Inductor, device having the inductor, and method for manufacturing the inductor

Abstract

An inductor, a device having the inductor, and a method for manufacturing the inductor are provided, which can improve the heat dissipation of an inductor having a flat coil structure made of a flat wire, and are applied to a use environment in a high frequency band. The inductor (1) has a plurality of coil parts (10, 20), which are formed into a flat coil by stacking a flat wire (2) with gaps provided in the radial direction, and the plurality of coil parts (10, 20) are arranged with gaps provided in the axial direction. By providing gaps between the plurality of coil parts, air flows in the gaps, thereby improving the heat dissipation.

Description

Technical Field

[0001] The present invention relates to an inductor, a device including the inductor, and a method for manufacturing the inductor. Background Art

[0002] Conventionally, an inductor having a coil having a flat-wound structure of a rectangular wire has been proposed. A rectangular wire can be wound densely to a higher density than a round wire, and thus has the advantage of increasing the self-inductance of the coil.

[0003] As an inductor of such a structure, an inductor having a single-layer toroidal coil formed of a flat wire with respect to an iron core has been proposed (for example, see Patent Document 1). By using an iron core, in addition to the effect of using a flat wire (higher density compared to a round wire), the effect of increasing the self-inductance of the coil compared to a hollow core is produced.

[0004] Prior Art Literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-69786 Summary of the invention

[0007] -Problems to be solved by the invention-

[0008] When a flat wire is tightly wound around an iron core into a flat coil structure, as in the inductor described in Patent Document 1, the inductance can be increased compared to a hollow core. However, the heat dissipation inside the coil (iron core side) is low, and the temperature inside the coil tends to increase. As a result, the heat near the inner side of the coil is transferred to the iron core, increasing the temperature of the iron core.

[0009] Furthermore, the iron loss in the iron core increases as the frequency of the current flowing through the coil increases, so the iron loss increases in the high frequency band, and the heat generated by the iron loss also increases. Therefore, when used in a high frequency band (for example, a wireless frequency band of hundreds of kHz or more), there is a possibility that the iron core will experience thermal runaway.

[0010] Furthermore, when used in a high frequency band, the heat generated by the coil itself increases, and in some cases, the insulating coating (eg, enamel plating) on ​​the coil surface (surface of the rectangular wire) may be damaged.

[0011] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inductor, a device including the inductor, and a method for manufacturing the inductor, which can improve the heat dissipation of the inductor having a flat-wound structure of a rectangular wire and can be applied to a use environment in a high-frequency band.

[0012] -Methods for solving problems-

[0013] The inductor according to the present invention includes a plurality of coil portions formed by stacking rectangular wires with gaps provided in the radial direction to form a flat roll, and the plurality of coil portions are arranged with gaps provided in the axial direction.

[0014] In the present invention, gaps are provided between the plurality of coil parts, and air flows through the gaps, thereby improving heat dissipation.

[0015] The inductor according to the present invention is formed by winding the rectangular wire so that the ratio between the radial dimension and the axial dimension of the portion where the rectangular wire is stacked among the plurality of coil parts becomes a predetermined ratio.

[0016] In the present invention, a desired inductance can be obtained by setting the ratio between the radial dimension and the axial dimension of the portion where the rectangular wires are stacked in the plurality of coil parts to a predetermined ratio.

[0017] The ratio of the radial dimension to the axial dimension of the inductor according to the present invention is substantially 1.

[0018] In the present invention, by making the ratio of the radial dimension to the axial dimension substantially 1, the inductance can be increased.

[0019] In the inductor according to the present invention, the coil portion is wound into a quadrilateral shape when viewed from the axial direction.

[0020] In the present invention, if the coil portion is wound in a quadrilateral shape, the influence of the mutual inductance can be minimized and the combined inductance of the coil portion per one turn can be maximized.

[0021] The coil portion of the inductor according to the present invention is air-core.

[0022] In the present invention, by making the coil part hollow, the iron loss can be reduced and the characteristics of the inductor can be made linear. When the coil part is provided with an iron core, the characteristics of the inductor show hysteresis, the variation of the inductor becomes large, and it cannot be used in devices (machines) requiring high-precision control.

[0023] In the inductor according to the present invention, the plurality of coil portions include a first coil portion and a second coil portion adjacent to each other in the axial direction, and the first coil portion and the second coil portion are arranged so that gaps between the rectangular wires in the first coil portion and gaps between the rectangular wires in the second coil portion are connected in the axial direction.

[0024] In the present invention, since the gaps between the rectangular wires constituting the first coil portion and the gaps between the rectangular wires constituting the second coil portion are connected in the axial direction, wind easily flows through the first coil portion and the second coil portion, thereby improving the cooling effect of the air.

[0025] A device according to the present invention includes any one of the above-mentioned inductors.

[0026] In the present invention, the same function as that of the above-mentioned inductor is exerted.

[0027] The inductor manufacturing method according to the present invention is a method for manufacturing an inductor having a plurality of coil portions formed by stacking rectangular wires with gaps in the radial direction to form a flat roll, wherein the plurality of coil portions are arranged with gaps in the axial direction.

[0028] In the present invention, gaps are provided between the plurality of coil parts, and air flows through the gaps, thereby improving heat dissipation.

[0029] The method for manufacturing an inductor according to the present invention winds the rectangular wire so that the ratio between the radial dimension and the axial dimension of the portion where the rectangular wires are stacked among the plurality of coil parts becomes a predetermined ratio.

[0030] In the present invention, a desired inductance can be obtained by setting the ratio between the radial dimension and the axial dimension of the portion where the rectangular wires are stacked in the plurality of coil parts to a predetermined ratio.

[0031] -Effects of the Invention-

[0032] In the inductor, the device including the inductor, and the method for manufacturing the inductor according to the present invention, since gaps are provided between the plurality of coil parts, air flows through the gaps, thereby improving heat dissipation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a three-dimensional diagram schematically showing an inductor.

[0034] Figure 2 This is a front view schematically showing an inductor.

[0035] Figure 3 It is a top view schematically showing an inductor.

[0036] Figure 4 This is a right side view schematically showing an inductor.

[0037] Figure 5 This is a left side view schematically showing an inductor.

[0038] Figure 6 This is a rear view schematically showing an inductor.

[0039] Figure 7 This is a bottom view schematically showing an inductor.

[0040] Figure 8 Yes Figure 3The VIII-VIII line shown is a simplified cross-sectional view as a cutting line.

[0041] Fig. 9 This is a graph showing the relationship between the aspect ratio of the cross-sectional shape of a portion of an inductor where rectangular wires are stacked and the combined inductance of the inductor.

[0042] Fig.10 This is a schematic cross-sectional view showing a case where the number of coil parts constituting the inductor is three.

[0043] Fig.11 It is a diagram showing a configuration example of a high-frequency power supply system.

[0044] Fig.12 This is a circuit diagram of an impedance adjusting circuit in an impedance adjusting device. DETAILED DESCRIPTION

[0045] Hereinafter, an inductor 1 according to an embodiment of the present invention will be described with reference to the drawings. Figure 1 is a perspective view schematically showing the inductor 1. Figure 2 is a front view schematically showing the inductor 1, Figure 3 is a top view schematically showing the inductor 1. Figure 4 is a right side view schematically showing the inductor 1, Figure 5 is a left side view schematically showing the inductor 1, Figure 6 is a rear view schematically showing the inductor 1, Figure 7 It is a bottom view schematically showing the inductor 1 .

[0046] The inductor 1 includes a first coil portion 10 and a second coil portion 20 arranged side by side in the axial direction. The first coil portion 10 and the second coil portion 20 are wound and connected by alpha winding. The first coil portion 10 and the second coil portion 20 are respectively formed by winding a rectangular wire 2 into a flat roll, and when viewed from the axial direction, they are in a quadrilateral shape, such as a square or a rectangle. The four corners of the first coil portion 10 and the second coil portion 20 are bent into an arc shape. In addition, the four corners of the first coil portion 10 and the second coil portion 20 may also be right angles.

[0047] The first coil portion 10 is quadrilateral in shape when viewed from the axial direction. The first coil portion 10 is formed by winding the flat wire 2 in a spiral shape from the outside to the inside. The flat wire 2 is stacked in the radial direction. The end of the flat wire 2 located at the outermost side of the first coil portion 10 protrudes outward in parallel with the side of the first coil portion 10 which is quadrilateral in top view, forming a first terminal 11.

[0048] When visually observed from the axial direction, the second coil portion 20 is in a quadrilateral shape. The second coil portion 20 is formed by winding the flat wire 2 into a spiral shape from the inside to the outside. The flat wire 2 is stacked in the radial direction. The end of the flat wire 2 located at the outermost side of the second coil portion 20 protrudes outward in parallel with the side of the second coil portion 20 in a quadrilateral shape when viewed from above, forming a second terminal 21. The second terminal 21 is arranged on the opposite side of the first terminal 11. The first coil portion 10 and the second coil portion 20 have the same number of turns.

[0049] Figure 8 Yes Figure 3 The VIII-VIII line shown is a simplified cross-sectional view as a cutting line. Figure 1 as well as Figure 8 As shown, the innermost flat wire 2 of the first coil portion 10 and the innermost flat wire 2 of the second coil portion 20 are connected via a connecting portion 3. No core is arranged in the radial center of the first coil portion 10 and the second coil portion 20, and the inductor 1 is hollow. The first coil portion 10 and the second coil portion 20 are arranged with a gap 15 provided in the axial direction. The distance of the gap 15 is d3.

[0050] like Figure 8 As shown, the radial dimension of the inductor 1 in the portion where the rectangular wire 2 is stacked is d1, and the axial dimension is d2. The rectangular wire 2 of the inductor 1 is wound so that the radial dimension d1 and the axial dimension d2 are equal. In other words, when the plane parallel to the axis of the inductor 1 is set as the cutting plane, the rectangular wire 2 is wound so that the cross-sectional shape of the portion where the rectangular wire 2 is stacked becomes a square.

[0051] like Figure 8 As shown, the gap 12 between two adjacent flat wires 2 in the first coil part 10 is connected to the gap 22 between two adjacent flat wires 2 in the second coil part 20 in the axial direction.

[0052] Fig. 9 : is a graph showing the relationship between the aspect ratio of the cross-sectional shape of the portion where the rectangular wires 2 are stacked in the inductor 1 and the composite inductance of the inductor 1. Fig. 9 In the figure, the horizontal axis represents the aspect ratio and the vertical axis represents the composite inductance. The aspect ratio corresponds to the radial dimension d1 / axial dimension d2. Fig. 9 As shown, when the aspect ratio is 1, that is, when the cross-sectional shape of the portion where the rectangular wires 2 are stacked is a square, the value of the combined inductance is the largest.

[0053] Therefore, if the aspect ratio is set to 1, the inductance per unit weight can be maximized, so that the inductor 1 can be miniaturized. Therefore, by providing an impedance adjusting device including the inductor 1, it is possible to contribute to miniaturization of the impedance adjusting device.

[0054] Thus, it is preferable to set the cross-sectional shape of the portion where the rectangular wires 2 are stacked to be a square (aspect ratio = 1), but as a practical problem, dimensional errors occur in manufacturing. Therefore, it is practical to set an allowable error with respect to a desired aspect ratio so that the aspect ratio falls within the allowable error.

[0055] In addition, by Fig. 9 It can be seen that the composite inductance can be adjusted by adjusting the aspect ratio. Therefore, the aspect ratio can be adjusted so as to obtain a desired composite inductance. Even in this case, it is realistic to set an allowable error with respect to the aspect ratio.

[0056] Thus, when the inductor 1 is assembled in a device (equipment) for use, more appropriate control can be performed. In addition, the aspect ratio can be adjusted by, for example, adjusting the distance d3 of the gap 15 between the first coil portion 10 and the second coil portion 20. Alternatively, the distance of the gap 12 between the flat wires 2 constituting the first coil portion 10 can be adjusted, and the distance of the gap 22 between the flat wires 2 constituting the second coil portion 20 can also be adjusted.

[0057] The distance adjustment of the gaps 12, 15, 22 as described above can be achieved by inserting an insulating member and changing the thickness of the insulating member. In addition, an insulating member may be inserted without adjusting the distance of the gaps 12, 15, 22 in order to reliably ensure the gaps.

[0058] Next, a method for manufacturing the inductor 1 is described. For example, after the first coil portion 10 is formed by winding the flat wire 2 from the outside to the inside in a spiral shape, the connecting portion 3 is formed, the position is shifted in the axial direction, and the flat wire 2 is wound from the inside to the outside in a spiral shape, thereby forming the second coil portion 20. The flat wire 2 is wound by alpha winding to manufacture the inductor. At this time, the inductor 1 is flatly wound so that the radial dimension and axial dimension of the portion where the flat wire 2 is stacked are equal. In addition, the first coil portion 10 may be formed after the second coil portion 20 is formed. In addition, the material of the flat wire 2 is, for example, copper, and an insulating coating (enamel plating, etc.) is applied to the surface.

[0059] In the inductor and the method for manufacturing the inductor according to the embodiment, the first coil portion 10 and the second coil portion 20 are arranged in the axial direction, so that the self-inductance can be increased compared with the case where the coil portion is further apart as in the prior art. In addition, the radial dimension and the axial dimension of the portion where the rectangular wire 2 is stacked in the inductor 1 are made equal, that is, the rectangular wire 2 is wound so that the cross-section shape when the portion where the rectangular wire 2 is stacked is a square when cut along a plane parallel to the axis, so that the self-inductance can be further increased.

[0060] Furthermore, since the inductor 1 is wound into a quadrilateral shape in a plan view, it is possible to obtain self-inductance while ensuring the occupancy rate of the winding.

[0061] In addition, by making the inductor 1 hollow, iron loss can be reduced and the characteristics of the inductor can be made linear. When the inductor 1 is provided with an iron core, the characteristics of the inductor are lagging and the variation of the inductor becomes large, and it cannot be used in devices (equipment) requiring high-precision control.

[0062] Furthermore, since the gaps 12 between the rectangular wires 2 constituting the first coil portion 10 and the gaps 22 between the rectangular wires 2 constituting the second coil portion 20 are connected in the axial direction, wind can easily flow through the first coil portion 10 and the second coil portion 20, thereby improving the cooling effect by forced air cooling.

[0063] That is, as described above, by forming the winding with the rectangular wires 2 and providing gaps between the rectangular wires 2, wind easily flows through the first coil portion 10 and the second coil portion 20, and the winding itself functions as a heat sink. Therefore, the distance of the gaps 12 between the rectangular wires 2 and the distance of the gaps 22 between the rectangular wires 2 can also be shortened. Therefore, the winding can be wound more densely, and thus the self-inductance per unit weight can be increased.

[0064] Furthermore, even in the case of a large current in a high frequency band, a sufficient cooling effect can be obtained, thereby preventing damage.

[0065] In addition, it is preferred that the gap 12 and the gap 22 are completely connected in the axial direction, but in reality some dimensional errors occur. Figure 8 As shown, it is difficult to completely connect the gap 12 and the gap 22 in the axial direction.

[0066] That is, sometimes the gap 12 and the gap 22 are not completely connected in the axial direction, but even in such a case, since there is a gap 15 between the first coil portion 10 and the second coil portion 20, air can flow through the gap 15 to cool the first coil portion 10 and the second coil portion 20.

[0067] Therefore, if air flows in the axial direction, that is, from the first coil portion 10 toward the second coil portion 20 or from the second coil portion 20 toward the first coil portion 10 , the wind flows in contact with most of the area of ​​the rectangular wire 2 , thereby improving the cooling effect of the air on the inductor 1 .

[0068] In addition, in order to generate air flow, for example, it can be achieved by setting an air cooling fan. Of course, it is also possible to generate air flow in a direction different from the above-mentioned axial direction. For example, it is also possible to generate air flow in a direction perpendicular to the above-mentioned axial direction, that is, Figure 8In the paper, air flows from the right to the left, or from the left to the right. Figure 8 In the embodiment, since wind flows over the first coil portion 10 , through the second coil portion 20 , and through the gap 15 between the first coil portion 10 and the second coil portion 20 , the inductor 1 can be cooled by the air.

[0069] In addition, the number of coil parts constituting the inductor 1 is not limited to two, and three or more coil parts may be arranged in the axial direction. Fig.10 As shown, the coil parts constituting the inductor 1 may be three coil parts, namely, the first coil part 10, the second coil part 20, and the third coil part 30. The first coil part 10 and the second coil part 20 are arranged along the axial direction with a gap 15. The second coil part 20 and the third coil part 30 are arranged along the axial direction with a gap 25. The distance of the gap 25 is d4.

[0070] Even when the coil parts constituting such an inductor 1 are three or more, the same concept as described above is applicable. Fig.10 In the example of , it is also preferred to set the aspect ratio (radial dimension d1 / axial dimension d2) to 1, but the aspect ratio can be adjusted to achieve a desired composite inductance. Even in this case, it is realistic to set an allowable error with respect to the aspect ratio.

[0071] The aspect ratio can be adjusted by, for example, adjusting the distances d3 and d4 of the gaps 15 and 25 between the coil portions or adjusting the distances of the gaps 12 , 22 and 32 between the rectangular wires 2 .

[0072] in addition, Fig.10 is with Figure 8 Therefore, although not shown in the figure Figure 8 The connecting portion 3 shown in FIG. Figure 8 Similarly, a connecting portion is provided for connecting the first coil portion 10 and the second coil portion 20 . In addition, the second coil portion 20 and the third coil portion 30 are connected outside the inductor 1 .

[0073] Next, as an example of incorporating the inductor described in the above embodiment into equipment (mainly industrial equipment), a case where the inductor is incorporated into an impedance adjusting device 300 which is a part of a high-frequency power supply system will be described.

[0074] Fig.11: is a diagram showing a structural example of a high-frequency power supply system. The high-frequency power supply system is a system for performing processing such as plasma etching and plasma CVD on a workpiece such as a semiconductor wafer or a liquid crystal substrate, and is composed of a high-frequency power supply device 100, a transmission line 200, an impedance adjustment device 300 (sometimes also referred to as an impedance matching device), a load connection portion 400, and a load 500 (plasma processing device). Moreover, the high-frequency power supply device 100 supplies high-frequency power to the load 500 via the transmission line 200, the impedance adjustment device 300, and the load connection portion 400. In the load 500 (plasma processing device), a plasma discharge gas is introduced into a chamber (not shown) in which the workpiece is arranged, and high-frequency power is supplied from the high-frequency power supply device 100 to an electrode (not shown) in the chamber, so that the plasma discharge gas is discharged and changes from a non-plasma state to a plasma state. Then, the workpiece is processed using the gas in the plasma state.

[0075] In addition, the high-frequency power supply device 100 has a frequency in the wireless band relative to the load 500 (generally, a frequency of about hundreds of kHz to tens of MHz. For example, frequencies such as 400kHz, 2MHz, 13.56MHz, 50MHz, etc., and is a device for supplying high-frequency power (high-frequency voltage) with a higher frequency band (several 100MHz, etc. can also be used).

[0076] In a load 500 such as a plasma processing device used in applications such as plasma etching and plasma CVD, the state of the plasma changes all the time as the manufacturing process proceeds. Furthermore, the impedance of the load 500 (load impedance) changes all the time. In order to efficiently supply power from the high-frequency power supply device 100 to such a load 500, it is necessary to adjust the impedance ZL (hereinafter referred to as the load side impedance ZL) observed from the output end of the high-frequency power supply device 100 as the load impedance changes. Therefore, in the high-frequency power supply system, an impedance adjustment device 300 is sandwiched between the high-frequency power supply device 100 and the load 500 (plasma processing device 5).

[0077] The impedance adjustment device 300 is provided between the high-frequency power supply device 100 that supplies high-frequency power to the load 500 and the load 500, and adjusts the load-side impedance ZL by adjusting the electrical characteristics (capacitance, inductance) of the variable electrical characteristic element (variable capacitor, variable inductor) provided therein. In the impedance adjustment device 300, by setting the electrical characteristics of the variable electrical characteristic element to an appropriate value, the impedance of the high-frequency power supply device 100 and the impedance of the load 500 can be matched, so that the reflected wave power from the load 500 toward the high-frequency power supply device 100 is minimized as much as possible and the power supplied to the load is maximized.

[0078] Fig.12 2 is a circuit diagram of an impedance adjustment circuit 210 in the impedance adjustment device 300. The impedance adjustment circuit 210 is composed of, for example, a first variable capacitor 211, a second variable capacitor 212, and an inductor 213. As the inductor 213, the inductor 1 described in the above embodiment can be applied. Fig.12 The impedance adjusting circuit 210 is of a so-called “inverted L-type” type, but the inductor 1 described in the above embodiment can also be applied as an inductor of the impedance adjusting circuit 210 of another type (for example, “π-type”, etc.).

[0079] However, in the impedance adjusting circuit 210 in the impedance adjusting device 300, a large current in a high frequency band flows through the inductor 213. Therefore, it is necessary to implement heat dissipation measures. In addition, since there is a strong demand for miniaturization of the impedance adjusting device 300, miniaturization of the components is desired.

[0080] As described above, the inductor 1 of this embodiment can increase the inductance per unit weight, so that the inductor 1 can be miniaturized. Therefore, by using the impedance adjusting device 300 including the inductor 213, it is possible to contribute to miniaturization of the impedance adjusting device 300. Of course, it can be assembled not only in the impedance adjusting device 300 but also in other devices. For example, it can also be applied to Fig.11 The high frequency power supply device 100 shown is particularly effective when a large current in a high frequency band flows through the inductor 1. As can be seen from the above description, if applied to a device used in a high frequency band or a device in which a large current flows through the inductor 1, it is effective.

[0081] The embodiments disclosed this time should be considered to be illustrative in all aspects and not restrictive. The technical features described in the embodiments can be combined with each other, and the scope of the present invention includes all changes within the claims and the scope equivalent to the claims.

[0082] -Explanation of symbols-

[0083] 1 Inductor

[0084] 2 Flat wire

[0085] 3 Connection

[0086] 10 First coil section

[0087] 12 Gap

[0088] 15 Gap

[0089] 20 Second coil section

[0090] 22 Gap

[0091] 25 gap.

Claims

1. An inductor, characterized in that: The invention comprises a plurality of coil parts, wherein the coil parts are formed into a flat roll by stacking rectangular wires while providing gaps in the radial direction. The plurality of coil parts are arranged with gaps provided in the axial direction. The plurality of coil portions include a first coil portion and a second coil portion adjacent to each other in the axial direction. The first coil portion and the second coil portion are arranged so that the gaps between the rectangular wires in the first coil portion and the gaps between the rectangular wires in the second coil portion are connected in the axial direction. The inductor is provided with an air cooling fan. The first coil portion and the second coil portion are configured such that the air cooling fan causes air to flow in a direction perpendicular to the axial direction through a gap between the first coil portion and the second coil portion in the axial direction, and causes air to flow in the axial direction through a gap between the flat wires in the first coil portion and a gap between the flat wires in the second coil portion. The rectangular wire is wound so that the ratio of the radial dimension to the axial dimension of the portion where the rectangular wire is stacked in the plurality of coil parts is approximately 1, When visually viewed from the axial direction, the coil portion is wound into a hollow quadrilateral shape.

2. A device, characterized in that: A device comprising the inductor according to claim 1.

3. A method for manufacturing an inductor, the inductor comprising a plurality of coil parts, the coil parts being formed into a flat roll by stacking rectangular wires with gaps provided in a radial direction, The method for manufacturing the inductor is characterized in that: The plurality of coil parts are arranged with gaps provided in the axial direction, The plurality of coil portions include a first coil portion and a second coil portion adjacent to each other in the axial direction. The first coil portion and the second coil portion are arranged so that the gaps between the rectangular wires in the first coil portion and the gaps between the rectangular wires in the second coil portion are connected in the axial direction. The inductor is provided with an air cooling fan. The first coil part and the second coil part are configured such that the air is blown in a direction perpendicular to the axial direction through the gap between the first coil part and the second coil part in the axial direction by the air cooling fan, and the air is blown in the axial direction between the flat wires in the first coil part. and the gaps between the rectangular wires in the second coil portion, The rectangular wire is wound so that the ratio of the radial dimension to the axial dimension of the portion where the rectangular wire is stacked in the plurality of coil parts is approximately 1, The rectangular wire is wound so that the coil portion has a hollow quadrilateral shape when viewed from the axial direction.

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