JP2013251378A - Laminated common-mode choke coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated common-mode choke coil having a high removal effect of common-mode noise by suppressing a common-mode component causing noise.SOLUTION: A laminated common-mode choke coil 11 includes first and second coils 31 and 41 that are spirally wound with the same number of turns, each of them being disposed at an upper layer and a lower layer. Ends of the first coil 31 are connected to first external-electrode connection conductors 33a and 33b via first coil-end draw-out portions 32a and 32b. Ends of the second coil 41 are connected to second external-electrode connection conductors 43a and 43b via second coil-end draw-out portions 42a and 42b. The first coil 31 includes a parallel portion 34 connected in parallel to a winding portion 31c located at the most outer periphery of the first coil 31. The parallel portion 34 constitutes an adjustment winding portion that increases the floating capacitance C formed between the first external-electrode connection conductors 33a and 33b.

Description

  The present invention relates to a laminated common mode choke coil composed of a pair of coils wound spirally with the same number of turns and arranged in a laminated manner.

  Conventionally, as this type of laminated common mode choke coil, for example, there is one disclosed in Patent Document 1. This laminated common mode choke coil is configured by first and second inner conductors being spirally wound in the same direction separated in the vertical direction inside the nonmagnetic insulating material layer. First and second magnetic material layers are provided on both upper and lower surfaces of the nonmagnetic insulating material layer to form a laminate, and the laminate is provided with external electrodes connected to the first and second internal conductors. . The nonmagnetic insulating material layer is formed by a second nonmagnetic insulating material in which the first spiral conductor is disposed, a fourth nonmagnetic insulating material in which the second spiral conductor is disposed, and the first and second external electrode connecting conductors. The third nonmagnetic material is laminated to form a structure. The first internal conductor is spirally wound with the first external electrode connection conductor connected to the first spiral conductor, and the second internal conductor is spiral with the second external electrode connection conductor connected to the second spiral conductor. It is wound.

  FIG. 1A is a plan view simply showing the winding configuration of the first inner conductor 1, and FIG. 1B is a plan view simply showing the winding configuration of the second inner conductor 2.

  As shown in FIG. 2A, the spirally wound first inner conductor 1 is formed on the nonmagnetic insulating material 3, and the end thereof is connected to the first coil end lead portions 4a and 4b via the first coil end lead portions 4a and 4b. 1 External electrode connection conductors 5a and 5b are connected. The first external electrode connection conductors 5a and 5b are connected to external electrodes provided on the outer periphery of the multilayer body, and become port 1 and port 2, respectively.

  As shown in FIG. 2B, the second inner conductor 2 is formed on the nonmagnetic insulating material 6 and spirally wound in the same pattern with the same number of turns as the first inner conductor 1. Second external electrode connection conductors 8a and 8b are connected to end portions of the second internal conductor 2 via second coil end lead portions 7a and 7b. The second external electrode connection conductors 8a and 8b are connected to external electrodes provided on the outer periphery of the multilayer body, and become port 3 and port 4, respectively.

JP 2005-142332 A

  In the conventional laminated common mode choke coil, when electric energy is supplied from the port 1 in the first coil formed by spirally winding the first inner conductor 1, it is adjacent to the first outer electrode connecting conductors 5a and 5b. Current flows in the opposite direction as shown by the arrow between the nearest coil winding portions 1a, 1b and the first coil end lead portions 4a, 4b. Further, in the second coil configured by spirally winding the second inner conductor 2, when electrical energy is supplied from the port 3, the nearest coil winding portion 2a adjacent to the second external electrode connection conductors 8a and 8b. , 2b and the second coil end lead portions 7a, 7b, currents flow in the same direction as indicated by arrows.

  For this reason, in the first coil configured by spirally winding the first inner conductor 1, magnetic flux cancellation occurs at the above location where current flows in the opposite direction. On the other hand, in the second coil configured by spirally winding the second inner conductor 2, the magnetic fluxes reinforce at the above-described locations where current flows in the same direction. Accordingly, there is a difference between the inductance acquired by the first coil and the inductance acquired by the second coil.

FIG. 2 is a graph showing an insertion loss characteristic S ₂₁ when electric energy is supplied from port 1 to port 2 and an insertion loss characteristic S ₄₃ when electric energy is supplied from port 3 to port 4. In the graph, the horizontal axis represents frequency [MHz] and the vertical axis represents insertion loss [dB]. The dotted line insertion loss characteristic curve A represents the insertion loss characteristics S _21, the solid line shows the insertion loss characteristic curve B representing the insertion loss characteristic S _43.

  As shown in the graph, the insertion loss represented by the insertion loss characteristic curve A and the insertion loss characteristic curve B is different in the high frequency band after 200 [MHz]. This is due to the difference in inductance obtained by the first and second coils described above. When a common mode choke coil with different insertion loss is inserted as a noise filter into the differential line, the filter itself generates a common mode component that causes noise. Therefore, the conventional laminated common mode choke coil cannot effectively remove common mode noise.

The present invention has been made to solve such problems,
A pair of first and second coils that are spirally wound with the same number of turns and arranged in layers, a first external electrode connection conductor that connects an end of the first coil to an external electrode, and a second coil A second external electrode connecting conductor connecting the end to the external electrode, and an end of the first coil through which current flows in a direction opposite to the winding portion of the first coil adjacent to the first external electrode connecting conductor The end of the second coil is connected to the second external portion through which current flows in the same direction as the first coil end lead portion connected to the external electrode connection conductor and the winding portion of the second coil adjacent to the second external electrode connection conductor. In the laminated common mode choke coil configured to include a second coil end lead portion connected to the electrode connection conductor,
The first coil includes an adjustment winding portion that increases the stray capacitance formed between the first external electrode connection conductor and matches the insertion loss with the insertion loss of the second coil at a specific frequency. Features.

  According to this configuration, since the first coil includes the adjustment winding portion, the stray capacitance formed between the first external electrode connection conductor and the first coil increases, and the insertion loss of the first coil is It coincides with the insertion loss of the second coil at a specific frequency. For this reason, the common mode components that cause noise are suppressed by being applied to differential transmission lines that transmit signals at a specific frequency. Provided.

  Further, according to the present invention, the adjustment winding portion is connected in parallel to the outermost winding portion of the first coil, and a part thereof is close to the first external electrode connection conductor to form a stray capacitance that increases. It is characterized by comprising a book or a plurality of conductors.

  According to this structure, an adjustment winding part is comprised from the 1 or several conductor connected in parallel with the winding part of the outermost periphery of a 1st coil. When a part of the adjustment winding part is close to the first external electrode connection conductor, the stray capacitance formed between the first external electrode connection conductor and the first coil increases, and the first coil The insertion loss matches the insertion loss of the second coil at a specific frequency.

  Further, according to the present invention, one conductor is formed at the outermost winding part, and a plurality of conductors are formed between the outermost winding part and the distance between them so that the decrease in inductance is suppressed. It is characterized by.

  According to this configuration, between one conductor and the outermost winding part, and for a plurality of conductors, between the outermost winding part and between the conductors, the conductors are close to a predetermined distance. By being formed, a decrease in inductance is suppressed. For this reason, even if one or a plurality of conductors are connected in parallel to the outermost winding portion of the first coil to form the adjustment winding portion, the decrease in inductance of the first coil is suppressed. The stray capacitance formed between the one external electrode connecting conductor and the first coil can be increased.

  Further, in the present invention, the adjustment winding portion is formed by increasing the distance at which the portion of the outermost winding portion of the first coil adjacent to the first external electrode connecting conductor forms a stray capacitance that is increased. It is characterized by being configured.

  According to this structure, an adjustment winding part is comprised by the part which adjoins the 1st external electrode connection conductor of the winding part of the outermost periphery of a 1st coil. Since the length of the adjacent portion is formed by increasing the distance for forming the stray capacitance to be increased, the stray capacitance formed between the first external electrode connection conductor and the first coil is increased. The insertion loss of the first coil coincides with the insertion loss of the second coil at a specific frequency.

  Further, the present invention is configured such that the adjustment winding portion has a length that forms a stray capacitance to be increased and a conductor facing the first external electrode connection conductor is added to the winding portion on the outermost periphery of the first coil. It is characterized by being.

  According to this configuration, the conductor facing the first external electrode connection conductor is added to the outermost winding portion of the first coil to constitute the adjustment winding portion. By setting the length of this conductor to a length that forms the stray capacitance to be increased, the stray capacitance formed between the first external electrode connecting conductor and the first coil is increased, and the insertion of the first coil is increased. The loss coincides with the insertion loss of the second coil at a specific frequency.

  According to the present invention, as described above, a laminated common mode choke coil that suppresses common mode components that cause noise and has a high effect of removing common mode noise is provided.

(A) is a top view which shows simply the winding structure of the 1st inner conductor in the conventional multilayer type common mode choke coil, (b) is a top view which shows the winding structure of the 2nd inner conductor simply. 2 is a graph showing insertion loss characteristics of each internal conductor in the conventional laminated common mode choke coil shown in FIG. 1 is an external perspective view of a laminated common mode choke coil according to an embodiment of the present invention. FIG. 4 is an exploded perspective view of the laminated common mode choke coil according to the embodiment shown in FIG. 3. (A) is a top view which shows the winding structure of the 1st coil in the laminated | stacked common mode choke coil by one Embodiment shown in FIG. 3, (b) is a top view which shows the winding structure of a 2nd coil. It is a graph which shows the insertion loss characteristic of the conductor line which comprises each coil of the lamination type common mode choke coil by one Embodiment shown in FIG. (A) is a top view which shows the 1st modification of the parallel part which comprises the adjustment winding part provided in the 1st coil shown to Fig.5 (a), (b) is the 2nd modification of the parallel part. It is a top view which shows an example. (A) is a top view which shows the adjustment winding part provided by the winding part of the outermost periphery of the 1st coil shown to Fig.5 (a), (b) is a top view which shows the modification. It is a top view which shows the adjustment winding part provided by adding a conductor to the winding part of the outermost periphery of the 1st coil shown to Fig.5 (a).

  Next, an embodiment of a laminated common mode choke coil according to the present invention will be described.

  FIG. 3 is an external perspective view of the stacked common mode choke coil 11 according to the present embodiment.

  The laminated common mode choke coil 11 is formed in a substantially rectangular parallelepiped shape with a laminated body 13 sandwiched between magnetic substrates 12a and 12b. A pair of first external electrodes 14 a and 14 b and second external electrodes 15 a and 15 b are provided around the opposing side surfaces of the stacked common mode choke coil 11.

  FIG. 4 is an exploded perspective view of the laminated common mode choke coil 11. In the figure, the same parts as those in FIG.

  The laminate 13 is configured by alternately laminating insulating layers 16 to 20 and electrode layers 21 to 24.

  The lowermost first insulating layer 16 of the stacked body 13 is formed on the magnetic substrate 12 a, and the first electrode layer 21 is formed on the first insulating layer 16. The first electrode layer 21 is formed by winding a conductor in a spiral. This conductor wound spirally constitutes the first coil 31, and its outer peripheral end is connected to the first external electrode connecting portion 33a via the first coil end leading portion 32a. The first external electrode connection portion 33a is connected to the external electrode 14a (see FIG. 3). Further, a parallel portion 34 composed of two conductors 34 a and 34 b is connected in parallel to the outermost winding portion of the first coil 31.

  A second electrode layer 22 is formed on the first electrode layer 21 via the second insulating layer 17. The second electrode layer 22 is formed by connecting the first external electrode connecting portion 33b to the conductor constituting the first coil end lead portion 32b. An end portion of the first coil end lead portion 32 b is connected to an inner peripheral side end portion of the first coil 31 through a via hole 35 formed in the second insulating layer 17. The first external electrode connection portion 33b is connected to the external electrode 14b (see FIG. 3).

  On the 2nd electrode layer 22, the 3rd electrode layer 23 is formed through the 3rd insulating layer 18 which consists of insulating layers 18a and 18b. The third electrode layer 23 is formed by winding a conductor constituting the second coil 41 in a spiral shape. The outer peripheral side end of the second coil 41 is connected to the second external electrode connecting portion 43a via the second coil end leading portion 42a. The second external electrode connection portion 43a is connected to the external electrode 15a (see FIG. 3).

  A fourth electrode layer 24 is formed on the third electrode layer 23 via a fourth insulating layer 19. The fourth electrode layer 24 is formed by connecting the second external electrode connection portion 43b to a conductor constituting the second coil end lead portion 42b. The end of the second coil end lead portion 42 b is connected to the inner peripheral end of the second coil 41 through a via hole 45 formed in the fourth insulating layer 19. The second external electrode connection portion 43b is connected to the external electrode 15b (see FIG. 3).

  A fifth insulating layer 20 as the uppermost layer of the multilayer body 13 is formed on the fourth electrode layer 24, and an adhesive layer 25 including a first adhesive layer 25 a and a second adhesive layer 25 b is stacked on the fifth insulating layer 20. Has been. The adhesive layer 25 is formed by adhering the laminated body 13 formed on the magnetic substrate 12a to the magnetic substrate 12b, and as shown in FIG. 3, the laminated common mode choke coil 11 is connected to the magnetic substrate 12a, The laminated body 13 is sandwiched between 12b.

  FIG. 5A is a plan view showing the winding configuration of the first coil 31 with the second insulating layer 17 omitted, and FIG. 5B shows the winding configuration of the second coil 41 in the fourth insulation. FIG. 6 is a plan view showing the layer 19 with illustration omitted.

  The first and second pair of coils 31 and 41 are spirally wound with the same number of turns and the same pattern, and are laminated on the upper layer and the lower layer as described above. The generated magnetic flux is linked to the same closed magnetic path.

  As shown in FIG. 5A, the end of the first coil 31 is connected to the first external electrode connection conductors 33a and 33b via the first coil end lead portions 32a and 32b. The first external electrode connection conductors 33a and 33b constitute port 1 and port 2, respectively, and the end of the first coil 31 is connected to the external electrodes 14a and 14b via the first coil end lead portions 32a and 32b. doing. When electric energy is supplied from the port 1 to the port 2, the first coil end lead portions 32a and 32b are provided with the nearest first adjacent electrode electrodes 33a and 33b adjacent to the first external electrode connection conductors 33a and 33b as indicated by arrows. A current flows in the opposite direction to the winding portions 31a and 31b of one coil 31.

  As shown in FIG. 2B, the end of the second coil 41 is connected to the second external electrode connection conductors 43a and 43b via the second coil end lead portions 42a and 42b. The second external electrode connection conductors 43a and 43b connect the end of the second coil 41 to the external electrodes 15a and 15b via the second coil end lead portions 42a and 42b. When electric energy is supplied from the port 3 to the port 4, the second coil end lead portions 42a and 42b are provided with the second outer electrode connection conductors 43a and 43b adjacent to the second outer electrode connection conductors 43a and 43b as indicated by arrows. A current flows in the same direction as the winding portions 41 a and 41 b of the two coils 41.

  Moreover, the 1st coil 31 shown to the figure (a) is provided with the parallel part 34 connected in parallel with the winding part 31c of the outermost periphery of the 1st coil 31. As shown in FIG. The parallel portion 34 increases the stray capacitance C formed between the first external electrode connection conductors 33a and 33b, and adjusts the insertion loss to match the insertion loss of the second coil 41 at a specific frequency. Parts. In the present embodiment, the parallel part 34 constituting the adjustment winding part has each part of both ends in the longitudinal direction of the two conductors 34a and 34b close to the first external electrode connection conductors 33a and 33b, A stray capacitance C to be increased is formed.

  In the present embodiment, the two conductors 34a and 34b constituting the parallel portion 34 are connected to the outermost winding part 31c and between the conductors, so that a decrease in inductance can be suppressed. It is formed very close to a distance of about μm].

  In such a stacked common mode choke coil 11, insulating layers 16 to 20 and electrode layers 21 to 24 are alternately stacked a plurality of times on a magnetic substrate 12a, and a desired circuit pattern is formed using a photolithography technique. By constructing the internal circuit layer, it is manufactured as follows.

First, the first insulating layer 16 is formed on the magnetic substrate 12a by a thin film forming method such as a spin method, a dip method, or a spray method. A magnetic material such as ferrite is used as the material of the substrates 12a and 12b, but a dielectric or an insulator is used depending on the use of the laminated common mode choke coil 11. Further, the insulating layer 16 to 20, polyimide resin, epoxy resin, various resin materials such as benzocyclobutene resin, or glass such as SiO _2, glass ceramic, insulating material of the dielectric and the like are used. When a photolithography method is used, a material to which a photosensitive function is added is used as each material. As a constituent material of the insulating layers 16 to 20, a combination of a plurality of materials may be used depending on the purpose. In the present embodiment, a photosensitive polyimide resin is used as the material for the insulating layers 16 to 20.

  Next, the conductive material film of the first electrode layer 21 is formed on the upper surface of the first insulating layer 16 by a film forming technique such as a thin film forming method such as sputtering or vapor deposition, or a thick film forming method such as a screen printing method. Thereafter, a series of photolithography techniques such as resist coating, exposure, development, etching, and the like are used to form conductor patterns of the first coil 31, the first coil end lead portion 32a, the first external electrode connection portion 33a, and the parallel portion 34. Is formed on the first electrode layer 21. Here, the first external electrode connection portion 33a is formed into a conductor pattern drawn out to the side surface of the component.

  The insulating layers 16 to 20 and the electrode layers 21 to 24 should be polished so that the surface roughness Ra is 0.5 [μm] or less so as not to hinder the formation by the photolithography method. Is desirable. Moreover, as an electrode material of the electrode layers 21-24, it is desirable to use metals, such as Ag, Pd, Cu, Al, etc. excellent in electroconductivity, or these alloys. In this embodiment, Ag is used as the electrode material of the electrode layers 21 to 24. However, the combination of the electrode material of the electrode layers 21 to 24 and the insulating material of the insulating layers 16 to 20 is a viewpoint of workability, adhesion, and the like. Therefore, it is desirable to select the combination so that there is no problem.

  Next, the second insulating layer 17 is formed on the first electrode layer 21 in the same manner as the first insulating layer 16. A hole is formed in the second insulating layer 17 by a photolithography technique at a position where the via hole 35 is formed. The inner peripheral side end of the first coil 31 is exposed in this hole. Next, the conductive material film of the second electrode layer 22 is formed on the upper surface of the second insulating layer 17 in the same manner as the first electrode layer 21. Thereafter, a conductive pattern of the first coil end lead portion 32b and the first external electrode connection portion 33b is formed on the second electrode layer 22 by using a photolithography technique. Here, the first external electrode connecting portion 33b is also formed into a conductor pattern drawn out to the side surface of the component. When the second electrode layer 22 is formed, the hole formed in the second insulating layer 17 is filled with a conductive material, and the inner peripheral side end portion of the first coil 31 is connected to the end portion of the first coil end lead portion 32b. A via hole 35 to be connected to is formed.

  Next, the insulating layers 18 a and 18 b of the third insulating layer 18 are sequentially formed on the second electrode layer 22 in the same manner as the first insulating layer 16. Then, the conductive material film of the third electrode layer 23 is formed on the upper surface of the third insulating layer 18 in the same manner as the first electrode layer 21. Thereafter, a conductor pattern of the second coil 41, the second coil end lead portion 42a, and the second external electrode connection portion 43a is formed on the third electrode layer 23 by using a photolithography technique. Here, the second external electrode connection portion 43a is also formed into a conductor pattern drawn out to the side surface of the component.

  Next, the fourth insulating layer 19 is formed on the third electrode layer 23 in the same manner as the first insulating layer 16. A hole is formed in the fourth insulating layer 19 by a photolithography technique at a position where the via hole 45 is formed. The inner peripheral side end of the second coil 41 is exposed in this hole. Next, the conductive material film of the fourth electrode layer 24 is formed on the upper surface of the fourth insulating layer 19 in the same manner as the first electrode layer 21. Thereafter, the conductive pattern of the second coil end lead portion 42 b and the second external electrode connection portion 43 b is formed on the fourth electrode layer 24 using a photolithography technique. Here, the second external electrode connecting portion 43b is also formed as a conductor pattern drawn out to the side surface of the component. When the fourth electrode layer 24 is formed, the hole formed in the fourth insulating layer 19 is filled with a conductive material, and the inner peripheral side end of the second coil 41 is connected to the end of the second coil end lead portion 42b. A via hole 45 to be connected to is formed.

  Next, the fifth insulating layer 20 is formed on the fourth electrode layer 24 in the same manner as the first insulating layer 16, and the laminate 13 is formed on the magnetic substrate 12a. Thereafter, the first adhesive layer 25a constituting the adhesive layer 25 is applied on the fifth insulating layer 20 as the uppermost layer of the laminated body 13, and the adhesive layer 25 is constituted on the surface of the magnetic substrate 12b facing the laminated body 13. The second adhesive layer 25b is applied. Next, the magnetic substrate 12b is placed on the upper surface of the laminate 13, and the laminate 13 is set in a vacuum hot press machine with the magnetic substrates 12a and 12b sandwiched therebetween. The magnetic substrate 12b is attached to the adhesive layer 25. Is bonded to the laminate 13 by thermocompression bonding.

  This bonding of the magnetic substrate 12b is performed by a process of heating and pressurizing in a vacuum or an inert gas and releasing the pressure after cooling. As a general method for mounting a small and low-profile electronic component on a circuit board, there is a reflow mounting. However, in most cases, the maximum temperature reached by the electronic component when reflow mounting is around 260 ° C. For this reason, a thermosetting polyimide resin is used as the material for the adhesive layer 25 of the present embodiment. However, when a thermoplastic resin is used as the material of the adhesive layer 25, the glass transition temperature is 270 ° C. or higher. Things are used.

  Further, at the time of joining the magnetic substrate 12b, a high temperature of 350 ° C. to 390 ° C. is applied and thermocompression bonding is performed. If gas flows out of the component material at this high temperature, voids are formed in the adhesive layer 25. This hole causes a decrease in adhesion at the joint, and when moisture accumulates in the hole, it leads to a short circuit of the conductor pattern forming the electrode layers 21 to 24. For this reason, in this embodiment, a material having a heat resistant temperature of 400 ° C. or higher is used as the material of the adhesive layer 25.

  In the laminated common mode choke coil 11, a large number of elements are simultaneously formed on a mother substrate. After element formation, the chip is cut out and divided from the mother substrate by cutting such as dicing. After dividing into chips, the laminated common mode choke coil 11 includes external electrodes 14a, 14b and 15a, 15b that are electrically connected to the first external electrode connection conductors 33a, 33b and the second external electrode connection conductors 43a, 43b, as shown in FIG. As shown in FIG. The external electrodes 14a, 14b and 15a, 15b are formed by applying a conductive paste containing a material such as Ag, Ab-Pd, Cu, NiCr or NiCu, or by depositing the material by sputtering or vapor deposition. ,It is formed. Thereafter, a metal film such as Ni, Sn, Sn-Pb or the like is formed on the external electrodes 14a, 14b and 15a, 15b, for example, by wet electrolytic plating.

FIG. 6 shows an insertion loss characteristic S ₂₁ when electric energy is supplied from the port 1 of the first coil 31 to the port 2, and an insertion loss characteristic when electric energy is supplied from the port 3 of the second coil 41 to the port 4. the S _43, is a graph illustrating a simulation. In the graph, the horizontal axis represents frequency [MHz] and the vertical axis represents insertion loss [dB]. The dotted line insertion loss characteristic curve C represents the insertion loss characteristics S _21, the solid line shows the insertion loss characteristic curve D representing the insertion loss characteristic S _43.

  As shown in the graph, in this simulation, the insertion loss represented by the insertion loss characteristic curve C and the insertion loss characteristic curve D coincide with each other at 6 [GHz] as indicated by a thick arrow in the graph. Yes. That is, the insertion loss of the first coil 31 matches the insertion loss of the second coil 41 at a specific frequency of 6 [GHz].

  According to the laminated common mode choke coil 11 of the present embodiment as described above, the first coil 31 includes the parallel part 34 constituting the adjustment winding part as shown in FIG. A part of the first external electrode connection conductors 33a and 33b is close to the first external electrode connection conductors 33a and 33b, so that the stray capacitance C formed between the first external electrode connection conductors 33a and 33b and the first coil 31 increases. The insertion loss of the first coil 31 coincides with the insertion loss of the second coil 41 at a specific frequency of 6 [GHz], for example, as shown in FIG. This specific frequency can be set to a desired value by adjusting the size of the stray capacitance C to be increased. For this reason, by being applied to a differential transmission system line that transmits a signal at a specific frequency, the common mode component that causes noise is suppressed, and the stacked common mode choke coil 11 having a high effect of removing common mode noise. Is provided.

  Further, the two conductors 34a and 34b constituting the parallel portion 34 are connected in parallel to the winding portion 31c, so that the normal inductance is reduced. However, in this embodiment, the two conductors 34a and 34b are very close to a predetermined distance of about 10 to 20 [μm] between the outermost winding part 31c and between the conductors. By being formed, a decrease in inductance is suppressed, and the inductance value is almost the same as the original value. For this reason, even if the two conductors 34a and 34b are connected in parallel to the outermost winding part 31c of the first coil 31 to form the adjustment winding part, a decrease in inductance of the first coil 31 is suppressed. Meanwhile, the stray capacitance C formed between the first external electrode connection conductors 33a and 33b and the first coil 31 can be increased.

  In the above embodiment, the case where the parallel portion 34 constituting the adjustment winding portion is formed by the two conductors 34a and 34b as shown in FIG. 5A has been described. Even if it is formed of three or more conductors depending on the size of the conductor, or even if it is formed of one conductor, the same effect as the above-described embodiment is achieved, and the common mode causes noise The laminated common mode choke coil 11 is provided which has a suppressed component and a high common mode noise removal effect. At this time, the distance between the outermost winding part 31c for one conductor and the distance between the outermost winding part 31 and the conductors for a plurality of conductors are about 10 to 20 [μm]. By being formed close to a predetermined distance, a decrease in inductance is suppressed. For this reason, as in the case of the above-described embodiment, the stray capacitance C formed between the first external electrode connection conductors 33a and 33b and the first coil 31 while suppressing the decrease in the inductance of the first coil 31. Can be increased.

  In the above embodiment, as shown in FIG. 7A, one conductor 34a may be omitted, and the parallel portion 34A may be formed by one conductor 34b. In FIG. 7, the same parts as those in FIG. In this configuration, the distance between the conductor 34b and the winding portion 31c is increased, and the inductance is reduced as compared with the case of the above embodiment. However, since the distance that a part of the parallel part 34A approaches the first external electrode connection conductors 33a and 33b becomes longer and the stray capacitance C increases, the self-resonance of the first coil 31 determined by the inductance and the stray capacitance C is increased. The frequency moves to the low frequency side. Therefore, the insertion loss of the first coil 31 matches the insertion loss of the second coil 41 at a specific frequency. For this reason, the effect similar to said embodiment is show | played by making this specific frequency into a signal frequency.

  Further, as shown in FIG. 4B, even if the parallel portion 34B is formed by the conductor 34b1 having a large line width, the distance that a part of the parallel portion 34B is close to the first external electrode connection conductors 33a and 33b is long. As a result, the stray capacitance C increases. Further, the inductance is reduced by increasing the line width of the conductor 34b1, but the conductor 34b1 and the outermost winding part 31c are formed close to a predetermined distance of about 10 to 20 [μm]. Thus, the decrease in inductance can be kept low. For this reason, also in this configuration, the self-resonant frequency of the first coil 31 moves to the low frequency side determined by the formed inductance and the increasing stray capacitance C, and the first coil 31 and the second coil 31 at the specific frequency. The insertion loss of the coil 41 matches, and the same effect as the above-described embodiment is achieved.

  Moreover, in said embodiment and each modification, it forms between 1st external electrode connection conductors 33a and 33b by the parallel parts 34, 34A, and 34B connected in parallel with the winding part 31c of the 1st coil 31. The adjustment winding part which increases the stray capacitance C to be formed was configured. However, as shown in FIG. 8A, the distance for forming the stray capacitance C that increases the portion of the outermost winding portion 31c of the first coil 31 adjacent to the first external electrode connection conductors 33a and 33b. The adjustment winding portion may be configured by forming a long detour. In FIG. 8, the same parts as those in FIG.

  According to this configuration, the lengths of the portions of the winding portion 31c adjacent to the first external electrode connection conductors 33a and 33b are formed to be long, so that the first external electrode connection conductors 33a and 33b, the first coil 31, and The stray capacitance C formed during the period increases. In addition, the winding portion 31c is formed to be detoured long because the inductance is reduced by the current flowing in the opposite direction to the first coil end lead portions 32a and 32b and the winding portions 31a and 31b adjacent thereto. As a result, the inductance of the first coil 31 increases by the decrease. Therefore, the insertion loss of the first coil 31 matches the insertion loss of the second coil 41 at a specific frequency. For this reason, also by this structure, the effect similar to said embodiment is show | played.

  Further, as shown in FIG. 5B, even if the first coil 31 is constituted by the outermost winding part 31c1 having a thick line width, the first external electrode connecting conductors 33a and 33b of the winding part 31c1 are formed. The length of the adjacent portion is increased by the distance for forming the stray capacitance C to be increased, so that the stray capacitance C formed between the first external electrode connection conductors 33a and 33b and the first coil 31 is increased. To do. However, a decrease in inductance due to an increase in the line width of the winding portion 31c1 is inevitable, but even in this configuration, the self-resonant frequency of the first coil 31 is determined by the formed inductance and the increasing stray capacitance C. Moving to a fixed low frequency side, the insertion loss of the first coil 31 and the second coil 41 coincides at a specific frequency, and the same effect as the above-described embodiment is achieved.

  Further, as shown in FIG. 9, the conductors 51 a and 51 b facing the first external electrode connection conductors 33 a and 33 b having a length that forms the stray capacitance C to be increased are wound around the outermost winding portion of the first coil 31. In addition to 31c, an adjustment winding part may be configured. In the figure, the same parts as those in FIG. 5A are denoted by the same reference numerals, and the description thereof is omitted. According to this configuration, the length of the conductors 51a and 51b facing the first external electrode connection conductors 33a and 33b is set to a length that forms the stray capacitance C to be increased, whereby the first external electrode connection conductor 33a. , 33b and the first coil 31 increase in stray capacitance C, and the insertion loss of the first coil 31 matches the insertion loss of the second coil 41 at a specific frequency. For this reason, also by this structure, the effect similar to said embodiment is show | played.

DESCRIPTION OF SYMBOLS 11 ... Laminated type common mode choke coil 12a, 12b ... Magnetic substrate 13 ... Laminated body 14a, 14b, 15a, 15b ... External electrode 16-20 ... Insulating layer 21-24 ... Electrode layer 31 ... 1st coil 41 ... 2nd Coils 31a, 31b, 31c, 31c1 ... winding portions 32a, 32b of the first coil ... first coil end lead portions 42a, 42b ... second coil end lead portions 33a, 33b ... first external electrode connection conductors 43a, 43b: second external electrode connection conductors 34a, 34b, 34b1, 51a, 51b ... conductors 34, 34A, 34B ... parallel portions 35, 45 ... via holes C ... stray capacitance

Claims (5)

A pair of first and second coils that are spirally wound with the same number of turns and stacked, a first external electrode connection conductor that connects an end of the first coil to an external electrode, and the second A second external electrode connecting conductor connecting an end of the coil to the external electrode, and a current flows in a direction opposite to a winding portion of the first coil adjacent to the first external electrode connecting conductor. A current flows in the same direction as a first coil end lead portion connecting an end portion to the first external electrode connection conductor and a winding portion of the second coil adjacent to the second external electrode connection conductor. In a laminated common mode choke coil configured to include a second coil end lead portion connecting an end portion of two coils to the second external electrode connecting conductor,
The first coil includes an adjustment winding portion that increases a stray capacitance formed between the first external electrode connection conductor and matches an insertion loss with the insertion loss of the second coil at a specific frequency. A laminated common mode choke coil.   The adjustment winding portion is connected in parallel to the outermost winding portion of the first coil, and a part of the adjustment winding portion is close to the first external electrode connection conductor to form the stray capacitance to be increased. 2. The laminated common mode choke coil according to claim 1, comprising a plurality of conductors.   One conductor is formed on the outermost winding part, and a plurality of the conductors are formed on the outermost winding part close to a distance at which a decrease in inductance is suppressed. The laminated common mode choke coil according to claim 2.   The adjustment winding portion is configured such that a portion of the outermost winding portion of the first coil that is close to the first external electrode connection conductor is formed to have a long distance to form the stray capacitance that is increased. The laminated common mode choke coil according to claim 1.   The adjustment winding portion is configured such that a conductor facing the first external electrode connection conductor having a length that forms the stray capacitance to be increased is added to the outermost winding portion of the first coil. The multilayer common mode choke coil according to claim 1.

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