 40B of the housing 4, the cross section excluding portion 3e may be an n-shaped cylindrical shape. Furthermore, the coils 2 and 3 may be cylindrical instead of rectangular cylindrical.

[0042] Although coil 2 has been described as being formed by bending a rectangular conductor in the longitudinal direction to form a rectangular tube shape including portions 2b, 2c, 2d, and 2e, portions 2b, 2c, 2d, and 2e may be formed separately and assembled into a rectangular tube shape. Similarly, coil 3 has been described as being formed by bending a rectangular conductor in the longitudinal direction to form a rectangular tube shape including portions 3b, 3c, 3d, and 3e, but portions 3b, 3c, 3d, and 3e may be formed separately and assembled into a rectangular tube shape.

[0043] <Modifications> The coil component 1 shown in FIGS. 1 to 3 illustrates an example in which a transformer coil is formed by magnetically coupling a single-turn coil 2 and a single-turn coil 3. However, this is not limiting, and a transformer coil may also be formed by magnetically coupling multiple-turn coils. A modification of a coil component in which a transformer coil is formed by magnetically coupling multiple-turn coils will be described with reference to the drawings. FIG. 8 is a perspective view of a coil component 1B according to a modification. FIG. 9 is a side view and a bottom view of the coil component 1B according to a modification. Regarding the X-axis, Y-axis, and Z-axis defined in FIGS. 8 to 9, the X-axis represents the front-rear direction of the coil component 1B, the Y-axis represents the left-right direction of the coil component 1B, and the Z-axis represents the up-down direction of the coil component 1B. Furthermore, in the coil component 1B shown in FIGS. 8 to 9, the same components as those in the coil component 1 shown in FIGS. 1 to 3 are designated by the same reference numerals, and detailed descriptions thereof will not be repeated.

[0044] The coil component 1B is, for example, a transformer coil mounted in a filter circuit 100 shown in Fig. 4 that is used to suppress noise in a power line, and is used in electronic devices such as power supply devices. The coil component 1B is not limited to power supply devices, and may also be used in electronic devices other than power supply devices. As will be described later, the coil component 1B has two magnetically coupled coils with multiple turns in order to cancel the parasitic inductance of a capacitor mounted in the filter circuit 100.

[0045] Coil component 1B includes a housing 4, a coil 2A (first coil), and a coil 3A (second coil). Coil 2A and coil 3A are arranged side by side in the X direction, rather than stacked in the Z direction. That is, in coil component 1B, as shown in FIG. 9( a), coil 2A and coil 3A are arranged so that the coil winding axes (the winding axis (first winding axis) of coil 2A and the winding axis (second winding axis) of coil 3A) are substantially parallel to intermediate electrodes 30a to 30c. Note that while FIGS. 8 and 9 do not show the substrate on which coil component 1B is mounted, they do show the input electrode 10, output electrode 20, and intermediate electrodes 30a to 30c provided on the substrate. Therefore, the coil winding axes (the winding axis (first winding axis) of coil 2A and the winding axis (second winding axis) of coil 3A) are substantially parallel to the substrate.

[0046] Coil 2A is a two-winding coil, with one winding at portions 21b, 21c, 21d, and 21e, and one winding at portions 22a, 22b, 22c, 22d, and 22e. Coil 2A has portion 21b connected to lead wire 21a (first lead wire), and portion 21e connected to lead wire 21f (second lead wire). Lead wire 21f, portion 21e, and portion 22e are electrically connected by intermediate electrode 30a. Coil 2A is formed by bending a rectangular conductor (first conductor) in the long-side direction into a cylindrical shape. Specifically, coil 2A has a rectangular cylindrical shape, and is formed from a single conductor together with lead wires 21a and 21f, for example, a metal plate or metal wire made of copper or an alloy of copper and other metals. Furthermore, the coil 2A and the lead wires 21 a, 21 f may be subjected to surface treatment such as Ni plating, Sn plating, or gold plating. When the coil 2A and the lead wires 21 a, 21 f are formed of a metal plate, the width W1 of the metal plate is, for example, 1.6 mm, and the thickness T is, for example, 0.4 mm, so that the width W1 is greater than the thickness T.

[0047] Coil 3A is a two-winding coil, with one winding at portions 31b, 31c, 31d, and 31e, and one winding at portions 32a, 32b, 32c, 32d, and 32e. Coil 3A is configured such that portion 31b is connected to lead wire 31a (fourth lead wire), and portion 31e is connected to lead wire 31f (third lead wire). Lead wire 31f, portion 31e, and portion 32e are electrically connected via intermediate electrode 30b. Coil 3A is configured by bending a rectangular conductor (second conductor) in the long-side direction to form a cylindrical shape. Specifically, coil 3A is configured in a rectangular cylindrical shape, and is formed from a single conductor together with lead wires 31a and 31f, for example, a metal plate or metal wire made of copper or an alloy of copper and other metals. Furthermore, the coil 3A and the lead wires 31 a, 31 f may be subjected to surface treatment such as Ni plating, Sn plating, or gold plating. When the coil 3A and the lead wires 31 a, 31 f are formed of a metal plate, the width W1 of the metal plate is, for example, 1.6 mm, and the thickness T is, for example, 0.4 mm, so that the width W1 is greater than the thickness T.

[0048] When coil component 1B is mounted on a substrate, lead wire 21a (first lead wire) is electrically connected to input electrode 10 on the substrate, and lead wire 31a (fourth lead wire) is electrically connected to output electrode 20 on the substrate. In other words, lead wire 21a constitutes the input terminal of coil component 1B, and lead wire 31a constitutes the output terminal of coil component 1B. Lead wire 21f (second lead wire) is electrically connected to intermediate electrode 30a on the substrate, and lead wire 31f (third lead wire) is electrically connected to intermediate electrode 30b on the substrate. Since portion 22a and portion 32e are electrically connected by intermediate electrode 30c, lead wires 21f and 31f constitute intermediate terminal t of coil component 1B.

[0049] Coil 2A and coil 3A are configured as a transformer coil by arranging them side by side in the X direction with the surfaces constituting their respective openings (hereinafter also referred to as opening surfaces) aligned with the YZ plane. Therefore, coil component 1B is arranged inside housing 4 so that the surfaces of the openings of coil 2A and coil 3A are approximately parallel to side surfaces 43 and 44 of housing 4, and the openings of coil 2A and coil 3A overlap when viewed from side surface 43 of housing 4. Coil component 1B configures a transformer coil with two-turn coil 2A and two-turn coil 3A, thereby enabling strong magnetic coupling between coil 2A and coil 3A.

[0050] In the coil component 1B, the transformer coil is formed by a two-turn coil 2A and a two-turn coil 3A, but the transformer coil may be formed by a one-turn coil 2A and a two or more-turn coil 3A, or a two or more-turn coil 2A and a one-turn coil 3A. Of course, the coil component according to the present disclosure may also form a transformer coil by magnetically coupling coils with two or more turns.

[0051] <Aspects> (1) A coil component according to the present disclosure includes a first coil formed by bending a rectangular first conductor in the long side direction to form a cylindrical shape; a second coil formed by bending a rectangular second conductor in the long side direction to form a cylindrical shape; first and second lead wires electrically connected to the first coil; and third and fourth lead wires electrically connected to the second coil, wherein the first lead wire constitutes an input terminal electrically connected to an input electrode formed on a substrate, the second and third lead wires constitute intermediate terminals electrically connected to intermediate electrodes formed on the substrate, and the fourth lead wire constitutes an output terminal electrically connected to an output electrode formed on the substrate, and the first coil and the second coil are arranged on the substrate such that the first winding axis of the first coil and the second winding axis of the second coil are substantially parallel to the substrate.

[0052] (2) In the coil component described in (1), the first coil and the second coil are arranged on the substrate so that the first winding axis and the second winding axis are on the same straight line.

[0053] (3) In the coil component described in (1) or (2), the first lead wire is electrically connected to the first coil on the side opposite to the side where the fourth lead wire is electrically connected to the second coil.

[0054] (4) In the coil component according to any one of (1) to (3), the intermediate terminal is provided on the first coil side or the second coil side.

[0055] (5) In the coil component according to any one of (1) to (3), the intermediate terminal has a first terminal provided on the side of the first coil and a second terminal provided on the side of the second coil.

[0056] (6) The coil component described in any one of (1) to (5) further includes a housing having a pair of first and second main surfaces facing each other and four side surfaces connecting the first and second main surfaces, and the housing is arranged so that the surfaces of the openings of the first coil and the second coil are approximately parallel to the side surfaces of the housing.

[0057] (7) In the coil component according to (6), each of the first conductor and the second conductor is made of a metal plate, and the housing is made of molded resin.

[0058] (8) In the coil component according to (7), the first conductor and the second conductor have a width greater than a thickness.

[0059] (9) In the coil component described in any one of (1) to (8), the first coil, the first lead wire, and the second lead wire are integrally formed from the first conductor, and the second coil, the third lead wire, and the fourth lead wire are integrally formed from the second conductor.

[0060] (10) In the coil component according to (9), the first conductor and the second conductor are one conductor.

[0061] (11) In the coil component according to any one of (1) to (10), the shape including the first coil, the first lead wire, and the second lead wire is substantially the same as the shape including the second coil, the third lead wire, and the fourth lead wire.

[0062] (12) An electronic device comprising the coil component according to any one of (1) to (11). The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0063] 1, 1A coil components, 2, 3, 200, 300 coils, 2a, 2f, 3a, 3f, 200a, 200b, 300a, 300b lead wires, 2b, 2c, 2d, 2e, 3b, 3c, 3d, 3e parts, 4, 400 housing, 10 input electrode, 20 output electrode, 30 intermediate electrode, 40A, 40B, 400A, 400B main surface, 41, 42, 43, 44 side surface, 50 capacitor, 50A capacitor, 50B inductor, 100 filter circuit.

Claims

1. A coil component comprising: a first coil formed by bending a rectangular first conductor in the long side direction into a cylindrical shape; a second coil formed by bending a rectangular second conductor in the long side direction into a cylindrical shape; first and second lead wires electrically connected to the first coil; and third and fourth lead wires electrically connected to the second coil, wherein the first lead wire constitutes an input terminal electrically connected to an input electrode formed on a substrate, the second and third lead wires constitute intermediate terminals electrically connected to intermediate electrodes formed on the substrate, and the fourth lead wire constitutes an output terminal electrically connected to an output electrode formed on the substrate, and the first coil and the second coil are arranged on the substrate so that a first winding axis of the first coil and a second winding axis of the second coil are approximately parallel to the substrate.

2. The coil component according to claim 1, wherein the first coil and the second coil are arranged on the substrate so that the first winding axis and the second winding axis are on the same straight line.

3. A coil component according to claim 1 or claim 2, wherein the first lead wire is electrically connected to the first coil on the side opposite to the side where the fourth lead wire is electrically connected to the second coil.

4. A coil component according to any one of claims 1 to 3, wherein the intermediate terminal is provided on the side of the first coil or the side of the second coil.

5. A coil component according to any one of claims 1 to 3, wherein the intermediate terminal has a first terminal provided on the side of the first coil and a second terminal provided on the side of the second coil.

6. A coil component according to any one of claims 1 to 5, further comprising a housing having a pair of first and second main surfaces facing each other and four side surfaces connecting the first and second main surfaces, wherein the housing is disposed so that the surfaces that define the openings of the first coil and the second coil are substantially parallel to the side surfaces of the housing.

7. The coil component according to claim 6, wherein the first conductor and the second conductor are each made of a metal plate, and the housing is made of molded resin.

8. The coil component according to claim 7, wherein the first conductor and the second conductor have a width greater than a thickness.

9. A coil component according to any one of claims 1 to 8, wherein the first coil, the first lead wire, and the second lead wire are integrally formed from the first conductor, and the second coil, the third lead wire, and the fourth lead wire are integrally formed from the second conductor.

10. The coil component according to claim 9, wherein the first conductor and the second conductor are a single conductor.

11. A coil component according to any one of claims 1 to 10, wherein the shape including the first coil, the first lead wire, and the second lead wire is substantially the same as the shape including the second coil, the third lead wire, and the fourth lead wire.

12. An electronic device comprising the coil component according to any one of claims 1 to 11.

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