JP6520536B2 - Coil parts - Google Patents

Description

  The present invention relates to a coil component used for a balun transformer, for example.

  In recent years, with wireless communication devices, such as cellular telephones, the amount of functionality provided to users continues to increase constantly while performance and computing capabilities have improved while the outer dimensions of the devices have decreased. A balun transformer is an example of a coil component used in such a device.

  In general, balun transformers convert single-ended or "unbalanced" signals normally transmitted and received by an antenna into differential or "balanced" signals found in the processing electronics of a wireless communication device.

  It has been studied to use a drum core as a coil component constituting such a balun transformer. Although not a balun transformer, as a common mode filter, for example, a coil component in which two wires are wound by substantially the same number of turns around a drum core as shown in Patent Document 1 below is known. There is.

  However, when coil components configured as shown in Patent Document 1 are used, for example, as a balun transformer, it has been difficult to adjust the inductances of the coil sections respectively formed of two wires to be substantially the same.

JP, 2014-207367, A

  The present invention has been made in view of such a situation, and an object thereof is to provide a coil component capable of adjusting the inductance of a coil section respectively composed of two wires to be substantially the same.

  As a result of intensive studies on coil parts by the present inventors, in order to make the inductance of a coil section composed of two wires wound around a winding core approach substantially the same, the difference between the line lengths of the two wires The present invention has been completed on the basis of the need to consider the influence of the core of the magnetic body.

That is, the coil component according to the first aspect of the present invention is
Core and
A first wire wound around the winding core;
And a second wire wound around the winding core separately from the first wire.
The first wire is separated from the winding core by a first near winding portion wound around the winding core near the winding core and the first near winding portion. And a first far side wound portion wound around the core portion;
The second wire is separated from the winding core portion by a second near side winding portion wound around the winding core portion near the winding core portion, and the second near side winding portion. And a second far side wound portion wound around the core portion;
The line length of the second wire is longer than the line length of the first wire,
The number of turns of the first wire of the first near-side winding portion is nn1, and the number of turns of the first wire of the first far-side winding portion is nf1.
When the number of turns of the second wire of the second near-side winding portion is nn2, and the number of turns of the second wire of the second far-side winding portion is nf2,
It is characterized in that nf2> nf1.

  In a coil component, it is considered that if two pieces of the first wire and the second wire are wound at the same time in the same winding number at the same time, the inductance of the coil part composed of these wires will be the same. The In fact, it is known that approximately the same inductance. However, in recent years where miniaturization of coil parts and high performance are required, there is a demand for electronic parts that can match the inductance with high accuracy even if the coil parts are small.

  Therefore, the present inventors simultaneously start winding the first wire and the second wire two at the same time on the common core, and at the beginning of the winding, the first wire is wound on the side of the core, After half of the total winding, from then on, the positional relationship between the first wire and the second wire was reversed, and a coil was produced in which the second wire was wound so as to come to the winding core side. In theory, the inductance of the coil component composed of these wires should have been the same.

  However, it has been found that the inductance of the coil portion wound with each wire varies with a change rate of 2% or more, even in the coil component thus prototyped. The present inventors earnestly studied about reducing the change rate of the inductance of the coil part wound by each wire, and obtained the following new knowledge. That is, even if the first wire and the second wire are wound with the same number of turns around the common winding core, the line lengths between the terminal electrodes of these wires slightly differ and the influence of the distance between the wire and the core Was found to be greatly affected.

  In the coil component of the present invention, the winding number nf2 of the second wire in which the line length is consequently long and wound on the side far from the winding core is the winding core in the first wire whose line length is relatively short. The number of turns nf1 is greater than the number of turns wound on the far side. Therefore, the inductance of the coil part which consists of 1st wire, and the coil part which consists of 2nd wire can be closely approached.

  Also, since the coil component is configured by winding the two first and second wires around a common single winding core, the variation in the characteristics of the coil composed of each wire and the variation in the temperature characteristics are reduced. can do. In addition, by using a single-chip coil component, miniaturization is possible.

  Preferably, the total number of turns (nn 2 + nf 2) of the second wire is approximately equal to the total number of turns (nn 1 + n f 1) of the first wire. By making the resistances substantially equal to each other, the inductances of the coil portion formed of the first wire and the coil portion formed of the second wire can be made close to each other.

  Alternatively, the total number of turns (nn2 + nf2) of the second wire may be slightly larger than the total number of turns (nn1 + nf1) of the first wire. By increasing the total number of turns (nn2 + nf2) of the second wire, the inductance of the coil formed of the second wire is increased. However, the number of turns nf2 wound on the side far from the winding core in the second wire is greater than the number of turns nf1 wound on the side far from the winding core in the first wire whose line length is relatively short. There is a possibility that you can cancel by making more.

  Preferably, the cross-sectional area of the conductor portion of the second wire is approximately equal to the cross-sectional area of the conductor portion of the first wire. By making the resistances substantially equal to each other, the inductances of the coil portion formed of the first wire and the coil portion formed of the second wire can be made close to each other.

  However, the cross-sectional area of the conductor portion of the second wire may be larger than the cross-sectional area of the conductor portion of the first wire. By increasing the cross-sectional area of the conductor portion of the second wire, the inductance of the coil made of the second wire is increased. However, there is a possibility that the number of turns nf2 wound on the side far from the winding core in the second wire can be canceled by setting the number of turns nf1 wound on the side far from the winding core in the first wire There is.

  Preferably, the number of turns nn2 is 2 or more, and nf2 / (nn2 + nf2) is 0.55 or more, more preferably 0.60 or more. By setting it as such a range, the inductance of the coil part which consists of 1st wire, and the coil part which consists of 2nd wire can be closely approached.

The coil component according to the second aspect of the present invention is
Core and
A first wire wound around the winding core;
And a second wire wound around the winding core separately from the first wire.
The first wire is separated from the winding core by a first near winding portion wound around the winding core near the winding core and the first near winding portion. And a first far side wound portion wound around the core portion;
The second wire is separated from the winding core portion by a second near side winding portion wound around the winding core portion near the winding core portion, and the second near side winding portion. And a second far side wound portion wound around the core portion;
The cross-sectional area of the conductor portion of the second wire is larger than the cross-sectional area of the conductor portion of the first wire,
The number of turns of the first wire of the first near-side winding portion is nn1, and the number of turns of the first wire of the first far-side winding portion is nf1.
When the number of turns of the second wire of the second near-side winding portion is nn2, and the number of turns of the second wire of the second far-side winding portion is nf2,
It is characterized by nf2> nf1.

The coil component according to the third aspect of the present invention is
Core and
A first wire wound around the winding core;
And a second wire wound around the winding core separately from the first wire.
The first wire is separated from the winding core by a first near winding portion wound around the winding core near the winding core and the first near winding portion. And a first far side wound portion wound around the core portion;
The second wire is separated from the winding core portion by a second near side winding portion wound around the winding core portion near the winding core portion, and the second near side winding portion. And a second far side wound portion wound around the core portion;
The cross-sectional area of the conductor portion of the second wire is larger than the cross-sectional area of the conductor portion of the first wire,
The line length of the first wire is longer than the line length of the second wire,
The number of turns of the first wire of the first near-side winding portion is nn1, and the number of turns of the first wire of the first far-side winding portion is nf1.
When the number of turns of the second wire of the second near-side winding portion is nn2, and the number of turns of the second wire of the second far-side winding portion is nf2,
nf2 is approximately equal to nf1.

  Also in the coil component according to the second and third aspects of the present invention, the inductance of the coil portion formed of the first wire and the coil portion formed of the second wire can be made close to each other.

FIG. 1 is a perspective view of a coil component according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the coil portion wound around the winding core portion of the coil portion shown in FIG. FIG. 3 is an equivalent circuit diagram of the coil component shown in FIG. 1 and FIG. FIG. 4 is a graph showing the effect of the coil component according to the embodiment of the present invention.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

First Embodiment As shown in FIG. 1, a coil component 10 according to an embodiment of the present invention has a drum core 20 and a coil portion 40 wound around a core portion 22 of the drum core 20.

  In the description of the coil component 10, the direction parallel to the mounting axis on which the coil component 10 is mounted and parallel to the winding axis of the winding core portion 22 of the drum core 20 is parallel to the mounting surface as with the X axis and X axis. The direction perpendicular to the X-axis is in the Y-axis direction, and the normal direction of the mounting surface is the Z-axis direction.

  The outer dimensions of the coil component 10 are, for example, (width 3.2 mm × height 2.8 mm × depth 3.2 mm), but the size of the coil component 10 is not limited thereto.

  The drum core 20 has a rod-shaped winding core portion 22 and a pair of flanges 24 as a pair of core end portions provided at both ends of the winding core portion 22.

  The outer shape of the collar portion 24 is a substantially rectangular parallelepiped, and the pair of collar portions 24 are arranged substantially parallel to each other at a predetermined interval in the X-axis direction. The winding core portion 22 is connected to the central portion of each of the surfaces facing each other in the pair of collar portions 24 and connects the pair of collar portions 24. The cross-sectional shape of the winding core 22 is rectangular in the present embodiment, but may be circular, and the cross-sectional shape is not particularly limited.

  A plate-like core may be adhered to the lower end portion in the Z-axis direction or the upper end portion in the Z-axis direction of the drum core 20.

  Terminals 51 to 54 are provided at each flange portion 24 of the drum core 20. The terminals 51 to 54 are formed of a metal fitting having a substantially L-shaped outer shape, and at least a part thereof is provided on the installation surface 24 b of the collar portion 24. In addition, the installation surface 24b of the collar part 24 is an upper surface of the Z-axis direction on the opposite side to the bottom surface 24a of the collar part 24. As shown in FIG.

  The two terminals 51-52 are provided in one collar portion 24, and the other two terminals 53-54 are provided in the other collar portion 24. The distance between the adjacent terminals 51, 52 or 53, 54 is not particularly limited as long as insulation is ensured.

  A coil portion 40 is formed on the winding core portion 22 of the drum core 20. The coil part 40 is comprised by two wires 41-42. The wires 41 to 42 are formed of, for example, a coated wire, and have a configuration in which a core made of a good conductor is covered with an insulating coating film, and wound around the winding core portion 22 with a two-layer structure described later. It has been turned. In the present embodiment, the cross-sectional areas of the conductor portions in the wires 41 to 42 are the same.

  As shown in FIG. 1, the wire ends 41a and 41b of the first wire 41 are connected to the terminals 51 and 53, respectively, and the wire ends 42a and 42b of the second wire 42 are connected to the terminals 52 and 54, respectively. As shown in FIG. 3, terminals 53 and 54 can be connected to external circuits such as capacitors 55 and 56, for example. As shown in FIG. 3, the first wire 41 constitutes a first coil 41A, and the second wire 42 constitutes a second coil 42A.

  As shown in FIG. 2, the first wire 41 and the second wire 42 are normally bifilar-wound around the winding core 22, but the predetermined reverse position 23 is bounded along the winding axis direction of the winding core 22. In the first section S1 on the side of one collar portion 24 and the second section S2 on the other side of the collar portion 24, the winding layer number order position with respect to the winding core portion 22 is reversed.

  That is, at the first partition position, the second wire 42 is located at the first layer position near the winding core 22, and the first wire 41 is located at the second layer position far from the winding core 22. In the second partition position, conversely, the first wire 41 is located at the first layer position near the winding core 22 and the second wire 42 is located at the second layer location far from the winding core 22. There is. At the reversing position 23, the first wire 41 and the second wire 42 are twisted by 180 degrees.

  As a result, the first wire 41 is closer to the winding core portion 22 than the first near-side winding portion 41α wound around the winding core portion 22 and the first near-side winding portion 41α from the winding core portion 22 And a first far side winding portion 41β wound around the winding core portion 22 separately. The second wire 42 is further separated from the winding core 22 than the second near winding portion 42α wound around the winding core 22 near the winding core 22 and the second near winding portion 42α. And the second far-side winding portion 42β wound around the winding core portion 22.

  The number of turns of the first wire 41 of the first near-side winding portion 41α with respect to the winding core portion 22 is nn1, and the number of turns of the first wire 41 of the first far-side winding portion 41β is nf1. Assuming that the number of turns of the second wire 42 of the turn portion 42α is nn2, and the number of turns of the second wire 42 of the second far-side winding portion 42β is nf2, a relationship of nf2> nf1 is satisfied in this embodiment. It holds. Preferably, the number of turns nn2 is 2 or more, and nf2 / (nn2 + nf2) is 0.55 or more, more preferably 0.60 or more.

  As shown in FIG. 1, in the present embodiment, the first wire 41 and the second wire 42 are wound around the winding core portion 22 in the same direction. Further, the total number of turns (nn1 + nf1) of the first wire 41 and the total number of turns (nn2 + nf2) of the second wire 42 are the same. However, for example, as shown in FIG. 1, the first wires 41 are different from each other in that the wire ends 41a, 41b, 42a, 42b drawn from the coil section 40 have different distances until they are connected to the respective terminal electrodes 51-54. The line length of the second wire 42 may differ from that of the second wire 42, and the line length of the second wire 42 may be longer than that of the first wire.

  The line length of the first wire 41 is the length in the longitudinal direction of the first wire 41 from the first terminal 51 to the third terminal 53, and the line length of the second wire 42 is the second terminal 52. The length of the second wire 42 in the longitudinal direction until it is connected to the fourth terminal 54.

  In the manufacture of the coil component 10, first, the drum-shaped drum core 20 and the wires 41 to 44 provided with the terminals 51 to 54 are prepared. The drum core 20 is made of a magnetic material, for example, a magnetic powder having a relatively high magnetic permeability such as a magnetic material such as Ni-Zn ferrite, Mn-Zn ferrite, or metallic magnetic material, It is produced by molding and sintering. The metal terminals 51 to 54 are fixed to the flange portion 24 of the drum core 20 by adhesion or the like. The terminals 51 to 54 may be provided on the flange portion 24 by forming a conductor film on the drum core 20 by printing, plating or the like and baking the conductor film.

  As the wires 41 to 42, for example, a core material made of a good conductor such as copper (Cu) is covered with an insulating material made of imide-modified polyurethane or the like, and further the outermost surface is covered with a thin resin film such as polyester. Can. The drum core 20 and the wires 41 to 42 provided with the prepared terminals 51 to 54 are set in a winding machine, and the wires 41 to 42 are wound around the winding core portion 22 of the drum core 20 in a predetermined order.

  In the present embodiment, bifilar winding of the first wire 41 and the second wire 42 is performed in the first section S1, and the layer number order of the first wire 41 and the second wire 42 is performed next in the second section S2. Inverts the bifilar winding. The wire ends 41a to 42a and 41b to 42b of the wound wires 41 to 42 are fixed to predetermined terminals 51 to 54 shown in FIG. 1 by silver brazing, thermocompression bonding, laser bonding or the like. The winding method of the wires 41 and 42 is not particularly limited. Further, it may be wound from the second section S2 in the direction of the first section S2.

  In the coil component 10 according to the present embodiment, the number of turns nf2 wound on the side far from the winding core portion 22 in the second wire 42 resulting in the increase in the line length is relatively short in the line length. The number of turns nf1 of the wire 41 wound on the side far from the winding core portion 22 is greater. Therefore, the inductance of the first coil 41A made of the first wire 41 shown in FIG. 3 can be brought close to the inductance of the second coil 42A made of the second wire 42 so as to coincide with each other.

  For example, as shown in FIG. 4, when the number of turns nn2 is 2 or more and nf2 / (nn2 + nf2) is 0.55 or more, more preferably 0.60 or more, the inductance of the first coil 41A and the second coil 41A are It has been found that the ratio (variation in change rate) different from the inductance of the coil 42A can be made 1% or less, preferably 0.8% or less.

  Further, in the present embodiment, since the coil component 10 is configured by winding the two first wires 41 and the second wires 42 around the common single winding core portion 22, the coils 41 and 42 are configured. Variations in the characteristics of the coils 41A and 42A and variations in the temperature characteristics can be reduced. In addition, miniaturization is possible by using a coil component 10 of one chip.

  In the coil component 10 of the present embodiment, the inductance of the first coil 41A and the inductance of the second coil 42A can be matched with an error within a range of preferably 1% or less, more preferably 0.5% or less. Therefore, it can be preferably used, for example, in the following applications. As a use of the coil component 10 preferably used, it can be used, for example, as a balun transformer used as a part of a circuit as shown in FIG. 3 or other use such as an array coil.

  In the present embodiment, the total number of turns (nn 2 + nf 2) of the second wire 42 may be slightly larger (about 0.1 to 1) than the total number of turns (nn 1 + nf 1) of the first wire 41. By increasing the total number of turns (nn 2 + nf 2) of the second wire 42, the inductance of the coil formed of the second wire 42 is increased. However, the number of turns nf2 of the second wire 42 wound on the side far from the winding core 22 is wound on the side far from the winding core 22 in the first wire 41 whose line length is relatively short. There is a possibility that the cancellation can be made by making the number more than several nf1.

  In the present embodiment, the cross-sectional area of the conductor portion of the second wire 42 may be larger than the cross-sectional area of the conductor portion of the first wire 41. By increasing the cross-sectional area of the conductor portion of the second wire 42, the inductance of the coil formed of the second wire 42 is increased. However, the number of turns nf2 of the second wire 42 wound on the side far from the winding core 22 is larger than the number of turns nf1 of the first wire 41 wound on the side far from the winding core 22 There is a possibility of cancellation.

Second Embodiment A coil component according to a second embodiment of the present invention is different only in the following points, and the other configuration is the same as that of the first embodiment described above, and exhibits the same function and effect. The description of the overlapping parts is omitted. In this embodiment, the cross-sectional area of the conductor portion of the second wire 42 is larger than the cross-sectional area of the conductor portion of the first wire 41.

  Moreover, in the present embodiment, the connection positions of the terminals 51 to 54 and the wire ends 41a, 41b, 42a, 42b are devised so that the line length of the second wire 42 is the same as the line length of the first wire 41. Yes. Alternatively, the connection positions of the terminals 51 to 54 and the wire ends 41a, 41b, 42a, 42b are devised so that the line length of the second wire 42 is shorter than the line length of the first wire 41.

  Also in the coil component according to the present embodiment, the inductances of the coil portion formed of the first wire 41 and the coil portion formed of the second wire 42 can be made close to each other.

Third Embodiment A coil component according to a third embodiment of the present invention is different only in the following points, and the other configuration is the same as that of the first embodiment described above, and exhibits the same function and effect. The description of the overlapping parts is omitted. In this embodiment, the cross-sectional area of the conductor portion of the second wire 42 is larger than the cross-sectional area of the conductor portion of the first wire 41.

  Moreover, in the present embodiment, the connection positions of the terminals 51 to 54 and the wire ends 41a, 41b, 42a, 42b are devised so that the line length of the first wire 41 is longer than the line length of the second wire 42. Yes. In the present embodiment, nf2 is substantially equal to nf1.

  Also in the coil component according to the present embodiment, the inductances of the coil portion formed of the first wire and the coil portion formed of the second wire can be made close to each other.

  The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.

  For example, the shape of the drum core 20 is not limited to the drum shape shown in the embodiment, and can be any shape including a pair of core end portions at both ends of the winding core portion, such as a U-shape. The two ridges 24 of the drum core 20 may have the same shape or different shapes.

DESCRIPTION OF SYMBOLS 10 ... Coil part 20 ... Drum core 22 ... Winding core part 24 ... Buttocks part (core end part)
40 ... coil portion 41 ... first wire 41 α ... first near side winding portion 41 β ... first far side winding portion 42 ... second wire 42 α ... second near side winding portion 42 β ... second far side winding portion

Claims (5)

Core and
A first wire wound around the winding core;
And a second wire wound around the winding core separately from the first wire.
The first wire is separated from the winding core by a first near winding portion wound around the winding core near the winding core and the first near winding portion. And a first far side wound portion wound around the core portion;
The second wire is separated from the winding core portion by a second near side winding portion wound around the winding core portion near the winding core portion, and the second near side winding portion. And a second far side wound portion wound around the core portion;
The line length of the second wire is longer than the line length of the first wire,
The number of turns of the first wire of the first near-side winding portion is nn1, and the number of turns of the first wire of the first far-side winding portion is nf1.
When the number of turns of the second wire of the second near-side winding portion is nn2, and the number of turns of the second wire of the second far-side winding portion is nf2,
a coil component in which nf2> nf1 and
The number of turns nn2 is two or more turns,
A coil component having nf2 / (nn2 + nf2) of 0.55 or more.     The coil component according to claim 1, wherein (nn2 + nf2) is substantially equal to or more than (nn1 + nf1).     The coil component according to claim 1, wherein a cross-sectional area of the conductor portion of the second wire is approximately equal to or larger than a cross-sectional area of the conductor portion of the first wire. Core and
A first wire wound around the winding core;
And a second wire wound around the winding core separately from the first wire.
The first wire is separated from the winding core by a first near winding portion wound around the winding core near the winding core and the first near winding portion. And a first far side wound portion wound around the core portion;
The second wire is separated from the winding core portion by a second near side winding portion wound around the winding core portion near the winding core portion, and the second near side winding portion. And a second far side wound portion wound around the core portion;
The cross-sectional area of the conductor portion of the second wire is larger than the cross-sectional area of the conductor portion of the first wire,
The number of turns of the first wire of the first near-side winding portion is nn1, and the number of turns of the first wire of the first far-side winding portion is nf1.
When the number of turns of the second wire of the second near-side winding portion is nn2, and the number of turns of the second wire of the second far-side winding portion is nf2,
A coil component in which nf2> nf1. Core and
A first wire wound around the winding core;
And a second wire wound around the winding core separately from the first wire.
The first wire is separated from the winding core by a first near winding portion wound around the winding core near the winding core and the first near winding portion. And a first far side wound portion wound around the core portion;
The second wire is separated from the winding core portion by a second near side winding portion wound around the winding core portion near the winding core portion, and the second near side winding portion. And a second far side wound portion wound around the core portion;
The cross-sectional area of the conductor portion of the second wire is larger than the cross-sectional area of the conductor portion of the first wire,
The line length of the first wire is longer than the line length of the second wire,
The number of turns of the first wire of the first near-side winding portion is nn1, and the number of turns of the first wire of the first far-side winding portion is nf1.
When the number of turns of the second wire of the second near-side winding portion is nn2, and the number of turns of the second wire of the second far-side winding portion is nf2,
A coil component in which nf2 is approximately equal to nf1.

Images