JP7562466B2 - Coil assembly and core - Google Patents

Description

The present invention relates to a coil device and its core.

In recent years, with the increase in communication speed, the required characteristics of coil devices mounted on electronic devices are becoming more complex and sophisticated. For example, in common mode filters, points to consider in meeting the required characteristics include a small inter-line capacitance and a stable winding shape of the wire.

One way to reduce the inter-line capacitance is to increase the spacing between each turn of the wire along the axial direction of the winding core. However, this makes it difficult to wind the wire around the winding core at a high density.

For example, as in the coil device described in Patent Document 1, when a recess (step) is formed on the surface of the winding core, by increasing the width of the step, it is possible to increase the distance between the turn located above the step and the turn located below the step along the height direction of the step. In this case, the distance between each turn along the axial direction of the winding core can be maintained, so that the wire can be wound around the winding core at a high density while reducing the line-to-line capacitance.

However, in this case, especially when the step height is large, the turns located above the step are likely to fall below the step, making it difficult to stabilize the winding shape of the wire, which may result in a deterioration in the characteristics of the coil device.

JP 2020-107861 A

The present invention was made in consideration of these circumstances, and its purpose is to provide a coil device and its core that have good characteristics.

In order to achieve the above object, a coil device according to the present invention comprises:
A core including a winding core portion and a flange portion formed at an end of the winding core portion;
A wire wound around the winding core,
At different circumferential positions of the winding core, a first step portion that becomes higher toward one side of the winding core, and a second step portion that becomes higher toward the other side of the winding core are formed.

In order to achieve the above object, the core according to the present invention comprises:
A core portion,
A flange portion is formed at an end of the winding core portion,
At different circumferential positions of the winding core, a first step portion that becomes higher toward one side of the winding core, and a second step portion that becomes higher toward the other side of the winding core are formed.

In the core of the coil device according to the present invention, a first step portion that increases toward one side of the winding core portion and a second step portion that increases toward the other side of the winding core portion are formed at different positions in the circumferential direction of the winding core portion. Therefore, at each position where the first step portion and the second step portion are formed, it is possible to increase the spacing between the turns of the wire along the height direction of each of the first step portion and the second step portion, thereby reducing the line-to-line capacitance. In addition, since the line-to-line capacitance can be reduced without increasing the spacing between each turn of the wire along the axial direction of the winding core portion, not only can the wire be wound around the winding core portion with high density, but when the wire is wound in multiple layers along the radial direction of the winding core portion, the upper layer wire can be stably arranged on top of the lower layer wire.

In addition, when the wire is wound around the winding core so as to pass above the first step and below the second step at the position where the first step and the second step are formed, the second step restricts the positional shift of the wire constituting this turn (positional shift to the other side of the winding core), making it possible to prevent the turn located above the first step from falling below the first step. In addition, when the wire is wound around the winding core so as to pass above the second step and below the first step, the first step restricts the positional shift of the wire constituting this turn (positional shift to one side of the winding core), making it possible to prevent the turn located above the second step from falling below the second step. This stabilizes the winding shape of the wire and realizes a coil device with good characteristics.

Preferably, when the core is viewed from the first direction, the width of the core is larger on one side of the core than the first step portion in the second direction than the other side of the core than the first step portion, and when the core is viewed from the second direction, the width of the core is smaller on one side of the core than the first step portion in the first direction than the other side of the core than the first step portion. In this case, the first step portion and the second step portion are formed on different circumferential faces of the core (the face seen from the first direction and the face seen from the second direction). Therefore, it is possible to prevent the above-mentioned positional deviation of the wire (turn) on different circumferential faces of the core, and it is possible to effectively prevent the wire from falling from the first step portion or the second step portion.

Preferably, the first step portion and the second step portion are adjacent to each other in the circumferential direction of the winding core portion and extend in different directions. With this configuration, when the wire is wound around the winding core portion in the circumferential direction, the first step portion and the second step portion can prevent misalignment of the parts of the wire (turn) that extend in different directions, and can effectively prevent the wire from falling off the first step portion or the second step portion at different circumferential positions of the winding core portion.

Preferably, the first step portion is made up of a plurality of first step portions, the second step portion is made up of a plurality of second step portions, and the plurality of first step portions and the plurality of second step portions are arranged alternately along the circumferential direction of the winding core portion. With this configuration, it becomes possible to prevent the above-mentioned wire (turn) from shifting alternately to one side and the other side of the winding core portion at a predetermined span according to the arrangement positions of the first step portion and the second step portion at each position in the circumferential direction of the winding core portion, and it is possible to effectively prevent the wire from falling off the first step portion or the second step portion.

Preferably, a plurality of sets of the first step portions and the second step portions are formed at a predetermined interval at a plurality of positions in the axial direction of the winding core portion. With this configuration, it is possible to increase the interval between the turns of the wire along the height direction of each of the first step portions and the second step portions at a plurality of positions in the axial direction of the winding core portion, and the line-to-line capacitance can be effectively reduced.

Preferably, the wire is made up of a plurality of wires, the plurality of wires are wound in a plurality of layers around the winding core, and the height of the first step portion or the second step portion is equal to or greater than the sum of the diameters of the plurality of wires. With this configuration, it is possible to prevent a malfunction in which, at the position where the first step portion is formed, the plurality of wires passing under the first step portion are displaced to one side of the winding core portion so as to exceed the first step portion. Also, at the position where the second step portion is formed, it is possible to prevent a malfunction in which, at the position where the second step portion is formed, the plurality of wires passing under the second step portion are displaced to the other side of the winding core portion so as to exceed the second step portion. Therefore, the function of restricting the positional displacement of the wires by the first step portion and the second step portion can be sufficiently enhanced.

Preferably, the rising position of the first step portion is located on the other side of the winding core portion from the rising position of the second step portion, and the rising position of the second step portion is located on one side of the winding core portion from the rising position of the first step portion. In this configuration, the area on one side of the winding core portion from the rising position of the first step portion and the area on the other side of the winding core portion from the rising position of the second step portion are arranged to overlap. Therefore, at the position where the first step portion is formed, it is possible to shift the passing position of the wire passing above the first step portion to one side of the winding core portion from the rising position of the first step portion (i.e., the rising position of the second step portion). As a result, the wire is arranged at a position away from the rising position of the first step portion, and the malfunction of the wire falling from the first step portion can be effectively prevented. In addition, at the position where the second step portion is formed, it is possible to shift the passing position of the wire passing above the second step portion to the other side of the winding core portion (i.e., the rising position of the first step portion) from the rising position of the second step portion. As a result, the wire is positioned at a position away from the rising position of the second step portion, and the problem of the wire falling from the second step portion can be effectively prevented.

FIG. 1A is a perspective view of a coil device according to a first embodiment of the present invention. FIG. 1B is a bottom view of the coil arrangement shown in FIG. 1A. FIG. 2 is a cross-sectional view of the coil device shown in FIG. 1A taken along line II-II. FIG. 3A is a perspective view of the core shown in FIG. 1A. FIG. 3B is a side view of the core shown in FIG. 3A. FIG. 3C is a plan view of the core shown in FIG. 3A. FIG. 4A is a perspective view of a core of a coil device according to a second embodiment of the present invention. FIG. 4B is a side view of the core shown in FIG. 4A. FIG. 4C is a plan view of the core shown in FIG. 4A. FIG. 5 is a perspective view of a modification of the core shown in FIG. 3A. FIG. 6 is a perspective view of a modification of the core shown in FIG. 4A. FIG. 7 is a plan view showing another modified example of the core shown in FIG. 3A. FIG. 8 is a perspective view showing still another modified example of the core shown in FIG. 3A. FIG. 9 is a perspective view showing a modification of the core shown in FIG.

The present invention will now be described based on the embodiments shown in the drawings.

1A, a coil device 10 according to a first embodiment of the present invention has a core 20, a first wire 30, and a second wire 40. The coil device 10 is, for example, a common mode filter, and is mounted on an electronic device or the like.

The X-axis shown in the figure is in a plane parallel to the mounting surface on which the coil device 10 is mounted, and is a direction parallel to the axial direction of the winding core portion 23 of the core 20. The Y-axis is in a plane parallel to the mounting surface, like the X-axis, and is a direction perpendicular to the axial direction of the winding core portion 23. The Z-axis is a direction perpendicular to the mounting surface (normal direction).

The core 20 is a drum core and has a winding core portion 23, a first flange portion 21, and a second flange portion 22. The size of the core 20 is not particularly limited, but its length in the X-axis direction is 2.0 to 5.0 mm, its length in the Y-axis direction is 1.2 to 5.0 mm, and its length in the Z-axis direction is 0.8 to 4.0 mm.

The winding core 23 has a generally rectangular cross-sectional shape, but the cross-sectional shape of the winding core 23 is not particularly limited and may be circular, generally octagonal, or another polygonal shape. In the coil device 10 according to this embodiment, the shape of the winding core 23 has a notable feature, the details of which will be described later.

The first flange 21 and the second flange 22 are disposed facing each other and substantially parallel to each other with a predetermined gap in the X-axis direction. The first flange 21 is formed at one end of the winding core 23 in the X-axis direction, and the second flange 22 is formed at the other end of the winding core 23 in the X-axis direction. The flanges 21 and 22 have the same external shape and are substantially rectangular parallelepipeds that are elongated in the Y-axis direction. The cross-sectional shape (Y-Z cross section) of the flanges 21 and 22 may be circular, substantially octagonal, or any other polygonal shape, and the cross-sectional shape is not particularly limited.

The bottom surfaces 21a, 22a of the flanges 21, 22 serve as mounting surfaces (ground surfaces) when the coil device 10 is mounted on a circuit board or the like. As shown in FIG. 1B, a terminal electrode 51 and a terminal electrode 52 are formed on the bottom surface 21a of the first flange 21 at a predetermined interval in the Y-axis direction. A terminal electrode 53 and a terminal electrode 54 are formed on the bottom surface 22a of the second flange 22 at a predetermined interval in the Y-axis direction.

The terminal electrodes 51 to 54 each have the same shape and are formed only on the bottom surfaces 21a and 22a. However, for example, the terminal electrodes 51 and 52 may be formed to straddle the outer end surface of the first flange 21 and the bottom surface 21a, and the terminal electrodes 53 and 54 may be formed to straddle the outer end surface of the second flange 22 and the bottom surface 22a. With this configuration, it is possible to form solder fillets on parts of the terminal electrodes 51 to 54 formed on the outer end surfaces of the flanges 21 and 22 when the coil device 10 is mounted on a circuit board.

The terminal electrodes 51 to 54 are made of a conductive material, for example, a metal paste baked film or a metal plating film. The terminal electrodes 51 to 54 may be made of conductive terminals made of metal or the like.

The terminal electrodes 51 to 54 are formed by applying, for example, Ag paste to the bottom surfaces 21a, 22a of the flanges 21, 22, baking the paste, and then subjecting the surface to, for example, electrolytic plating or electroless plating to form a plating film. The material of the metal paste is not particularly limited, and examples include Cu paste and Ag paste. The plating film may be a single layer or multiple layers, and examples include plating films such as Cu plating, Ni plating, Sn plating, Ni-Sn plating, Cu-Ni-Sn plating, Ni-Au plating, and Au plating. The thickness of the terminal electrodes 51 to 54 is not particularly limited, but is preferably 0.1 to 15 μm.

The first lead portion 30a of the first wire 30 is connected to the terminal electrode 51, for example, by thermocompression bonding. The second lead portion 40a of the second wire 40 is connected to the terminal electrode 52, for example, by thermocompression bonding. The other first lead portion 30b of the first wire 30 is connected to the terminal electrode 53, for example, by thermocompression bonding. The other second lead portion 40b of the second wire 40 is connected to the terminal electrode 54, for example, by thermocompression bonding.

As shown in FIG. 2, the first wire 30 is wound directly on the outer peripheral surface of the winding core 23, and the first coil section 32 is formed by winding the first wire 30 around the outer peripheral surface of the winding core 23. The second wire 40 is wound around the outer peripheral surface of the first coil section 32 (above the first wire 30), and the second coil section 42 is formed by winding the second wire 40 around the outer peripheral surface of the first coil section 32. In other words, the winding core 23 has a two-layer coil section formed of the first coil section 32 and the second coil section 42.

The number of layers along the X-axis direction of each of the first wire 30 and the second wire 40 is not particularly limited, but it is preferable that the first wire 30 and the second wire 40 are wound at high density around the winding core 23 along the X-axis direction. It is also preferable that the first wire 30 and the second wire 40 are wound tightly (without gaps) along the X-axis direction.

The first wire 30 and the second wire 40 each have approximately the same wire length, and it is preferable that the turn ratio between the number of turns of the first wire 30 and the number of turns of the second wire 40 is equal. One of the first wire 30 and the second wire 40 constitutes the primary winding, and the other constitutes the secondary winding.

In this embodiment, a step is formed midway in the X-axis direction of the winding core 23. Details of this step will be described below. In the following description, the surface of the winding core 23 on the positive Z-axis side will be referred to as the "upper surface", the surface on the negative Z-axis side will be referred to as the "lower surface", the side on the positive Y-axis side will be referred to as the "first side", and the side on the negative Y-axis side will be referred to as the "second side".

As shown in Figures 3A and 3B, at approximately the center of the winding core 23 in the X-axis direction, a step portion 60a is formed on the upper surface of the winding core 23, and a step portion 60b is formed on the lower surface of the winding core 23. Also, as shown in Figures 3A and 3C, at approximately the center of the winding core 23 in the X-axis direction, a step portion 70a is formed on the first side surface of the winding core 23, and a step portion 70b is formed on the second side surface of the winding core 23.

The step portions 60a and 60b constitute the same type of step portion (first step portion) in the sense that they are raised in the Z-axis direction from the upper and lower surfaces of the winding core portion 23, respectively. The step portions 70a and 70b constitute the same type of step portion (second step portion) in the sense that they are raised in the Y-axis direction from the first and second side surfaces of the winding core portion 23, respectively.

As shown in Figures 3A to 3C, in the approximate center of the winding core 23 in the X-axis direction, the steps 60a, 60b and the steps 70a, 70b are formed at different circumferential positions of the winding core 23, and are arranged along the circumferential direction of the winding core 23. The steps 60a, 60b and the steps 70a, 70b are formed on adjacent surfaces of the winding core 23 in the circumferential direction. A block (section) B1 is formed on the positive X-axis side of the steps 60a, 60b and the steps 70a, 70b, and a block (section) B2 is formed on the negative X-axis side of the steps 60a, 60b and the steps 70a, 70b.

As shown in Figures 3A and 3B, the step 60a rises from the top surface of the winding core 23 toward the Z-axis positive side (upward), and is formed continuously from one end of the top surface of the winding core 23 in the Y-axis direction to the other end. The step 60a extends linearly along the Y-axis direction, and the top surface 231a of the winding core 23 located on the X-axis positive side (one side in the X-axis direction) of the step 60a protrudes upward from the top surface 231b of the winding core 23 located on the X-axis negative side (the other side in the X-axis direction) of the step 60a. In other words, the step 60a is a step whose step height increases toward the X-axis positive side of the winding core 23 when the top surface 231b of the winding core 23 is used as a reference.

Using the position of the step 60a as a reference (boundary), the relative height in the Z-axis direction of the upper surface of the winding core 23 differs between the positive and negative sides of the X-axis direction. On the positive side of the X-axis from the step 60a, the relative height in the Z-axis direction of the upper surface 231a of the winding core 23 (height based on the lower surface 232a described later) is approximately constant, and the upper surface 231a forms a flat surface (a horizontal surface parallel to the X-Y plane). On the negative side of the X-axis from the step 60a, the relative height in the Z-axis direction of the upper surface 231b of the winding core 23 (height based on the lower surface 232b described later) is approximately constant, and the upper surface 231b forms a flat surface (a horizontal surface parallel to the X-Y plane).

The step portion 60a has a tapered surface 61a. The tapered surface 61a is inclined at a predetermined angle with respect to the Z-axis direction and is formed for the convenience of winding the wires 30, 40 around the winding core portion 23. More specifically, the tapered surface 61a is intended to prevent the wires 30, 40 from contacting and being damaged by the corners of the step portion 60a. The end position of the rise of the step portion 60a is shifted toward the positive direction of the X-axis by a distance corresponding to the inclination angle of the tapered surface 61a relative to the start position of the rise of the step portion 60a. The inclination angle of the tapered surface 61a with respect to the X-axis (the angle between the tapered surface 61a and the X-axis) is preferably 45° to 80°.

The tapered surface 61 is not essential and may be omitted. In this case, the step portion 60a is raised along the Z-axis direction, and the step surface of the step portion 60a (a surface parallel to the Y-Z plane) and the upper surface of the winding core portion 23 are perpendicular to each other.

Here, the diameter of the first wire 30 (FIG. 1A) is D1, the diameter of the second wire 40 (FIG. 1A) is D2, and the height of the step portion 60a along the Z-axis direction is H1. As described above, the second wire 40 is wound on the first wire 30. In this case, the relationship between the height H1 of the step portion 60a and the diameters D1 and D2 of the wires 30 and 40 is preferably H1≧D1 or H1≧D2, more preferably H1≧D1+(D2/2), and particularly preferably H1≧D1+D2. In other words, it is particularly preferable that the height H1 of the step portion 60a along the Z-axis direction is equal to or greater than the sum of the diameters D1 and D2 of the wires 30 and 40.

When the height of the winding core 23 (height of the winding core 23 at the position of the block B1) is H2, the ratio H1/H2 of the height H1 of the step portion 60a to the height H2 of the winding core 23 is preferably 1/20 to 1/4, and more preferably 1/10 to 1/6.

The step portion 60b is formed at approximately the same position as the step portion 60a in the X-axis direction of the winding core portion 23, and the step portion 60b has a shape corresponding to the step portion 60a (a symmetrical shape). The height H1 of the step portion 60b is approximately the same as the height H1 of the step portion 60a. When the core 20 is turned upside down, the external shape of the step portion 60b matches the external shape of the step portion 60a.

The step portion 60b rises from the bottom surface of the winding core 23 toward the Z-axis negative side (downward), and is formed continuously from one end of the bottom surface of the winding core 23 in the Y-axis direction to the other end. The step portion 60b extends linearly along the Y-axis direction, and the bottom surface 232a of the winding core 23 located on the X-axis positive side (one side in the X-axis direction) of the step portion 60b protrudes downward from the bottom surface 232b of the winding core 23 located on the X-axis negative side (the other side in the X-axis direction) of the step portion 60b. In other words, the step portion 60b is a step portion whose step height increases toward the X-axis positive side of the winding core 23 relative to the bottom surface 231b of the winding core 23. Note that the step height increases when the step height changes in the direction of increasing the step.

The relative height of the lower surface of the winding core 23 in the Z-axis direction differs between the positive and negative sides of the X-axis direction, with the position of the step 60b as the reference (boundary). On the positive side of the X-axis from the step 60b, the relative height of the lower surface 232a of the winding core 23 in the Z-axis direction (height based on the upper surface 231a) is approximately constant, and the lower surface 232a forms a flat surface (horizontal surface parallel to the X-Y plane). On the negative side of the X-axis from the step 60b, the relative height of the lower surface 232b of the winding core 23 in the Z-axis direction (height based on the upper surface 231b) is approximately constant, and the lower surface 232b forms a flat surface (horizontal surface parallel to the X-Y plane). That is, the upper surface 231a and the lower surface 232a are approximately parallel, and the upper surface 231b and the lower surface 232b are approximately parallel.

The step portion 60b has a tapered surface 61b. The tapered surface 61b has a similar shape to the tapered surface 61a, so a detailed description of it will be omitted.

3A and 3C, the step portion 70a rises from the first side surface of the winding core 23 toward the Y-axis positive side (side), and is formed continuously from one end of the first side surface of the winding core 23 in the Z-axis direction to the other end. The step portion 70a extends linearly along the Z-axis direction, and the first side surface 233b of the winding core 23 located on the X-axis negative side (the other side in the X-axis direction) of the step portion 70a protrudes laterally from the first side surface 233a of the winding core 23 located on the X-axis positive side (one side in the X-axis direction) of the step portion 70a. In other words, the step portion 70a is a step portion whose step height increases relatively toward the X-axis negative side of the winding core 23 when the first side surface 233a of the winding core 23 is used as a reference.

Using the position of the step 70a as a reference (boundary), the relative height of the first side of the winding core 23 in the Y-axis direction differs between the positive and negative sides in the X-axis direction. On the positive side of the X-axis from the step 70a, the relative height of the first side 233a of the winding core 23 in the Y-axis direction (height based on the second side 234a described later) is approximately constant, and the first side 233a forms a flat surface (vertical surface parallel to the X-Z plane). On the negative side of the X-axis from the step 70a, the relative height of the first side 233b of the winding core 23 in the Y-axis direction (height based on the second side 234b described later) is approximately constant, and the first side 233b forms a flat surface (vertical surface parallel to the X-Z plane).

Step portion 70a does not have a tapered surface like steps 60a and 60b. However, for convenience when winding wires 30 and 40 around winding core 23, step portion 70a may have a tapered surface. The same applies to step portion 70b, which will be described later.

Here, the width of the step portion 70a along the Y-axis direction is W1. In this case, the relationship between the width W1 of the step portion 70a and the diameters D1 and D2 of the wires 30 and 40 is preferably W1 ≧ D1 or W1 ≧ D2, more preferably W1 ≧ D1 + (D2/2), and particularly preferably W1 ≧ D1 + D2. In other words, it is particularly preferable that the width W1 of the step portion 70a along the Y-axis direction is equal to or greater than the sum of the diameters D1 and D2 of the wires 30 and 40.

When the width of the winding core 23 (however, the width of the winding core 23 at the position of the block B2) is W2, the ratio W1/W2 of the width W1 of the step portion 70a to the width W2 of the winding core 23 is preferably 1/25 to 1/6, and more preferably 1/15 to 1/9.

Step portion 70b is formed at approximately the same position as step portion 70a in the X-axis direction of winding core portion 23, and step portion 70b has a shape corresponding to step portion 70a (symmetrical shape). Width W1 of step portion 70b is the same as width W1 of step portion 70a. When core 20 is turned upside down, the external shape of step portion 70b matches the external shape of step portion 70a.

The step portion 70b rises from the second side surface of the winding core 23 toward the Y-axis negative direction (side), and is formed continuously from one end of the second side surface of the winding core 23 in the Z-axis direction to the other end. The step portion 70b extends linearly along the Z-axis direction, and the second side surface 234b of the winding core 23 located on the X-axis negative direction side (the other side in the X-axis direction) of the step portion 70b protrudes laterally from the second side surface 234a of the winding core 23 located on the X-axis positive direction side (one side in the X-axis direction) of the step portion 70b. In other words, the step portion 70b is a step portion whose step height increases relatively toward the X-axis negative direction side of the winding core 23 when the second side surface 234a of the winding core 23 is used as a reference.

Using the position of the step 70b as a reference (boundary), the relative height of the second side of the winding core 23 in the Y-axis direction differs between the positive and negative sides in the X-axis direction. On the positive side of the X-axis from the step 70b, the relative height of the second side 234a of the winding core 23 in the Y-axis direction (height based on the first side 233a) is approximately constant, and the second side 234a forms a flat surface (vertical surface parallel to the X-Z plane). On the negative side of the X-axis from the step 70b, the relative height of the second side 234b of the winding core 23 in the Y-axis direction (height based on the first side 233b) is approximately constant, and the second side 234b forms a flat surface (vertical surface parallel to the X-Z plane).

As shown in Figures 3A to 3C, the step portions 60a, 60b and the step portions 70a, 70b are formed continuously along the circumferential direction of the winding core portion 23. Note that "continuous" does not necessarily mean that these step portions are smoothly connected, but rather that these step portions are connected without interruption.

The step portion 60a and the step portion 70a are adjacent to each other in the circumferential direction of the winding core portion 23 and are perpendicular to each other. The step portion 70a and the step portion 60b are adjacent to each other in the circumferential direction of the winding core portion 23 and are perpendicular to each other. The step portion 60b and the step portion 70b are adjacent to each other in the circumferential direction of the winding core portion 23 and are perpendicular to each other. The step portion 70b and the step portion 60a are adjacent to each other in the circumferential direction of the winding core portion 23 and are perpendicular to each other. The step portions 60a and 60b extend along the Y-axis direction, while the step portions 70a and 70b extend along the Z-axis direction. In other words, the step portions 60a and 60b and the step portions 70a and 70b extend in different directions from each other along the circumferential direction of the winding core portion 23. In this embodiment, the step portions 60a, 60b and the step portions 70a, 70b, which extend in different directions, are alternately arranged along the circumferential direction of the winding core portion 23.

The step portions 60a and 60b are formed on the upper and lower surfaces of the winding core portion 23, respectively, and the step portions 70a and 70b are formed on the first and second side surfaces of the winding core portion 23, respectively. In this embodiment, step portions are formed on all surfaces of the winding core portion 23.

The rising positions of the step portions 60a, 60b and the rising positions of the step portions 70a, 70b are substantially the same in the X-axis direction, but these rising positions may be spaced apart at a predetermined interval along the X-axis direction. The distance in the X-axis direction between the rising positions of the step portions 60a, 60b and the rising positions of the step portions 70a, 70b is preferably smaller than the wire diameters D1, D2 of the wires 30, 40, and more preferably 0.

As shown in FIG. 3B, when the winding core 23 is viewed from the Y-axis direction (first direction), the width of the winding core 23 along the Z-axis direction (second direction) is larger on the X-axis positive side of the winding core 23 than the step portions 60a, 60b compared to the X-axis negative side of the winding core 23 than the step portions 60a, 60b. Also, as shown in FIG. 3C, when the winding core 23 is viewed from the Z-axis direction (second direction), the width of the winding core 23 along the Y-axis direction (first direction) is smaller on the X-axis positive side of the winding core 23 than the step portions 60a, 60b compared to the X-axis negative side of the winding core 23 than the step portions 60a, 60b.

In this way, the winding core portion 23 in this embodiment is composed of two blocks B1 and B2 with different shapes on one side and the other side in the X-axis direction of the positions of the step portions 60a, 60b and the step portions 70a, 70b.

As shown in FIG. 2, it is preferable that the number of turns of the first wire 30 wound around the winding core 23 and the number of turns of the second wire 40 are equal on the positive side of the X-axis from the step portions 60a and 60b. It is also preferable that the number of turns of the first wire 30 wound around the winding core 23 and the number of turns of the second wire 40 are equal on the negative side of the X-axis from the step portions 60a and 60b.

As shown in Figures 1B and 2, the shape of the coil parts 32, 42 formed in block B1 is different from the shape of the coil parts 32, 42 formed in block B2. The diameter in the Z-axis direction of the coil parts 32, 42 formed in block B1 is larger than the diameter in the Z-axis direction of the coil parts 32, 42 formed in block B2. In addition, the diameter in the Y-axis direction of the coil parts 32, 42 formed in block B1 is smaller than the diameter in the Y-axis direction of the coil parts 32, 42 formed in block B2.

As shown in Fig. 1B and Fig. 2, in the winding core 23, the wires 30 and 40 pass around the periphery of the step portions 60a, 60b and step portions 70a, 70b in the circumferential direction of the winding core 23. Here, as shown in Fig. 1B, at the position where the step portions 60a, 60b and step portions 70a, 70b are formed (i.e., approximately the center in the X-axis direction of the winding core 23), the turns of the wires 30 and 40 that pass above the step portions 60a, 60b (the side where the step height is higher) are denoted as "turns 30c, 40c". Also, the turns of the wires 30 and 40 that pass below the step portions 60a, 60b (the side where the step height is lower) are denoted as "turns 30d, 40d".

As shown in Figures 1B and 2, turns 30c and 40c pass above steps 60a and 60b on the upper and lower surfaces of winding core 23 on the positive X-axis side of steps 60a and 60b and steps 70a and 70b (see Figure 2), while passing below steps 70a and 70b on the first and second side surfaces of winding core 23 (see Figure 1B).

In this case, as shown in FIG. 1B, the step surface (a surface parallel to the Y-Z plane) of the step portions 70a and 70b is located on the negative X-axis side of the turns 30c and 40c, and this step surface makes it possible to restrict the positional deviation of the turns 30c and 40c in the negative X-axis direction. In this way, by restricting the positional deviation of the turns 30c and 40c in the negative X-axis direction at the positions of the step portions 70a and 70b, it is possible to restrict the positional deviation of the turns 30c and 40c in the negative X-axis direction that passes above the step portions 60a and 60b shown in FIG. 2 in the negative X-axis direction. As a result, in this embodiment, the turns 30c and 40c as a whole can be prevented from being shifted in the negative X-axis direction. In other words, the step portions 70a and 70b function as a means for preventing the turns 30c and 40c from being shifted in the negative X-axis direction.

As shown in Figures 1B and 2, turns 30d and 40d pass below steps 60a and 60b on the upper and lower surfaces of winding core 23 on the negative X-axis side of steps 60a and 60b and steps 70a and 70b (see Figure 2), while passing above steps 70a and 70b on the first and second side surfaces of winding core 23 (see Figure 1B).

In this case, as shown in FIG. 2, the step surfaces (surfaces parallel to the Y-Z plane) of the step portions 60a and 60b are located on the X-axis positive side of the turns 30d and 40d, and this step surface makes it possible to restrict the positional deviation of the turns 30d and 40d in the X-axis positive direction. In this way, by restricting the positional deviation of the turns 30d and 40d in the X-axis positive direction at the positions of the step portions 60a and 60b, it is possible to restrict the positional deviation of the turns 30d and 40d in the X-axis positive direction that passes above the step portions 70a and 70b shown in FIG. 1B. As a result, in this embodiment, the turns 30d and 40d as a whole can be prevented from being shifted in the X-axis positive direction. In other words, the step portions 60a and 60b function as a means for preventing the turns 30d and 40d from being shifted in the X-axis positive direction.

Next, a method for manufacturing the coil device 10 will be described with reference to Figures 1A, 1B, and 2. In manufacturing the coil device 10, first, a drum-shaped core 20, a first wire 30, and a second wire 40 are prepared. The wires 30 and 40 may be, for example, a core material made of a good conductor such as copper (Cu), covered with an insulating material such as imide-modified polyurethane, and the outermost surface covered with a thin resin film such as polyester.

The magnetic material constituting the core 20 may be, for example, a magnetic material with a relatively high magnetic permeability, such as Ni-Zn ferrite, Mn-Zn ferrite, or a metallic magnetic material, and the core 20 is produced by molding and sintering powder of these magnetic materials. Steps 60a, 60b and steps 70a, 70b are formed in the winding core portion 23 of the core 20.

Next, a metal paste is applied to the flanges 21 and 22 of the core 20 and baked at a predetermined temperature. Then, the surface is subjected to electrolytic plating or electroless plating to form the terminal electrodes 51 to 54.

Next, the core 20 with the terminal electrodes 51-54 formed thereon, the first wire 30, and the second wire 40 are set in a winding machine (not shown). Then, the first lead portion 30a of the first wire 30 is connected to the terminal electrode 51, and at the same time (or afterwards), the second lead portion 40a of the second wire 40 is connected to the terminal electrode 54.

The method for connection is not particularly limited, but for example, a heater chip is pressed against the wires 30, 40 so as to sandwich them between the terminal electrodes 51, 52, and the wires 30, 40 are thermally bonded to the terminal electrodes 51, 52.

Then, the first wire 30 is wound around the outer periphery of the winding core 23 to form the first coil section 32, and the second wire 40 is wound around the first coil section 32 to form the second coil section 42. As shown in FIG. 2, when the wire 30, 40 is wound around the block B1 of the winding core 23, the wire 30, 40 (turns 30c, 40c) is wound so as to pass above the step sections 60a, 60b and step sections 70a, 70b on the upper and lower surfaces of the winding core 23, and the wire 30, 40 (turns 30c, 40c) is wound so as to pass below the step sections 70a, 70b on the first and second side surfaces of the winding core 23, as shown in FIG. 1B.

When winding the wires 30 and 40 from block B1 to block B2 of the winding core 23, the wires 30 and 40 are pulled out from block B1 to block B2 so as to straddle the steps 60a, 60b and 70a, 70b. After being pulled out toward the negative X-axis direction side beyond the steps 60a, 60b and 70a, 70b, the wires 30 and 40 (turns 30d and 40d) are wound so as to pass under the steps 60a and 60b on the upper and lower surfaces of the winding core 23 as shown in FIG. 2, and the wires 30 and 40 (turns 30d and 40d) are wound so as to pass over the steps 70a and 70b on the first and second side surfaces of the winding core 23 as shown in FIG. 1B.

By winding the wires 30, 40 around the winding core 23 in the above manner, a first region of the coils 32, 42 is formed on the positive side of the X-axis, sandwiching the step portions 60a, 60b and the step portions 70a, 70b, and a second region of the coils 32, 42 is formed on the negative side of the X-axis.

Next, the first lead portion 30b of the first wire 30 is connected to the terminal electrode 53, and at the same time (or afterwards), the second lead portion 40b of the second wire 40 is connected to the terminal electrode 54.

As described above, in the core 20 of the coil device 10 according to this embodiment, as shown in Figs. 3A to 3C, the step portions 60a, 60b and the step portions 70a, 70b are formed at different positions in the circumferential direction of the winding core portion 23. Therefore, as shown in Figs. 1B and 2, at each position where the step portions 60a, 60b and the step portions 70a, 70b are formed, it is possible to increase the interval between the turns 30c, 40c and the turns 30d, 40d along the height direction of the step portions 60a, 60b and the step portions 70a, 70b, respectively, and the line-to-line capacitance can be reduced. In addition, at this time, the line-to-line capacitance can be reduced without increasing the interval between the turns of the wires 30, 40 along the X-axis direction throughout the entire coil portion 32, 42, so that the wires 30, 40 can be wound around the winding core portion 23 at a high density. Furthermore, when the wires 30, 40 are wound in multiple layers (two layers in the illustrated example) along the radial direction of the winding core 23 as in this embodiment, the upper layer wires 30, 40 can be stably positioned on top of the lower layer wires 30, 40.

In addition, at the position where the step portions 60a, 60b and the step portions 70a, 70b are formed, the wires 30, 40 (turns 30c, 40c) are wound around the winding core 23 so as to pass above the step portions 60a, 60b and below the step portions 70a, 70b. Therefore, the positional deviation (positional deviation toward the negative X-axis direction) of the wires 30, 40 constituting the turns 30c, 40c is restricted by the step portions 70a, 70b, and it is possible to prevent the turns 30c, 40c located above the step portions 60a, 60b from falling below the step portions 60a, 60b. In addition, the wires 30, 40 (turns 30d, 40d) are wound around the winding core 23 so as to pass above the step portions 70a, 70b and below the step portions 60a, 60b. Therefore, the step portions 60a and 60b can regulate the positional deviation (positional deviation in the positive direction of the X-axis) of the wires 30 and 40 that make up the turns 30d and 40d, and it is possible to prevent the turns 30d and 40d located above the step portions 70a and 70b from falling below the step portions 70a and 70b. This makes it possible to stabilize the shape of the coil portions 32 and 42 and realize a coil device 10 with good characteristics.

In addition, in this embodiment, the step portions 60a, 60b and the step portions 70a, 70b are formed on different circumferential surfaces (upper surface, lower surface, first side surface, and second side surface) of the winding core portion 23. Therefore, it is possible to prevent the above-mentioned wires 30, 40 (turns 30c, 40c, 30d, 40d) from shifting in position on different circumferential surfaces of the winding core portion 23, and it is possible to effectively prevent the wires 30, 40 from falling off the step portions 60a, 60b or the step portions 70a, 70b.

In addition, in this embodiment, the step portions 60a, 60b and the step portions 70a, 70b are adjacent to each other in the circumferential direction of the winding core portion 23 and extend in different directions (Y-axis direction or Z-axis direction). Therefore, when the wires 30, 40 are wound around the winding core portion 23 in the circumferential direction, the step portions 60a, 60b can prevent the wires 30, 40 (turns 30d, 40d) extending in the Y-axis direction from being displaced in the positive direction of the X-axis, and the step portions 70a, 70b can prevent the wires 30, 40 (turns 30c, 40c) extending in the Z-axis direction from being displaced in the negative direction of the X-axis. This can effectively prevent the wires 30, 40 from falling off the step portions 60a, 60b or the step portions 70a, 70b at different positions in the circumferential direction of the winding core portion 23.

In addition, in this embodiment, the multiple step portions 60a, 60b and the multiple step portions 70a, 70b are arranged alternately along the circumferential direction of the winding core portion 23. Therefore, at each position in the circumferential direction of the winding core portion 23, it is possible to prevent the above-mentioned wires 30, 40 from shifting in position toward the positive side of the X-axis and the negative side of the X-axis at a predetermined span according to the arrangement positions of the step portions 60a, 60b and the step portions 70a, 70b, and it is possible to effectively prevent the wires 30, 40 from falling off the step portions 60a, 60b or the step portions 70a, 70b.

In addition, in this embodiment, the height H1 of the step portions 60a, 60b or the width W1 of the step portions 70a, 70b is equal to or greater than the sum of the diameters D1, D2 of the wires 30, 40. Therefore, it is possible to prevent a malfunction in which the turns 30d, 40d of the wires 30, 40 passing under the step portions 60a, 60b at the position where the step portions 60a, 60b are formed are displaced to the positive X-axis side of the winding core portion 23 so as to exceed the remaining step portions 60a, 60b. In addition, it is possible to prevent a malfunction in which the turns 30c, 40c of the multiple wires 30, 40 passing under the step portions 70a, 70b at the position where the step portions 70a, 70b are formed are displaced to the negative X-axis side of the winding core portion 23 so as to exceed the remaining step portions 70a, 70b. Therefore, the function of the steps 60a, 60b and 70a, 70b to prevent the wires 30, 40 from shifting can be sufficiently improved.

4A to 4C according to a second embodiment of the present invention is similar to the first embodiment in other respects, except for the following differences: In the drawings, members common to the first embodiment are designated by the same reference numerals, and detailed descriptions thereof will be omitted.

As shown in FIG. 4A, steps 60a, 60b and steps 70a, 70b are formed at position L1 in the X-axis direction of the winding core 23. Steps 60a, 60b and steps 70a, 70b are also formed at position L2, a predetermined distance away from position L1 in the X-axis direction of the winding core 23 in the positive X-axis direction. That is, in this embodiment, multiple (two in the illustrated example) sets of step portions 60a, 60b and step portions 70a, 70b are formed at multiple (two in the illustrated example) positions L1 and L2 in the axial direction of the winding core 23 at predetermined intervals.

The stepped portions 60a, 60b and 70a, 70b formed at position L1 and the stepped portions 60a, 60b and 70a, 70b formed at position L2 have corresponding shapes. When the core 120 is rotated 180° around the Z axis as the rotation axis, it has the same shape before and after the rotation. The tapered surfaces 61a, 61b of the stepped portions 60a, 60b formed at position L1 are formed so as to be lower toward the negative X-axis direction, while the tapered surfaces 61a, 61b of the stepped portions 60a, 60b formed at position L2 are formed so as to be lower toward the positive X-axis direction. In other words, the tapered surfaces 61a, 61b are inclined toward opposite directions.

The shape of the winding core 123 (blocks B1, B2) on the negative X-axis side of position L2 is similar to the shape of the winding core 23 (blocks B1, B2) in the first embodiment shown in FIG. 3A. As shown in FIGS. 4B and 4C, the winding core 123 is provided with a block B3 having an upper surface 231c, a lower surface 232c, a first side surface 233c, and a second side surface 234c on the positive X-axis side of position L2. In this embodiment, the winding core 123 is composed of three blocks B1 to B3 separated by positions L1 and L2.

Of the three blocks B1 to B3, blocks B1 and B3 have approximately the same shape, and only block B2, located between blocks B1 and B2, has a different shape.

As shown in FIG. 4B, when the winding core 123 is viewed from the Y-axis direction (first direction), the width of the winding core 123 along the Z-axis direction (second direction) is smaller on the X-axis positive side of the winding core 123 than the step portions 60a, 60b at position L2 (i.e., block B3) than the X-axis negative side of the winding core 123 than the step portions 60a, 60b (i.e., block B2). Also, as shown in FIG. 4C, when the winding core 123 is viewed from the Z-axis direction (second direction), the width of the winding core 123 along the Y-axis direction (first direction) is larger on the X-axis positive side of the winding core 123 than the step portions 60a, 60b at position L2 (i.e., block B3) than the X-axis negative side of the winding core 23 than the step portions 60a, 60b (i.e., block B2).

Therefore, when wire 30, 40 (Fig. 1A) is wound around winding core 123 at position L2 so as to pass above step portions 60a, 60b and below step portions 70a, 70b, step portions 70a, 70b regulate the misalignment of wire 30, 40 constituting this turn (misalignment toward the positive X-axis direction of winding core 123), making it possible to prevent the turn located above step portions 60a, 60b from falling below step portions 60a, 60b. In addition, when the wires 30 and 40 are wound around the winding core 123 so as to pass above the steps 70a and 70b and below the steps 60a and 60b, the steps 60a and 60b regulate the positional deviation of the wires 30 and 40 that constitute the turns (the positional deviation of the winding core 123 toward the negative X-axis direction), so that it is possible to prevent the turns located above the steps 70a and 70b from falling below the steps 70a and 70b. This stabilizes the winding shape of the wires 30 and 40, and realizes a coil device with good characteristics.

In this embodiment, multiple (two) sets of step portions 60a, 60b and step portions 70a, 70b are formed at multiple (two) positions L1, L2 in the axial direction of the winding core portion 123 at a predetermined interval. Therefore, at multiple positions L1, L2, it is possible to increase the interval between the turns of the wires 30, 40 along the height direction of each of the step portions 60a, 60b and step portions 70a, 70b, and the line-to-line capacitance can be effectively reduced.

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

(1) In the first embodiment, the rising positions of the steps 60a, 60b and 70a, 70b may be changed as appropriate. For example, as shown in FIG. 5, the rising position L3 of the steps 60a, 60b may be located on the negative X-axis side of the winding core 23 relative to the rising position L4 of the steps 70a, 70b, and the rising position L4 of the steps 70a, 70b may be located on the positive X-axis side of the winding core 23 relative to the rising position L3 of the steps 60a, 60b.

In this case, the area of the winding core 23 on the positive side of the X-axis from the rising position L3 of the steps 60a and 60b and the area of the winding core 23 on the negative side of the X-axis from the rising position L4 of the steps 70a and 70b are arranged to overlap. The steps 60a and 60b are formed in a state where they protrude further in the negative X-axis direction than the steps 70a and 70b so as to occupy a portion of each of the upper surface 231b and the lower surface 232b of the winding core 23. The steps 70a and 70b are formed in a state where they protrude further in the positive X-axis direction than the steps 60a and 60b so as to occupy a portion of each of the first side surface 233a and the second side surface 234a of the winding core 23.

The distance D along the X-axis between the rising position L3 of the step portions 60a, 60b and the rising position L4 of the step portions 70a, 70b is preferably equal to or greater than the diameters D1, D2 of the wires 30, 40. Preferably, D≧D1 or D≧D2, and more preferably, D≧2D1 or D≧2D2.

In this modified example, at the position where the step portions 60a, 60b are formed, the passing position of the wires 30, 40 passing above the step portions 60a, 60b is shifted by a distance corresponding to the above-mentioned interval D toward the positive X-axis direction side of the winding core portion 23 (i.e., the rising position L4 of the step portions 70a, 70b) from the rising position L3 of the step portions 60a, 60b. As a result, the wires 30, 40 are positioned away from the rising position L3 of the step portions 60a, 60b, and the problem of the wires 30, 40 falling from the step portions 60a, 60b can be effectively prevented.

In addition, at the position where the step portions 70a, 70b are formed, the passing position of the wires 30, 40 passing above the step portions 70a, 70b is shifted by a distance corresponding to the above-mentioned interval D toward the negative X-axis direction side of the winding core portion 23 (i.e., the rising position L3 of the step portions 60a, 60b) from the rising position L4 of the step portions 70a, 70b. As a result, the wires 30, 40 are positioned away from the rising position L4 of the step portions 70a, 70b, and the problem of the wires 30, 40 falling from the step portions 70a, 70b can be effectively prevented. In addition, the wires 30, 40 can be prevented from being wound around the lower surfaces of both the step portions 60a, 60b and the step portions 70a, 70b.

(2) The above modified example (1) may be applied to the above second embodiment. That is, as shown in FIG. 6, the rising position L5 of the step portions 60a, 60b formed between the blocks B2 and B3 of the winding core portion 123 may be located on the positive X-axis side of the winding core portion 123 relative to the rising position L6 of the step portions 70a, 70b, and the rising position L6 of the step portions 70a, 70b may be located on the negative X-axis side of the winding core portion 123 relative to the rising position L5 of the step portions 60a, 60b. In this case, the same effect as the above modified example (1) can be obtained.

(3) In the first embodiment, the step portions 60a, 60b or the step portions 70a, 70b are formed on all surfaces (upper surface, lower surface, first side surface, and second side surface) of the winding core portion 23. However, the step portions 60a, 60b or the step portions 70a, 70b may be formed only on some surfaces of the winding core portion 23. For example, as shown in FIG. 7, the step portion 60a may be formed only on the upper surface of the upper and lower surfaces of the winding core portion 23, and the step portion 70a may be formed only on the first side surface of the first and second side surfaces of the winding core portion 23. In this case, the same effect as in the first embodiment can be obtained. Note that the step portion 60a may be formed on the upper surface of the winding core portion 23, and the step portion 70b may be formed on the second side surface of the winding core portion 23. Alternatively, the step portion 60b may be formed on the lower surface of the winding core portion 23, and the step portion 70a may be formed on the first side surface of the winding core portion 23. Alternatively, a step portion 60b may be formed on the lower surface of the winding core portion 23, and a step portion 70b may be formed on the second side surface of the winding core portion 23. This is also true for the second embodiment. As described above, the number of step portions is not limited to four or two, and may be three, or five or more.

(4) In the first embodiment, the cross-sectional shape of the winding core 23 is a rectangle, but it may be a hexagon as shown in FIG. 8. In this case, two sides of the hexagon are located on the upper surface 231a and the lower surface 231b (not shown) on the X-axis positive side of the steps 60a, 60b and the steps 70a, 70b. Also, two sides of the hexagon are located on the first side surface 233b and the second side surface 234b on the X-axis negative side of the steps 60a, 60b and the steps 70a, 70b. That is, two sides of the hexagon in the cross-sectional shape of the winding core 23 are located on the upper surfaces of the steps 60a, 60b and the steps 70a, 70b. In this modified example, the same effects as in the first embodiment can be obtained. This modified example may be applied to the second embodiment.

(5) In the above modification (4), as shown in FIG. 9, the cross-sectional shape of the winding core 23 may be octagonal. In this case, on the X-axis positive side of the steps 60a, 60b and 70a, 70b, three sides of the octagon are located on the upper surface 231a and the lower surface 231b. On the X-axis negative side of the steps 60a, 60b and 70a, 70b, three sides of the octagon are located on the first side surface 233b and the second side surface 234b. That is, the three sides of the octagonal cross-sectional shape of the winding core 23 are located on the upper surfaces of the steps 60a, 60b and 70a, 70b. In this modification, the same effects as in the first embodiment can be obtained. This modification may also be applied to the second embodiment.

(6) In each of the above embodiments, the application of the present invention to a common mode filter has been described, but the present invention may also be applied to coil devices other than common mode filters. Examples of coil devices to which the present invention can be applied include coils for power lines, coils for signal lines, and coils for PoC (Power over Coaxial) filters.

(7) In each of the above embodiments, two wires 30, 40 are wound around the winding core 23, but only one wire may be wound around the winding core 23. Alternatively, three or more wires may be wound around the winding core 23.

(8) In the second embodiment described above, three or more sets of step portions 60a, 60b and step portions 70a, 70b may be formed at multiple positions along the X-axis direction of the winding core portion 23, and four or more blocks may be formed along the X-axis direction on the winding core portion 23.

(9) In the first embodiment described above, as shown in FIG. 3B, the length of block B1 of winding core 23 along the X-axis direction is approximately equal to the length of block B2 along the X-axis direction. However, the positions of steps 60a, 60b and steps 70a, 70b in winding core 23 in the X-axis direction may be appropriately adjusted to appropriately change the lengths of blocks B1 and B2 along the X-axis direction. The same applies to the second embodiment.

10... Coil device 20, 120... Core 21... First flange portion 21a... Bottom surface 22... Second flange portion 22a... Bottom surface 23, 123... Winding core portion 231a, 231b, 231c... Upper surface 232a, 232b, 232c... Lower surface 233a, 233b, 233c... First side surface 234a, 234b, 234c... Second side surface 30... First wire 30a, 30b... Lead portion 30c, 30d... Turn 40... Second wire 40a, 40b... Lead portion 40c, 40d... Turn 51 to 54... Terminal electrode 60a, 60b... Step portion (first step portion)
61a, 61b... Tapered surfaces 70a, 70b... Step portion (second step portion)
71a, 71b... Tapered surfaces B1 to B3... Blocks

Claims (14)

A core including a winding core portion and a flange portion formed at an end of the winding core portion;
A wire wound around the winding core,
A first step portion that becomes higher toward one side of the winding core portion and a second step portion that becomes higher toward the other side of the winding core portion are formed at different positions in a circumferential direction of the winding core portion,
When the winding core portion is viewed from a first direction, a width of the winding core portion along a second direction is larger on one side of the winding core portion relative to the first step portion than on the other side of the winding core portion relative to the first step portion,
A coil device in which, when the winding core portion is viewed from a second direction, the width of the winding core portion along the first direction is smaller on one side of the winding core portion relative to the first step portion than on the other side of the winding core portion relative to the first step portion. A core including a winding core portion and a flange portion formed at an end of the winding core portion;
A wire wound around the winding core,
A first step portion that becomes higher toward one side of the winding core portion and a second step portion that becomes higher toward the other side of the winding core portion are formed at different positions in a circumferential direction of the winding core portion,
A coil device in which the first step portion and the second step portion are adjacent to each other in a circumferential direction of the winding core portion and extend in different directions. A core including a winding core portion and a flange portion formed at an end of the winding core portion;
A wire wound around the winding core,
A first step portion that becomes higher toward one side of the winding core portion and a second step portion that becomes higher toward the other side of the winding core portion are formed at different positions in a circumferential direction of the winding core portion,
The first step portion is made up of a plurality of first step portions,
The second step portion is made up of a plurality of second step portions,
A coil device in which a plurality of the first step portions and a plurality of the second step portions are alternately arranged along a circumferential direction of the winding core portion. A core including a winding core portion and a flange portion formed at an end of the winding core portion;
A wire wound around the winding core,
A first step portion that becomes higher toward one side of the winding core portion and a second step portion that becomes higher toward the other side of the winding core portion are formed at different positions in a circumferential direction of the winding core portion,
A coil device in which a plurality of sets of the first step portion and the second step portion are formed at a plurality of positions in the axial direction of the winding core portion at predetermined intervals. A core including a winding core portion and a flange portion formed at an end of the winding core portion;
A wire wound around the winding core,
A first step portion that becomes higher toward one side of the winding core portion and a second step portion that becomes higher toward the other side of the winding core portion are formed at different positions in a circumferential direction of the winding core portion,
The wire is made up of a plurality of wires,
A plurality of the wires are wound in a plurality of layers around the winding core,
A coil device, wherein the height of the first step portion or the second step portion is equal to or greater than the sum of the diameters of each of the plurality of wires. When the winding core portion is viewed from a first direction, a width of the winding core portion along a second direction is larger on one side of the winding core portion relative to the first step portion than on the other side of the winding core portion relative to the first step portion,
The coil device according to any one of claims 2 to 5, wherein when the winding core portion is viewed from the second direction, a width of the winding core portion along the first direction is smaller on one side of the winding core portion relative to the first step portion than on the other side of the winding core portion relative to the first step portion. The coil device according to any one of claims 3 to 5 , wherein the first step portion and the second step portion are adjacent to each other in the circumferential direction of the winding core portion and extend in different directions. The first step portion is made up of a plurality of first step portions,
The second step portion is made up of a plurality of second step portions,
The coil device according to any one of claims 4 to 5 , wherein a plurality of the first step portions and a plurality of the second step portions are alternately arranged along a circumferential direction of the winding core portion. The coil device according to claim 5 , wherein a plurality of pairs of the first step portion and the second step portion are formed at a plurality of positions in the axial direction of the winding core portion at predetermined intervals. a rising position of the first step portion is located on the other side of the winding core portion relative to a rising position of the second step portion,
The coil device according to any one of claims 3 to 9 , wherein a rising position of the second step portion is located on one side of the winding core portion relative to a rising position of the first step portion. A core portion,
A flange portion is formed at an end of the winding core portion,
A core in which a first step portion that becomes higher toward one side of the winding core portion and a second step portion that becomes higher toward the other side of the winding core portion are formed at different positions in a circumferential direction of the winding core portion,
When the winding core portion (23) is viewed from a first direction, a width of the winding core portion (23) along a second direction is larger on one side of the winding core portion relative to the first step portion than on the other side of the winding core portion relative to the first step portion,
A core in which, when the winding core portion is viewed from a second direction, the width of the winding core portion along the first direction is smaller on one side of the winding core portion relative to the first step portion than on the other side of the winding core portion relative to the first step portion. A core portion,
A flange portion is formed at an end of the winding core portion,
A core in which a first step portion that becomes higher toward one side of the winding core portion and a second step portion that becomes higher toward the other side of the winding core portion are formed at different positions in a circumferential direction of the winding core portion,
The first step portion and the second step portion are adjacent to each other in the circumferential direction of the winding core portion and extend in different directions. A core portion,
A flange portion is formed at an end of the winding core portion,
A core having a first step portion that is higher toward one side of the winding core portion and a second step portion that is higher toward the other side of the winding core portion at different positions in the circumferential direction of the winding core portion.
And,
The first step portion is made up of a plurality of first step portions,
The second step portion is made up of a plurality of second step portions,
A core in which a plurality of the first step portions and a plurality of the second step portions are alternately arranged along a circumferential direction of the winding core portion. A core portion,
A flange portion is formed at an end of the winding core portion,
A core in which a first step portion that becomes higher toward one side of the winding core portion and a second step portion that becomes higher toward the other side of the winding core portion are formed at different positions in a circumferential direction of the winding core portion,
A core in which a plurality of sets of the first step portion and the second step portion are formed at a plurality of positions in the axial direction of the winding core portion at predetermined intervals.

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