JP2013008837A - Coil component and inductance setting method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil component capable of setting inductance to be a desirable value without adjusting gap of a center core.SOLUTION: The coil component includes a core 1 in which a pair of flat plate parts 3 are arranged in parallel with a predetermined gap G and a winding 4 of which an axis is arranged at the gap G so as to be perpendicular to the flat plate part 3, in which a closed magnetic circuit containing the gap G is formed by the core 1 as a passage of a magnetic flux occurring at the winding 4. The gap G is preferably set to be 1 cm or less. The winding 4 which is wound about bobbins 5a, 5b or a sheet coil may be used.

Description

  The present invention relates to a coil component having a closed magnetic circuit type core and an inductance setting method thereof.

  In recent years, with the miniaturization of electronic devices, high-density mounting has progressed, so the influence of leakage magnetic flux from coil components such as reactors and transformers used in power supply circuits on other components cannot be ignored. In addition, as electronic devices are made thinner, it is required to make coil components thinner. Therefore, a closed magnetic circuit type thin coil component capable of reducing leakage magnetic flux is demanded (for example, see Patent Documents 1 and 2).

  For example, as shown in FIG. 6, the closed magnetic circuit type coil component is made of a magnetic material such as ferrite and has an E-shaped cross section having a middle leg portion 11 serving as a center core and a pair of outer leg portions 12. A mold core 10 is used. A closed magnetic circuit is formed by using two E-shaped cores 10 and overlapping them so that the middle leg portion 11 and the outer leg portion 12 face each other. That is, a winding (not shown) is wound around the center leg 11 serving as a center core, and a magnetic flux generated from the winding is configured to pass through a closed magnetic path indicated by a dotted arrow in FIG.

  In the conventional closed magnetic circuit type coil components as shown in Patent Documents 1 and 2 and FIG. 6, there is at least a center core, and the inductance is set to a desired value by adjusting the gap G of the center core. Yes. As shown in FIG. 6 (a), the center core gap G is adjusted by providing an inductance adjusting spacer 20 between the opposed outer legs 12, or as shown in FIG. 6 (b). It is done by shaving.

JP 2000-77239 A Japanese Patent No. 4176755

  However, in order to adjust the gap G of the center core, as shown in FIG. 6A, when the inductance adjusting spacer 20 is provided, the height changes depending on the inductance adjusting spacer 20, so that a thin coil component is obtained. It is difficult to apply, and as shown in FIG. 6 (b), when the middle leg portion 11 is cut, the manufacturing process becomes complicated, there is no versatility, and the cost becomes high. there were.

  In view of the above problems, an object of the present invention is to solve the problems of the prior art and provide a coil component that can set the inductance to a desired value without adjusting the gap of the center core.

The coil component of the present invention includes a core in which a pair of flat plate portions are arranged in parallel with a predetermined gap, and a winding arranged in the gap so that an axis is perpendicular to the flat plate portion. As a path of magnetic flux generated from the wire, a closed magnetic circuit including the gap is formed by the core.
Furthermore, the coil component of the present invention is characterized in that the gap is set to 1 cm or less.
Furthermore, in the coil component according to the present invention, the winding is wound around a bobbin.
Alternatively, in the coil component of the present invention, the winding is a sheet coil.
The coil component inductance setting method according to the present invention includes a core having a pair of flat plate portions arranged in parallel with a predetermined gap, and a winding arranged in the gap so that the axis is perpendicular to the flat plate portion. In a coil component in which a closed magnetic circuit including the gap is formed by the core as a path of magnetic flux generated from the winding, an inductance value is set by adjusting an inner diameter area of the winding Furthermore, in the inductance setting method for a coil component according to the present invention, the winding is wound around a bobbin, and the inductance value is set by changing the outer periphery of the bobbin winding core. It is characterized by that.
Alternatively, in the coil component inductance setting method of the present invention, the winding is a sheet coil.

  According to the present invention, a pair of flat plate portions includes a core disposed in parallel with a predetermined gap, and a winding disposed in the gap so that an axis is perpendicular to the flat plate portion, and is generated from the winding. By configuring the magnetic flux path so that a closed magnetic circuit including a gap is formed by the core, the inductance is adjusted to a desired value without adjusting the gap of the center core by adjusting the inner diameter area of the winding. It is easy to set, and there is an effect that thinning, low profile and low cost can be realized.

It is a figure which shows the structure of embodiment of the coil component which concerns on this invention, (a) is a perspective view, (b) is a X-X 'cross section shown to (a). It is a cross-sectional schematic diagram for demonstrating the winding example of the coil | winding shown in FIG. It is a cross-sectional schematic diagram for demonstrating the path | route of the magnetic flux generate | occur | produced with the coil | winding shown in FIG. It is a graph which shows the relationship between the internal diameter of the coil | winding shown in FIG. 1, and the value of an inductance. It is a graph which shows the electric current superimposition characteristic of the value of the inductance in embodiment of the coil components which concern on this invention. It is a cross-sectional schematic diagram which shows the structure of the conventional coil components.

Next, embodiments of the present invention will be specifically described with reference to the drawings.
Referring to FIG. 1, the coil component of the present embodiment includes a closed magnetic circuit type core 1 composed of an upper core 1a, a lower core 1b having the same shape as the upper core 1a, and a winding 4. .

  The upper core 1 a and the lower core 1 b are made of a magnetic material such as ferrite, and are composed of an outer leg portion 2 and a flat plate portion 3. As shown in FIG. 1A, the flat plate portions 3 of the upper core 1a and the lower core 1b have notches formed in a part of the disk and are symmetrical with respect to the center C of the disk. In addition, an outer leg portion 2 is formed on the outer edge portion of the disc so as to stand substantially perpendicular to the flat plate portion 3. Therefore, the cross-sectional view taken along the line XX ′ shown in FIG. 1A, which cuts the portion where the outer leg portion 2 is formed through the center C of the flat plate portion 3, is shown in FIG. The outer leg portion 2 has a plate shape connected by the flat plate portion 3. The upper core 1a and the lower core 1b are used in an overlapping manner so that the outer leg portions 2 face each other, whereby the flat plate portion 3 of the upper core 1a and the flat plate portion 3 of the lower core 1b are used. A gap G is formed between the flat plate portion 3 of the upper core 1a and the flat plate portion 3 of the lower core 1b. The shape of the flat plate portion 3 shown in FIG. 1A is an example, and may be a disc shape without a notch, and if the gap G is formed by the outer leg portions 2 facing each other. Alternatively, an asymmetric shape with respect to the center C of the disk may be employed. Or you may employ | adopt a square shape with respect to the center C of a disc. In the present embodiment, the upper core 1a and the lower core 1b are configured in the same shape, but the length of the outer leg 2 may be changed between the upper core 1a and the lower core 1b. One of the la core 1b or the lower core 1b may be a plate-like core composed of only the flat plate portion 3.

  The winding 4 is centered on the center C of the flat plate portion 3 so that the axis is perpendicular to the flat plate portion 3 in the gap between the flat plate portion 3 of the upper core 1a and the flat plate portion 3 of the lower core 1b. It is wound around. In the present embodiment, the gap G is set to 1 cm or less, preferably 5 mm or less. That is, the total length of the outer leg portions 2 of the upper core 1a and the lower core 1b is set to 1 cm or less, preferably 5 mm or less. As a result, even if there is no center core, as a path of magnetic flux generated by the winding 4, "gap G"-"upper core 1a"-"outer leg 2 of upper core 1a"-"outside of lower core 1b A closed magnetic circuit composed of the legs 2 "-" lower core 1b "is formed.

  As shown in FIG. 2A, the winding 4 can be wound using, for example, a bobbin 5a. The bobbin 5a is made of a resin body that is an insulator, for example, and the winding 4 is wound around the winding core 51a, and the inner diameter of the winding 4 is determined by the winding core 51a. As the winding 4, a sheet coil (laminated coil on a printed circuit board), for example, a spiral printed planar coil formed on a double-sided or single-sided flexible printed wiring board, or a fusible insulating conductor is wound and fixed. Alternatively, a fused coil may be used. By using a sheet coil as the winding 4, it is possible to realize a thinner, lower profile and lower cost. Alternatively, a planar coil may be formed on a printed circuit board together with other elements, and the upper core 1a and the lower core 1b may be attached to the place where the planar coil is formed to constitute a coil component.

  In the coil component of the present embodiment, the center core located at the center of the winding 4 is not formed. Therefore, the inductance is set to a desired value by adjusting the inner diameter of the winding 4 without adjusting the gap G between the flat plate portion 3 of the upper core 1a and the flat plate portion 3 of the lower core 1b. The Although it can be set by the number of turns of the winding 4, in this embodiment, the inductance can be set to a desired value by adjusting the inner diameter of the winding 4 even if the number of turns is the same. .

  For adjusting the inner diameter of the winding 4, as shown in FIG. 2B, for example, a bobbin 5b having a winding core portion 51b having a different diameter is used. The bobbin 5a shown in FIG. 2 (a) is used to wind the winding 4 near the center of the core, and the bobbin 5b shown in FIG. 2 (b) winds the winding 4 near the outer leg 2. Used for. In addition, without using a different bobbin, as shown in FIG. 2 (c), the barrier tape 6 may be wound around the winding core portion 51a of the bobbin 5a to the position to be wound, and the inner diameter of the winding 4 may be changed. good. Moreover, if there is no problem in manufacturing, the configuration may be configured with only the winding core portions 51 a and 51 b or may be configured with only the winding 4.

  FIG. 3A shows that the winding 4 is wound around the center of the core by winding the winding 4 around the bobbin 5a shown in FIG. 2A, and the inner diameter area of the winding 4 is adjusted to be small. An example is shown. As described above, when the winding 4 is wound around the central portion of the core, the inner diameter area is reduced, so that the magnetic flux passing through the inner diameter of the winding 4 is reduced and the inductance value is reduced. That is, the magnetic flux generated from the winding 4 is divided into a magnetic flux A that returns to the winding 4 through the gap G before reaching the outer leg 2 and a magnetic flux B that returns to the winding 4 through the outer leg 2. Divided. Therefore, the magnetic flux passing through the inner diameter of the winding 4 has a small inductance value because the gap G is increased.

  3 (b) shows that the winding 4 is wound around the outer leg 2 by winding the winding 4 around the bobbin 5b shown in FIG. 2 (b), and the inner diameter area of the winding 4 is greatly adjusted. An example is shown. As described above, when the winding 4 is wound around the outer leg 2, the inner diameter area increases, so that the magnetic flux passing through the inner diameter increases and the inductance value increases. That is, most of the magnetic flux generated from the winding 4 passes through the outer leg 2 that is present in the immediate vicinity. For this reason, the magnetic flux passing through the inner diameter of the winding 4 appears to have a smaller gap G than the example in which the winding 4 shown in FIG.

  As described above, in the present embodiment, when the inductance value is desired to be lowered, the winding 4 having a reduced inner diameter is used, and when the inductance value is desired to be increased, the winding 4 having an enlarged inner diameter is used. The inductance value is determined in proportion to the inner diameter area of the winding 4.

  [Table 1] As shown in [Table 1], using the same core without a center core, producing prototypes (i) to (d) with different inner diameter radii of the winding 4, and determining the inductance value for each of the prototypes (i) to (d). It was measured. In the trial productions A to D, all wires of the winding 4 have the same conditions.

  FIG. 4A is a graph showing the relationship between the inner radius of the winding 4 and the value of inductance in the trials A to D, and FIG. It is a graph which shows the relationship with the value of an inductance.

  Referring to FIG. 4A, it can be seen that the larger the inner radius of the winding 4, the larger the inductance value. Referring to FIG. 4B, the inner diameter area of the winding 4 and the inductance value are almost equal. You can see that they are proportional.

  As shown in [Table 2], using the same core without the center core, prototypes A and B with different inner diameter radii of the winding 4 are manufactured, and the inductance values of the prototypes A and B are set. The current superposition characteristics were measured. In the prototypes A and B, the wires 4 of the winding 4 were all the same conditions.

FIG. 5 shows current superposition characteristics of inductance values in prototypes A and B. In FIG. 5, the inductance value and current value when the inductance value becomes −20%,
[Table 3] shows the magnetic flux density when the core cross-sectional area of the core 1 is constant and the number of turns of the winding 4 is 50.

  According to [Table 3], the magnetic flux densities of the prototypes A and B have almost the same value, and it can be said that the inductance value and the DC superimposition characteristic have a constant relationship of inductance value * DC superposition current. This is considered to be a constant value because the NI of the core (number of turns * superimposed current) and the gap G (fixed value because it is center coreless) are fixed.

  As described above, according to the present embodiment, the pair of flat plate portions 3 are arranged in the gap G so that the axis 1 is perpendicular to the flat plate portion 3 and the core 1 arranged in parallel with the predetermined gap G. By adjusting the inner diameter area of the winding 4 by forming the closed magnetic circuit including the gap G by the core 1 as a path of the magnetic flux generated from the winding 4. The inductance can be easily set to a desired value without adjusting the gap of the center core, and there is an effect that a reduction in thickness, a reduction in height, and a reduction in cost can be realized.

  In addition, according to the present embodiment, the winding 4 is configured to be wound around the bobbins 5a and 5b, so that the outer periphery of the cores 51a and 51b of the bobbins 5a and 5b can be easily changed. 4 can be adjusted, and the inductance value can be easily set.

  In the present embodiment, the single winding 4 is arranged in the gap between the flat plate portion 3 of the upper core 1a and the flat plate portion 3 of the lower core 1b. A transformer structure in which a plurality of windings 4 are arranged in a gap between the portion 3 and the flat plate portion 3 of the lower core 1b may be employed.

  Note that the present invention is not limited to the above-described embodiments, and it is obvious that the embodiments can be appropriately changed within the scope of the technical idea of the present invention. In addition, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment, and can be set to a suitable number, position, shape, and the like in practicing the present invention. In each figure, the same numerals are given to the same component.

DESCRIPTION OF SYMBOLS 1 Core 1a Upper core 1b Lower core 2 Outer leg part 3 Flat plate part 4 Winding 5a, 5b Bobbin 51a, 51b Winding part 6 Barrier tape

Claims (7)

A core in which a pair of flat plate portions are arranged in parallel with a predetermined gap;
A winding disposed in the gap such that an axis is perpendicular to the flat plate portion,
A coil component characterized in that a closed magnetic path including the gap is formed by the core as a path of magnetic flux generated from the winding.   The coil component according to claim 1, wherein the gap is set to 1 cm or less.   The coil component according to claim 1 or 2, wherein the winding is wound around a bobbin.   The coil component according to claim 1, wherein the winding is a sheet coil. A core in which a pair of flat plate portions are arranged in parallel with a predetermined gap;
A winding disposed in the gap such that an axis is perpendicular to the flat plate portion,
In a coil component in which a closed magnetic circuit including the gap is formed by the core as a path of magnetic flux generated from the winding,
An inductance setting method for a coil component, wherein an inductance value is set by adjusting an inner diameter area of the winding. The winding is wound around a bobbin,
6. The inductance setting method for a coil component according to claim 5, wherein an inductance value is set by changing an outer periphery of the bobbin core.   6. The inductance setting method for a coil component according to claim 5, wherein the winding is a sheet coil.

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