JP7835596B2 - Manufacturing method for coil components - Google Patents

Description

This invention relates to a method for manufacturing coil components.

A coil component is known in which a coil circumference is formed on the core's winding portion, and a resin portion is formed around this coil circumference. One known method for forming the resin portion involves screen printing a resin paste onto one side of a pallet on which the coil component is placed, then inverting the pallet and screen printing the resin paste onto the other side to form the resin portion around the coil circumference (for example, Patent Document 1). Another known method involves fixing the outer bottom surface of one flange portion of the core to a holder, then placing a protective sheet against the inner bottom surface of that flange, and then immersing the core in liquid resin to form the resin portion around the coil circumference (for example, Patent Document 2).

Japanese Patent Publication No. 2003-100540 Japanese Patent Publication No. 2014-093460

However, in the method described in Patent Document 1, since the resin paste is screen-printed on both sides of the pallet on which the coil components are arranged, it is difficult to evenly apply the resin material around the coil circumference. In the method described in Patent Document 2, since the core is immersed in liquid resin, more resin material than necessary is applied around the coil circumference.

This invention has been made in view of the above-mentioned problems, and aims to provide a method for manufacturing a coil component that allows for the even and appropriate application of a resin material around the coil's peripheral portion.

The present invention is a method for manufacturing a coil component, comprising the steps of: preparing a core having a winding core and a flange provided at the end of the winding core in the stretching direction; winding a conductor around the winding core to form a coil circumference made of the conductor; and rotating the coil circumference around the winding core and bringing a resin material into contact with the coil circumference to form a resin portion, wherein the step of forming the resin portion includes bringing the resin material into contact only a first portion of the circumference of the coil circumference to coat the first portion with the resin material, then moving the resin material away from the circumference of the coil circumference, and then bringing the resin material into contact with a second portion of the circumference of the coil circumference other than the first portion to coat the second portion with the resin material .

In the above configuration, the resin portion can be formed by the resin material, provided on the outer circumference of a disk that rotates around a second rotation axis substantially parallel to the first rotation axis of the coil circumference, contacting the coil circumference.

In the above configuration, the width dimension of the resin material provided on the outer circumference of the disc in the stretching direction can be smaller than the length dimension of the core portion in the stretching direction.

In the above configuration, at the point where the coil circumference and the resin material are in contact, the coil circumference rotates in the same direction relative to the rotation of the disk, and the relative peripheral velocity of the outer circumference of the coil circumference with respect to the outer circumference of the disk is approximately the same as the peripheral velocity of the outer circumference of the disk.

In the above configuration, at the point where the coil circumference and the resin material are in contact, the coil circumference rotates in the same direction relative to the rotation of the disk, and the peripheral velocity of the outer circumference of the coil circumference relative to the outer circumference of the disk can be configured to be faster than the peripheral velocity of the outer circumference of the disk.

In the above configuration, at the point where the coil circumference and the resin material are in contact, the coil circumference rotates in the same direction relative to the rotation of the disk, and the peripheral velocity of the outer circumference of the coil circumference relative to the outer circumference of the disk can be configured to be slower than the peripheral velocity of the outer circumference of the disk.

In the above configuration, at the point where the coil circumference and the resin material come into contact, the coil circumference rotates in the opposite direction relative to the rotation of the disk, and the peripheral velocity of the outer circumference of the coil circumference relative to the outer circumference of the disk can be configured to be slower than the peripheral velocity of the outer circumference of the disk.

In the above configuration, the coil circumference revolves around a third rotation axis substantially parallel to the first rotation axis of the coil circumference, and the resin portion is formed by the resin material coming into contact with the coil circumference while the coil circumference revolves and rotates.

According to the present invention, a resin material can be applied evenly and in an appropriate amount around the coil circumference.

Figures 1(a) to 1(c) are diagrams (part 1) showing a method for manufacturing a coil component according to the first embodiment. Figures 2(a) to 2(c) are diagrams (part 2) showing a method for manufacturing a coil component according to the first embodiment. Figures 3(a) and 3(b) are diagrams (part 3) showing a method for manufacturing a coil component according to the first embodiment. Figure 4 is a cross-sectional view showing the relationship between the length of the core's winding portion and the width of the resin material provided on the outer circumference of the disc. Figures 5(a) to 5(c) are side views showing the method of applying resin material to the periphery of the coil in Modification 1 to Modification 3 of the first embodiment. Figures 6(a) and 6(b) are side views showing a method for applying resin material when the cross-sectional shape of the winding core is rectangular. Figure 7 is a cross-sectional view showing a method for applying resin material to the periphery of the coil in the second embodiment.

The embodiments of the present invention will be described below with reference to the drawings as appropriate. However, the present invention is not limited to the illustrated embodiments. Furthermore, common components in multiple drawings are given the same reference numerals throughout those drawings. Please note that, for the sake of clarity, the drawings are not necessarily drawn to an exact scale.

[First Embodiment]
Figures 1(a) to 1(c), 2(a) to 2(c), 3(a), and 3(b) show a method for manufacturing a coil component according to the first embodiment. Figure 1(a) is a cross-sectional view showing the process of preparing the core 10, and Figure 1(b) is a plan view seen from direction A in Figure 1(a). In Figure 1(b), the winding core portion 12 is shown by a dotted line. Figure 1(c) is a cross-sectional view after the formation of the coil circumferential portion 42. Figure 2(a) is a side view showing the method of applying the resin material 70 around the coil circumferential portion 42 in the first embodiment, Figure 2(b) is an enlarged view of the core 10 in area A of Figure 2(a), and Figure 2(c) is an enlarged view of the core 10 in area B of Figure 2(a). In Figures 2(b) and 2(c), the winding core portion 12, the coil circumferential portion 42, and the resin material 70 are shown through the flange portion 16. Figure 3(a) is a side view showing a method for applying resin material 70 around the coil circumference 42 in the first embodiment. In Figure 3(a), the winding core 12, the coil circumference 42, and the resin material 70 are shown through the flange 16. Also, in Figures 2(a) to 2(c) and 3(a), hatching is applied to the resin material 70 for clarity. Figure 3(b) is a cross-sectional view of a coil component on which the resin portion 48 is formed. In this first embodiment, the drum core 10 is shown as an example, having flanges 14 and 16 at both ends of the winding core 12, but a T-core with a flange at only one end of the winding core 12 is also possible. The coil component may be a power inductor incorporated into a power line, an inductor used in a signal line, or something else.

As shown in Figures 1(a) and 1(b), a drum core 10 is prepared, having a winding core portion 12 extending in the Z-axis direction, one flange portion 14 provided at the -Z end of the winding core portion 12, and the other flange portion 16 provided at the +Z end. Two grooves 20 may be provided on the outer surface 18 of the flange portion 14 opposite to the inner surface to which the winding core portion 12 is connected. The two grooves 20 may extend substantially parallel to each other and open to opposing outer surfaces of the flange portion 14.

The core 10 is formed by, for example, filling a mold cavity with granules of a mixture of magnetic powder and resin and press-molding it to create a molded body, and then performing a heat treatment on this molded body at, for example, around 200°C to solidify the resin. The magnetic powder used is, for example, ferrite magnetic powder or metallic magnetic powder. Examples of ferrite magnetic powder include ferrite materials such as Ni-Zn or Mn-Zn. Examples of metallic magnetic powder include soft magnetic alloy materials such as Fe-Si-Cr, Fe-Si-Al, or Fe-Si-Cr-Al, magnetic metal materials such as Fe or Ni, amorphous magnetic metal materials, or nanocrystalline magnetic metal materials. The resin used is, for example, a resin with excellent insulating properties such as polyvinyl butyral (PVB) resin or epoxy resin.

The core 10 may also be formed by processing a large block of molded material to create a molded body having a core portion 12 and flange portions 14 and 16, and then performing heat treatment on this molded body. The heat treatment may be performed before or after processing the molded body having the core portion 12 and flange portions 14 and 16. Furthermore, the core 10 is not limited to being formed by solidifying magnetic powder with resin; it may also be formed by bonding magnetic powders together with an inorganic material. In this case, the core 10 is formed by performing heat treatment on a molded body press-molded from magnetic powder to, for example, a temperature of 600°C to 1100°C. Also, the core 10 is not limited to being a magnetic material; it may be a non-magnetic material formed from aluminum oxide (alumina) or silicon oxide (glass), etc.

The cross-sectional shape of the core portion 12, parallel to the XY plane, is, for example, circular. The cross-sectional shape of the flange portions 14 and 16, parallel to the XY plane, is, for example, approximately rectangular. The flange portions 14 and 16 are, for example, plate-shaped with thickness in the Z-axis direction. The core portion 12, viewed in the Z-axis direction, is smaller than the outer shape of the flange portions 14 and 16, and is positioned near the center of the flange portions 14 and 16. The length dimensions of the core 10 in the X-axis direction, Y-axis direction, and Z-axis direction are set appropriately as needed.

As shown in Figure 1(c), after preparing the core 10, a metal film 30 is formed on the outer surface 18 of the flange portion 14. If a groove 20 is formed on the outer surface 18 of the flange portion 14, the metal film 30 is formed on the inner surface of the groove 20. The metal film 30 is formed, for example, by forming a metal film of copper (Cu) or silver (Ag) by sputtering or by applying a conductive paste. The metal film 30 is not limited to a single layer of metal; it may also be a multi-layer metal film with a plating layer formed on top of the metal layer using a plating method. The metal film 30 may have an adhesion layer of titanium (Ti) or chromium (Cr) for adhesion to the flange portion 14.

After forming the metal film 30, the conductor 40 is wound around the core 12 of the core 10 to form a coil circumference 42 made of the conductor 40. The conductor 40 is then pulled out from each of the pair of ends of the coil circumference 42 beyond the flange 14, and the conductor 40 is bent so that the ends 44 of the conductor 40 are positioned on the outer surface 18 of the flange 14. If the metal film 30 is formed on the inner surface of the groove 20, the ends 44 of the conductor 40 are pulled into the groove 20 so that they are positioned on the metal film 30.

The coil circumference 42 may be wound around the core 12 in a single layer, or it may be wound in multiple layers, either partially or entirely. The conductor 40 is a metal wire, for example, made of copper, with its circumference covered by an insulating coating made of urethane. The metal wire may be made of a metal other than copper. The insulating coating may be made of an insulating material other than urethane, such as polyimide, polyamide-imide, or a resin material like polyester. The cross-sectional shape of the metal wire is, for example, circular, but it may also be rectangular.

As shown in Figures 2(a) to 2(c), the core 10, with the coil circumference 42 formed therein, is installed on a disc-shaped rotating jig 50 in a state where it can rotate. The core 10 is installed along the circumference of the rotating jig 50 at predetermined intervals (for example, at regular intervals). The core 10 can be installed on the rotating jig 50 in any manner as long as the core 10 can rotate. For example, the core 10 can be installed on the rotating jig 50 via a member provided on the rotating jig 50 and capable of rotating within the rotating jig 50.

The core 10 rotates around the winding core 12. As a result, the coil circumference 42 formed around the winding core 12 also rotates around the winding core 12. The first axis of rotation 52 of the core 10 and the coil circumference 42 substantially coincides with the central axis of the winding core 12. The direction of rotation of the core 10 and the coil circumference 42 is indicated by arrow 56.

The rotating jig 50 rotates around the third rotation axis 54. Therefore, the core 10 and coil circumference 42, fixed to the circumference of the rotating jig 50, revolve around the third rotation axis 54. The third rotation axis 54 and the first rotation axis 52 are approximately parallel. The direction of revolution of the core 10 and coil circumference 42 (i.e., the direction of rotation of the rotating jig 50) is indicated by arrow 58.

Adjacent to the rotating jig 50 is a coating device 60 for applying the resin material 70. The coating device 60 comprises a resin material tank 62 filled with liquid resin material 70, and a disc 64 that rotates around a second rotation axis 66, supplying the resin material 70 from the resin material tank 62 onto its outer circumference 68. The second rotation axis 66 of the disc 64 is approximately parallel to the first rotation axis 52 of the core 10 and coil circumference 42, and the third rotation axis 54 of the rotating jig 50. The direction of rotation of the disc 64 is indicated by arrow 72.

The resin material 70 is preferably a thermosetting resin, and may contain, for example, epoxy resin or polyimide resin. The resin material 70 may also contain magnetic material fillers, such as magnetic particles with an average particle size of 30 μm or less. For example, the resin material 70 may be a mixture of ferrite magnetic particles (40 vol% or less) and epoxy resin (60 vol% or more) as fixed components. Furthermore, the resin material 70 may contain non-magnetic material fillers such as silica particles, or a combination of magnetic and non-magnetic materials, or it may contain solvents, etc.

The disc 64 is movable in parallel towards and away from the rotating jig 50. The direction in which the disc 64 can move is indicated by the arrow 74. When applying the resin material 70 around the coil circumference 42, the disc 64 moves towards the rotating jig 50. This causes the resin material 70 on the outer circumference 68 of the disc 64 to contact the coil circumference 42, and the resin material 70 is applied around the coil circumference 42.

For example, the rotation period of the coil circumference 42 around the first rotation axis 52 and the revolution period around the third rotation axis 54 may be appropriately set so that when the coil circumference 42 reaches the coating position by the coating device 60 through its revolution, the resin material 70 is applied to a part of the area around the coil circumference 42 (see Figure 2(b)), and when it completes one rotation and returns to the coating position again, the resin material 70 is applied to the remaining part or all of it (see Figure 2(c)). Alternatively, for example, the rotating jig 50 may rotate by a predetermined angle using a stepping motor or the like, stop for a predetermined time, and then rotate by the predetermined angle repeatedly. In this case, when the coil circumference 42 reaches the coating position by the coating device 60 through its orbit, the resin material 70 is applied to a portion of the area around the coil circumference 42 (see Figure 2(a)). Alternatively, while the coil circumference 42 rotates once in place without orbiting, the disc 64 moves in the direction of arrow 74, combining movements toward and away from the coil circumference 42 to apply the resin material 70. That is, in Figure 2(a), when the core 10 reaches the position of region B, the orbit may stop for a predetermined time. While the orbit is stopped, the coil circumference 42 rotates once, and, similar to Figures 2(b) and 2(c), the disc 64 moves in the direction of arrow 74 to apply the resin material 70 around the coil circumference 42. In this way, the resin material 70 is applied to the area around the coil circumference 42 by contacting it multiple times.

Furthermore, when providing the resin material 70 to the disc 64, the thickness of the resin material 70 on the outer circumference of the disc 64 may be adjusted to be thinner by a mechanism for adjusting the thickness of the resin material 70 provided in a part of the coating device 60. In this way, the thickness of the resin material 70 provided on the outer circumference of the disc 64 can be made thin and uniform.

As shown in Figure 3(a), the coil circumference 42 rotates in the direction of arrow 56 around the first rotation axis 52. The disc 64 of the coating device 60 rotates in the direction of arrow 72 around the second rotation axis 66. This ensures that the resin material 70 on the outer circumference 68 of the disc 64 is evenly and appropriately coated around the coil circumference 42.

In this first embodiment, the rotation direction of the coil circumference portion 42 is clockwise, and the rotation direction of the disk 64 is counterclockwise. Therefore, at the point where the coil circumference portion 42 and the resin material 70 on the outer circumference 68 of the disk 64 come into contact, the coil circumference portion 42 rotates in the same direction relative to the disk 64. Furthermore, in this first embodiment, the relative peripheral velocity of the outer circumference of the coil circumference portion 42 with respect to the outer circumference of the disk 64 is approximately the same as the peripheral velocity of the outer circumference of the disk 64. In this case, when the coil circumference portion 42 comes into contact with the resin material 70 on the outer circumference 68 of the disk 64, an amount of resin material 70 corresponding to the amount of resin material 70 on the outer circumference 68 of the disk 64 is applied to the coil circumference portion 42.

As shown in Figure 3(b), after applying the resin material 70 around the coil circumference 42, the resin material 70 is cured to form a resin portion 48 that covers the periphery of the coil circumference 42. It is preferable that the resin portion 48 covers the entire coil circumference 42, but it is sufficient if it covers 90% or more, and more preferably 95% or more. After forming the resin portion 48, a solder film 32 is applied to the surface of the metal film 30, and the metal wire at the end 44 of the conductor 40 is joined to the metal film 30 and the solder film 32 to form an external electrode 34 electrically connected to the coil circumference 42. This completes the formation of the coil component according to the first embodiment. Note that the external electrode 34 may be formed before forming the resin portion 48.

As described above, according to this first embodiment, as shown in Figures 2(a) to 3(b), the resin material 70 is brought into contact with the coil circumference 42 while rotating the coil circumference 42 around the winding core 12, thereby forming the resin portion 48. By bringing the resin material 70 into contact with the coil circumference 42 while rotating it around the winding core 12 in this way, the resin material 70 can be applied evenly and in an appropriate amount around the coil circumference 42. Therefore, a resin portion 48 of uniform thickness is formed around the coil circumference 42.

Furthermore, according to this first embodiment, as shown in Figures 2(a) to 2(c), the resin portion 48 is formed by the resin material 70 contacting the coil circumference portion 42 multiple times. This makes it easier for the resin material 70 to be applied evenly and in an appropriate amount around the coil circumference portion 42, and facilitates the formation of a resin portion 48 with a uniform thickness around the coil circumference portion 42. From the perspective of even and appropriate application of the resin material 70 around the coil circumference portion 42, it is preferable that the resin material 70 contacts the coil circumference portion 42 many times; for example, three times or more is preferable, four times or more is more preferable, and six times or more is even more preferable.

Furthermore, according to this first embodiment, as shown in Figures 2(a) to 3(b), the resin portion 48 is formed by the contact of resin material 70, provided on the outer circumference 68 of a disk 64 that rotates around a second rotation axis 66 substantially parallel to the first rotation axis 52 of the coil circumference portion 42, with the coil circumference portion 42. This allows for control of the amount of resin material 70 applied to the coil circumference portion 42 by adjusting the amount of resin material 70 provided on the outer circumference 68 of the disk 64 and the rotation speed of the coil circumference portion 42 and/or the disk 64. Therefore, it becomes easier to apply an appropriate amount of resin material 70 around the coil circumference portion 42. "Substantially parallel" means allowing deviations of a manufacturing error, and refers to a case where the inclination angle of the second rotation axis 66 with respect to the first rotation axis 52 is 2° or less.

Furthermore, according to this first embodiment, as shown in Figure 3(a), at the position where the coil circumference portion 42 and the resin material 70 on the outer circumference 68 of the disk 64 come into contact, the coil circumference portion 42 rotates in the same direction relative to the rotation of the disk 64. The peripheral velocity of the outer circumference of the coil circumference portion 42 relative to the outer circumference of the disk 64 is approximately the same as the peripheral velocity of the outer circumference of the disk 64. As a result, when the coil circumference portion 42 comes into contact with the resin material 70 on the outer circumference 68 of the disk 64, an amount of resin material 70 corresponding to the amount of resin material 70 on the outer circumference 68 of the disk 64 is applied to the coil circumference portion 42. Therefore, by adjusting the amount of resin material 70 on the outer circumference 68 of the disk 64, the amount of resin material 70 applied around the coil circumference portion 42 can be controlled. Approximately the same peripheral velocity means that a deviation of the magnitude of control error is allowed, and this is when the peripheral velocity of the coil circumference portion 42 is 98% or more and 102% or less relative to the peripheral velocity of the disk 64.

Furthermore, according to this first embodiment, as shown in Figures 2(a) to 2(c), the coil circumference 42 revolves around a third rotation axis 54 that is substantially parallel to the first rotation axis 52 of the coil circumference 42's rotation. The resin portion 48 is formed when the resin material 70 comes into contact with the coil circumference 42 while the coil circumference 42 rotates around the first rotation axis 52 while revolving around the third rotation axis 54. This allows for the formation of resin portions 48 by sequentially applying the resin material 70 around the coil circumference 42 of multiple cores 10. "Substantially parallel" means that a deviation of a manufacturing error is tolerated, and the inclination angle of the third rotation axis 54 with respect to the first rotation axis 52 is 2° or less.

Figure 4 is a cross-sectional view showing the relationship between the length of the core 12 of the core 10 and the width of the resin material 70 provided on the outer circumference 68 of the disc 64. As shown in Figure 4, the width dimension W of the resin material 70 provided on the outer circumference 68 of the disc 64 in the stretching direction (Z-axis direction) of the core 12 is smaller than the length dimension L of the core 12 in the stretching direction (Z-axis direction). This allows the resin material 70 to be selectively applied around the coil circumference 42, and prevents the resin material 70 from adhering to the flanges 14 and 16. The width dimension W of the resin material 70 is preferably 80% to 95% of the length dimension L of the core 12, more preferably 85% to 95%, and even more preferably 90% to 95%.

[Variations]
In the first embodiment described above, the coil circumference portion 42 rotates in the same direction relative to the disk 64 at the point where it contacts the resin material 70 on the outer circumference 68 of the disk 64, and the case shown as an example where the peripheral velocity of the outer circumference of the coil circumference portion 42 relative to the outer circumference of the disk 64 is approximately the same as the peripheral velocity of the outer circumference of the disk 64. However, other cases will be described in the modified examples.

Figure 5(a) is a side view showing a method for applying the resin material 70 around the coil circumference 42 in Modification 1 of the first embodiment. As shown in Figure 5(a), in this Modification 1, the coil circumference 42 rotates in the same direction relative to the disk 64 at the point where it contacts the resin material 70 on the outer circumference 68 of the disk 64, similar to the first embodiment. However, it differs from the first embodiment in that the relative peripheral velocity of the outer circumference of the coil circumference 42 with respect to the outer circumference of the disk 64 is faster than the peripheral velocity of the outer circumference of the disk 64.

As shown in this Modification 1, when the coil circumference 42 rotates in the same direction relative to the rotation of the disk 64 at the point where it contacts the resin material 70 on the outer circumference 68 of the disk 64, the relative peripheral speed of the outer circumference of the coil circumference 42 with respect to the outer circumference of the disk 64 is faster than the peripheral speed of the outer circumference of the disk 64, resulting in a reduced amount of resin material 70 being applied around the coil circumference 42. For example, even without changing the amount of resin material 70 on the outer circumference 68 of the disk 64 from the first embodiment, the amount of resin material 70 applied around the coil circumference 42 can be reduced by simply increasing the peripheral speed of the coil circumference 42. This Modification 1 is suitable when it is desired to reduce the amount of resin material 70 applied around the coil circumference 42. The relative peripheral speed of the outer circumference of the coil circumference 42 is faster than the peripheral speed of the outer circumference of the disk 64 if the relative peripheral speed of the outer circumference of the coil circumference 42 is 1.5 times or more than the peripheral speed of the outer circumference of the disk 64, and may also be 1.8 times or more, or 2 times or more.

Figure 5(b) is a side view showing the method of applying the resin material 70 around the coil circumference 42 in Modification 2 of the first embodiment. As shown in Figure 5(b), in this Modification 2, the coil circumference 42 rotates in the same direction relative to the disk 64 at the point where it contacts the resin material 70 on the outer circumference 68 of the disk 64, just like in the first embodiment. However, it differs from the first embodiment in that the relative peripheral speed of the outer circumference of the coil circumference 42 with respect to the outer circumference of the disk 64 is slower than the peripheral speed of the outer circumference of the disk 64.

As shown in this Modified Example 2, when the coil circumference 42 rotates in the same direction relative to the rotation of the disk 64 at the point where it contacts the resin material 70 on the outer circumference 68 of the disk 64, the relative peripheral speed of the outer circumference of the coil circumference 42 with respect to the outer circumference of the disk 64 is slower than the peripheral speed of the outer circumference of the disk 64, resulting in a larger amount of resin material 70 being applied around the coil circumference 42. For example, even without changing the amount of resin material 70 on the outer circumference 68 of the disk 64 from the first embodiment, the amount of resin material 70 applied around the coil circumference 42 can be increased by simply slowing down the peripheral speed of the coil circumference 42. This Modified Example 2 is suitable when it is desired to increase the amount of resin material 70 applied around the coil circumference 42. For example, even if the cross-sectional shape of the winding core 12 is rectangular, the increased amount of resin material 70 makes it easier to apply the resin material 70 evenly around the coil circumference 42. The relative peripheral speed of the outer circumference of the coil circumference 42 being slower than the peripheral speed of the outer circumference of the disk 64 means that the relative peripheral speed of the outer circumference of the coil circumference 42 is 0.7 times or less the peripheral speed of the outer circumference of the disk 64, and may also be 0.5 times or less, or 0.3 times or less.

Figure 5(c) is a side view showing the method of applying the resin material 70 around the coil circumference 42 in Modification 3 of the first embodiment. As shown in Figure 5(c), in this Modification 3, the coil circumference 42 rotates in opposite directions relative to the disk 64 at the point where it contacts the resin material 70 on the outer circumference 68 of the disk 64. This differs from the first embodiment in that the relative peripheral velocity of the outer circumference of the coil circumference 42 with respect to the outer circumference of the disk 64 is slower than the peripheral velocity of the outer circumference of the disk 64.

As shown in this modified example 3, at the point where the coil circumference portion 42 and the resin material 70 on the outer circumference 68 of the disk 64 come into contact, the coil circumference portion 42 rotates in the opposite direction relative to the rotation of the disk 64. As a result, the relative peripheral speed of the outer circumference of the coil circumference portion 42 to the outer circumference of the disk 64 is slower than the peripheral speed of the outer circumference of the disk 64, which increases the amount of resin material 70 applied around the coil circumference portion 42. For example, even without changing the amount of resin material 70 on the outer circumference 68 of the disk 64 from the first embodiment, the amount of resin material 70 applied around the coil circumference portion 42 can be increased by changing the rotation direction of the coil circumference portion 42 and slowing down its peripheral speed. This modified example 3 is suitable when it is desired to increase the amount of resin material 70 applied around the coil circumference portion 42. The relative peripheral speed of the outer circumference of the coil circumference 42 being slower than the peripheral speed of the outer circumference of the disk 64 means that the relative peripheral speed of the outer circumference of the coil circumference 42 is 0.7 times or less the peripheral speed of the outer circumference of the disk 64, and may also be 0.5 times or less, or 0.3 times or less.

In the first embodiment and its modifications described above, the case where the cross-sectional shape of the winding core 12 is circular is shown as an example, but other cases such as rectangular are also possible. In the case of a rectangular shape, the corners may be chamfered and rounded. Figures 6(a) and 6(b) are side views showing a method of applying the resin material 70 when the cross-sectional shape of the winding core 12 is rectangular. As shown in Figure 6(a), when the cross-sectional shape of the winding core 12 is close to a square, the rotation period of the coil circumference 42 around the first rotation axis 52 and the revolution period around the third rotation axis 54 (see Figure 2(a)) may be appropriately set, and the resin material 70 may be applied in four separate steps to the locations corresponding to each side of the rectangle. Alternatively, while the coil circumference 42 rotates once in place without revolutionizing, the disc 64 may move in the direction of the arrow 74, combining movements of approaching and moving away from the coil circumference 42, and the resin material 70 may be applied in four separate steps to the locations corresponding to each side of the rectangle.

As shown in Figure 6(b), if the cross-sectional shape of the core 12 is an elongated rectangle, the period of rotation of the coil circumference 42 around the first rotation axis 52 and the period of revolution around the third rotation axis 54 (see Figure 2(a)) may be appropriately set, and the resin material 70 may be applied in two stages to the areas corresponding to the longer sides of the rectangle. Alternatively, while the coil circumference 42 rotates once in place without revolutionizing, the disc 64 may move in the direction of the arrow 74, combining movements of approaching and moving away from the coil circumference 42, to apply the resin material 70 in two stages to the areas corresponding to the longer sides of the rectangle. Since the shorter sides of the rectangle are short, the applied resin material 70 will wrap around to the shorter sides, resulting in the resin material 70 being applied around the coil circumference 42.

When the cross-sectional shape of the winding core 12 is rectangular, the core 10 rotates around the first rotation axis 52. Therefore, the disk 64 of the coating device 60 is moved in the direction of arrow 74 (see Figure 2(a)), and the resin material 70 is applied around the coil circumference 42 while changing the distance between the disk 64 and the coil circumference 42. In this case, by using a method that increases the amount of resin material 70 applied, as shown in Figures 5(b) and 5(c), the movement distance of the disk 64 can be kept small. Therefore, the decrease in productivity associated with the movement of the disk 64 can be suppressed.

[Second Embodiment]
In the first embodiment and its modifications described above, an example was shown in which resin material 70 is applied around the coil circumference 42 using a coating device 60 equipped with a resin material tank 62 and a disc 64. In this second embodiment, however, a case in which resin material 70 is applied around the coil circumference 42 using a dispenser device 80 will be described. Since this is the same as the manufacturing method of the coil component according to the first embodiment, except for the method of applying the resin material 70 to the coil circumference 42, the manufacturing process other than the application of the resin material 70 will not be described.

Figure 7 is a cross-sectional view showing the method of applying the resin material 70 around the coil circumference 42 in the second embodiment. As shown in Figure 7, while rotating the coil circumference 42 around the winding core 12, the resin material 70 is discharged from the dispensing nozzle 82 of the dispenser device 80, bringing the resin material 70 into contact with the coil circumference 42. Then, as shown in Figure 3(b) of the first embodiment, the resin material 70 formed around the coil circumference 42 is cured to form a resin portion 48 that covers the periphery of the coil circumference 42.

As in this second embodiment, the resin material 70 may be applied to the coil circumference 42 using a dispenser device 80. Even when applying the resin material 70 using a commonly available dispenser device 80, the resin material 70 can be applied evenly and in an appropriate amount around the coil circumference 42 by rotating the coil circumference 42 around the core 12 while bringing the resin material 70 into contact with the coil circumference 42.

Although embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims.

10 Core 12 Winding core 14, 16 Flange 18 Outer surface 20 Groove 30 Metal film 32 Solder film 34 External electrode 40 Conductor 42 Coil circumference 44 End of conductor 48 Resin part 50 Rotating jig 52 First rotation axis 54 Third rotation axis 60 Coating device 62 Resin material tank 64 Disc 66 Second rotation axis 68 Outer circumference 70 Resin material 80 Dispenser device 82 Dispensing nozzle

Claims (8)

A step of preparing a core having a winding core portion and a flange portion provided at the end of the winding core portion in the extension direction,
The process of winding a conductor around the aforementioned core to form a coil circumference made of the conductor,
The process includes rotating the coil circumference around the winding core and bringing a resin material into contact with the coil circumference to form a resin portion ,
A method for manufacturing a coil component, comprising the step of forming the resin portion, which includes contacting the resin material only with a first portion of the area around the coil circumference to coat the first portion with the resin material, then separating the resin material from the area around the coil circumference, and then contacting the resin material with a second portion of the area around the coil circumference other than the first portion to coat the second portion with the resin material . The method for manufacturing a coil component according to claim 1, wherein the resin portion is formed by the resin material provided on the outer circumference of a disk that rotates about a second rotation axis substantially parallel to the first rotation axis of the coil circumference, and the resin material comes into contact with the coil circumference . The method for manufacturing a coil component according to claim 2 , wherein the width dimension of the resin material provided on the outer circumference of the disc in the stretching direction is smaller than the length dimension of the core portion in the stretching direction. At the position where the coil circumference and the resin material come into contact, the coil circumference rotates in the same direction relative to the rotation of the disc.
The method for manufacturing a coil component according to claim 2 or 3 , wherein the relative peripheral velocity of the outer circumference of the coil circumferential portion with respect to the outer circumference of the disk is substantially the same as the peripheral velocity of the outer circumference of the disk. At the position where the coil circumference and the resin material come into contact, the coil circumference rotates in the same direction relative to the rotation of the disc.
The method for manufacturing a coil component according to claim 2 or 3 , wherein the relative peripheral velocity of the outer circumference of the coil circumferential portion with respect to the outer circumference of the disk is faster than the peripheral velocity of the outer circumference of the disk. At the position where the coil circumference and the resin material come into contact, the coil circumference rotates in the same direction relative to the rotation of the disc.
The method for manufacturing a coil component according to claim 2 or 3 , wherein the relative peripheral speed of the outer circumference of the coil circumferential portion with respect to the outer circumference of the disk is slower than the peripheral speed of the outer circumference of the disk. At the position where the coil circumference and the resin material come into contact, the coil circumference rotates in a direction opposite to the rotation of the disc.
The method for manufacturing a coil component according to claim 2 or 3 , wherein the relative peripheral speed of the outer circumference of the coil circumferential portion with respect to the outer circumference of the disk is slower than the peripheral speed of the outer circumference of the disk. The coil circumference revolves around a third axis of rotation that is substantially parallel to the first axis of rotation of the coil circumference.
The method for manufacturing a coil component according to any one of claims 1 to 7 , wherein the resin portion is formed by the resin material coming into contact with the coil circumference while the coil circumference rotates and revolves.