JP2006147728A - Common mode choke coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a common mode choke coil capable of precisely adjusting characteristic impedance, preventing deterioration in production efficiency, and being mounted quickly without considering a signal I/O direction. <P>SOLUTION: In the common mode choke coil 10, wires 13A, 13B wound around a winding core 11A in a core 11 are connected to electrodes 12, 12 extracted from the winding core 11A. In this case, resin sections 14, 14 made of a polymer material are provided at one portion of the wires 13A, 13B wound around the winding core 11A to adjust capacitance. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a common mode choke coil, and more particularly to a common mode choke coil capable of controlling characteristic impedance.

  Patent Document 1 describes a common mode noise filter. In this common mode noise filter, as shown in FIGS. 8A to 8C, a pair of conductor wires 1 and 2 having a line-to-line distance (a) is formed on the core 12 of the drum core 11 with an insulating layer 3. An electrode in which an integrated pair wire P is wound, a winding interval (b) is provided between conductor wires of adjacent pair wires P, and a conductor wire terminal of the pair wire P is provided on the flange portion 13 of the drum core 11, respectively. The ratio a / R of the distance (a) between the wires and the diameter (R) of the wire is set to a / R ≧ 0.5, and the winding interval (b) and the wire The ratio b / R of the diameter (R) of b is set to b / R ≧ 0.5, thereby reducing the variation in characteristic impedance. In the case of this common mode noise filter, by changing a / R in a region where the cutoff frequency is 2.5 GHz or more where a / R ≧ 0.5, or the cutoff frequency 2 where b / R ≧ 0.5. The characteristic impedance can be set to a desired value by changing b / R in the region of .5 GHz or higher.

  Further, by adhering the magnetic or non-magnetic plate-like core 20 between the upper surfaces of both the flanges 13 and 13 of the drum core 11, the drum core 11 and the plate-like core 20 can be adsorbed by the adsorption nozzle of the automatic mounting machine. In the case of a magnetic material, leakage magnetic flux can be reduced and common mode noise suppression characteristics can be improved.

JP 2004-146683 A

  However, in the case of the conventional common mode noise filter described in Patent Document 1, the characteristic impedance is obtained by combining two parameters of the distance (a) between the pair wires and the winding interval (b) between the adjacent pair wires P. However, since the distance (a) between the conductor wires 1 and 2 of the pair wire rod P has a great influence on the characteristic impedance, the pair wire rod is used when a plurality of lineups of common mode impedance values are prepared. A plurality of Ps must be prepared, and the pair wire P must be changed each time the common mode impedance value changes, resulting in poor production efficiency. Further, the pair wire P is more expensive than the single wire, and the processing of the terminal portion for connecting to the electrodes 12 and 12 is complicated and causes an increase in cost.

  Furthermore, the characteristic impedance of the common mode noise filter is represented by √ (L / C). If the adhesive adheres to the pair wire P wound around the core portion 12 of the common mode noise filter, Since the capacitance component C varies depending on the amount of adhesion and adversely affects the characteristic impedance, it is difficult to set the characteristic impedance to a desired value. Also, if the adhesive is attached, the characteristic impedance seen from the input side of the common mode noise filter and the characteristic impedance seen from the output side cannot be made the same. must not.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a common mode choke coil in which the characteristic impedance can be accurately adjusted and the production efficiency is not lowered. Another object of the present invention is to provide a common mode choke coil that can be quickly mounted without considering the signal input / output direction.

  The common mode choke coil according to claim 1 of the present invention is wound around the core portion, a core having flange portions at both ends thereof, an electrode formed integrally with the flange portion, and the core portion. A common mode choke coil in which the wire is drawn from the core portion and connected to the electrode, and a part of the wire wound around the core portion is made of a polymer material. The resin portion is provided for capacitance adjustment.

  A common mode choke coil according to a second aspect of the present invention is the common mode choke coil according to the first aspect, wherein the resin portion is at an equal distance from the input end and the output end of the wire at least one place. It is characterized by the arrangement.

  Moreover, the common mode choke coil according to claim 3 of the present invention is characterized in that, in the invention according to claim 1 or 2, the dielectric constant of the resin portion is 1.5 to 4.5. To do.

  According to a fourth aspect of the present invention, there is provided the common mode choke coil according to any one of the first to third aspects, wherein a magnetic material or a nonmagnetic material is provided between the pair of flanges. A plate-like core made of is constructed with an adhesive interposed therebetween.

  A common mode choke coil according to a fifth aspect of the present invention is the common mode choke coil according to the fourth aspect, wherein the adhesive is made of the same material as the resin portion.

  The common mode choke coil according to claim 6 of the present invention is the common mode choke coil according to any one of claims 1 to 3, wherein the core portion has a surface opposite to the electrode. A wire protective layer is formed, and the surface of the protective layer opposite to the wire side is formed flat.

  According to the first to sixth aspects of the present invention, the characteristic impedance can be adjusted with high accuracy, the production efficiency is not lowered, and the signal input / output direction is taken into consideration quickly. A common mode choke coil can be provided.

  Hereinafter, the present invention will be described based on the embodiment shown in FIGS. 1 is a perspective view showing one embodiment of the common mode choke coil of the present invention, FIGS. 2 to 5 are perspective views showing other embodiments of the common mode choke coil of the present invention, and FIG. 6 is FIG. FIG. 7 is a graph showing the asymmetry of the characteristic impedance of the common mode choke coil to which the adhesive is adhered asymmetrically.

  The common mode choke coil 10 according to the present embodiment includes, for example, a winding core portion 11A and flange portions 11B and 11B formed at both ends thereof as shown in FIG. 1, and is formed of a magnetic material or a nonmagnetic material. Core 11, a pair of electrodes 12, 12 formed on the lower surfaces of the pair of flanges 11 B, 11 B, respectively, and a pair of wires with an insulation coating (hereinafter simply referred to as “winding core 11 A”). A pair of wires 13A and 13B wound around the core portion 11A is provided at both ends (not shown) of the flange portions 11B and 11B. It is connected to the electrodes 12 and 12 and is configured as a common mode choke coil for differential transmission. The common mode choke coil 10 is mounted on a mounting substrate such as a mother board via electrodes 12 and 12.

  The common mode choke coil 10 for differential transmission is required to have a function of removing common mode noise and passing a signal waveform without deteriorating. As for the differential transmission signal, there is a concern that the signal waveform deteriorates as the speed increases. Therefore, in order to prevent the deterioration of the signal waveform via the common mode choke coil 10, the characteristic impedance of the common mode choke coil 10 is important, and this characteristic impedance needs to match the characteristic impedance of the transmission line. is there.

  The characteristic impedance of the common mode choke coil 10 is expressed by √ (L / C) from the inductance component L and the capacitance component C as described above. In other words, this characteristic impedance can be controlled by two parameters, an inductance component L and a capacitance component C. Of the two parameters, the inductance component L is determined by the number of turns of the wires 13A and 13B, the wire diameter, the size of the core 11, the magnetic characteristics, and the like in order to obtain a desired noise removal performance. It is difficult to adjust. On the other hand, the electrostatic capacitance component C mainly depends on the line-to-line distribution capacity between the wires 13A and 13B.

  Therefore, in the present embodiment, as shown in FIG. 1, the resin portion 14 made of a polymer material is electrostatically attached to a part of a pair of wires 13A and 13B wound around the core portion 11A of the common mode choke coil 10. Provided for capacity adjustment, the resin section 14 adjusts the distributed capacity between the wires 13A and 13B, and thereby controls the characteristic impedance of the common mode choke coil 10. A part of the pair of wires 13A and 13B may be one place of the winding core part 11A, but it is usually preferable to provide at a plurality of places, and even numbers so as to be symmetrical when viewed from the signal input side and the signal output side. More preferably, it is provided at a location.

  The distributed capacity of the resin part 14 can be adjusted and controlled by either the dielectric constant ε or the area of the resin part 14. The dielectric constant ε of the resin portion 14 is not particularly limited, but is preferably in the range of 1.5 to 4.5. By giving the dielectric constant ε a width, the adjustment range of the characteristic impedance can be widened. If the dielectric constant ε is less than 1.5, the amount of resin for adjusting the capacitance component C increases, so the area of the resin portion 14 must be increased. Since the capacitance component C varies greatly depending on the amount of the resin, it is difficult to adjust the characteristic impedance. The resin part 14 can be formed with high accuracy by applying the paint to a corresponding part while accurately measuring the paint using a supply means such as a dispenser. Although it does not restrict | limit especially as a polymeric material used for the resin part 14, For example, an epoxy resin, a silicon resin, a polyimide resin, a polyurethane resin, a cyanoacrylate resin etc. are preferable.

  In the present embodiment, as shown in FIG. 1, the ends of the pair of wires 13A and 13B on the signal input side (left side of the core 11 in the figure) and the end on the signal output side (right side of the core 11 in the figure). Resin portions 14 are provided at two locations that are equidistant from each other. As shown in the drawing, the input side resin portion 14 is formed on the front side of the winding wires 13A and 13B closest to the signal input side flange portion 11B on the upper surface of the winding core portion 11A, and the output side resin portion 14 is The winding wires 13 </ b> A and 13 </ b> B are formed on the back side of the winding core portion 11 </ b> A closest to the flange 11 </ b> B on the signal output side. Accordingly, since the two resin parts 14 and 14 are formed symmetrically about the center in the longitudinal direction of the core part 11A, signals are input from either of the left and right ends of the wires 13A and 13B. However, the characteristic impedance of the common mode choke coil 10 is substantially the same, and the characteristic impedance has no directivity. Therefore, even if the common mode choke coil 10 is mounted on the transmission line without distinguishing between the signal input side and the signal output side, the same characteristic impedance can be obtained.

  Further, the resin part formed on the core part 11A may be provided symmetrically when viewed from the signal input side and the signal output side. For example, the resin part may be provided as shown in FIGS. good. In the case of the common mode choke coil 10A shown in FIG. 2, the two resin portions 14A and 14A are respectively the winding wires 13A closest to the signal output side and the signal output side at the center in the width direction of the upper surface of the winding core portion 11A. , 13B. Further, in the case of the common mode choke coil 10B shown in FIG. 3, the resin portion 14B on the input side extends over the entire side surface to the first winding wires 13A and 13B closest to the flange portion 11B on the front side surface of the winding core portion 11A. The resin portion (not shown) on the output side is formed over the entire side surface of the winding wires 13A and 13B closest to the flange portion 11B on the back side surface of the winding core portion 11A.

  As described above, according to the present embodiment, the resin portion 14 made of a polymer material is used for capacitance adjustment on a part of the pair of wires 13A and 13B wound around the core portion 11A of the core 11. Therefore, the distribution capacity between the wires 13A and 13B can be adjusted by appropriately setting the dielectric constant ε of the resin portion 14 and the coating area of the resin portion 14, and thus the characteristic impedance of the common mode choke coil 10 can be adjusted. It can be finely controlled to a desired value, and only one type of wire is prepared regardless of the size of the capacitance component C, and it is not necessary to prepare a plurality of types of wires. In this embodiment, since the two independent wires 13A and 13B are used as a pair of differential transmission lines as a transmission line, the common mode choke coil 10 does not have to deal with terminal processing like a paired wire. Can be produced efficiently.

  In addition, according to the present embodiment, since the resin portion 14 is arranged at an equal distance from the end portion on the signal input side and the end portion on the signal output side of the pair of wires 13A and 13B, the common portion 14 The mode choke coil 10 can be mounted without considering the input / output direction, and the same characteristic impedance can be obtained regardless of the mounting direction. Moreover, since the dielectric constant ε of the resin portion 14 is 1.5 to 4.5, the adjustment range of the characteristic impedance of the common mode choke coil 10 can be expanded. Further, since the resin portion 14 does not affect the common mode impedance, a plurality of common mode impedance lineups can be easily prepared.

  Further, the common mode choke coil 10C shown in FIG. 4 has a configuration in which a plate-like core 15 made of a magnetic material or a nonmagnetic material is installed on the upper surface of the flanges 11B and 11B of the common mode choke coil 10A shown in FIG. The same configuration as that of the common mode choke coil 10A shown in FIG. The plate-like core 15 is fixed to the upper surfaces of the left and right flange portions 11B and 11B via adhesives 16 and 16 made of a polymer material. The adhesive 16 is preferably made of the same material as the resin portion 14. By using the same material for the adhesive 16 and the resin part 14, the formation of the resin part 14 and the application of the adhesive 16 can be performed in the same application process, and the production efficiency can be increased and the cost can be reduced. . Moreover, by laying the plate-like core 15 between the left and right flange portions 11B, 11B, the common mode impedance can be increased and the noise removal performance can be improved. Further, since the upper surface is flattened by the plate-like core 15, for example, the suction and conveyance of the common mode choke coil 10C can be facilitated, and the mounting workability of the common mode choke coil 10 can be improved.

  Further, the common mode choke coil 10D shown in FIG. 5 has the same configuration except that a protective layer 17 for protecting the wires 13A and 13B is formed on the upper surface of the core portion 11A of the common mode choke coil 10B shown in FIG. 3 is configured similarly to the common mode choke coil 10B shown in FIG. As the coating material, for example, epoxy acrylate can be used. The protective layer 17 has a flat upper surface and is formed so as to reach the wires 13A and 13B on the upper surface of the core portion 11A, and enhances workability during mounting as in the case shown in FIG.

  6 and 7 are graphs showing the relationship between the characteristic impedance of the common mode choke coil and the left-right symmetry when the resin portion is provided. 6 uses the common mode choke coil (same as that shown in FIG. 4) shown in FIG. 6A, and causes a high-frequency signal to flow in the signal direction 1 and the signal direction 2 respectively. The characteristic impedance of the coil was measured using TDR (Time Domain Reflectometry), and the measurement results are shown in FIG. According to the result shown in (b) of the figure, the frequency and the characteristic impedance of the common mode choke coil substantially coincide with each other regardless of whether the high frequency signal flows from the signal direction 1 or 2, and this common mode choke coil It can be seen that the characteristic impedance is substantially the same depending on the direction in which the signal flows, and that there is no directionality to the signal.

  On the other hand, as shown in FIG. 7A, the common mode choke coil in the case where the resin portion (hatched portion) is provided asymmetrically is similar to the case shown in FIG. The characteristic impedance was measured, and the result is shown in FIG. According to the result shown in (b) of the figure, when the high-frequency signal is flowed in the signal direction 1 and when the high-frequency signal is flowed in the signal direction 2, the characteristic impedance is different. It can be seen that the characteristic impedance varies depending on the direction in which the signal flows, and that the signal has directionality.

  The present invention is not limited to the above embodiments. For example, in each of the embodiments described above, the case where the resin portion for adjusting the characteristic impedance is provided one by one from the input / output side to the inside of the collar portion, but a plurality of locations may be provided, and the resin portion may be provided. The same number of capacitance components C need not be provided from the input / output side as long as the capacitance component C is equal. In short, it is included in the present invention unless it is contrary to the gist of the present invention.

  The present invention can be widely used in a common mode choke coil configured by winding a wire around a core.

It is a perspective view which shows one Embodiment of the common mode choke coil of this invention. It is a perspective view which shows other embodiment of the common mode choke coil of this invention. It is a perspective view which shows other embodiment of the common mode choke coil of this invention. It is a perspective view which shows other embodiment of the common mode choke coil of this invention. It is a perspective view which shows other embodiment of the common mode choke coil of this invention. It is a graph which shows the symmetry of the characteristic impedance of the common mode choke coil shown in FIG. It is a graph which shows the asymmetry of the characteristic impedance of the common mode choke coil to which the adhesive agent adhered asymmetrically. (A)-(c) is a figure which respectively shows the conventional common mode choke coil, (a) is the exploded perspective view, (b) is sectional drawing which shows the cross section of the axial center direction of a core part, (c) FIG. 3 is an enlarged cross-sectional view of the wire (b).

Explanation of symbols

10, 10A, 10B, 10C, 10D Common mode choke coil 11 Core 11A Winding core part 11B Hook part 12 Electrode 13A, 13B Insulated coating wire 14, 14A, 14B Resin part 15 Plate core 16 Adhesive

Claims (6)

  A core having a core part and a flange part at both ends thereof, an electrode formed integrally with the flange part, and a wire wound around the core part, and the wire is drawn from the core part. In the common mode choke coil connected to the electrode, a resin part made of a polymer material is provided for adjusting the capacitance on a part of the wire wound around the core part. Common mode choke coil.   2. The common mode choke coil according to claim 1, wherein the resin portion is disposed at at least one location at an equal distance from the input end and the output end of the wire.   The common mode choke coil according to claim 1 or 2, wherein the resin portion has a dielectric constant of 1.5 to 4.5.   4. The common according to claim 1, wherein a plate-like core made of a magnetic material or a non-magnetic material is installed between the pair of flanges via an adhesive. 5. Mode choke coil.   The common mode choke coil according to claim 4, wherein the adhesive is made of the same material as the resin portion. The protective layer of the wire is formed on the surface of the core portion opposite to the electrode, and the surface of the protective layer opposite to the wire side is formed flat. The common mode choke coil according to claim 3.

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