Loop device

Abstract

The present disclosure provides a circuit device that can suppress changes in the parasitic inductance of a capacitor. In the present disclosure, a circuit device (100) comprises a substrate (60) and a coil component (1). The coil component (1) is configured by magnetically coupling a coil (L1) and a coil (L2). A wiring pattern includes a first wiring (70a), a second wiring (70b), a third wiring (71) in which capacitors (C1, C2) are mounted in series, and a fourth wiring (72) that electrically connects a ground electrode (72a) and either of the first wiring (70a) or the second wiring (70b). The spacing between a first current path through which current flows from the coil component (1) to a ground electrode (71a) through the third wiring (71) and a second current path through which current flows from the first wiring (70a) or the second wiring (70b) to the ground electrode (72a) through the fourth wiring (72) on which capacitors (C3, C4) are mounted is not fixed.

Description

[Technical field]

[0001] The present disclosure relates to a circuit device that mounts a coil component. [Background technology]

[0002] In electronic devices, noise is suppressed by using filter circuits. Filter circuits used for noise suppression include, for example, EMI (Electro-Magnetic Interference) suppression filters, which allow necessary components of the current flowing through a conductor to pass through, while removing unnecessary components. In addition, since filter circuits use capacitors, which are capacitance elements, it is known that the noise suppression effect is reduced by the equivalent series inductance (ESL), which is the parasitic inductance of the capacitor.

[0003] There is a known technology for canceling out the equivalent series inductance ESL of a capacitor with the negative inductance generated by magnetically coupling two coils, thereby broadening the bandwidth of the noise suppression effect of a filter circuit (for example, Patent Document 1).

[0004] Furthermore, when a circuit using a capacitor is installed in a vehicle, two capacitors are sometimes arranged in series to provide a redundant circuit configuration so that the circuit does not short out even if the capacitor fails. Therefore, when a filter circuit is installed in a vehicle, a similar redundant circuit configuration must be applied to the filter circuit (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2001-160728 A [Patent Document 2] JP 2004-022561 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, when canceling out the parasitic inductance of a capacitor with the negative inductance generated by magnetically coupling two coils, if there is wiring for another capacitor other than the capacitor that generates the parasitic inductance, the parasitic inductance may change due to the influence of that wiring.In addition, it is difficult to grasp the noise generation conditions in advance, and it is difficult to specify the parasitic inductance of a capacitor by determining in advance the number and placement of capacitors to be mounted in a filter circuit.

[0007] Therefore, an object of the present disclosure is to provide a circuit device capable of suppressing changes in the parasitic inductance of a capacitor. [Means for solving the problem]

[0008] A circuit device according to an embodiment of the present disclosure includes a substrate on which a wiring pattern is formed, and a coil component mounted on the substrate. The coil component includes a first coil and a second coil, the first coil and the second coil are magnetically coupled, a first end of the first coil is connected to an input terminal, a second end of the first coil and a first end of the second coil are connected to an intermediate terminal, and a second end of the second coil is connected to an output terminal. The wiring pattern includes a first wiring connected to the input terminal of the coil component, a second wiring connected to the output terminal of the coil component, a third wiring on which at least one capacitor is mounted in series and electrically connecting the intermediate terminal and a ground electrode, and a fourth wiring provided with an electrode for mounting at least one capacitor in series and electrically connecting the first wiring or the second wiring and the ground electrode. The distance between a first current path in which current flows from the coil component through the third wiring to the ground electrode, and a second current path in which current flows from the first wiring or the second wiring through a fourth wiring having a capacitor mounted on the electrode to the ground electrode, is not constant. Effect of the Invention

[0009] According to one embodiment of the present disclosure, since the third wiring and the fourth wiring have a portion where they are not parallel to each other, it is possible to suppress a change in the parasitic inductance of the capacitor. [Brief description of the drawings]

[0010] [Figure 1] 1 is a plan view of a circuit device according to a first embodiment. [Diagram 2] 1 is a circuit diagram of a circuit device according to a first embodiment. [Diagram 3] FIG. 2 is a perspective view of a coil component according to the first embodiment. [Figure 4] 4 is a graph illustrating a change in parasitic inductance in the circuit device according to the first embodiment. [Diagram 5] FIG. 11 is a plan view of a circuit device according to a comparative example. [Figure 6] 4 is a plan view of the circuit device according to the first embodiment in which some capacitors are not mounted. FIG. [Figure 7] 11 is a plan view of a circuit device according to a first modified example of the first embodiment. FIG. [Figure 8] 13 is a plan view of a circuit device according to a second modified example of the first embodiment. FIG. [Figure 9] 13 is a plan view of a circuit device according to a third modified example of the first embodiment. FIG. [Figure 10] FIG. 13 is a plan view of a circuit device according to a fourth modified example of the first embodiment. [Figure 11] FIG. 11 is a plan view of a circuit device according to a second embodiment. [Figure 12] 13 is a plan view of a circuit device according to a first modified example of the second embodiment. FIG. [Figure 13] 13 is a plan view of a circuit device according to a second modified example of the second embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <Embodiment 1> A circuit device according to a first embodiment will be described below. Fig. 1 is a plan view of a circuit device 100 according to the first embodiment. The circuit device 100 is, for example, a filter circuit used to reduce noise in a power supply line 70, and is equipped with a coil component 1 including two magnetically coupled coils to cancel the parasitic inductance of capacitors C1 and C2. Of course, the circuit device 100 is not limited to a filter circuit used to reduce noise in the power supply line 70, and may be a filter circuit used to reduce noise in other signal lines, etc.

[0012] In the circuit device 100, a wiring pattern of a power supply line 70 is formed on the surface of a substrate 60, and a coil component 1 is mounted in series with the power supply line 70. The power supply line 70 includes a first wiring 70a connected to an input terminal 4a of the coil component 1, and a second wiring 70b connected to an output terminal 4b of the coil component 1.

[0013] The substrate 60 is formed by laminating a plurality of insulating layers, and is made of, for example, low-temperature co-fired ceramics, glass epoxy resin, etc. On the surface of the substrate 60, wiring patterns such as the first wiring 70a and the second wiring 70b, and electrode patterns for mounting components such as the coil component 1 and the capacitors C1 to C4 are formed, and each of these is made of a metal material generally used as an electrode material, such as Cu, Ag, or Al.

[0014] Furthermore, in the circuit device 100, two capacitors C1 and C2 are connected in series to the intermediate terminal 4c of the coil component 1. A wiring pattern of a third wiring 71 is formed on the substrate 60 as wiring for mounting the capacitors C1 and C2. The third wiring 71 electrically connects the intermediate terminal 4c between the two coils included in the coil component 1 and the ground electrode 71a by mounting the capacitors C1 and C2. Furthermore, in the circuit device 100, two capacitors C3 and C4 are connected in series between the second wiring 70b near the coil component 1 and the ground electrode 72a. A wiring pattern of a fourth wiring 72 is formed on the substrate 60 as wiring for mounting the capacitors C3 and C4. The fourth wiring 72 electrically connects the second wiring 70b and the ground electrode 72a by mounting the capacitors C3 and C4. The fourth wiring 72 may be provided on the first wiring 70a instead of the second wiring 70b. The ground electrode is an electrode electrically connected to a ground potential, and is formed, for example, from a conductive via electrically connected to a ground potential disposed in an inner layer of the substrate 60. The third wiring 71 and the fourth wiring 72 refer to wiring for electrically connecting the coil component, the first wiring 70a, and the second wiring 70b to the ground electrode 71a and the ground electrode 72a, including the capacitor, and are represented as a group of multiple wirings.

[0015] 1, the fourth wiring 72 extends in a straight line from the second wiring 70b to the ground electrode 72a and has a straight line shape. However, the third wiring 71 has a U-shape that bends twice from the intermediate terminal 4c to the ground electrode 71a. In this way, by making the third wiring 71 have a U-shape instead of a straight line shape like the fourth wiring 72, it is possible to suppress changes in the parasitic inductance of the capacitors C1 and C2, as will be described later.

[0016] 2 is a circuit diagram of the circuit device 100 according to the first embodiment. Specifically, the circuit device 100 is an EMI elimination filter circuit, and is a third-order T-type LC filter circuit. Note that in this disclosure, the circuit device 100 will be described using a third-order T-type LC filter circuit as the configuration thereof, but a similar configuration can also be applied to a fifth-order T-type LC filter circuit or a higher-order T-type LC filter circuit. First, as shown in FIG. 2, the circuit device 100 includes a coil component 1 and capacitors C1 to C4.

[0017] The coil component 1 includes an input terminal 4a, an output terminal 4b, an intermediate terminal 4c, a coil L1 (a first coil), and a coil L2 (a second coil).

[0018] The capacitors C1 and C2 are connected in series between the input terminal 4a and the ground electrode 71a as shown in Fig. 2. Although either one of the capacitors C1 and C2 may be used, two capacitors are connected in series to provide a redundant circuit configuration in anticipation of being mounted on a vehicle, etc. Similarly, the capacitors C3 and C4 are connected in series between the second wiring 70b and the ground electrode 72a.

[0019] The capacitors C1 to C4 are not limited to multilayer ceramic capacitors whose main component is BaTiO3 (barium titanate), but may also be multilayer ceramic capacitors whose main component is another material, or may be other types of capacitors other than multilayer ceramic capacitors, such as aluminum electrolytic capacitors.

[0020] The capacitors C1 and C2 connected to the coil component 1 have an inductor L3 as a parasitic inductance (equivalent series inductance (ESL)). Therefore, the circuit device 100 is equivalent to a circuit configuration in which the inductor L3 is connected in series to the capacitors C1 and C2, as shown in FIG.

[0021] In addition to the capacitors C1 and C2, coils L1 and L2 are connected to the intermediate terminal 4c. Coils L1 and L2 are magnetically coupled, generating a negative inductance component (mutual inductance M). This negative inductance component can be used to cancel out the parasitic inductance (inductor L3) of capacitors C1 and C2, making the inductance components of capacitors C1 and C2 appear smaller. In FIG. 2, mutual inductance M (-M) for canceling inductor L3 is connected in series to capacitors C1 and C2, and is illustrated as an equivalent circuit in which mutual inductance M (+M) is added to each of coils L1 and L2.

[0022] The circuit device 100 composed of capacitors C1, C2, coil L1 and coil L2 can improve the noise suppression effect in the high frequency band by canceling out the parasitic inductance of capacitors C1 and C2 with the negative inductance component due to the mutual inductance M between coils L1 and L2.

[0023] The coil component 1 is a transformer coil, and includes a coil L1 (first coil) and a coil L2 (second coil) provided in a laminate such that the coil surfaces face each other in the lamination direction, and is mounted such that the coil surfaces are parallel to the surface of the substrate 60. The configuration of the coil component 1 will be described with reference to the drawings. FIG. 3 is a perspective view of the coil component 1 according to the first embodiment. Here, in FIG. 3, 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. The lamination direction of the substrate is the Z direction, and the direction of the arrow indicates the upper layer direction.

[0024] The coil component 1 is composed of a ceramic layer laminate 3 (ceramic element body) in which multiple substrates (ceramic green sheets) on which coil wiring is formed are stacked as shown in Fig. 3. The laminate 3 has a pair of main surfaces facing each other and a side surface connecting the main surfaces. A plurality of wiring patterns 10 constituting the coils L1 and L2 are stacked in order from the bottom up in parallel to the main surfaces of the laminate 3.

[0025] The side surfaces of the laminate 3 include a first side surface (the side surface on which the input terminal 4a (first external electrode) is formed) and a second side surface (the side surface on which the output terminal 4b (second external electrode) is formed) on the long side, and a third side surface (the side surface on which the intermediate terminal 4c (third external electrode) is formed) and a fourth side surface (the side surface on which the terminal 4d is formed) on the short side.

[0026] In the coil component 1, a plurality of wiring patterns 10 constituting the coils L1 and L2 are disposed inside the laminate 3. A portion of the plurality of wiring patterns 10 constitutes the coil L1, and the remaining portion constitutes the coil L2. In other words, the plurality of wiring patterns 10 have a common portion constituting the coils L1 and L2, thereby making it possible to reduce fluctuations in the magnetic coupling between the coils L1 and L2.

[0027] Of the multiple wiring patterns 10, an end 11 of the wiring pattern 10 in the top layer is electrically connected to the input terminal 4a. Of the multiple wiring patterns 10, an end 21 of the wiring pattern 10 in the bottom layer is electrically connected to the output terminal 4b. Of the multiple wiring patterns 10, an end 31 of the wiring pattern 10 in the middle layer is electrically connected to the intermediate terminal 4c. By adopting a configuration as shown in Fig. 3, the coil component 1 has a constant mutual inductance M between the coils L1 and L2.

[0028] Next, a change in parasitic inductance in the circuit device 100 will be described. Fig. 4 is a graph illustrating a change in parasitic inductance in the circuit device 100 according to the first embodiment. In Fig. 4, the horizontal axis represents the distance between the wirings, and the vertical axis represents the amount of change in parasitic inductance. Fig. 5 is a plan view of a circuit device 300 according to a comparative example. In the circuit device 300 shown in Fig. 5, the same components as those in the circuit device 100 shown in Fig. 1 are given the same reference numerals and detailed description will not be repeated.

[0029] First, as shown in FIG. 5, in the circuit device 300 according to the comparative example, the third wiring 71A for mounting the capacitors C1 and C2 is not U-shaped, but extends in a straight line from the intermediate terminal 4c to the ground electrode 71a, and is linear. Therefore, the third wiring 71A and the fourth wiring 72 are formed in parallel on the substrate 60. When the third wiring 71A and the fourth wiring 72 are formed in parallel, the direction of the current flowing through the third wiring 71A and the direction of the current flowing through the fourth wiring 72 are always the same, so that the magnetic coupling between the third wiring 71A and the fourth wiring 72 is strengthened. Note that, although it is described in the present disclosure that the two wirings are formed in parallel on the substrate, it is sufficient that at least the direction of the current flowing through the wirings is parallel, and the two wirings do not have to be formed geometrically parallel.

[0030] The magnetic coupling between the third wiring 71A and the fourth wiring 72 strengthens, so that the parasitic inductance of the capacitors C1 and C2 increases, and in the circuit device 300, the mutual inductance M of the coil part 1 cannot sufficiently cancel out the parasitic inductance.

[0031] 1, in the circuit device 100, the third wiring 71 mounting the capacitors C1 and C2 is U-shaped, so that the direction of the current flowing through the capacitor C1 is opposite to the direction of the current flowing through the capacitor C2, and the magnetic coupling between the part mounting the capacitor C1 and the part mounting the capacitor C2 is weakened. Here, the path through which the current flows from the coil component 1 through the third wiring 71 mounting the capacitors C1 and C2 to the ground electrode 71a is called the first current path. The first current path includes a path in which the current flows in the opposite direction.

[0032] Furthermore, the magnetic coupling between the portion where capacitor C1 is mounted and the portion where capacitor C2 is mounted is weakened, which also weakens the magnetic coupling between the third wiring 71 and the fourth wiring 72. In other words, by making the third wiring 71 U-shaped, it becomes less susceptible to the influence of the magnetic coupling with the fourth wiring 72, and the change in the parasitic inductance of the capacitors C1 and C2 can be reduced.

[0033] As shown in FIG. 1, the third wiring 71 has a U-shape with a capacitor C1 mounted on one long side and a capacitor C2 mounted on the other long side, but is not limited to this shape and may have any shape that has a portion that is not parallel to the fourth wiring 72. By having a portion that is not parallel to the fourth wiring 72, the third wiring 71 can mitigate the effect of magnetic coupling of the fourth wiring 72 on the third wiring 71. Here, a path through which a current flows from the second wiring 70b through the fourth wiring 72 having the capacitors C3 and C4 mounted on the electrode to the ground electrode 72a is called a second current path. The third wiring 71 having a portion that is not parallel to the fourth wiring 72 means that the interval between the first current path and the second current path is not constant.

[0034] In addition, in the U-shaped third wiring 71, the capacitors C1 and C2 are mounted in parallel. This allows the capacitors C1 and C2 to be mounted in the same direction, facilitating mounting of the capacitors C1 and C2 on the substrate 60. The first current path (path of the third wiring 71) connected to the coil component 1 and the second current path (path of the fourth wiring 72) connected to the second wiring 70b are arranged in parallel. However, the first current path (path of the third wiring 71) is bent at a right angle midway. The angle at which the path bends does not have to be a right angle.

[0035] The strength of the magnetic coupling between the third wiring and the fourth wiring also depends on the distance between the wirings. In the graph shown in Fig. 4, the solid line indicates the amount of change in the parasitic inductance of the capacitors C1, C2 due to the distance (shortest distance) between the U-shaped third wiring 71 and the fourth wiring 72 in the circuit device 100, and the dashed line indicates the amount of change in the parasitic inductance of the capacitors C1, C2 due to the distance between the straight-line shaped third wiring 71A and the fourth wiring 72 in the circuit device 300.

[0036] In the circuit device 300, when the distance between the linear third wiring 71A and the fourth wiring 72 is short, for example about 1 mm, the parasitic inductance of the capacitors C1 and C2 is about 0.23 nH larger than in a circuit device configuration without the fourth wiring 72. Even when the distance between the third wiring 71A and the fourth wiring 72 is about 4 mm, the parasitic inductance of the capacitors C1 and C2 is about 0.11 nH larger.

[0037] On the other hand, when the distance between the U-shaped third wiring 71 and the fourth wiring 72 in the circuit device 100 is short, for example about 1 mm, the parasitic inductance of the capacitors C1 and C2 changes by only about 0.03 nH compared to the configuration of a circuit device without the fourth wiring 72. Even when the distance between the third wiring 71 and the fourth wiring 72 is about 4 mm, the parasitic inductance of the capacitors C1 and C2 changes by only about 0.02 nH.

[0038] As can be seen from Fig. 4, by making the third wiring 71 U-shaped, even if the fourth wiring 72 is provided nearby, the third wiring 71 is less susceptible to the influence of magnetic coupling with the fourth wiring 72. Specifically, in Fig. 4, even if the wiring width of the third wiring 71 or the fourth wiring 72 is about 1 mm and the shortest distance between the third wiring 71 and the fourth wiring 72 is about 4 mm or less (four times the wiring width or less), the third wiring 71 is less susceptible to the influence of magnetic coupling of the fourth wiring 72. That is, regardless of the distance between the surrounding wirings, the change in parasitic inductance is small, and it can be said that the change is small because the amount of parasitic inductance is small compared to when there is no wiring.

[0039] In the circuit device 100, by forming the third wiring 71 connected to the coil component 1 in a U-shape, the circuit device 100 is less susceptible to the influence of magnetic coupling between the fourth wiring 72 and the third wiring 71. However, the circuit device 100 may not include the capacitors C3 and C4 depending on the noise generation state. Fig. 6 is a plan view of the circuit device 100 according to the first embodiment when some of the capacitors are not mounted.

[0040] 6, in the circuit device 100, if the capacitors C3 and C4 are not mounted, no magnetic coupling occurs between the third wiring 71 and the fourth wiring 72. However, the capacitors C3 and C4 may be mounted depending on the noise generation state, and in the circuit device 100 in which the fourth wiring 72 provided with the electrodes 72b and 72c for mounting the capacitors C3 and C4 is formed on the substrate 60, it is useful to make the third wiring 71 U-shaped. In other words, in the circuit device 100, it is not necessary to customize coil components for canceling the parasitic inductance of the capacitors C1 and C2 depending on the number and arrangement of the capacitors to be mounted, and the manufacturing cost can be significantly reduced.

[0041] As described above, the circuit device 100 according to the first embodiment includes the substrate 60 on which the wiring pattern is formed, and the coil component 1 mounted on the substrate 60. The coil component 1 includes the coil L1 and the coil L2, and the coil L1 and the coil L2 are magnetically coupled to each other. The first end of the coil L1 is connected to the input terminal 4a, the second end of the coil L2 and the first end of the coil L2 are connected to the intermediate terminal 4c, and the second end of the coil L2 is connected to the output terminal 4b. The wiring pattern includes a first wiring 70a connected to the input terminal 4a of the coil component 1, a second wiring 70b connected to the output terminal 4b of the coil component 1, a third wiring 71 on which the capacitors C1 and C2 are mounted in series and which connects the intermediate terminal 4c between the coil L1 and the coil L2 and the ground electrode 71a, and a fourth wiring 72 on which electrodes for mounting the capacitors C3 and C4 in series are provided and which connects the first wiring 70a or the second wiring 70b to the ground electrode 72a. The third wiring 71 and the fourth wiring 72 have a portion where they are not parallel to each other.

[0042] As a result, the circuit device 100 of embodiment 1 has a portion where the third wiring 71 and the fourth wiring 72 are not parallel, thereby weakening the effect of magnetic coupling between the third wiring 71 and the fourth wiring 72, and suppressing changes in the parasitic inductance of the capacitors C1 and C2.

[0043] It is preferable that two or more capacitors are mounted on each of the third wiring 71 and the fourth wiring 72. This makes it possible to realize a redundant circuit configuration that does not cause a short circuit even if one capacitor fails.

[0044] It is preferable that the shortest distance between the third wiring 71 and the fourth wiring 72 is four times or less the wiring width of the third wiring 71 or the fourth wiring 72. As a result, the circuit device 100 has a portion where the third wiring 71 and the fourth wiring 72 are not parallel, and thus can effectively weaken the effect of magnetic coupling of the fourth wiring 72 with respect to the third wiring 71.

[0045] The third wiring 71 or the fourth wiring 72 is preferably U-shaped. This can further weaken the effect of magnetic coupling between the third wiring 71 and the fourth wiring 72. Furthermore, the portion where the capacitor is mounted can be made compact.

[0046] When two or more capacitors are mounted on the U-shaped third wiring 71, it is preferable to mount the capacitors in positions parallel to each other, so that the capacitors can be mounted in the same direction, making it easier to mount the capacitors on the substrate 60.

[0047] <Variation 1-1> Although the third wiring 71 has been described as being U-shaped in Fig. 1, the present invention is not limited thereto and may be, for example, L-shaped. Fig. 7 is a plan view of a circuit device 100A according to a first modified example of the first embodiment. In the circuit device 100A shown in Fig. 7, the same components as those in the circuit device 100 shown in Fig. 1 are denoted by the same reference numerals and detailed description thereof will not be repeated.

[0048] In the circuit device 100A, the third wiring 71B for mounting the capacitors C1 and C2 is not U-shaped but is L-shaped, bending once from the intermediate terminal 4c to the ground electrode 71a. The L-shaped third wiring 71B has a portion that is not parallel to the fourth wiring 72, and therefore it is possible to reduce the effect of magnetic coupling of the fourth wiring 72 with respect to the third wiring 71B.

[0049] It is preferable that the mounting directions of the L-shaped third wiring 71B are parallel to each other with respect to the capacitor C1 (first capacitor) that is closest to the coil component 1 among the mounted capacitors and the capacitor C3 (second capacitor) that is closest to the coil component 1 among the capacitors mounted on the fourth wiring 72. Thus, by making the third wiring 71B have an L-shape, the circuit device 100A can effectively weaken the influence of the magnetic coupling of the fourth wiring 72 on the third wiring 71B.

[0050] <Variation 1-2> 1, the circuit device 100 has been described as having the fourth wiring 72 connected to the second wiring 70b, but this is not limited thereto, and for example, a fifth wiring connected to the first wiring 70a may be further provided in addition to the fourth wiring 72. Fig. 8 is a plan view of a circuit device 100B according to a second modified example of the first embodiment. In the circuit device 100B shown in Fig. 8, the same components as those in the circuit device 100 shown in Fig. 1 are denoted by the same reference numerals and detailed description will not be repeated.

[0051] In the circuit device 100B, a wiring pattern of the fifth wiring 73 is formed on the substrate 60 as wiring for mounting the capacitors C5 and C6. The fifth wiring 73 electrically connects the first wiring 70a and the ground electrode 73a by mounting the capacitors C5 and C6. The fifth wiring 73 extends in a straight line from the first wiring 70a to the ground electrode 73a as shown in FIG. 8, and has a straight line shape. The fifth wiring 73 exerts a magnetic coupling effect on the adjacent third wiring 71, but the third wiring 71 is U-shaped, so that the effect is mitigated.

[0052] The wiring pattern preferably has electrodes for mounting capacitors C5 and C6, further includes a fifth wiring 73 connecting the first wiring 70a or the second wiring 70b different from the wiring to which the fourth wiring 72 is connected to the ground electrode 73a, and has a portion where the third wiring 71 and the fifth wiring 73 are not parallel to each other.

[0053] As a result, the circuit device 100B has a portion where the third wiring 71 and the fifth wiring 73 are not parallel, thereby weakening the effect of magnetic coupling between the third wiring 71 and the fifth wiring 73, and suppressing changes in the parasitic inductance of the capacitors C1 and C2.

[0054] It is preferable that at least one capacitor is mounted on an electrode provided on the fifth wiring 73. By mounting a capacitor on the fifth wiring 73, magnetic coupling occurs between the third wiring 71 and the fifth wiring 73, and therefore, by having a portion where the third wiring 71 and the fifth wiring 73 are not parallel, the circuit device 100B can effectively weaken the influence of the magnetic coupling of the fifth wiring 73 on the third wiring 71.

[0055] It is preferable that two or more capacitors are mounted on each of the third wiring 71 and the fifth wiring 73. This makes it possible to realize a redundant circuit configuration that does not cause a short circuit even if one capacitor fails.

[0056] The circuit device 100B may have a plurality of fourth wirings and a plurality of fifth wirings as shown in FIG. 8. Specifically, the plurality of fourth wirings includes, in addition to the fourth wiring 72, a fourth wiring 74 for mounting the capacitors C7 and C8, and a fourth wiring 75 for mounting the capacitors C9 and C10. The fourth wiring 74 electrically connects the second wiring 70b and the ground electrode 74a by mounting the capacitors C7 and C8. The fourth wiring 75 electrically connects the second wiring 70b and the ground electrode 75a by mounting the capacitors C9 and C10. The plurality of fifth wirings includes, in addition to the fifth wiring 73, a fifth wiring 76 for mounting the capacitors C11 and C12. The fifth wiring 76 electrically connects the first wiring 70a and the ground electrode 76a by mounting the capacitors C11 and C12. The path in which a current flows from the second wiring 70b through the fourth wiring 74 having capacitors C7 and C8 mounted on the electrode to the ground electrode 74a, and the path in which a current flows from the second wiring 70b through the fourth wiring 75 having capacitors C9 and C10 mounted on the electrode to the ground electrode 75a are also examples of the second current path. In addition, the path in which a current flows from the first wiring 70a through the fifth wiring 73 having capacitors C5 and C6 mounted on the electrode to the ground electrode 73a, and the path in which a current flows from the first wiring 70a through the fifth wiring 76 having capacitors C11 and C12 mounted on the electrode to the ground electrode 76a are examples of the third current path. However, the path of the fourth wiring 72, 74, and 75 electrically connected to the second wiring 70b may be called the third current path, and the path of the fifth wiring 73 and 76 electrically connected to the first wiring 70a may be called the second current path.

[0057] <Modification 1-3> Although the fourth wiring 72 has been described as having a linear shape in Fig. 1, this is not limited thereto and may be, for example, a U-shape. Fig. 9 is a plan view of circuit devices 100C1, C2 according to a third modified example of the first embodiment. In the circuit devices 100C1, C2 shown in Fig. 9, the same components as those in the circuit device 100 shown in Fig. 1 are denoted by the same reference numerals and detailed description thereof will not be repeated.

[0058] 9(a), the fourth wiring 72A for mounting the capacitors C3 and C4 is not linear but is U-shaped, bending twice from the second wiring 70b to the ground electrode 72a. The third wiring 71 and the fourth wiring 72A are both U-shaped. This allows the circuit device 100C1 to further weaken the effect of magnetic coupling of the fourth wiring 72A with respect to the third wiring 71.

[0059] Furthermore, in the circuit device 100C1, the third wiring 71 and the fourth wiring 72A are bent in the same direction. That is, the first current path (path of the third wiring 71) and the second current path (path of the fourth wiring 72A) have the same shape, and each path has at least one bending point. Therefore, the direction of the current flowing in the part of the capacitor C1 of the third wiring 71 is opposite to that in the part of the capacitor C4 of the fourth wiring 72A. That is, in the circuit device 100C1, the direction of the current flowing in the adjacent wirings is opposite, so that the parasitic inductance of the capacitors C1 and C2 can be further reduced.

[0060] 9(b), the fourth wiring 72A1 for mounting the capacitors C3 and C4 is not linear but is U-shaped, bending twice from the second wiring 70b to the ground electrode 72a. The third wiring 71 and the fourth wiring 72A1 are both U-shaped. This allows the circuit device 100C2 to further weaken the effect of magnetic coupling of the fourth wiring 72A1 with respect to the third wiring 71.

[0061] Furthermore, in the circuit device 100C2, the third wiring 71 and the fourth wiring 72A1 are bent in different directions. That is, the distance between the first current path (path of the third wiring 71) and the second current path (path of the fourth wiring 72A1) is not constant, and both are U-shaped.

[0062] When the circuit devices 100C1 and 100C2 are provided with the fifth wiring, the shape of the fifth wiring may also be U-shaped. This allows the circuit devices 100C1 and 100C2 to further weaken the influence of the magnetic coupling of the fifth wiring with respect to the third wiring 71.

[0063] <Modification 1-4> In the circuit device 100A shown in Fig. 7, two capacitors C1 and C2 are mounted on the L-shaped third wiring 71B, and two capacitors C3 and C4 are mounted on the straight-line fourth wiring 72. However, this is not limited to this, and only one capacitor may be mounted on the wiring. Fig. 10 is a plan view of circuit devices 100D1 and D2 according to a fourth modified example of the first embodiment. In the circuit devices 100D1 and D2 shown in Fig. 10, the same components as those in the circuit device 100 shown in Fig. 7 are denoted by the same reference numerals and detailed description will not be repeated.

[0064] 10(a), one capacitor C1 is mounted on the L-shaped third wiring 71B, and one capacitor C3 is mounted on the straight-line fourth wiring 72. Although not shown, the circuit device 100D1 may also have two capacitors C1 and C2 mounted on the L-shaped third wiring 71B, and one capacitor C3 mounted on the straight-line fourth wiring 72. Furthermore, the circuit device 100D1 may also have one capacitor C1 mounted on the L-shaped third wiring 71B, and two capacitors C3 and C4 mounted on the straight-line fourth wiring 72.

[0065] In the circuit device 100D2 shown in FIG. 10(b), one capacitor C1 is mounted on the L-shaped third wiring 71B, and one capacitor C3 is mounted on the L-shaped fourth wiring 72B that has the same orientation. Although not shown, the circuit device 100D2 may mount two capacitors C1 and C2 on the L-shaped third wiring 71B, and mount one capacitor C3 on the L-shaped fourth wiring 72B that has the same orientation. Furthermore, the circuit device 100D2 may mount one capacitor C1 on the L-shaped third wiring 71B, and mount two capacitors C3 and C4 on the L-shaped fourth wiring 72B that has the same orientation. Furthermore, the circuit device 100D2 may have the L-shaped third wiring 71B and the L-shaped fourth wiring 72B that has the different orientations.

[0066] When the circuit devices 100D1 and 100D2 are provided with the fifth wiring, the shape of the fifth wiring may also be L-shaped. This allows the circuit devices 100D1 and 100D2 to further weaken the influence of the magnetic coupling of the fifth wiring with respect to the third wiring 71.

[0067] <Embodiment 2> In the circuit device 100 according to the first embodiment, the third wiring 71 connected to the intermediate terminal 4c is bent to provide a portion that is not parallel to the fourth wiring 72. In the circuit device according to the second embodiment, the third wiring is not bent, but the fourth wiring is bent to provide a portion where the fourth wiring is not parallel to the third wiring. FIG. 11 is a plan view of a circuit device 200 according to the second embodiment. In the circuit device 200 shown in FIG. 11, the same components as those in the circuit device 100 shown in FIG. 1 are denoted by the same reference numerals and detailed description will not be repeated.

[0068] In the circuit device 200, a wiring pattern of a power supply line 70 is formed on the surface of a substrate 60, and a coil component 1 is mounted in series with the power supply line 70. The power supply line 70 includes a first wiring 70a connected to an input terminal 4a of the coil component 1, and a second wiring 70b connected to an output terminal 4b of the coil component 1.

[0069] Furthermore, in the circuit device 200, two capacitors C1 and C2 are connected in series to the intermediate terminal 4c of the coil component 1. On the substrate 60, a wiring pattern of a third wiring 71A is formed as wiring for mounting the capacitors C1 and C2. The third wiring 71A electrically connects the intermediate terminal 4c between the two coils included in the coil component 1 and the ground electrode 71a by mounting the capacitors C1 and C2. Furthermore, in the circuit device 200, two capacitors C3 and C4 are connected in series to the second wiring 70b near the coil component 1. On the substrate 60, a wiring pattern of a fourth wiring 72A is formed as wiring for mounting the capacitors C3 and C4. The fourth wiring 72A electrically connects the second wiring 70b and the ground electrode 72a by mounting the capacitors C3 and C4. The fourth wiring 72A may be provided on the first wiring 70a instead of the second wiring 70b.

[0070] 11, the third wiring 71A extends in a straight line from the intermediate terminal 4c to the ground electrode 71a and has a straight line shape. However, the fourth wiring 72A has a U-shape that bends twice from the second wiring 70b to the ground electrode 72a. In this way, by making the shape of the fourth wiring 72A U-shaped instead of the straight line shape like the third wiring 71A, it is possible to reduce the effect of magnetic coupling of the fourth wiring 72A with respect to the third wiring 71A and suppress changes in the parasitic inductance of the capacitors C1 and C2.

[0071] As described above, in the circuit device 200 of embodiment 2, the third wiring 71A has a straight line shape, while the fourth wiring 72A has a U-shape, so that the third wiring 71A and the fourth wiring 72A have a portion where they are not parallel to each other.

[0072] As a result, the circuit device 200 of embodiment 2 has a portion where the third wiring 71A and the fourth wiring 72A are not parallel, thereby weakening the effect of magnetic coupling between the third wiring 71A and the fourth wiring 72A, and suppressing changes in the parasitic inductance of the capacitors C1 and C2.

[0073] It is preferable that at least one capacitor is mounted on an electrode provided on the fourth wiring 72A. It is also preferable that two or more capacitors are mounted on each of the third wiring 71A and the fourth wiring 72A.

[0074] <Variation 2-1> Although the fourth wiring 72A has been described as being U-shaped in Fig. 11, the present invention is not limited thereto and may be, for example, L-shaped. Fig. 12 is a plan view of a circuit device 200A according to a first modified example of the second embodiment. In the circuit device 200A shown in Fig. 12, the same components as those in the circuit device 200 shown in Fig. 11 are denoted by the same reference numerals and detailed description thereof will not be repeated.

[0075] In the circuit device 200A, the fourth wiring 72B for mounting the capacitors C3 and C4 is not U-shaped but L-shaped, bending once from the second wiring 70b to the ground electrode 72a. The L-shaped fourth wiring 72B has a portion that is not parallel to the third wiring 71A, and therefore it is possible to reduce the effect of magnetic coupling of the fourth wiring 72B to the third wiring 71A.

[0076] In the L-shaped fourth wiring 72B, it is preferable that the mounting directions of the capacitor C3, which is closest to the coil component 1 among the mounted capacitors, and the capacitor C1, which is closest to the coil component 1 among the capacitors mounted on the third wiring 71A, are parallel to each other. Thus, by making the shape of the fourth wiring 72B L-shaped, the circuit device 200A can effectively weaken the influence of the magnetic coupling of the fourth wiring 72B with the third wiring 71A.

[0077] <Variation 2-2> In the circuit device 200, as shown in Fig. 11, the fourth wiring 72A connected to the second wiring 70b is provided, but this is not limited thereto. For example, in addition to the fourth wiring 72A, a fifth wiring connected to the first wiring 70a may be further provided. Fig. 13 is a plan view of a circuit device 200B according to a second modified example of the second embodiment. In the circuit device 200B shown in Fig. 13, the same components as those in the circuit device 200 shown in Fig. 11 are denoted by the same reference numerals and detailed description will not be repeated.

[0078] In the circuit device 200B, a wiring pattern of the fifth wiring 73A is formed on the substrate 60 as wiring for mounting the capacitors C5 and C6. The fifth wiring 73A electrically connects the first wiring 70a and the ground electrode 73a by mounting the capacitors C5 and C6. The fifth wiring 73A is U-shaped, bending twice from the first wiring 70a to the ground electrode 73a, as shown in FIG. 13. The fifth wiring 73A exerts an influence of magnetic coupling on the adjacent third wiring 71A, but the influence can be mitigated because of the U-shape.

[0079] The wiring pattern preferably has electrodes for mounting capacitors C5 and C6, further includes a fifth wiring 73A connecting the first wiring 70a or the second wiring 70b different from the wiring to which the fourth wiring 72A is connected to the ground electrode 73a, and has a portion where the third wiring 71A and the fifth wiring 73A are not parallel to each other.

[0080] In FIG. 13, the fourth wiring 72A and the fifth wiring 73A are bent in the same direction, but this is not necessarily required. For example, the fourth wiring 72A may be bent so that the capacitor C4 is on the first wiring 70a side.

[0081] As a result, the circuit device 200B has a portion where the third wiring 71A and the fifth wiring 73A are not parallel, thereby weakening the effect of magnetic coupling between the third wiring 71A and the fifth wiring 73A, and suppressing changes in the parasitic inductance of the capacitors C1 and C2.

[0082] It is preferable that at least one capacitor is mounted on an electrode provided on the fifth wiring 73A. By mounting a capacitor on the fifth wiring 73A, magnetic coupling occurs between the third wiring 71A and the fifth wiring 73A, and therefore, by having a portion where the third wiring 71A and the fifth wiring 73A are not parallel, the circuit device 200B can effectively weaken the influence of the magnetic coupling of the fifth wiring 73A on the third wiring 71A.

[0083] It is preferable that two or more capacitors are mounted on each of the third wiring 71A and the fifth wiring 73A, thereby realizing a redundant circuit configuration that does not cause a short circuit even if one of the capacitors breaks down.

[0084] The circuit device 200B may have a plurality of fourth wirings and a plurality of fifth wirings as shown in FIG. 13. Specifically, the plurality of fourth wirings includes a fourth wiring 74 for mounting the capacitors C7 and C8 in addition to the fourth wiring 72A. The fourth wiring 74 electrically connects the second wiring 70b and the ground electrode 74a by mounting the capacitors C7 and C8 thereon. The plurality of fifth wirings includes a fifth wiring 76 for mounting the capacitors C11 and C12 in addition to the fifth wiring 73A. The fifth wiring 76 electrically connects the first wiring 70a and the ground electrode 76a by mounting the capacitors C11 and C12 thereon.

[0085] Although the fifth wiring 73A has been described as being U-shaped in FIG. 13, the shape is not limited to this and may be, for example, an L-shape.

[0086] As described above, in the circuit devices 100, 100A to 100D1, D2, 200, 200A to 200B, in order to suppress a change in the parasitic inductance of the capacitor, it is preferable that at least one of the first current path (path of the third wiring 71) connected to the coil component 1 and the second current path (path of the fifth wiring 73 or the fourth wiring 72) connected to the first wiring 70a or the second wiring 70b is bent midway. In particular, since a capacitor is always mounted on the first current path (path of the third wiring 71), it is preferable that the first current path (path of the third wiring 71) is bent midway (U-shaped third wiring 71, L-shaped third wiring 71B).

[0087] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the scope and meaning equivalent to the claims. [Explanation of symbols]

[0088] 1 coil component, 3 laminate, 4a input terminal, 4b output terminal, 4c, 4d terminal, 10 wiring pattern, 11, 21, 31 end portion, 60 substrate, 70 power supply line, 70a first wiring, 70b second wiring, 71, 71A, 71B third wiring, 72, 72A, 72B, 74, 75 fourth wiring, 73, 73A, 76 fifth wiring, 100, 100A, 100B, 100C, 200, 200A, 200B, 300 circuit device.

Claims

1. A substrate on which a wiring pattern is formed; a coil component mounted on the substrate, The coil component includes: a first coil and a second coil, the first coil and the second coil being magnetically coupled; a first end of the first coil is connected to an input terminal, a second end of the first coil and a first end of the second coil are connected to an intermediate terminal, and a second end of the second coil is connected to an output terminal; The wiring pattern is a first wiring connected to the input terminal of the coil component; A second wiring connected to the output terminal of the coil component; a third wiring having at least one capacitor mounted in series thereon and electrically connecting the intermediate terminal and a ground electrode; an electrode is provided for mounting at least one or more capacitors in series; and a fourth wiring electrically connecting the first wiring or the second wiring to a ground electrode; A circuit device, in which the spacing between a first current path along which a current flows from the coil component through the third wiring to the ground electrode, and a second current path along which a current flows from the first wiring or the second wiring to the ground electrode through the fourth wiring having a capacitor mounted on an electrode, is not constant.

2. 2. The circuit device according to claim 1, wherein the first current path connected to the coil component and the second current path connected to the first wiring or the second wiring are arranged in parallel, and the path is bent midway through the first current path or midway through the second current path.

3. The circuit device according to claim 2 , wherein the first current path or the second current path is bent at a right angle midway through.

4. 4. The circuit device according to claim 1, wherein at least one capacitor is mounted on an electrode provided on the fourth wiring.

5. The circuit device according to claim 4 , wherein two or more capacitors are mounted on the third wiring and the fourth wiring, respectively.

6. 5. The circuit device according to claim 4, wherein a first capacitor among the capacitors mounted on the third wiring and a second capacitor among the capacitors mounted on the fourth wiring and close to the coil component are mounted in parallel directions.

7. The circuit device according to any one of claims 1 to 3, wherein the distance at which the gap between the third wiring and the fourth wiring is shortest is less than four times the wiring width of the third wiring or the fourth wiring.

8. 4. The circuit device according to claim 1, wherein the first current path or the second current path includes a path in which a current flows in an opposite direction.

9. 9. The circuit device according to claim 8, wherein when two or more capacitors are mounted on the third wiring or the fourth wiring, the capacitors are mounted in positions where the capacitors are parallel to each other and currents flowing through the capacitors are in opposite directions.

10. A substrate on which a wiring pattern is formed; a coil component mounted on the substrate, The coil component includes: a first coil and a second coil, the first coil and the second coil being magnetically coupled; a first end of the first coil is connected to an input terminal, a second end of the first coil and a first end of the second coil are connected to an intermediate terminal, and a second end of the second coil is connected to an output terminal; The wiring pattern is a first wiring connected to the input terminal of the coil component; A second wiring connected to the output terminal of the coil component; a third wiring having at least one capacitor mounted in series thereon and electrically connecting the intermediate terminal and a ground electrode; an electrode is provided for mounting at least one or more capacitors in series; and a fourth wiring electrically connecting the first wiring or the second wiring to a ground electrode; A circuit device, wherein a first current path through which a current flows from the coil component through the third wiring to the ground electrode, and a second current path through which a current flows from the first wiring or the second wiring to the ground electrode through the fourth wiring having a capacitor mounted on an electrode, have the same shape, and each path has at least one bend point.

11. The circuit device according to claim 10 , wherein the first current path and the second current path are arranged such that a current flows in an opposite direction between adjacent paths.

12. the wiring pattern is provided with an electrode for mounting at least one capacitor, and further includes a fifth wiring that electrically connects the first wiring or the second wiring different from a wiring to which the fourth wiring is connected to a ground electrode; The circuit device according to any one of claims 1 to 3 and claim 11, wherein the distance between the first current path and a third current path in which a current flows from the first wiring or the second wiring through the fifth wiring having a capacitor mounted on an electrode to a ground electrode is not constant.

13. The circuit device according to claim 12 , wherein at least one capacitor is mounted on an electrode provided on the fifth wiring.

14. The circuit device according to claim 13 , wherein the third wiring and the fifth wiring each have two or more capacitors mounted thereon.

15. The circuit device according to claim 13 , wherein the third current path includes a path in which a current flows in a reverse direction.

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