JP2008186996A - Coil component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coil component which makes winding work to a core member easy and can secure a middle point of a winding without winding a wire. <P>SOLUTION: A coil component 10 comprises a core member 11 having a rod-like winding core, first to fourth wires 14 to 17 wound on the winding core, and first to fourth terminal electrode pairs 18 or 21 to which both ends of these wires are connected, respectively. The first to fourth wires 14 to 17 are constituted as one strand. Line lengths of wiring portions of the wires are set to be substantially the same. The coil component 10 is mounted to a printed-circuit board 30. A land 32A of a first land pattern pair 32 and a land 34B of a third land pattern pair 34 are connected by a first connection conductive pattern 36. A land 33A of a second land pattern pair 33 and a land 35B of a fourth land pattern pair 35 are connected by a second connection conductive pattern 37. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a coil component, and more particularly to a core shape and a winding structure of the coil component.

  A pulse transformer is used as one of coil components in which a plurality of wires are wound around a core member (see, for example, Patent Document 1).

  FIG. 11 is a schematic perspective view showing an example of the configuration of a conventional pulse transformer, and FIG. 12 shows an equivalent circuit diagram of the pulse transformer shown in FIG.

As shown in FIGS. 11 and 12, this pulse transformer 600 has a structure in which a primary winding 42 and a secondary winding 43 are wound around a toroidal core 41, and a pair of transformer primary windings 42 are used. Input ends 42a and 42b, a midpoint 42c of the primary winding, and a pair of output ends 43a and 43b formed by the secondary winding 43 of the transformer.
JP-A-7-161535

  In the conventional pulse transformer 600 described above, the primary winding 42 and the secondary winding 43 are formed by winding a plurality of wires around the toroidal core 41. Further, the middle point 42c of the primary winding 42 is formed by connecting the ends of two wires.

  However, there is a problem that the winding work around the toroidal core 41 is very complicated and difficult to automate. Further, since the wiring state becomes complicated due to the connection between the wires, there are problems such as variations in characteristics and a decrease in reliability. In addition, since the wiring state is complicated, there is a problem that it is difficult to reduce the size of the product.

  As the core member constituting the closed magnetic path, there are various shapes other than the toroidal core. For example, a combination of a drum core and a plate-like core is known. According to this, although the winding work is easier than that of the toroidal core, there is a problem that when a plurality of wires are wound, the wire lengths of the winding portions of the respective wires are easily shifted and the inductance characteristics vary.

  Accordingly, an object of the present invention is to provide a coil component that facilitates winding work around a core member and that has small variations in inductance characteristics.

  The above object of the present invention is to provide a core member having a winding core portion made of a rod-shaped magnetic body, at least three wires wound around the winding core portion, and a connecting portion where the ends of each wire are connected. This is achieved by a coil component characterized in that the wire length of the winding portion of each wire is substantially the same. According to the present invention, since the wire lengths of the winding portions of the wires are substantially the same, the wires can be coupled in a well-balanced manner, and variations in inductance characteristics can be reduced. Further, according to the coil component of the present invention, it can be used as a pulse transformer or a common mode filter depending on the connection method between the ends of the wire, and can also be used as a normal coil. A highly versatile coil component can be realized.

  In the present invention, it is preferable that at least three wires are configured as one stranded wire. According to this, the wire lengths of the winding portions of the respective wires can be surely aligned, and variations in characteristics can be reliably reduced.

  In the present invention, it is preferable that at least three wires are integrated through an insulating coating. According to this, insulation can be improved while sufficiently securing the magnetic coupling between the wires, and the wire length of the winding portion of each wire can be surely aligned, and a more reliable winding structure Can be realized.

  In the present invention, the wire is preferably composed of first and fourth wires. In particular, in the half region of the core, the first and second wires are bifilar wound on the inner periphery and the third and fourth wires are bifilar wound on the outer periphery, while the remaining half of the core is In this region, it is preferable that the third and fourth wires are bifilar wound on the inner periphery and the first and second wires are bifilar wound on the outer periphery. Also in this case, the wire lengths of the winding portions of the respective wires can be surely aligned, the wires can be coupled in a well-balanced manner, and variations in inductance characteristics can be reliably reduced.

  As described above, according to the present invention, it is possible to easily perform the winding work around the core and to provide a coil component having a small variation in inductance characteristics.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic perspective view showing an external structure of a coil component according to the first embodiment of the present invention. FIG. 2 is a schematic bottom view showing the structure of the bottom surface of the coil component.

  As shown in FIGS. 1 and 2, the coil component 10 includes a core member 11 having a rod-shaped core part, first to fourth wires 14 to 17 wound around the core part, The first terminal electrode pair 18 to which both ends of the wire 14 are connected, the second terminal electrode pair 19 to which both ends of the second wire 15 are connected, and the both ends of the third wire 16 are connected to each other. And the fourth terminal electrode pair 21 to which both ends of the fourth wire 17 are connected.

  The core member 11 includes a drum core 12 and a plate-like core 13 attached to the top of the drum core 12. The drum core 12 includes a rod-shaped core portion 12A and first and second flange portions 12B and 12C provided at both ends of the core portion 12A, respectively, and has an integrated configuration. . The plate-like core 13 is a separate body from the drum core 12, but is bonded and fixed to the upper surfaces of the first and second flanges 12B and 12C. Thus, the drum core 12 and the plate core 13 constitute one closed magnetic path.

The core portion 12A of the drum core 12 four wires 14 to 17 is wound in the same direction, whereby the first to fourth coil L ₁ through L ₄ is configured. The four wires 14 to 17 are preferably wound in a highly coupled state. In order to set the first to fourth wires 14 to 17 in a highly coupled state, as shown in FIG. 3, the first to fourth wires 14 to 17 may be configured as one stranded wire, Or you may comprise as a twisted wire of a pair wire. Further, as shown in FIG. 4, the first to fourth wires 14 to 17 covered with the insulator 22 may be integrated in a single strand. Alternatively, the first to fourth wires 14 to 17 may be a bi-layered bifilar winding. That is, as shown in FIG. 5, in the half region of the core portion 12A, the wires 14, 15 are bifilar wound on the inner periphery, and the wires 16, 17 are bifilar wound on the outer periphery, while the core portion 12A In the remaining half region, the wires 16 and 17 may be bifilar wound on the inner circumference, and the wires 14 and 15 may be bifilar wound on the outer circumference. In these cases, since the wire lengths of the winding portions of the first to fourth wires 14 to 17 are substantially the same, the wires 14 to 17 can be coupled in a balanced manner, and the coils L _{1 to} L ₁ can be coupled. characteristics of L ₄ are approximately the same.

  When the wire is a single strand, a pair of strands, or two layers of bifilar winding, the four wires are preferably bundled from a position in contact with the core portion 12A. In this way, the stray capacitance can be reduced because the lead portions are separated. Moreover, the wiring of the lead wire is facilitated, and the manufacture of the coil component 10 is facilitated. Further, when the wire is a single strand, a pair of strands, or two layers of bifilar winding, four wires are formed at a hollow position between the terminal electrode and a position in contact with the core portion 12A. You may start to bundle. In this way, since the coupling is further improved, the characteristics can be further improved.

  The first to fourth terminal electrode pairs 18 to 21 are connecting portions to which the ends of the wires 14 to 17 are connected, and the first and second terminal electrodes provided at both ends of the core portion 12A. It is provided on the bottom surface of the flanges 12B and 12C. In particular, one terminal electrode 18A to 21A is provided on the bottom surface of the first flange portion 12B, and the other terminal electrode 18B to 21B is provided on the bottom surface of the second flange portion 12C. These terminal electrode pairs 18 to 21 are arranged in order along the longitudinal direction of the bottom surfaces of the first and second flange portions 12B and 12C, and one terminal electrode 18A to 21A and the other terminal electrode 18B. The positions of 21B coincide with each other.

  One end 14 a of the first wire 14 is connected to one terminal electrode 18 A of the first terminal electrode pair 18, and the other end 14 b of the first wire 14 is connected to the other terminal electrode of the first terminal electrode pair 18. 18B. Similarly, one end 15a and the other end 15b of the second wire 15 are connected to one terminal electrode 19A and the other terminal electrode 19B of the second terminal electrode pair 19, respectively, and one end 16a and the other end of the third wire 16 are respectively connected. 16b is connected to one and the other terminal electrodes 20A and 20B of the third terminal electrode pair 20, respectively, and one end 17a and the other end 17b of the fourth wire 17 are connected to one and the other of the fourth terminal electrode pair 21, respectively. Terminal electrodes 21A and 21B.

  On the other hand, the printed circuit board 30 includes a first land pattern pair 32A, 32B, a second land pattern pair 33A, 33B, and a third land pattern pair 34A, 34B provided in the mounting region 31 of the coil component 10. And a fourth land pattern pair 35A, 35B. Further, the printed circuit board 30 includes a first connection conductor pattern 36 that connects one land 32A of the first land pattern pair 32 and the other land 34B of the third land pattern pair 34, and a second land pattern. A second connection conductor pattern 37 that connects a land 33A on one end side of the pair 33 and a land 35B on the other end side of the fourth land pattern pair 35 is provided.

  The first and second connection conductor patterns 36 and 37 are provided in the mounting region 31 of the coil component 10 and are formed directly below the coil component 10. Therefore, the transformer component mounting area 31 can be effectively used, and other component mounting areas on the printed circuit board can be made wider. The first and second connection conductor patterns 36 and 37 are wired in parallel with each other close to each other. Thereby, the shift | offset | difference of the impedance resulting from the connection conductor patterns 36 and 37 can be prevented.

  FIG. 6 is a circuit diagram of the coil component 10 mounted on the printed board 30.

As shown in FIG. 6, one end of the third wire 16 constituting the coil L ₃ is connected to the land 34 A forming the input terminal 1, and the other end of the wire 16 is connected to the coil L ₁ via the connection conductor pattern 36. The first wire 14 is connected to one end of the first wire 14, and the other end of the first wire is connected to the land 32 </ b> B forming the input terminal 2. One end of the fourth wire 17 constituting the coil L ₄ is connected to the land 35 A forming the output terminal 1, and the other end of the wire 17 is connected to the second wire 15 via the second connection conductor pattern 37. Connected to one end. Thus, the transformer circuit is configured with a primary winding consisting of coils L ₃ and the coil L _1, and a secondary winding consisting of coils L ₄ and the coil L _2. Further, the midpoint of the primary winding is formed by the lands 34 </ b> B and 33 </ b> A that are connection points between the third wire 16 and the first wire 14.

  As described above, according to this embodiment, since the wire lengths of the winding portions of the first to fourth wires 14 to 17 are substantially the same, the variation in the characteristics of the coil components is sufficiently small. And the product can be miniaturized. Further, since the drum core 12 is used as the core member 11, the wires 14 to 17 can be easily wound and automatic winding is also possible. Further, terminal electrode pairs 18 to 21 of the respective wires are provided on the bottom surface of the drum core 12, and the connection between the wires is performed not by connecting the ends of the wires but by connecting conductor patterns 36 and 37 on the printed circuit board 30. Therefore, it becomes easy to secure the connection between the wires and the middle point of the winding.

  FIGS. 7A and 7B are views showing a second mounting form of the coil component 10. FIG. 7A is a circuit diagram, and FIG. 7B is a pattern layout on the printed circuit board 30. Show.

  As shown in FIGS. 7A and 7B, in this mounting form, the first and second terminal electrode pairs 18 located outside one of the first to fourth terminal electrode pairs 18 to 21 are the first and second terminals. This is characterized in that the terminal electrode pair 21 located outside the other terminal terminal constitutes the first and second output terminals. Therefore, in the coil component 10, the other end 14b of the first wire 14 is connected to the terminal electrode 19B, and the other end 15b of the second wire 15 is connected to the terminal electrode 18B. The other end 14b of the first wire 14 is connected to the terminal electrode 19B, and the other end 15b of the second wire 15 is connected to the terminal electrode 18B. Further, the first connection conductor pattern 36 connects the lands 33A and 33B, and the second connection conductor pattern 37 connects the lands 34A and 34B. Since other configurations are the same as those of the first mounting form, detailed description thereof is omitted.

  According to the second mounting form, since the pair of input terminals and output terminals are arranged on the outermost side of the terminal electrode array, the pair of input signal lines 1 and 2 are laid in parallel on the printed circuit board 30. The pair of output signal lines 3 and 4 can be laid in parallel. This eliminates the need for bypassing the wiring pattern on the printed circuit board 30. Therefore, the area occupied by the wiring pattern on the printed circuit board 30 does not increase more than necessary, and symmetry can be ensured. As a result, it is possible to simultaneously reduce the size of the entire apparatus and improve the signal quality.

  8A and 8B are views showing a third mounting form of the coil component 10, where FIG. 8A is a circuit diagram, and FIG. 8B is a pattern layout on the printed circuit board 30. Show.

As shown in FIG. 8 (a) and (b), in this implementation, a primary winding coil component 10 is composed of a coil L ₄ and the coil L _3, the secondary winding comprising a coil L ₂ and the coil L ₁ It is characterized in that it is configured as a transformer circuit including In this case, the midpoint of the primary winding is formed by the lands 35 </ b> B and 34 </ b> A that are connection points between the fourth wire 17 and the third wire 16. The first and second connection conductor patterns 36 and 37 are wired in parallel with each other close to each other. Thereby, the shift | offset | difference of the impedance resulting from the connection conductor patterns 36 and 37 can be prevented. Since other configurations are the same as those of the first embodiment, detailed description thereof is omitted. As described above, according to the present embodiment, since the connection between the wires is performed by routing the connection conductor patterns 36 and 37 on the printed circuit board 30, the same effects as those of the first embodiment can be obtained.

  FIGS. 9A and 9B are views showing a fourth mounting form of the coil component 10. FIG. 9A is a circuit diagram, and FIG. 9B is a pattern layout on the printed circuit board 30. Show.

As shown in FIG. 9 (a) and (b), in this implementation, it is characterized in that the coil L ₁ through coil L ₃ are connected in series. Thereby, a transformer having a winding ratio of 3 to 1 can be configured. Here, as in the first mounting form, the first and second connection conductor patterns 36 and 37 are wired close to each other in parallel. Thereby, the shift | offset | difference of the impedance resulting from the connection conductor patterns 36 and 37 can be prevented. Since other configurations are the same as those of the first mounting form, detailed description thereof is omitted. As described above, according to the fourth mounting form, since the connection between the wires is performed by routing the connection conductor patterns 36 and 37 on the printed circuit board 30, the same effects as those of the first mounting form can be obtained. it can.

  FIGS. 10A and 10B are views showing a fifth mounting form of the coil component 10. FIG. 10A is a circuit diagram, and FIG. 10B is a pattern layout on the printed circuit board 30. Show.

As shown in FIG. 10 (a) and (b), in this implementation, it is characterized in that all coils L ₁ through coil L ₄ are connected in series. As a result, one coil having four times the number of turns can be formed. In this case, the first to third connection conductor patterns 36 to 38 are used. Since other configurations are the same as those of the first mounting form, detailed description thereof is omitted. As described above, according to the fifth embodiment, since the connection between the wires is performed by routing the connection conductor patterns 36 to 38 on the printed circuit board 30, the same effects as those of the first mounting form can be obtained. it can.

  As described above, according to the coil component of the present embodiment, it can be used as a pulse transformer or a common mode filter depending on the connection method between the ends of the wire, and can also be used as a normal coil. Since it is possible, a highly versatile coil component can be realized.

  The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention, and these are also included in the scope of the present invention. Needless to say.

  For example, in the above embodiment, the connection conductor pattern is formed on the front surface (the same surface as the land pattern) of the printed circuit board, but may be formed on the back surface of the printed circuit board through the through-hole conductor.

  Moreover, in the said embodiment, although the case where four wires were wound around the core member was demonstrated, the number of wires is not specifically limited. However, when two wires are wound, it is easy to ensure the magnetic coupling between the wires, and the wire length of the winding portion is very easy to adjust, so the number of wires is three or more. It can be said that it is preferable.

FIG. 1 is a schematic perspective view showing an external structure of a coil component according to the first embodiment of the present invention. FIG. 2 is a schematic bottom view showing the structure of the bottom surface of the transformer component. FIG. 3 is a schematic perspective view showing the first to fourth wires 14 to 17 configured as one stranded wire. FIG. 4 is a schematic cross-sectional view showing the first to fourth wires 14 to 17 covered with the insulator 22 and configured as one stranded wire. FIG. 5 is a schematic cross-sectional view illustrating a configuration of a bilayer bifilar winding. FIG. 6 is a circuit diagram of the coil component 10 mounted on the printed board 30. FIGS. 7A and 7B are views showing a second mounting form of the coil component 10. FIG. 7A is a circuit diagram, and FIG. 7B is a pattern layout on the printed circuit board 30. Show. 8A and 8B are views showing a third mounting form of the coil component 10, where FIG. 8A is a circuit diagram, and FIG. 8B is a pattern layout on the printed circuit board 30. Show. FIGS. 9A and 9B are views showing a fourth mounting form of the coil component 10. FIG. 9A is a circuit diagram, and FIG. 9B is a pattern layout on the printed circuit board 30. Show. FIGS. 10A and 10B are views showing a fifth mounting form of the coil component 10. FIG. 10A is a circuit diagram, and FIG. 10B is a pattern layout on the printed circuit board 30. Show. FIG. 11 is a schematic external perspective view showing an example of the configuration of a conventional pulse transformer. FIG. 12 is an equivalent circuit diagram of the pulse transformer shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Transformer part 11 Core member 12 Drum core 12A Core part 12B Collar part 12C Collar part 13 Plate core 14 1st wire 14a 1st end 14b of 1st wire 15nd other end 15 of 1st wire 2nd wire 15a 2nd One end 15b of the second wire 16 Other end 16 of the second wire 16a Third wire 16a One end 16b of the third wire 17 Other end of the third wire 17 Fourth wire 17a One end of the fourth wire 17b Other end 18 First terminal electrode pair 18A One terminal electrode 18B Other terminal electrode 19 Second terminal electrode pair 19A One terminal electrode 19B Other terminal electrode 20 Third terminal electrode pair 20A One terminal electrode 20B The other Terminal electrode 21 Fourth terminal electrode pair 21A One terminal electrode 21B The other terminal electrode 22 Insulator 30 Printed circuit board 31 Transformer mounting region 32 First Land pattern pair 32A One land 32B The other land 33 Land pattern pair 33A One land 33B The other land 34 Land pattern pair 34A One land 34B The other land 35 Land pattern pair 35A One land 35B The other land 36 First Connection conductor pattern 37 second connection conductor pattern 38 third connection conductor pattern 41 toroidal core 42 primary winding 42a one input end 42b other input end 42c middle point 43 secondary winding 43a one output end 43b other Output end 22 coating 600 pulse transformer L ₁ first coil L ₂ second coil L ₃ third coil L ₄ fourth coil

Claims (5)

A core member having a core portion made of a rod-shaped magnetic body;
At least three wires wound around the core,
A wire connecting portion where the end of each wire is connected,
A coil component, wherein the wire lengths of the winding portions of the wires are substantially the same.   The coil component according to claim 1, wherein the at least three wires are configured as one stranded wire.   The coil component according to claim 2, wherein the at least three wires are integrated through an insulating coating.   The coil component according to any one of claims 1 to 3, wherein the wire includes a first wire and a fourth wire. In the half region of the core part, the first and second wires are bifilar wound on the inner periphery, and the third and fourth wires are bifilar wound on the outer periphery,
In the remaining half region of the core, the third and fourth wires are bifilar wound on the inner periphery, and the first and second wires are bifilar wound on the outer periphery. Item 5. The coil component according to Item 4.

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