Circuit device and filter circuit

Abstract

The present disclosure provides: a circuit device for which manufacturing costs are low and which is capable of realizing a filter circuit that uses a coil component that has stable mutual inductance; and a filter circuit. A circuit device (10) includes: a coil component (1); and a substrate (60). The coil component (1) includes: a first coil (L1); a second coil (L2) having an opening that overlaps the first coil (L1); a terminal (6a) connected to one end of the first coil (L1); a terminal (6b) connected to another end of the first coil (L1); a terminal (6c) connected to one end of the second coil (L2); and a terminal (6d) connected to another end of the second coil (L2). The substrate (60) includes: a power supply line (8a) electrically connected to the terminal (6a); a power supply line (8b) electrically connected to the terminal (6d); and a wiring (8c) electrically connected to the terminal (6b) and the terminal (6c). The wiring (8c) is also electrically connected to a capacitor (C1).

Description

[Technical field]

[0001] The present disclosure relates to a circuit device that implements a coil component, and a filter circuit. [Background technology]

[0002] Electronic devices use filter circuits that remove unnecessary noise components from the current flowing through a conductor. Filter circuits used for noise suppression include, for example, EMI (Electro-Magnetic Interference) removal filters, which use capacitors, which are capacitance elements. It is known that the noise suppression effect of the filter circuit 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). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-160728 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, to obtain negative inductance, the direction of the current flowing through the two magnetically coupled coils must be the same. When magnetically coupled coils are realized using a coil component in which wire is wound around a bobbin, as in the structure of a typical transformer coil or common mode choke coil (CMCC), if two wires wound in the same direction are electrically connected at the terminals of the same flange to form an intermediate terminal, the direction of the current will be reversed, and negative inductance will not be obtained.

[0006] Therefore, the coil component in question, in which the intermediate terminal is formed on the same flange, must be manufactured by winding the wire around the bobbin from the input terminal to the intermediate terminal, then changing the setting and winding the wire around the bobbin from the intermediate terminal to the output terminal, resulting in a problem of high manufacturing costs. Also, in a coil component with a small number of turns, it is relatively easy to keep the coil spacing constant if two wires are wound around the bobbin in the same direction. However, in a coil component in which the setting is changed and the wire is wound around the bobbin in two separate turns, it is difficult to keep the coil spacing constant, resulting in a problem of unstable mutual inductance.

[0007] Therefore, an object of the present disclosure is to provide a circuit device and a filter circuit that can realize a filter circuit using coil components that have low manufacturing costs and stable mutual inductance. [Means for solving the problem]

[0008] A circuit device according to an embodiment of the present disclosure includes a coil component and a substrate on which the coil component is mounted. The coil component includes a first coil, a second coil whose opening overlaps with the first coil when viewed from the opening direction of the first coil, a first terminal connected to one end of the first coil, a second terminal connected to the other end of the first coil, a third terminal connected to one end of the second coil, and a fourth terminal connected to the other end of the second coil. The direction of a magnetic field generated in the first coil when a current flows from the first terminal to the second terminal is the same as the direction of a magnetic field generated in the second coil when a current flows from the third terminal to the fourth terminal. The substrate includes a first wiring electrically connected to the first terminal, a second wiring electrically connected to the fourth terminal, and a third wiring electrically connected to the second terminal and the third terminal. The third wiring is , at least a portion of which is disposed outside a space between a plane including the opening of the first coil and a plane including the opening of the second coil; It is also electrically connected to the capacitor.

[0009] A filter circuit according to an embodiment of the present disclosure includes the above circuit device and the capacitor electrically connected to the third wiring of the circuit device. Effect of the Invention

[0010] According to one embodiment of the present disclosure, a filter circuit can be realized using a coil component that includes a third wiring electrically connected to the second terminal and the third terminal of the coil component, and the third wiring is also electrically connected to the capacitor, thereby making it possible to realize a filter circuit using a coil component that has low manufacturing costs and stable mutual inductance. [Brief description of the drawings]

[0011] [Figure 1] 1 is a plan view of a circuit device according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view of a coil component according to the first embodiment. [Diagram 3] 1 is a circuit diagram of a filter circuit according to a first embodiment. [Figure 4] FIG. 13 is a plan view of a circuit device according to a modified example 1-1. [Diagram 5] FIG. 13 is a plan view of a circuit device according to Modification 1-2. [Figure 6]FIG. 11 is a perspective view of a circuit device according to a second modified example. [Figure 7] FIG. 11 is a perspective view of a coil component according to a third modified example. [Figure 8] FIG. 11 is a side view of a coil component according to a third modified example. [Figure 9] FIG. 11 is a plan view of a circuit device according to a second embodiment. [Figure 10] FIG. 11 is a perspective view of a coil component according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] <Embodiment 1> A circuit device according to a first embodiment will be described below. Fig. 1 is a plan view of a circuit device 10 according to the first embodiment. The circuit device 10 is, for example, a filter circuit used to reduce noise on power supply lines 8a and 8b, and is equipped with a coil component 1 including two magnetically coupled coils to cancel the parasitic inductance of a capacitor C1. Of course, the circuit device 10 is not limited to a filter circuit used to reduce noise on the power supply lines 8a and 8b, and may be a filter circuit used to reduce noise on other signal lines, etc.

[0013] The coil component 1 mounted on the circuit device 10 is formed by winding two wires in the same direction around a bobbin as described below. Therefore, compared to a case where the coil component 1 is formed by winding a wire around a bobbin so that the winding direction from the input terminal to the intermediate terminal is opposite to the winding direction from the intermediate terminal to the output terminal, it is possible to wind two wires together, and therefore the manufacturing cost is low. In addition, since the coil component 1 has two wires wound around the bobbin in the same direction, it is relatively easy to keep the coil spacing constant, and the mutual inductance is stable. Note that the coil component 1 will be described taking a wound coil in which a wire is wound around a bobbin as an example, but coil components of other configurations may be used.

[0014] Since the coil component 1 has two wires wound around a bobbin in the same direction, the coil component 1 has a terminal 6a (first terminal) connected to one end of the first wire 4, a terminal 6b (second terminal) connected to the other end of the first wire 4, a terminal 6c (third terminal) connected to one end of the second wire 5, and a terminal 6d (fourth terminal) connected to the other end of the second wire 5. That is, the coil component 1 has four terminals, 6a to 6d. The four terminals (terminals 6a to 6d) are provided at the four corners of the coil component 1. The first wire 4 wound around the bobbin forms the first coil L1, and the second wire 5 wound around the bobbin forms the second coil L2.

[0015] In a filter circuit, a coil component that cancels the parasitic inductance of a capacitor only needs to have three terminals (input terminal, intermediate terminal, and output terminal) functionally. However, in general electronic components, a rectangular parallelepiped shape is often adopted for ease of manufacturing, and the coil component is often shaped like a rectangular parallelepiped and has four terminals by adopting terminals that are not connected to anything (NC (Non-Connection) terminals) from the viewpoint of mechanical strength. Even if a coil component with four terminals is formed by adding an NC terminal, only three terminals are used functionally, so the orientation of the coil component becomes a problem when the coil component is mounted on a substrate 60. For this reason, it is necessary to provide a mark indicating the direction on the coil component, and it is necessary to align the direction of the coil component during characteristic selection and taping, which is a factor of high manufacturing costs. On the other hand, the coil component 1 according to the present embodiment 1 does not require an NC terminal, so the orientation does not become a problem as described later.

[0016] 1, the coil component 1 has a rectangular shape when viewed from a direction perpendicular to the substrate 60. The terminals 6a to 6d are provided on the same plane of the coil component 1. The terminals 6a to 6d are arranged so that the direction from the terminal 6a to the terminal 6b crosses the direction from the terminal 6c to the terminal 6d.

[0017] In the circuit device 10, a wiring pattern of power supply lines 8a, 8b is formed on the surface of a substrate 60, and a coil component 1 is mounted in series with the power supply lines 8a, 8b. The power supply line 8a (first wiring) is provided with an electrode 7a (first electrode) that is electrically connected to a terminal 6a of the coil component 1 and is used to input a current from the power supply line 8a to the coil component 1. The terminal 6a that is electrically connected to the electrode 7a functions as an input terminal of the coil component 1. Meanwhile, the power supply line 8b (second wiring) is provided with an electrode 7d (fourth electrode) that is electrically connected to a terminal 6d of the coil component 1 and is used to output a current from the coil component 1 to the power supply line 8b. The terminal 6d that is electrically connected to the electrode 7d functions as an output terminal of the coil component 1.

[0018] 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, or the like. On the surface of the substrate 60, wiring patterns such as the power line 8a, electrodes for connecting components such as the coil component 1 and the capacitor C1, and the like are formed, and are made of metal materials generally adopted as electrode materials such as Cu, Ag, and Al. For example, when the substrate 60 is made of glass epoxy resin, the wiring pattern is formed on the glass epoxy resin with Cu, and an insulating resin is further formed on the glass epoxy resin including the wiring pattern. The electrodes for electrically connecting the components such as the coil component 1 and the capacitor C1 to be mounted to the wiring pattern are formed by removing the insulating resin on the wiring pattern. The electrodes formed on the wiring pattern are, for example, the places where the Cu of the wiring pattern and the terminals of the components are electrically connected by solder.

[0019] Furthermore, in the circuit device 10, the capacitor C1 is connected in series to the terminals 6b and 6c that function as intermediate terminals of the coil component 1. The substrate 60 is provided with a wiring 8c (third wiring) that connects the electrode 7b (second electrode) for connecting the terminal 6b and the electrode 7c (third electrode) for connecting the terminal 6c in a straight line. As shown in FIG. 1, the wiring 8c connects the terminals 6b and 6c at the shortest distance, so that the parasitic inductance can be reduced compared to a case where the wiring connected to the terminals 6b and the wiring connected to the terminals 6c are connected by a separate wiring, and most of the negative mutual inductance generated in the coil component 1 can be used to cancel the parasitic inductance. By changing the wiring distance connecting the terminals 6b and 6c (not shown), the parasitic inductance can be increased or decreased, so that the negative mutual inductance of the entire circuit can be adjusted.

[0020] The wiring 8c is formed with an electrode 7e (fifth electrode) for electrically connecting to the capacitor C1. In the circuit device 10 shown in FIG. 1, the wiring 8c has a T-shape when viewed perpendicular to the substrate 60. Specifically, the wiring 8c has a T-shape when viewed perpendicular to the substrate 60, with a portion that connects the connection point (electrode 7b) of the wiring 8c and the terminal 6b with a connection point (electrode 7c) of the wiring 8c and the terminal 6c with a straight line, and a portion that extends from the center of the straight line connection and reaches the connection point (electrode 7e) of the capacitor C1. That is, the wiring direction of the portion of the wiring 8c that connects the capacitor C1 is perpendicular to the wiring direction of the portion of the wiring 8c that connects the electrode 7b and the electrode 7c with a straight line. The portion of the wiring 8c that connects the capacitor C1 and the portion of the wiring 8c that connects the electrode 7b and the electrode 7c with a straight line may be formed integrally or separately.

[0021] Therefore, the wiring direction of the wiring 8c connecting the capacitor C1 is perpendicular to the opening direction of the first coil L1 and the second coil L2, and the opening direction of the first coil L1 and the second coil L2 is perpendicular to the arrangement direction of the capacitor C1 (the direction connecting the electrodes of the capacitor C1). Since the capacitor C1 is not arranged in the direction in which the magnetic field of the first coil L1 and the second coil L2 is generated, the effect of the capacitor C1 on the magnetic field of the first coil L1 and the second coil L2 can be reduced. Since the coil component 1 is a small chip component, heat dissipation from the substrate 60 side on which it is mounted is generally dominant. Therefore, the wiring 8c provided so as to straddle the terminals 6b and 6c functioning as the intermediate terminals of the coil component 1 can improve the heat dissipation from the coil component 1, and the current that can flow through the coil component 1 itself can be increased. From the viewpoint of heat dissipation, the width B of the wiring 8c may be twice the width A of the electrode 7b or the electrode 7c. The wider the width B of the wiring 8c, the better the heat dissipation, but the longer the distance between the coil component 1 and the capacitor C1, and the greater the parasitic inductance caused by the wiring from the coil component 1 to the capacitor C1. Therefore, it is preferable to set the width B of the wiring 8c to about 1.3 to 4 times the width A of the electrode 7b or the electrode 7c.

[0022] As described above, if the width B of the wiring 8c is made wider, the heat dissipation is improved, but it becomes impossible to arrange components other than the coil component 1 and the capacitor C1, and the design freedom of the substrate 60 is reduced. The coil included in the coil component 1 is designed to be able to pass a constant current, so heat generation is not a particular problem, but the path from the electrode 7c provided on the substrate 60 through the wiring 8c to the electrode 7b becomes a problem of heat generation. Therefore, it is sufficient that heat dissipation measures are taken in the section between the electrodes 7c and 7b. That is, in the case of the T-shaped wiring 8c as shown in FIG. 1, it is preferable that the length b of the part of the wiring 8c connected to the capacitor C1 is longer than the distance a between the electrodes 7c and 7b. On the other hand, the length b of the part of the wiring 8c connected to the capacitor C1 is preferably shorter than the length c of the coil component 1, and a space for freely arranging components in the left and right directions of the capacitor C1 in the figure can be secured compared to the case where the width B of the wiring 8c is made wider. The same can be applied to the wiring 8c1 shown in FIG. 4 and the wiring 8c2 shown in FIG. 5, which will be described later.

[0023] The capacitor C1 is connected in series to the wiring 8c, and is electrically connected to a wiring 8d (fourth wiring) on ​​the side opposite to the side electrically connected to the wiring 8c. An electrode 7f for electrically connecting to the capacitor C1 is formed on the wiring 8d. The wiring 8d is grounded via a ground electrode 70. By mounting the capacitor C1 between the wiring 8c and the wiring 8d, the terminals 6b and 6c between the two coils (the first coil L1 and the second coil L2) included in the coil component 1 are electrically connected to the ground electrode 70 (GND). The ground electrode 70 is an electrode electrically connected to a ground potential, and is formed of a conductive via electrically connected to a ground potential arranged in an inner layer of the substrate 60, for example.

[0024] Next, the coil component 1 mounted on the circuit device 10 will be described. FIG. 2 is a perspective view of the coil component 1 according to the first embodiment. The coil component 1 includes a bobbin 2, a first wire 4, and a second wire 5. The bobbin 2 has a body portion 2a around which the wire is wound, and flange portions 2b, 2c provided at both ends of the body portion 2a. The bobbin 2 is made of a non-conductive material, specifically, a non-magnetic material such as alumina, a magnetic material such as Ni-Zn ferrite, or a resin. When the bobbin 2 is made of resin, it is made of, for example, a resin containing magnetic powder such as metal powder or ferrite powder, a resin containing non-magnetic powder such as silica powder, or a resin not containing a filler such as powder.

[0025] When the size of the coil component 1 is 2.0 mm × 1.25 mm, the body portion 2a of the bobbin 2 is a prism of 1.0 mm × 1.0 mm. In this disclosure, the body portion 2a is described as a prism, but it may be a cylinder or a polygonal prism. In the coil component 1, the first wire 4 and the second wire 5 are wound directly around the body portion 2a. The first wire 4 and the second wire 5 are, for example, copper wires.

[0026] In order to stabilize the mutual inductance in the coil component 1, it is necessary to keep constant the opening diameter of the first coil L1 and the second coil L2 and the coil interval between the first coil L1 and the second coil L2. Therefore, the coil component 1 is formed by simultaneously winding the first wire 4 and the second wire 5 in the same direction around the body part 2a. Furthermore, as shown in FIG. 2, the first wire 4 is wound once around the body part 2a to form the first coil L1, and the second wire 5 is wound once around the body part 2a to form the second coil L2. Strictly speaking, the first wire 4 is wound 3 / 4 times around the three faces of the body part 2a from the terminal 6a to the terminal 6b, and the second wire 5 is wound 5 / 4 times around the five faces of the body part 2a from the terminal 6c to the terminal 6d. Here, winding the wire once around the body portion 2a means that the wire is wound around the body portion 2a once, and also includes winding the wire 3 / 4 or 5 / 4 times around the body portion 2a.

[0027] Next, a terminal for fixing the first wire 4 and a terminal for fixing the second wire 5 will be described. As shown in Fig. 2, the flange portions 2b, 2c provided on both sides of the bobbin 2 are provided with terminals 6a, 6b for connection with an end of the first wire 4 and terminals 6c, 6d for connection with an end of the second wire 5. Specifically, the flange portion 2b is provided with terminals 6a, 6c, and the flange portion 2c is provided with terminals 6b, 6d.

[0028] For example, Ag paste is baked on the terminals 6a to 6d, and Ni or Sn plating is applied. Therefore, the end of the first wire 4 is applied to the terminals 6a and 6b, and the end of the second wire 5 is applied to the terminals 6c and 6d, and the wires and terminals are fixed by thermocompression bonding or laser welding. Of course, the method of fixing the wires and terminals is not limited to this, and fixing methods such as crimping using a metal terminal, crimping, or soldering may also be adopted. Furthermore, the wires and terminals may be fixed by crimping using a metal terminal and then laser welding may be performed.

[0029] In the coil component 1, the position of the terminal 6a provided on the flange portion 2b and the position of the terminal 6d provided on the flange portion 2c are on the same side (upper side in FIG. 1) among the terminals 6a to 6d provided on the same surface of the coil component 1. Therefore, the first wire 4 and the second wire 5 wound in the same direction around the body portion 2a as shown in FIG. 2 are connected to the terminals 6a to 6d, so that the first coil L1 and the second coil L2 are arranged to cross as shown in FIG.

[0030] If the first coil L1 and the second coil L2 are arranged crosswise and a current can be passed through the first coil L1 from either of the terminals 6a and 6b, and a current can be passed through the second coil L2 from either of the terminals 6c and 6d, there will be no difference in characteristics due to the orientation of the coil component 1. In other words, the orientation of the coil component 1 does not matter when mounting the coil component 1 on the substrate 60. This eliminates the need to provide a mark indicating the direction on the coil component 1, and eliminates the need to align the orientation of the coil components during characteristic selection and taping, thereby reducing manufacturing costs.

[0031] Specifically, when the orientation of the coil component 1 is rotated 180 degrees (as shown in parentheses in FIG. 1), the terminal 6b of the coil component 1 is electrically connected to the power supply line 8a, the terminal 6c of the coil component 1 is electrically connected to the power supply line 8b, and the terminals 6a and 6d function as intermediate terminals of the coil component 1 and are connected to the electrodes 7b and 7c of the wiring 8c. Since the first coil L1 and the second coil L2 are arranged crosswise, the terminals 6a and 6b serving as input terminals and the terminals 6d and 6c serving as output terminals are aligned in a straight line as shown in FIG. 1, which makes it easy to use the input terminals and the output terminals when connecting them to other devices.

[0032] When the coil component 1 is mounted on the substrate 60, the opening direction of the first coil L1 and the second coil L2 is parallel to the surface of the substrate 60 on which the coil component 1 is mounted.

[0033] 3 is a circuit diagram of a filter circuit 100 according to the first embodiment. Specifically, the filter circuit 100 is an EMI elimination filter circuit, and is a third-order T-type LC filter circuit. In this disclosure, the filter circuit 100 is described using a third-order T-type LC filter circuit as the configuration, but the same 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. 3, the filter circuit 100 includes a coil component 1 and a capacitor C1.

[0034] Capacitor C1 is connected in series between terminals 6b and 6c, which are intermediate terminals, and the ground electrode (GND), as shown in Fig. 3. Although a single capacitor C1 is sufficient, two capacitors may be connected in series to provide a redundant circuit configuration, assuming that the capacitor is mounted on a vehicle.

[0035] The capacitor C1 is not limited to a multilayer ceramic capacitor whose main component is BaTiO3 (barium titanate), but may be a multilayer ceramic capacitor whose main component is another material, or may be another type of capacitor other than a multilayer ceramic capacitor, such as an aluminum electrolytic capacitor.

[0036] The capacitor C1 connected to the coil component 1 has an inductor L3 as a parasitic inductance (equivalent series inductance (ESL)). Therefore, the filter circuit 100 is equivalent to a circuit configuration in which the inductor L3 is connected in series to the capacitor C1, as shown in FIG.

[0037] In addition to the capacitor C1, the first coil L1 and the second coil L2 are connected to the terminals 6b and 6c. The first coil L1 and the second coil L2 are magnetically coupled to generate a negative inductance component (mutual inductance M). This negative inductance component can be used to cancel out the parasitic inductance (inductor L3) of the capacitor C1, and the inductance component of the capacitor C1 can be made smaller in appearance. In FIG. 3, the mutual inductance M (-M) for canceling out the inductor L3 is connected in series to the capacitor C1, and the mutual inductance M (+M) is added to each of the first coil L1 and the second coil L2, as shown as an equivalent circuit.

[0038] The filter circuit 100, which is composed of the capacitor C1, the first coil L1 and the second coil L2, can improve the noise suppression effect in the high frequency band by canceling out the parasitic inductance of the capacitor C1 with the negative inductance component due to the mutual inductance M between the first coil L1 and the second coil L2.

[0039] In addition, the parasitic inductance due to the wiring 8c electrically connecting the terminals 6b and 6c of the coil component 1 occurs in series with the capacitor C1 and the inductor L3 which is the parasitic inductance of the capacitor C1. Therefore, by changing the length of the wiring 8c to change the parasitic inductance, it is possible to adjust the inductor L3 and the mutual inductance M so that they cancel each other out.

[0040] As described above, the circuit device 10 according to the first embodiment includes the coil component 1 and the substrate 60 on which the coil component 1 is mounted. The coil component 1 includes the first coil L1, the second coil L2 whose opening overlaps with the first coil L1 when viewed from the opening direction of the first coil L1, the terminal 6a connected to one end of the first coil L1, the terminal 6b connected to the other end of the first coil L1, the terminal 6c connected to one end of the second coil L2, and the terminal 6d connected to the other end of the second coil L2. The direction of the magnetic field generated in the first coil L1 when a current flows from the terminal 6a to the terminal 6b is the same as the direction of the magnetic field generated in the second coil L2 when a current flows from the terminal 6c to the terminal 6d. The substrate 60 includes the power supply line 8a electrically connected to the terminal 6a, the power supply line 8b electrically connected to the terminal 6d, and the wiring 8c electrically connected to the terminals 6b and 6c. The wiring 8c is also electrically connected to the capacitor C1.

[0041] As a result, the circuit device 10 of embodiment 1 includes a wiring 8c electrically connected to the terminals 6b and 6c of the coil component 1, and the wiring 8c is also electrically connected to the capacitor C1, thereby realizing a filter circuit 100 using the coil component 1 which has low manufacturing costs and stable mutual inductance.

[0042] Moreover, the filter circuit 100 according to the first embodiment includes the above-described circuit device 10 and a capacitor C1 electrically connected to the wiring 8c of the circuit device 10. As a result, the filter circuit 100 can cancel the parasitic inductance of the capacitor C1 and improve the effect of suppressing noise in the high frequency band.

[0043] <Variation 1> In the circuit device 10 shown in Fig. 1, the shape of the wiring 8c has been described as T-shaped, but this is not limited thereto, and the part of the wiring to which the capacitor C1 is connected may be provided at a location other than the center of the wiring 8c. Fig. 4 is a plan view of a circuit device 10A according to a modified example 1-1. Fig. 5 is a plan view of a circuit device 10B according to a modified example 1-2. In the circuit devices 10A and 10B shown in Figs. 4 and 5, the same components as those in the circuit device 10 shown in Fig. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0044] In the circuit device 10A shown in FIG. 4, the wiring 8c1 has an L-shape when viewed from a direction perpendicular to the substrate 60. Specifically, the wiring 8c1 forms an L-shape by extending a portion of the wiring that connects the capacitor C1 from the long side of the wiring that connects the electrodes 7b and 7c in a straight line, on the electrode 7c side. The capacitor C1 is connected in series to the wiring 8c1, and is electrically connected to the wiring 8d on the side opposite to the side electrically connected to the wiring 8c1. Note that the wiring 8c1 may form an L-shape by extending a portion of the wiring that connects the capacitor C1 from the long side of the wiring that connects the electrodes 7b and 7c in a straight line, on the electrode 7b side.

[0045] In the circuit device 10B shown in FIG. 5, the shape of the wiring 8c2 when viewed from a direction perpendicular to the substrate 60 is I-shaped. Specifically, the wiring 8c2 forms an I-shape by extending a portion of the wiring connecting the capacitor C1 from a short side of the wiring connecting the electrodes 7b and 7c in a straight line on the electrode 7b side. The capacitor C1 is connected in series to the wiring 8c2, and is electrically connected to the wiring 8d on the side opposite to the side electrically connected to the wiring 8c2. Note that the wiring 8c2 may form an I-shape by extending a portion of the wiring connecting the capacitor C1 from a short side of the wiring connecting the electrodes 7b and 7c in a straight line on the electrode 7c side.

[0046] 4 and 5, the wiring that connects capacitor C1 can be connected to various parts. Therefore, the position where capacitor C1 is mounted can be freely changed, improving the design freedom of set manufacturers that use the circuit device.

[0047] <Variation 2> As shown in Fig. 1, the circuit device 10 has been described as mounting the coil component 1 and the capacitor C1 on the substrate 60 on which the power supply lines 8a, 8b and wirings 8c, 8d are formed, but the present invention is not limited to this, and an interposer substrate provided with the power supply lines and wirings may be attached to the coil component to form a single component. Fig. 6 is a perspective view of a circuit device according to Modification 2. In the circuit device 10C shown in Fig. 6, the same components as those in the circuit device 10 shown in Fig. 1 are denoted by the same reference numerals and detailed description thereof will be omitted.

[0048] 6 is formed as a single component by attaching an interposer substrate 62 on which power lines 8a, 8b and wiring 8c are formed to the surface on which the terminals 6a to 6d of the coil component 1 are provided. The interposer substrate 62 has the power lines 8a, 8b and wiring 8c formed on the surface in contact with the coil component 1, and electrodes electrically connected to the power lines 8a, 8b and wiring 8c by through electrodes (not shown) formed on the back surface.

[0049] Specifically, an electrode 80a electrically connected to the power supply line 8a by a through electrode, an electrode (not shown) electrically connected to the power supply line 8b by a through electrode, and an electrode 80c electrically connected to the wiring 8c by a through electrode are formed on the back surface of the interposer substrate 62. The electrode 80a is connected to the power supply line of the device on which the circuit device 10C is mounted, and the electrode 80c is connected to the capacitor C1.

[0050] <Variation 3> In the above-described first embodiment, it has been described that the coil component 1 has a configuration in which the first wire 4 and the second wire 5 are wound around the bobbin 2, as shown in FIG. 2. However, the coil component mounted on the circuit device 10 is not limited to a coil component in which a wire is wound around a bobbin, and may be, for example, a coil component in which a coil formed of a metal plate or a metal wire is molded with resin. FIG. 7 is a perspective view of the coil component 1A according to the third modification. FIG. 8 is a side view of the coil component 1A according to the third modification. Note that FIG. 8(a) is a side view of the coil component 1A in the XZ plane, and FIG. 8(b) is a side view of the coil component 1A in the YZ plane.

[0051] The coil component 1A includes a coil portion 4a (first coil L1) and a coil portion 5a (second coil L2) in a housing 9. The coil portion 4a has a rectangular opening and is disposed inside the housing 9 approximately parallel to the main surface 90A (first main surface). The coil portion 4a has a spiral structure wound 1.5 times by punching a metal plate and inclining a part of it, and the part drawn out from the side surface 91 (first side surface) of the housing 9 constitutes a terminal 6a (first terminal), and the part drawn out from the side surface 92 (second side surface) constitutes a terminal 6b (second terminal). The coil portion 5a has a rectangular opening and is disposed above the coil portion 4a inside the housing 9 approximately parallel to the main surface 90A. In addition, the coil portion 5a has a spiral structure in which a metal plate is punched and partially inclined so as to be wound 1.5 times, with the portion pulled out from the side surface 91 of the housing 9 forming the terminal 6c (third terminal) and the portion pulled out from the side surface 92 forming the terminal 6d (fourth terminal).

[0052] The terminals 6a to 6d are provided up to the main surface 90B and are provided on the same plane of the coil component 1A. The terminals 6a to 6d are arranged so that the direction from the terminal 6a to the terminal 6b crosses the direction from the terminal 6c to the terminal 6d. In other words, the terminals 6a to 6d are arranged in a staggered manner on the main surface 90B. When the coil component 1A is mounted on the substrate 60 so that the terminals 6a to 6d provided on the main surface 90B are electrically connected to the electrodes 7a to 7d provided on the substrate 60, the opening direction of the coil portions 4a and 5a is perpendicular to the substrate 60, and the arrangement relationship between the terminal 6c of the coil portion 4a and the capacitor C1 connected to the terminal 6d of the coil portion 5a is also perpendicular.

[0053] The housing 9 fixes the relative positions of the coil portion 4a and the coil portion 5a, and is made of, for example, molded resin. Specifically, the molded resin is made of epoxy resin with silica filler added, silicone resin, liquid crystal polymer, or various resins with metallic magnetic material mixed in.

[0054] The coil portion 4a and the terminals 6a, 6b may be formed from a single metal plate or a single metal wire, or the coil portion 4a and the terminals 6a, 6b may be formed from separate metal plates or metal wires. Similarly, the coil portion 5a and the terminals 6c, 6d may be integrally formed from a single metal plate or a single metal wire, or the coil portion 5a and the terminals 6c, 6d may be formed from separate metal plates or metal wires.

[0055] <Embodiment 2> In the first embodiment, a configuration has been described in which the connection positions of both ends of the first coil L1 and the connection positions of both ends of the second coil L2 cross in the coil component 1 mounted on the circuit device 10, but this is not limited thereto. In the second embodiment, a configuration in which the connection positions of both ends of the first coil L1 and the connection positions of both ends of the second coil L2 do not cross in the coil component is described. Fig. 9 is a plan view of a circuit device 10D according to the second embodiment. Note that in the circuit device 10D shown in Fig. 9, the same components as those in the circuit device 10 shown in Fig. 1 are denoted by the same reference numerals and detailed description will not be repeated.

[0056] In the circuit device 10D shown in FIG. 9, the configuration of the coil component 1B mounted on the substrate 60 is different. Specifically, the coil component 1B has a terminal 6a (first terminal) connected to one end of the first wiring 4B constituting the first coil L1, a terminal 6c (second terminal) connected to the other end of the first wiring 4B, a terminal 6b (third terminal) connected to one end of the second wiring 5B constituting the second coil L2, and a terminal 6d (fourth terminal) connected to the other end of the second wiring 5B. The first wiring 4B of the first coil L1 is connected to the side of the electrodes 7a and 7c provided on the substrate 60, and the second wiring 5B of the second coil L2 is connected to the side of the electrodes 7b and 7d. Therefore, the coil component 1B is arranged such that the connection positions of both ends of the first coil L1 and the connection positions of both ends of the second coil L2 do not cross.

[0057] Coil component 1B may have a configuration in which a first wire and a second wire are wound around a bobbin, or a configuration in which a coil formed of a metal plate or a metal wire is molded with resin. Fig. 10 is a perspective view of coil component 1B according to embodiment 2. Note that in coil component 1B shown in Fig. 10, the same components as those in coil component 1A shown in Fig. 7 are denoted by the same reference numerals and detailed description thereof will not be repeated.

[0058] The coil component 1B includes a coil portion 4b (first coil L1) and a coil portion 5b (second coil L2) in a housing 9. The coil portion 4b has a rectangular opening, and is embedded inside the housing 9 substantially parallel to a main surface 90A (first main surface). One portion of the coil portion 4b drawn out from a side surface 91 (first side surface) of the housing 9 constitutes a terminal 6a, and the other portion constitutes a terminal 6c. The coil portion 4b, the terminal 6a, and the terminal 6c are formed by punching out a metal plate, and correspond to the first wiring 4B shown in FIG.

[0059] The coil portion 5b has a rectangular opening, and is disposed above the coil portion 4a inside the housing 9, approximately parallel to the main surface 90A. One portion of the coil portion 5a that is pulled out from the side surface 92 of the housing 9 constitutes the terminal 6b, and the other portion constitutes the terminal 6d. The coil portion 5b, the terminal 6b, and the terminal 6d are formed by punching out a metal plate, and correspond to the second wiring 5B shown in FIG.

[0060] The terminals 6a to 6d are provided up to the main surface 90B. The terminals 6a to 6d provided on the main surface 90B are electrically connected to the electrodes 7a to 7d provided on the substrate 60. In the coil component 1B, the terminals 6a to 6d are arranged on the main surface 90B without the direction from the terminal 6a to the terminal 6c crossing the direction from the terminal 6d to the terminal 6b. Therefore, in the circuit device 10D in which the substrate 60 and the coil component 1B are combined, the coil component 1B can be mounted on the substrate 60 regardless of the orientation thereof, and a filter circuit utilizing negative mutual inductance can be configured.

[0061] <Aspects> (1) A circuit device disclosed herein includes a coil component and a substrate on which the coil component is mounted, the coil component including a first coil, a second coil whose opening overlaps with that of the first coil when viewed from the opening direction of the first coil, a first terminal connected to one end of the first coil, a second terminal connected to the other end of the first coil, a third terminal connected to one end of the second coil, and a fourth terminal connected to the other end of the second coil, wherein a direction of a magnetic field generated in the first coil when a current flows from the first terminal to the second terminal is the same as a direction of a magnetic field generated in the second coil when a current flows from the third terminal to the fourth terminal, the substrate includes a first wiring electrically connected to the first terminal, a second wiring electrically connected to the fourth terminal, and a third wiring electrically connected to the second terminal and the third terminal, the third wiring being electrically connected to a capacitor.

[0062] The circuit device disclosed herein includes a third wiring electrically connected to the second terminal and the third terminal of the coil component, and the third wiring is also electrically connected to the capacitor, thereby making it possible to realize a filter circuit using a coil component with low manufacturing costs and stable mutual inductance.

[0063] (2) The circuit device according to (1), wherein the coil component has a rectangular shape when viewed from a direction perpendicular to the substrate, the first terminal to the fourth terminal are provided on the same plane of the coil component, and the terminals are arranged such that the direction from the first terminal to the second terminal crosses the direction from the third terminal to the fourth terminal, thereby allowing the first coil and the second coil to be arranged crosswise.

[0064] (3) In the circuit device according to (1) or (2), the capacitor is connected in series to the third wiring, the substrate further includes a fourth wiring electrically connected to the capacitor on the side opposite to the side electrically connected to the third wiring, and the fourth wiring is grounded, thereby forming a filter circuit.

[0065] (4) In the circuit device according to any one of (1) to (3), the opening direction of the first coil and the second coil is perpendicular to the arrangement direction of the capacitor, thereby reducing the effect of the capacitor C1 on the magnetic fields of the first coil and the second coil.

[0066] (5) The circuit device according to any one of (1) to (4), wherein the third wiring includes a portion that connects the connection point of the third wiring and the second terminal and the connection point of the third wiring and the third terminal by a straight line when viewed from a direction perpendicular to the substrate, thereby realizing a filter circuit using coil components with stable mutual inductance.

[0067] (6) The circuit device according to any one of (1) to (5), wherein the coil component includes a bobbin having a body portion around which a wire is wound and flange portions provided on both ends of the body portion, a first wire wound around the body portion to form the first coil, and a second wire wound around the body portion to form the second coil, and the first terminal to the fourth terminal are formed on the flange portions. This makes it possible to realize a filter circuit using a wound wire coil.

[0068] (7) In the circuit device according to (6), the opening direction of the first coil and the second coil is parallel to a surface of the substrate on which the coil component is mounted, thereby reducing the effect of the capacitor C1 on the magnetic fields of the first coil and the second coil.

[0069] (8) In the circuit device according to (6) or (7), the first wire and the second wire are wound in the same direction, thereby making it possible to adjust the mutual inductance by changing the winding direction of the wires.

[0070] (9) The circuit device according to any one of (6) to (8), wherein the number of turns of the first wire and the number of turns of the second wire are 1. This makes it possible to adjust the inductance of the two coils by the number of turns of the first wire and the second wire.

[0071] (10) A circuit device according to any one of (1) to (5), wherein the coil component comprises a housing, a first coil disposed inside the housing and disposed substantially parallel to a first main surface of the housing, and a second coil disposed inside the housing such that an opening of the first coil overlaps with an opening when viewed from the direction of the first main surface, the first coil has a first terminal drawn from a first side surface side of the housing and a second terminal drawn from a second side surface side, the second coil has a third terminal drawn from the first side surface side of the housing and a fourth terminal drawn from the second side surface side, the first terminal and the third terminal extending in the direction of the second main surface along the first side surface side, and the second terminal and the fourth terminal extending in the direction of the second main surface along the second side surface side.

[0072] (11) The circuit device according to (10), wherein the opening direction of the first coil and the second coil is perpendicular to a surface of the substrate on which the coil components are mounted.

[0073] (12) The circuit device according to (10) or (11), wherein the first coil, the first terminal, and the second terminal are integrally formed, and the second coil, the third terminal, and the fourth terminal are integrally formed.

[0074] (13) A filter circuit according to the present disclosure includes the circuit device according to any one of (1) to (12) above, and a capacitor electrically connected to the third wiring of the circuit device, thereby canceling the parasitic inductance of the capacitor and improving the noise suppression effect in the high frequency band.

[0075] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure 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]

[0076] 1 coil component, 2 bobbin, 2a body portion, 2b, 2c flange portion, 4 first wire, 5 second wire, 6a to 6d terminals, 7a to 7f, 80a, 80d electrodes, 8a, 8b power lines, 8c, 8c1, 8c2, 8d wiring, 10, 10A to 10C circuit devices, 60 substrate, 62 interposer substrate, 70 ground electrode, 100 filter circuit.

Claims

1. A coil component; A substrate on which the coil component is mounted, The coil component includes: A first coil; a second coil whose opening overlaps with the first coil when viewed from a direction of the opening of the first coil; A first terminal connected to one end of the first coil; a second terminal connected to the other end of the first coil; a third terminal connected to one end of the second coil; a fourth terminal connected to the other end of the second coil, a direction of a magnetic field generated in the first coil when a current flows from the first terminal to the second terminal is the same as a direction of a magnetic field generated in the second coil when a current flows from the third terminal to the fourth terminal, The substrate is A first wiring electrically connected to the first terminal; A second wiring electrically connected to the fourth terminal; a third wiring electrically connected to the second terminal and the third terminal; A circuit device, wherein at least a portion of the third wiring is arranged outside the space sandwiched between a plane including an opening of the first coil and a plane including an opening of the second coil, and is also electrically connected to a capacitor.

2. the coil component has a rectangular shape when viewed in a direction perpendicular to the substrate, the first terminal to the fourth terminal are provided on the same plane of the coil component, 2. The circuit device according to claim 1, wherein the terminals are arranged such that a direction from the first terminal to the second terminal and a direction from the third terminal to the fourth terminal cross each other.

3. the capacitor is connected in series to the third wiring, The substrate is a fourth wiring electrically connected to the capacitor on the side opposite to the side electrically connected to the third wiring, The circuit device according to claim 1 , wherein the fourth wiring is grounded.

4. 3. The circuit device according to claim 1, wherein a direction in which the first coil and the second coil are opened is perpendicular to a direction in which the capacitors are arranged.

5. 3. The circuit device according to claim 1, wherein the third wiring includes a portion that connects, in a straight line, a connection point between the third wiring and the second terminal and a connection point between the third wiring and the third terminal when viewed from a direction perpendicular to the substrate.

6. The coil component includes: a bobbin having a body portion around which a wire is wound and flange portions provided on both ends of the body portion; a first wire wound around the body portion to form the first coil; a second wire wound around the body portion to form the second coil; 3. The circuit device according to claim 1, wherein the first terminal to the fourth terminal are formed on the flange portion.

7. The circuit device according to claim 6 , wherein an opening direction of the first coil and the second coil is parallel to a surface of the substrate on which the coil component is mounted.

8. The circuit device according to claim 6 , wherein the first wire and the second wire are wound in the same direction.

9. The circuit device according to claim 6 , wherein the number of turns of the first wire and the number of turns of the second wire are one turn.

10. The coil component includes: A housing and The first coil is disposed inside the housing; and the second coil is disposed inside the housing such that an opening of the first coil overlaps an opening of the second coil when viewed from a direction of a first main surface of the housing, the first coil has the first terminal drawn out from a first side surface side of the housing and the second terminal drawn out from a second side surface side of the housing, the second coil has the third terminal drawn out from the first side surface side of the housing and the fourth terminal drawn out from the second side surface side of the housing, the first terminal and the third terminal extend along the first side surface toward a second main surface of the housing, 3 . The circuit device according to claim 1 , wherein the second terminal and the fourth terminal extend along the second side surface toward the second main surface.

11. The circuit device according to claim 10 , wherein a surface including the openings of the first coil and the second coil faces a surface of the substrate on which the coil component is mounted.

12. The circuit device according to claim 10 , wherein the first coil, the first terminal, and the second terminal are integrally formed, and the second coil, the third terminal, and the fourth terminal are integrally formed.

13. The circuit device according to claim 1 or 2; the capacitor electrically connected to the third wiring of the circuit device.

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