Coil component and filter circuit

Abstract

Provided are: a coil component in which two wires are wrapped in opposite directions, the coil component having a structure that is easy to produce; and a filter circuit in which said coil component is mounted. The coil component (1) according to the present disclosure comprises: a bobbin (2) that includes a body section (2a) around which wires are wound, and a first collar section (2b) and second collar section (2c) provided at both ends of the body section (2a); and a first wire (4) and second wire (5) wound around the body section (2a). The bobbin (2) includes a plurality of mounting terminals (6a-6d) and a plurality of connection terminals (8a-8d). On surfaces of the coil component (1) having depressions (7a, 7b) respectively provided in one surface of the first collar section (2b) and one surface of the second collar section (2c), the first connection terminal (8a) is located at a position diagonal from the second connection terminal (8b), and the third connection terminal (8c) is located at a position diagonal from the fourth connection terminal (8d).

Description

Coil components and filter circuits

[0001] The present disclosure relates to a coil component and a filter circuit that implements the coil component.

[0002] 2. Description of the Related Art Filter circuits are used in electronic devices to combat noise. Examples of filter circuits include EMI (Electro-Magnetic Interference) removal filters, which include a capacitor as a capacitance element and a coil component in which two coils are magnetically coupled.

[0003] It is desirable to stabilize the coupling coefficient of a coil component included in a filter circuit, and a known configuration for stabilizing the coupling coefficient of a coil component is one in which a recess is formed inward from the mounting terminal of the flange portion to maintain a constant distance between the wires (see, for example, Patent Document 1).

[0004] JP 2012-28684 A

[0005] The coil component of Patent Document 1 has two magnetically coupled coils with the same winding direction, so it is manufactured by first crimping two wires into a recess in one of the flanges, then winding the two wires around the body, and finally crimping the two wires into a recess in the other flange. When two wires are wound in the same direction, as in the coil component of Patent Document 1, the two wires can be crimped into the recess in the flange at the same time, making the process easy. However, when two wires are wound in opposite directions, the two wires cannot be wound around the body at the same time, making it impossible to crimp the two wires into the recess in the flange at the same time. In other words, while one wire is crimped into the recess in the flange, the other wire must be crimped across it and then crimped into the recess in the flange, which requires crimping work to be done in a small space, making it difficult to manufacture the coil component.

[0006] An object of the present disclosure is to provide a coil component having an easy-to-manufacture structure in which two wires are wound in opposite directions, and a filter circuit in which the coil component is mounted.

[0007] A coil component according to one embodiment of the present disclosure is a coil component having a first coil and a second coil. The coil component includes a bobbin having a body portion around which a wire is wound and first and second flange portions provided at 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 in an opposite direction to the first wire to form the second coil. The bobbin includes a plurality of mounting terminals formed on one surface of the first flange portion and the second flange portion for mounting the coil component to a substrate, and a plurality of connection terminals formed on one surface of the first flange portion and the second flange portion for connecting ends of the first wire and the second wire. Among the multiple mounting terminals, the first mounting terminal is formed on one surface of the first flange and is electrically connected to a first connection terminal that connects to one end of the first wire, the second mounting terminal is formed on one surface of the second flange and is electrically connected to a second connection terminal that connects to the other end of the first wire, the third mounting terminal is formed on one surface of the first flange and is electrically connected to a third connection terminal that connects to one end of the second wire, and the fourth mounting terminal is formed on one surface of the second flange and is electrically connected to a fourth connection terminal that connects to the other end of the second wire. On a surface of the coil component having recesses provided on one surface of the first flange and one surface of the second flange, the first connection terminal is located diagonally relative to the second connection terminal, and the third connection terminal is located diagonally relative to the fourth connection terminal.

[0008] A filter circuit according to one embodiment of the present disclosure includes the above-described coil component, a substrate on which the coil component is mounted, and a capacitor mounted on the substrate and having one electrode electrically connected to the second mounting terminal and the fourth mounting terminal of the coil component.

[0009] According to one embodiment of the present disclosure, the first connection terminal is located diagonally relative to the second connection terminal, and the third connection terminal is located diagonally relative to the fourth connection terminal, so there is no need to cross the wire and crimp it into a recess formed in the flange portion, making it easier to manufacture the coil component.

[0010] 1 is a perspective view of a coil component according to a first embodiment; FIG. 2 is a perspective view of the coil component according to the first embodiment, seen from another direction; FIG. 3 is a bottom view of the coil component according to the first embodiment; FIG. 4 is a plan view of a substrate on which the coil component according to the first embodiment is mounted; FIG. 5 is a circuit diagram of a filter circuit according to the first embodiment; FIG. 6 is a view for explaining the relationship between the width of a body portion and the width of a recess in the coil component; FIG. 7 is a view for explaining the range of a connection terminal to which an end of a wire in the coil component is connected; FIG. 8 is a perspective view of a coil component according to a second embodiment; FIG. 9 is a perspective view of the coil component according to the second embodiment, seen from another direction; FIG. 10 is a bottom view of the coil component according to the second embodiment; FIG. 11 is a plan view of a substrate on which the coil component according to the second embodiment is mounted; FIG. 12 is a view for explaining the shape of a recess formed in a flange portion of the coil component; FIG. 13 is a view for explaining a recess of a different shape formed in a flange portion of the coil component.

[0011] <First Embodiment> A coil component according to the first embodiment will be described below. Fig. 1 is a perspective view of the coil component 1 according to the first embodiment. Fig. 2 is a perspective view of the coil component 1 according to the first embodiment as viewed from another direction. Fig. 3 is a bottom view of the coil component 1 according to the first embodiment. When the X-axis, Y-axis, and Z-axis are defined as shown in Figs. 1 to 3, the X-axis direction is the length direction of the coil component 1, the Y-axis direction is the width direction of the coil component 1, and the Z-axis direction is the height direction of the coil component 1.

[0012] The coil component 1 is, for example, a transformer coil mounted in a filter circuit used to suppress noise in a power line. As will be described later, the coil component 1 includes two magnetically coupled coils to cancel the parasitic inductance of a capacitor mounted in the filter circuit.

[0013] 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 a first flange portion 2b and a second flange portion 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 may be 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 that does not contain a filler such as powder.

[0014] The body portion 2 a of the bobbin 2 has a shape of, for example, a rectangular prism. Note that, in this disclosure, the body portion 2 a is described as a rectangular prism, but it may also be a circular cylinder or a polygonal prism. In the coil device 1, the first wire 4 and the second wire 5 are wound directly around the body portion 2 a. Note that the first wire 4 and the second wire 5 are, for example, copper wires, and are entirely covered with an insulating material.

[0015] In the coil component 1, the first wire 4 and the second wire 5 are wound in opposite directions around the body portion 2a to form two coils. In the coil component 1, the first wire 4 is wound once around the body portion 2a to form the first coil L1, and the second wire 5 is wound once around the body portion 2a to form the second coil L2. Note that the first wire 4 and the second wire 5 are wound once, but this is an example, and they may each be wound multiple times.

[0016] In the coil component 1, the length of the wire (the length of the wire wound around the body portion 2 a) and the distance between the wires have a significant effect on the coupling coefficient. In the coil component 1, the first wire 4 and the second wire 5 are wound around the body portion 2 a so as to keep the wire lengths constant in order to stabilize the coupling coefficient.

[0017] Furthermore, in order to maintain a constant distance between the wires and stabilize the coupling coefficient, the coil component 1 has connection terminals 8a-8d provided in recesses 7a and 7b formed in the flange portion, through which the first wire 4 and the second wire 5 are connected and fixed. Specifically, one end of the first wire 4 is connected by thermocompression to the connection terminal 8a (first connection terminal) in the recess 7a formed in the first flange portion 2b. The other end of the first wire 4 is connected by thermocompression to the connection terminal 8b (second connection terminal) in the recess 7b formed in the second flange portion 2c. As shown in FIG. 3 , on the surface (bottom surface) of the coil component 1 on which the recesses 7a and 7b are provided, the connection terminal 8a is located diagonally relative to the connection terminal 8b. Furthermore, the method of connecting the end of the first wire 4 to the connection terminals 8a and 8b is not limited to thermocompression bonding and may be, for example, laser welding. The recess provided on one surface of the flange may be provided by forming a recess in the flange or by changing the thickness of the mounting terminal.

[0018] One end of the second wire 5 is connected by thermocompression to a connection terminal 8c (third connection terminal) in a recess 7a formed in the first flange 2b. The other end of the second wire 5 is connected by thermocompression to a connection terminal 8d (fourth connection terminal) in a recess 7b formed in the second flange 2c. As shown in FIG. 3 , the connection terminal 8c is provided diagonally to the connection terminal 8d on the surface (bottom surface) of the coil component 1 on which the recesses 7a and 7b are provided. The method of connecting the end of the second wire 5 to the connection terminals 8c and 8d is not limited to thermocompression, and may be, for example, laser welding.

[0019] 3 , in the coil device 1, connection terminals 8a and 8b for fixing both ends of the first wire 4 are arranged on one diagonal line on one surface (bottom surface) of the coil device 1, and connection terminals 8c and 8d for fixing both ends of the second wire 5 are arranged on the other diagonal line. In other words, the connection terminals 8a and 8b and the connection terminals 8c and 8d are arranged in a staggered pattern on one surface (bottom surface) of the coil device 1.

[0020] Because the first wire 4 and the second wire 5 are wound around the body portion 2a in opposite directions, arranging the connection terminals 8a to 8d in a staggered pattern eliminates the need to cross the first wire 4 and the second wire 5 at the portions where the first wire 4 and the second wire 5 are thermocompression-bonded to the connection terminals 8a to 8d. If the first wire 4 and the second wire 5 were arranged in the same row in the width direction, the first wire 4 and the second wire 5 would cross when attempting to thermocompression-bond the first wire 4 and the second wire 5 to the connection terminals 8a to 8d to prevent the coil winding from loosening. If the first wire 4 and the second wire 5 cross, the first wire 4 and the second wire 5 may rub against each other, causing the insulating coating to peel off and potentially causing a short circuit between the first wire 4 and the second wire 5.

[0021] If the first wires 4 and the second wires 5 are arranged in the same row in the width direction and then bent in the short direction of the first flange 2b and the second flange 2c to thermocompression bond the first wires 4 and the second wires 5 to the connection terminals 8a to 8d, the coil winding may loosen during thermocompression bonding, or the wires may break due to excessive bending. In other words, if the connection terminals 8a to 8d are not arranged in a staggered pattern, it is difficult to thermocompression bond the ends of the first wires 4 and the second wires 5 to the connection terminals 8a to 8d in a direction perpendicular to the longitudinal direction of the first flange 2b and the second flange 2c (the short direction of the first flange 2b and the second flange 2c), as shown in FIG.

[0022] Furthermore, if the second wire 5 is crimped into the recess 7a formed in the first flange 2b while the first wire 4 is crimped into the recess 7a formed in the first flange 2b, the crimping operation must be performed in a small space, making it difficult to fabricate the coil component 1. However, by arranging the connection terminals 8a to 8d in a staggered pattern as shown in Figure 3, it is not necessary to cross the first wire 4 and the second wire 5 at the portions where the connection terminals 8a to 8d are thermocompression-bonded to the first wire 4 and the second wire 5, making it easier to fabricate the coil component 1. Furthermore, because it is not necessary to cross the first wire 4 and the second wire 5 at the portions where the first wire 4 and the second wire 5 are thermocompression-bonded to the connection terminals 8a to 8d, it becomes possible to form a coil using thicker wires.

[0023] Next, the mounting terminals for mounting the coil component 1 on a substrate will be described. As shown in FIGS. 1 to 3 , the first flange 2b and the second flange 2c provided on both sides of the bobbin 2 are provided with mounting terminals 6a (first mounting terminal) and 6b (second mounting terminal) that are electrically connected to the first wire 4 and used for mounting the coil component 1 on a substrate, and mounting terminals 6c (third mounting terminal) and 6d (fourth mounting terminal) that are electrically connected to the second wire 5 and used for mounting the coil component 1 on a substrate. Specifically, the first flange 2b is provided with the mounting terminals 6a and 6c, and the second flange 2c is provided with the mounting terminals 6b and 6d. The surfaces of the first flange 2b and the second flange 2c on which the mounting terminals 6a to 6d are provided are one surface (bottom surface) of the coil component 1.

[0024] The mounting terminal 6a is formed on one surface of the first flange 2b and is electrically connected to a connection terminal 8a that connects to one end of the first wire 4. The mounting terminal 6b is formed on one surface of the second flange 2c and is electrically connected to a connection terminal 8b that connects to the other end of the first wire 4. The mounting terminal 6c is formed on one surface of the first flange 2b and is electrically connected to a connection terminal 8c that connects to one end of the second wire 5. The mounting terminal 6d is formed on one surface of the second flange 2c and is electrically connected to a connection terminal 8d that connects to the other end of the second wire 5.

[0025] As shown in Fig. 3, the mounting terminals 6a and 6c formed on the first flange 2b are separated by the bottom surface 70 (second bottom surface) of the recess 7a and are not electrically connected, whereas the mounting terminals 6b and 6d formed on the second flange 2c are connected via the recess 7b and are electrically connected.

[0026] Mounting terminals 6a to 6d can be formed, for example, by applying Ag paste to one surface of first flange 2b and second flange 2c by a dipping method. When mounting terminals 6a to 6d are formed by a dipping method, by adjusting the depth of recesses 7a and 7b, mounting terminals 6b and 6d can be electrically connected without electrically connecting mounting terminals 6a and 6c.

[0027] As shown in FIG. 1 , the recess 7 a has two bottom surfaces with different depths. Specifically, the recess 7 a has a bottom surface with a depth D1 (bottom surface 70 (second bottom surface) shown in FIG. 3 ) and a bottom surface with a depth D2 (<D1) (bottom surfaces 71 a, 71 c (first bottom surface) shown in FIG. 3 ) that forms the connection terminals 8 a, 8 c. When Ag paste is applied by dipping to the surface of the first flange portion 2 b in which the recess 7 a is formed, even if the coil component 1 is dipped in the Ag paste to the extent that the Ag paste is applied to the bottom surfaces 71 a, 71 c, the Ag paste is not applied to the bottom surface 70, which is deeper than the bottom surfaces 71 a, 71 c. Note that when one end of the first wire 4 is crushed against the connection terminal 8 a and one end of the second wire 5 is crushed against the connection terminal 8 c by thermocompression bonding, the depth D1 is preferably greater than half the wire diameters of the first wire 4 and the second wire 5. By setting the depth D1 in this manner, the wires are less likely to protrude from the mounting terminal surface (bottom surface 70), and mounting problems are less likely to occur.

[0028] On the other hand, as shown in FIG. 2 , recess 7b has a single-step bottom surface. Specifically, recess 7b has a bottom surface with a depth D3 (=D2) that forms connection terminals 8b and 8d. When Ag paste is applied by dipping to the surface of second flange portion 2c where recess 7b is formed, the Ag paste is applied to the bottom surfaces 71a and 71c, so that the Ag paste is applied to the entire bottom surface of recess 7b, which has a similar depth. Note that when the other end of first wire 4 is crushed onto connection terminal 8b and the other end of second wire 5 is crushed onto connection terminal 8d by thermocompression bonding, depth D3 is preferably deeper than half the wire diameters of first wire 4 and second wire 5. Depth D3 may be smaller than depth D1 and may be different from depth D2.

[0029] In this way, the mounting terminals 6a to 6d and the connection terminals 8a to 8d can be formed simultaneously, and in reality they form an integrated electrode, but in this disclosure the electrodes to which the wires are connected are defined as connection terminals.

[0030] The coil component 1 is realized as a three-terminal coil component by electrically connecting the mounting terminals 6b and 6d via the recess 7b without electrically connecting the mounting terminals 6a and 6c at the bottom surface 70 of the recess 7a. Therefore, the coil component 1 does not need to electrically connect the mounting terminals 6b and 6d on the substrate side.

[0031] 4 is a plan view of a substrate 10 on which the coil component 1 according to the first embodiment is mounted. When the coil component 1 is mounted on the substrate 10, the substrate 10 is provided with a land electrode 11a for electrical connection with the mounting terminal 6a, a land electrode 11b for electrical connection with the mounting terminal 6b, a land electrode 11c for electrical connection with the mounting terminal 6c, and a land electrode 11d for electrical connection with the mounting terminal 6d. By providing the land electrodes 11a to 11d on the substrate 10 with four terminals and also providing the mounting terminals 6a to 6d connected to the land electrodes 11a to 11d with four terminals, it is possible to reduce the occurrence of mounting defects (e.g., chip standing (Manhattan phenomenon)) due to differences in the size of the land electrodes. When the substrate 10 on which the coil component 1 is mounted constitutes a filter circuit, the land electrode 11a is connected to input wiring, the land electrode 11c is connected to output wiring, and a capacitor is connected to at least one of the land electrodes 11b and 11d, as described below.

[0032] Next, a filter circuit 100 including the coil component 1 will be described. FIG. 5 is a circuit diagram of the filter circuit 100 according to the first embodiment. Specifically, the filter circuit 100 is an EMI removal filter circuit, and is a third-order T-type LC filter circuit. Note that, in this disclosure, a third-order T-type LC filter circuit will be used as the configuration of the filter circuit 100, 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. As shown in FIG. 5, the filter circuit 100 includes the coil component 1 and a capacitor C1.

[0033] The coil component 1 includes a mounting terminal 6a serving as an input terminal, a mounting terminal 6c serving as an output terminal, mounting terminals 6b and 6d serving as intermediate terminals, a first coil L1, and a second coil L2. Note that the coil component 1 may have the mounting terminal 6c as the input terminal and the mounting terminal 6a as the output terminal.

[0034] The capacitor C1 is connected in series between the mounting terminals 6b and 6d, which serve as intermediate terminals, and the ground electrode (GND), as shown in Fig. 5. Although one capacitor C1 may be used, a circuit configuration in which two capacitors are connected in series may also be used, assuming that the device is mounted on a vehicle.

[0035] The capacitor C1 is made of BaTiO ３ The present invention is not limited to multilayer ceramic capacitors whose main component is barium titanate (BAT), but may also include multilayer ceramic capacitors whose main component is another material, or other types of capacitors other than multilayer ceramic capacitors, such as aluminum electrolytic capacitors.

[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, a first coil L1 and a second coil L2 are connected to the mounting terminals 6b and 6d. The first coil L1 and the second coil 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 the capacitor C1, thereby making the inductance component of the capacitor C1 appear smaller. Note that in FIG. 5, a mutual inductance M (-M) for canceling out the inductor L3 is connected in series with the capacitor C1, and an equivalent circuit is illustrated in which a mutual inductance M (+M) is added to each of the first coil L1 and the second coil L2.

[0038] The filter circuit 100, which is composed of a capacitor C1, a first coil L1, and a 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] Next, the features of the coil device 1 will be described. FIG. 6 is a diagram illustrating the relationship between the width of the body portion 2a and the width of the recess 7b in the coil device 1. As shown in FIG. 6, in the coil device 1, the width W2 of the recess 7b formed in the second flange portion 2c is preferably shorter than the width W1 of the body portion 2a of the bobbin 2. By making the width W2 of the recess 7b shorter than the width W1 of the body portion 2a, it is possible to maintain a high tension in the wire that begins to be wound from the first flange portion 2b. It is preferable that the width W2 of the recess 7b is shortened inward from the end of the width W1 of the body portion 2a by the thickness of one wire. This makes it possible to maintain a high tension in the wire while ensuring a wide width W2 that serves as the crimping space.

[0040] As shown in Fig. 3, the portions of the bottom surfaces 71a and 71c of the recess 7a that are thermocompression bonded to the first wire 4 and the second wire 5 are the connection terminals 8a and 8c. Therefore, the connection terminal 8a is provided within the area of ​​the bottom surface 71a, and the connection terminal 8c is provided within the area of ​​the bottom surface 71c. Meanwhile, the portions of the bottom surface of the recess 7a that are thermocompression bonded to the first wire 4 and the second wire 5 are the connection terminals 8b and 8d, so the range in which the connection terminals 8a and 8c can be provided is wide. The connection terminals 8b and 8d are formed in the same recess 7b formed in the second flange 2c, but it is sufficient that the connection terminals 8b and 8d are arranged so that at least the first wire 4 and the second wire 5 do not cross each other.

[0041] More preferably, the connection terminals 8b, 8d may be arranged within a range not exceeding halfway along the width of the recess 7b formed in the second flange portion 2c. FIG. 7 is a diagram illustrating the range of the connection terminals 8b, 8d to which the ends of the wires in the coil component 1 are connected. As shown in FIG. 7, the connection terminals 8b, 8d may be arranged diagonally within a range not exceeding the center of the recess 7b. That is, the connection terminal 8b to be connected to the first wire 4 is arranged within a range of half (W2 / 2) of the width W2 of the recess 7b. Furthermore, the connection terminal 8d to be connected to the second wire 5 is arranged within a range of half (W2 / 2) of the width W2 of the opposite recess 7b. As a result, when two wires are thermocompressed at different times, such as thermocompressing the first wire 4 to the connection terminal 8b and then thermocompressing the second wire 5 to the connection terminal 8d, by thermocompressing one wire within a range of half the width W2 (W2 / 2) of the recess 7b, the wire to be thermocompressed later can be reliably thermocompressed to the recess 7b.

[0042] As described above, in the coil component 1 according to the first embodiment, on the surface of the coil component 1 on which the recesses 7a and 7b are provided, the connection terminal 8a is positioned diagonally relative to the connection terminal 8b, and the connection terminal 8c is positioned diagonally relative to the connection terminal 8d. This eliminates the need to cross the first wire 4 and the second wire 5 to connect the first wire 4 and the second wire 5 to the connection terminals 8a to 8d provided in the recesses 7a and 7b, making it easier to manufacture the coil component 1.

[0043] In the coil component 1, the second flange portion 2c electrically connects the two terminals, the mounting terminal 6b and the mounting terminal 6d, but the recess 7b is provided to make the portion forming the connection terminal 8b and the connection terminal 8d higher than the mounting surface, so that solder does not adhere to the portion, thereby reducing the occurrence of mounting defects (for example, chip standing (Manhattan phenomenon)).

[0044] When the first wire 4 and the second wire 5 are thermocompression-bonded to the connection terminals 8a-8b, the thermocompression-bonded portions oxidize, reducing the solder wettability. Therefore, by thermocompression-bonding the first wire 4 to the connection terminal 8b and the second wire 5 to the connection terminal 8b near the wall surface of the recess 7b, the spread of the solder can be prevented at the thermocompression-bonded portions when the coil component 1 is mounted on the substrate 10. Therefore, when the coil component 1 is mounted on the substrate 10 by soldering, the size of the solder that adheres to each of the mounting terminals 6a-6d can be kept the same. Furthermore, by taking advantage of the fact that the solder wettability of the thermocompression-bonded portions is reduced, unnecessary solder adhesion can be avoided when the coil component 1 is mounted on the substrate 10 by soldering.

[0045] In the coil component 1, when mounted on the substrate 10 with solder, a deep recess 7a may be provided in the first flange 2b to prevent the mounting terminals 6a and 6c from being electrically connected, while the recess 7b provided in the second flange 2c may be shallower, so that the electrical connection between the mounting terminals 6b and 6d is reinforced with solder.

[0046] <Embodiment 2> In the coil component 1 according to embodiment 1, the second flange portion 2c is used to electrically connect the two mounting terminals 6b and 6d to form a single terminal. However, the two mounting terminals 6b and 6d may be electrically connected on the substrate 10, rather than on the coil component 1 side. A coil component according to embodiment 2, in which the two terminals are not electrically connected on the coil component side, will be described below. FIG. 8 is a perspective view of a coil component 1A according to embodiment 2. FIG. 9 is a perspective view of the coil component 1A according to embodiment 2, viewed from a different direction. FIG. 10 is a bottom view of the coil component 1A according to embodiment 2. When the X-axis, Y-axis, and Z-axis are defined as shown in FIGS. 8 to 10 , the X-axis direction is the length direction of the coil component 1A, the Y-axis direction is the width direction of the coil component 1A, and the Z-axis direction is the height direction of the coil component 1A. Note that in the coil component 1A according to embodiment 2, the same components as those in the coil component 1 according to embodiment 1 shown in FIGS. 1 to 3 are designated by the same reference numerals, and detailed description thereof will not be repeated.

[0047] The coil device 1A 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 a first flange portion 2b and a second flange portion 2c provided on both ends of the body portion 2a.

[0048] In coil component 1A, two coils are formed by winding a first wire 4 and a second wire 5 in opposite directions around body portion 2a. In coil component 1A, the first wire 4 is wound once around body portion 2a to form first coil L1, and the second wire 5 is wound once around body portion 2a to form second coil L2. Note that the first wire 4 and the second wire 5 each having one winding are merely an example, and they may each have multiple windings.

[0049] In the coil component 1A, in order to maintain a constant distance between the wires to stabilize the coupling coefficient, connection terminals 8a-8d are provided in recesses 7a and 7c formed in the flange portion, and the first wire 4 and the second wire 5 are connected and fixed thereto. Specifically, one end of the first wire 4 is connected by thermocompression to connection terminal 8a (first connection terminal) in recess 7a formed in the first flange portion 2b. The other end of the first wire 4 is connected by thermocompression to connection terminal 8b (second connection terminal) in recess 7c formed in the second flange portion 2c. As shown in FIG. 10 , on the surface (bottom surface) of the coil component 1A where recesses 7a and 7c are provided, connection terminal 8a is located diagonally relative to connection terminal 8b. Furthermore, the method of connecting the end of the first wire 4 to connection terminals 8a and 8b is not limited to thermocompression bonding and may be, for example, laser welding.

[0050] One end of the second wire 5 is connected by thermocompression to a connection terminal 8c (third connection terminal) in a recess 7a formed in the first flange 2b. The other end of the second wire 5 is connected by thermocompression to a connection terminal 8d (fourth connection terminal) in a recess 7c formed in the second flange 2c. As shown in FIG. 10 , on the surface (bottom surface) of the coil component 1A on which the recesses 7a and 7c are provided, the connection terminal 8c is located diagonally relative to the connection terminal 8d. The method of connecting the end of the second wire 5 to the connection terminals 8c and 8d is not limited to thermocompression bonding and may be, for example, laser welding.

[0051] The mounting terminal 6a is formed on one surface of the first flange 2b and is electrically connected to a connection terminal 8a that connects to one end of the first wire 4. The mounting terminal 6c is formed on one surface of the first flange 2b and is electrically connected to a connection terminal 8c that connects to one end of the second wire 5. As shown in Fig. 10 , the mounting terminals 6a and 6c formed on the first flange 2b are separated by the bottom surface 70 (second bottom surface) of the recess 7a and are not electrically connected.

[0052] On the other hand, mounting terminal 6b is formed on one surface of second flange 2c and is electrically connected to connection terminal 8b, which connects to the other end of first wire 4. Mounting terminal 6d is formed on one surface of second flange 2c and is electrically connected to connection terminal 8d, which connects to the other end of second wire 5. Mounting terminals 6b and 6d, which are formed on second flange 2c, are separated by bottom surface 72 (fourth bottom surface) of recess 7c, as shown in Fig. 10, and are not electrically connected.

[0053] As shown in Fig. 8, the recess 7a has two bottom surfaces with different depths. Specifically, the recess 7a has a bottom surface with a depth D1 (bottom surface 70 (second bottom surface) shown in Fig. 10) and a bottom surface with a depth D2 (<D1) where the connection terminals 8a and 8c are formed (bottom surfaces 71a and 71c (first bottom surface) shown in Fig. 10). When Ag paste is applied by dipping to the surface of the first flange portion 2b where the recess 7a is formed, even if the coil component 1A is dipped in the Ag paste to the extent that the Ag paste is applied to the bottom surfaces 71a and 71c, the Ag paste is not applied to the bottom surface 70, which is deeper than the bottom surfaces 71a and 71c.

[0054] As shown in FIG. 9 , the recess 7c has two bottom surfaces with different depths. Specifically, the recess 7c has a bottom surface with a depth D1 (bottom surface 72 (fourth bottom surface) shown in FIG. 10 ) and a bottom surface with a depth D2 (<D1) where the connection terminals 8b and 8d are formed (bottom surfaces 71b and 71d (third bottom surface) shown in FIG. 10 ). When applying Ag paste to the surface of the second flange portion 2c in which the recess 7c is formed by dipping, even if the coil component 1A is dipped in the Ag paste to the extent that the Ag paste is applied to the bottom surfaces 71b and 71d, the Ag paste is not applied to the bottom surface 72, which is deeper than the bottom surfaces 71b and 71d. Note that although the bottom surface 70 of the recess 7a and the bottom surface 72 of the recess 7c have been described as having the same depth D1, they may have different depths. Furthermore, although the bottom surfaces 71a and 71c of the recess 7a and the bottom surfaces 71b and 71d of the recess 7c have been described as having the same depth D2, they may have different depths.

[0055] Coil component 1A is a four-terminal coil component by not electrically connecting mounting terminal 6a and mounting terminal 6c at bottom surface 70 of recess 7a, and not electrically connecting mounting terminal 6b and mounting terminal 6d at bottom surface 72 of recess 7c. Therefore, when coil component 1A is used in filter circuit 100, mounting terminal 6b and mounting terminal 6d must be electrically connected on the substrate side.

[0056] 11 is a plan view of a substrate 10A on which a coil component 1A according to embodiment 2 is mounted. When the coil component 1A is mounted on the substrate 10A, a land electrode 11a for electrically connecting to the mounting terminal 6a, a land electrode 11b for electrically connecting to the mounting terminal 6b, a land electrode 11c for electrically connecting to the mounting terminal 6c, and a land electrode 11d for electrically connecting to the mounting terminal 6d are formed. The substrate 10A is provided with wiring 12 for electrically connecting the land electrode 11b and the land electrode 11d. By electrically connecting the land electrode 11b and the land electrode 11d with the wiring 12, the mounting terminals 6b and 6d can both be connected to one electrode of the capacitor C1 as intermediate terminals.

[0057] Although the board 10A has been described as electrically connecting the land electrodes 11b and 11d via the wiring 12, the land electrodes 11b and 11d and the wiring 12 may be formed as a single land electrode. Since the two terminals of the coil component 1A are electrically connected on the board 10A side, there is no need to worry about the orientation of the coil component 1A relative to the board 10A, and there is no need to attach an identification mark when manufacturing the coil component 1A. In other words, the coil component 1A may have the mounting terminal 6a connected to the land electrode 11d and the mounting terminal 6c connected to the land electrode 11b, and the mounting terminals 6a and 6c may be electrically connected on the board 10A side.

[0058] When the land electrodes 11b and 11d on the substrate 10A are electrically connected by the wiring 12, the wiring 12 may be covered with an insulating solder resist, the height of the land electrodes 11b and 11d may be made higher than the height of the wiring 12, or the wiring 12 may be provided inside the substrate 10A or on the back surface of the substrate 10A. This allows the sizes of the mounting terminals 6a to 6d and the land electrodes 11a to 11d of the coil component 1A to be kept the same when the coil component 1A is mounted on the substrate 10A, thereby reducing chip floating of the coil component 1A mounted on the substrate 10A.

[0059] 11 has a configuration in which land electrode 11b and land electrode 11d are electrically connected by wiring 12, but it is also possible to mount a coil component 1 in which mounting terminal 6b and mounting terminal 6d are electrically connected on the coil component 1 side. By mounting coil component 1 on substrate 10A, mounting terminal 6b and mounting terminal 6d can be electrically connected on both the coil component 1 side and the substrate 10A side, thereby providing redundancy.

[0060] <Modification 2> The recess 7a formed in the first flange 2b has a two-tiered bottom surface with different depths as shown in Fig. 1. Fig. 12 is a diagram for explaining the shape of the recess 7a formed in the flange of the coil component 1. The recess 7a has a deep bottom surface 70 (second bottom surface) and shallow bottom surfaces 71a and 71c (first bottom surfaces).

[0061] The deep bottom surface 70 is not coated with an electrode material (e.g., Ag paste), but the shallow bottom surfaces 71a, 71c are coated with the electrode material. The first wire 4 and the second wire 5 are thermocompression-bonded to the bottom surfaces 71a, 71c to which the electrode material is applied, thereby forming the connection terminals 8a, 8c. The first wire 4 and the second wire 5 may be thermocompression-bonded to the bottom surfaces 71a, 71c or to the wall surfaces of the recess 7a adjacent to the bottom surfaces 71a, 71c.

[0062] When the electrode material is applied to the bottom surfaces 71a and 71c by dipping, the electrode material is also applied to the portions that will become the mounting terminals 6a and 6c. Therefore, the connection terminal 8a and the mounting terminal 6a are electrically connected, and the connection terminal 8c and the mounting terminal 6c are electrically connected. However, because the electrode material is not applied to the bottom surface 70, the mounting terminals 6a and 6c are not electrically connected.

[0063] When the mounting terminals 6a, 6c and the connection terminals 8a, 8c are formed by the dipping method in this manner, it is preferable that the recess 7a has a two-step bottom surface with different depths as shown in Fig. 12. However, when the mounting terminals 6a, 6c and the connection terminals 8a, 8c are formed by, for example, a sputtering method instead of the dipping method, the recess may simply have a single-step bottom surface.

[0064] 13 is a diagram illustrating a recess 7d of another shape formed in the flange portion of the coil device 1. The recess 7d formed in the first flange portion 2b simply has a single-step bottom surface 75 as shown in Fig. 13. The bottom surface 75 of the recess 7d may have the same depth as the bottom surface 70 of the recess 7a, or may have a different depth.

[0065] When forming the connection terminals 8a and 8c on the bottom surface 75 by sputtering, a portion of the bottom surface 75 can be left uncoated with electrode material, and the connection terminals 8a and 8c can be formed so that they are not electrically connected to each other. The portions that will become the mounting terminals 6a and 6c are coated with electrode material by dipping or sputtering to form the mounting terminals 6a and 6c that are electrically connected to the connection terminals 8a and 8c. By forming the connection terminals 8a and 8c by sputtering in this way, even if the bottom surface 75 is simply one-stage, portions of the bottom surface 75 can be left uncoated with electrode material, and the mounting terminals 6a and 6c can be formed so that they are not electrically connected to each other.

[0066] The configuration of the recess 7d shown in FIG. 13 can be similarly applied to the recess 7c formed in the second flange portion 2c shown in FIG.

[0067] <Variation 3> When the coil component 1, 1A is applied to a filter circuit used in a power line, for example, a current of approximately 3 A or more is expected to flow through the first wire 4 and the second wire 5, so the DC resistance of the wires needs to be approximately 20 mΩ or less. Therefore, the wire diameter of the first wire 4 and the second wire 5 is preferably approximately 100 μm or more. In the coil component 1, 1A, the first wire 4 and the second wire 5 are thermocompression-bonded using a depression, so the depth of the depression is preferably greater than the thickness of a wire having a diameter of approximately 100 μm or more after being crushed. For example, if the wire diameter of the first wire 4 and the second wire 5 is to be crushed to half by thermocompression, the depth of the depression should preferably be greater than approximately 50 μm.

[0068] <Aspects> (1) A coil component having a first coil and a second coil, comprising: a bobbin having a body portion around which a wire is wound, and first and second 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 in an opposite direction to the first wire to form the second coil, wherein the bobbin includes: a plurality of mounting terminals formed on one surface of the first flange portion and the second flange portion for mounting the coil component to a substrate; and a plurality of connection terminals formed on one surface of the first flange portion and the second flange portion for connecting ends of the first wire and the second wire, wherein among the plurality of mounting terminals, a first mounting terminal is formed on one surface of the first flange portion and is electrically connected to a first connection terminal that connects to one end of the first wire, the second mounting terminal is formed on one surface of the second flange and is electrically connected to the second connection terminal that connects to the other end of the first wire; the third mounting terminal is formed on one surface of the first flange and is electrically connected to the third connection terminal that connects to one end of the second wire; the fourth mounting terminal is formed on one surface of the second flange and is electrically connected to the fourth connection terminal that connects to the other end of the second wire; and a coil component having recesses on one surface of the first flange and the second flange, wherein the first connection terminal is located diagonally to the second connection terminal and the third connection terminal is located diagonally to the fourth connection terminal.

[0069] (2) A coil component as described in (1), wherein the second connection terminal and the fourth connection terminal are formed in the same recess formed in the second flange portion, and are arranged so that the first wire and the second wire do not cross each other.

[0070] (3) In the coil component according to (1) or (2), the width of the recess formed in the second flange portion is shorter than the width of the body portion.

[0071] (4) A coil component according to any one of (1) to (3), wherein the second connection terminal is connected to the first wire within a range up to halfway along the width of the recess formed in the second flange, and the fourth connection terminal is connected to the second wire within a range up to halfway along the width of the recess formed in the second flange.

[0072] (5) In the coil component according to any one of (1) to (4), the second mounting terminal and the fourth mounting terminal are electrically connected to each other.

[0073] (6) In the coil component according to any one of (1) to (5), the depth of the recess formed in the second flange portion is different from the depth of the recess formed in the first flange portion.

[0074] (7) A coil component according to any one of (1) to (6), wherein the recess formed in the first flange portion has a first bottom surface at a first depth and a second bottom surface at a second depth deeper than the first depth, and the first mounting terminal and the third mounting terminal are provided on the first bottom surface.

[0075] (8) The coil component according to (7), wherein the first depth is deeper than half the wire diameter of the first wire and the second wire.

[0076] (9) A coil component according to any one of (1) to (8), wherein the first mounting terminal and the third mounting terminal are provided on a part of the wall surface and the bottom surface of a recess formed in the first flange portion.

[0077] (10) The coil component according to any one of (1) to (9), wherein the number of windings of the first wire around the body portion and the number of windings of the second wire around the body portion are one winding.

[0078] (11) The coil component according to any one of (1) to (10), wherein the first mounting terminal, the second mounting terminal, the third mounting terminal, and the fourth mounting terminal are all provided on the same surface of the bobbin.

[0079] (12) A filter circuit according to the present disclosure includes: a coil component according to any one of (1) to (11); a substrate on which the coil component is mounted; and a capacitor mounted on the substrate, the capacitor having one electrode electrically connected to the second mounting terminal and the fourth mounting terminal of the coil component.

[0080] (13) A filter circuit according to (12), wherein the substrate has land electrodes for electrically connecting to the first mounting terminal, the second mounting terminal, the third mounting terminal, and the fourth mounting terminal, and the land electrode for electrically connecting to the second mounting terminal and the land electrode for electrically connecting to the fourth mounting terminal are electrically connected.

[0081] (14) Another filter circuit of the present disclosure includes the coil component according to (5); a substrate on which the coil component is mounted; and a capacitor mounted on the substrate, the capacitor having one electrode electrically connected to at least one of the second mounting terminal and the fourth mounting terminal of the coil component.

[0082] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0083] 1, 1A Coil component, 2 Bobbin, 2a Body portion, 2b First flange portion, 2c Second flange portion, 4 First wire, 5 Second wire, 6a to 6d Mounting terminals, 8a to 8d Connection terminals, 10, 10A Substrate, 100 Filter circuit.

Claims

1. A coil component having a first coil and a second coil, a bobbin having a body portion around which a wire is wound and a first flange portion and a second flange portion provided on both ends of the body portion; a first wire wound around the body to form the first coil; a second wire wound around the body in a direction opposite to that of the first wire to form the second coil; The bobbin is a plurality of mounting terminals formed on one surface of the first flange portion and the second flange portion for mounting the coil component on a substrate; a plurality of connection terminals formed on one surface of the first flange portion and the second flange portion for connecting ends of the first wire and the second wire; Among the plurality of mounting terminals, a first mounting terminal formed on one surface of the first flange portion and electrically connected to a first connection terminal connected to one end of the first wire; a second mounting terminal formed on one surface of the second flange portion and electrically connected to a second connection terminal connected to the other end of the first wire; a third mounting terminal formed on one surface of the first flange portion and electrically connected to a third connection terminal connected to one end of the second wire; a fourth mounting terminal formed on one surface of the second flange portion and electrically connected to a fourth connection terminal connected to the other end of the second wire; on a surface of the coil component having a recess provided on one surface of the first flange portion and the second flange portion, the first connection terminal is located diagonally with respect to the second connection terminal, and the third connection terminal is located diagonally with respect to the fourth connection terminal, the recess formed in the first flange portion has a first bottom surface at a first depth and a second bottom surface at a second depth deeper than the first depth, The first mounting terminal and the third mounting terminal are provided on the first bottom surface.

2. The coil component according to claim 1 , wherein the second connection terminal and the fourth connection terminal are formed in the same recess formed in the second flange portion, and are arranged so that the first wire and the second wire do not cross each other.

3. The coil component according to claim 1 or 2, wherein a width of the recess formed in the second flange portion is shorter than a width of the body portion.

4. the second connection terminal is connected to the first wire within a range up to a halfway position in a width direction of the recess formed in the second flange portion, 3 . The coil component according to claim 1 , wherein the fourth connection terminal is connected to the second wire within a range up to a halfway position in a width direction of the recess formed in the second flange portion.

5. The coil component according to claim 1 , wherein the second mounting terminal and the fourth mounting terminal are electrically connected to each other.

6. 3. The coil component according to claim 1, wherein a depth of the recess formed in the second flange portion is different from a depth of the recess formed in the first flange portion.

7. The coil component according to claim 1 , wherein the first depth is deeper than half a wire diameter of the first wire and the second wire.

8. 3 . The coil component according to claim 1 , wherein the first mounting terminal and the third mounting terminal are provided on a part of a wall surface and a part of a bottom surface of the recess formed in the first flange portion.

9. The coil component according to claim 1 , wherein the number of turns of the first wire around the body portion and the number of turns of the second wire around the body portion are one turn.

10. 3. The coil component according to claim 1, wherein the first mounting terminal, the second mounting terminal, the third mounting terminal and the fourth mounting terminal are all provided on the same surface of the bobbin.

11. The coil component according to claim 1 or 2; A substrate on which the coil component is mounted; a capacitor mounted on the substrate, the capacitor having one electrode electrically connected to the second mounting terminal and the fourth mounting terminal of the coil component.

12. the substrate has land electrodes for electrically connecting to the first mounting terminal, the second mounting terminal, the third mounting terminal, and the fourth mounting terminal, The filter circuit according to claim 11 , wherein the land electrode for electrical connection with the second mounting terminal and the land electrode for electrical connection with the fourth mounting terminal are electrically connected to each other.

13. The coil component according to claim 5 ; A substrate on which the coil component is mounted; a capacitor mounted on the substrate and having one electrode electrically connected to at least one of the second mounting terminal and the fourth mounting terminal of the coil component.