JP7658774B2 - Manufacturing method of base body of coil component - Google Patents

Description

The present invention relates to a method for manufacturing a base body for a coil component.

The substrate used for coil parts, etc., is obtained by forming a compact by pressure molding a mixture containing inorganic powder and resin, and then heat treating the compact. Methods have been proposed for removing burrs that are generated when forming the compact (for example, Patent Documents 1 and 2).

Special Publication No. 2015-194353 JP 2017-108029 A

After forming a molded body, it is common to process the surface of the molded body by barrel polishing. However, as electronic components become smaller, the media used in barrel polishing becomes smaller, which reduces the weight of the media and reduces the kinetic energy, making it difficult to properly process the surface of the molded body. In addition, the methods described in Patent Documents 1 and 2 process the surface of the molded body mainly by frictional energy, which means that the processing time is long and there is room for improvement.

The present invention was developed in consideration of the above problems, and aims to make it possible to appropriately process the surface of a molded body even when electronic components are miniaturized.

The present invention is a method for manufacturing the base of a coil component, comprising the steps of: forming a molded body by pressure-molding a mixture containing inorganic powder and a resin; placing a processed portion, which is a part of the molded body, on a rail portion, which is the processing portion of a processing device, so that the processed portion is in contact with the rail portion, and moving the molded body in a conveying direction in which the rail portion extends, while repeatedly moving the molded body diagonally downward and diagonally upward in a direction different from the conveying direction, thereby processing the processed portion, which is a part of the molded body; and heat-treating the molded body.

In the above configuration, the rail portion may extend in the conveying direction while alternately forming valleys and peaks.

In the above configuration, the rail portion can be configured to extend in the conveying direction while bending left and right when viewed from above.

In the above configuration, the processed portion, which is a part of the molded body, can be configured to be a concave portion when the molded body is viewed in cross section on a plane perpendicular to the conveying direction.

In the above configuration, the width of the upper portion of the rail portion in a direction perpendicular to the conveying direction may be smaller than the width between the inner surfaces of the recessed portion when viewed in cross section on a plane perpendicular to the conveying direction.

In the above configuration, the molded body can be configured to include a shaft portion around which the coil conductor is wound, and a flange portion provided at the end of the shaft portion and having the recessed portion through which the coil conductor is pulled out.

In the above configuration, the processed portion, which is part of the molded body, can be configured to be a ridge portion of the molded body.

In the above configuration, a width of the upper portion of the rail portion in a direction perpendicular to the conveying direction may vary in the conveying direction.

In the above configuration, the processing device can be configured to include the rail portion and a holding portion that faces the rail portion across a gap in a direction perpendicular to the conveying direction and holds the rail portion, and to vibrate the rail portion to move the molded body in the conveying direction.

In the above configuration, the processing device can be configured to include the rail portion and a conveying portion, and to vibrate the conveying portion to move the molded body in the conveying direction, and to vibrate the rail portion to process the processed portion, which is part of the molded body.

According to the present invention, the surface of the molded body can be appropriately processed.

FIG. 1 is a flowchart showing an example of a method for manufacturing a substrate according to the first embodiment. FIG. 2(a) is a plan view showing an example of a molded body, and FIG. 2(b) is a side view seen from a direction A in FIG. 2(a). Figure 3(a) is a top view showing the processing of the molded body in the first embodiment, Figure 3(b) is a side view seen from direction A in Figure 3(a), and Figure 3(c) is a side view seen from direction B in Figure 3(b). 4(a) and 4(b) are side views illustrating the processing by the processing unit. FIG. 5(a) is a top view of a processing apparatus of a first modified example according to the first embodiment, FIG. 5(b) is a side view seen from direction A in FIG. 5(a), and FIG. 5(c) is a side view seen from direction B in FIG. 5(b). 6(a) is a top view of a processing apparatus of a second modified example according to the first embodiment, FIG. 6(b) is a side view seen from direction A in FIG. 6(a), and FIG. 6(c) is a side view seen from direction B in FIG. 5(b). 7(a) is a top view of a processing apparatus of a third modified example according to the first embodiment, FIG. 7(b) is a side view seen from direction A in FIG. 7(a), and FIG. 7(c) is a side view seen from direction B in FIG. 7(b). FIG. 8(a) is a top view of a processing apparatus of a fourth modified example according to the first embodiment, and FIG. 8(b) is a side view seen from a direction A in FIG. 8(a). 9A and 9B are top views showing other examples of bending of the processing unit of the processing device of the fourth modified example according to the first embodiment. Figure 10(a) is a top view showing the processing of a molded body in the second embodiment, Figure 10(b) is a side view seen from direction A in Figure 10(a), and Figure 10(c) is a side view seen from direction B in Figure 10(b). FIG. 11A is a top view of a processing apparatus of a first modified example according to the second embodiment, and FIG. 11B is a side view seen from a direction A in FIG. 11A. 12(a) and 12(b) are views of the molded body according to the third embodiment before surface processing, and FIG. 12(c) and FIG. 12(d) are views of the molded body after surface processing.

Below, an embodiment of the present invention will be described with reference to the drawings as appropriate. However, the present invention is not limited to the illustrated embodiment. Also, components common to multiple drawings are given the same reference numerals throughout the multiple drawings. Please note that the drawings are not necessarily drawn to scale for ease of explanation.

[First embodiment]
Fig. 1 is a flow chart showing an example of a method for manufacturing a substrate according to the first embodiment. As shown in Fig. 1, first, a mixture containing an inorganic powder and a resin is pressure-molded to form a molded body (step S10). For example, a magnetic paste, which is a mixture of a magnetic powder and a resin, is filled into a cavity of a mold and press-molded to form a molded body. As the magnetic powder, a ferrite powder or a metal magnetic powder is used. Note that a non-magnetic powder such as a dielectric powder or a glass powder may be used instead of the magnetic powder.

2(a) is a plan view showing an example of the molded body 10, FIG. 2(b) is a side view seen from the A direction of FIG. 2(a), and FIG. 2(c) is a side view seen from the B direction of FIG. 2(a). As shown in FIG. 2(a) to FIG. 2(c), the molded body 10 is, for example, a drum core having a shaft portion 12 and flange portions 14a and 14b provided at both ends of the shaft portion 12. On the surface of the flange portion 14a opposite to the surface to which the shaft portion 12 is connected, two groove portions 16 are provided from which the coil conductor wound around the shaft portion 12 is drawn out. The width W of the groove portion 16 is, for example, 0.5 mm or less. The groove portion 16 is composed of at least three flat surfaces, and the angle between the adjacent surfaces is 90° or more. The groove portion 16 may have a shape in which the surface side is wider than the back side.

In the molded body 10, burrs 18 may occur on the inner surface 17 of the groove portion 16. The burrs 18 are formed when part of the inorganic powder gets into the gaps in the mold during pressure molding to form the molded body 10. The size of the burrs 18 varies depending on the size of the inorganic powder, the size of the mold clearance, and/or the pressure during pressure molding. When the size of the mold clearance is larger than the size of the inorganic powder, large burrs 18 are likely to form.

Returning to FIG. 1, in order to remove the burrs 18, the inside of the groove portion 16 provided in the molded body 10 is processed (step S12). FIG. 3(a) is a top view showing the molded body 10 in the first embodiment when being processed, FIG. 3(b) is a side view seen from the A direction of FIG. 3(a), and FIG. 3(c) is a side view seen from the B direction of FIG. 3(b). In FIG. 3(a) to FIG. 3(c), the processing device 30 is hatched to clarify the figures (the same applies to the following similar figures). In FIG. 3(a) and FIG. 3(b), the intermediate state of the molded body 10 during its movement is illustrated by dotted lines. As shown in FIG. 3(a) to FIG. 3(c), the processing device 30 used to process the molded body 10 includes a processing unit 32 and a holding unit 34 that holds the processing unit 32. The surface of the molded body 10 is processed by moving on the processing unit 32 in the direction in which the processing unit 32 extends (the conveying direction). The processed portion 32 is, for example, a rail portion that extends in the conveying direction while repeating valleys and peaks. The direction in which the molded body 10 is conveyed is the X-axis direction, the vertical direction is the Z-axis direction, and the direction perpendicular to the X-axis direction and the Z-axis direction is the Y-axis direction.

The processing section 32 is formed of a material harder than the molded body 10. The processing section 32 is formed of, for example, stainless steel, high-speed steel, or cemented carbide. The surface of the processing section 32 may be coated with a grindstone or abrasive powder. The holding section 34 is formed of a material capable of holding the processing section 32, for example, metal. In the processing device 30, a gap 36 may be formed between the processing section 32 and the holding section 34 in the Y-axis direction perpendicular to the transport direction.

Two processing parts 32 are provided parallel to each other in the Y-axis direction. The number of processing parts 32 may be increased or decreased depending on the number of processed parts 19 (the number of grooves 16 in this first embodiment). By having two or more processing parts 32, the molded body 10 can be easily transported, and the molded body 10 whose posture changes due to processing can be stably held. The minimum length by which the processing part 32 protrudes from the holding part 34 in the Z-axis direction is greater than the depth of the groove 16 provided in the flange part 14a, and the width of the upper part of the processing part 32 in the Y-axis direction is smaller than the width of the groove 16 in the Y-axis direction. For this reason, the processing part 32 can be inserted into the groove 16. In order to remove the burrs 18 generated on the inner surface 17 of the groove 16, the upper part of the processing part 32 is inserted into the groove 16 and placed so that the groove 16 is in contact with the processing part 32. Then, while moving the molded body 10 in the transport direction (+X direction) in which the processed portion 32 extends, the molded body 10 is repeatedly moved diagonally vertically downward and vertically upward along the valleys and peaks of the processed portion 32, thereby processing only the groove portion 16 and removing the burrs 18 that have occurred on the inner surface 17 of the groove portion 16. The molded body 10 moves in the transport direction (+X direction) as the processed portion 32 vibrates.

The groove 16 is placed on the processing section 32, and the molded body 10 is moved in the conveying direction (+X direction) while being repeatedly moved vertically diagonally downward and vertically diagonally upward, which are different from the conveying direction (+X direction), so that the posture of the molded body 10 is such that the lower surface of the flange 14a repeatedly tilts downward and upward in the conveying direction (+X direction) with respect to the horizontal plane. That is, the lower surface of the flange 14a of the molded body 10 repeatedly becomes an elevation angle (positive angle) and a depression angle (negative angle) with respect to the horizontal plane in the conveying direction. The contact between the processing section 32 and the groove 16 is repeatedly line contact or point contact. In line contact and point contact, the processing energy, which is a combination of the first energy generated by the molded body 10 moving in the conveying direction (+X direction) and the second energy generated by the molded body 10 moving vertically diagonally downward and vertically diagonally upward, is concentrated at the contact area. That is, the first energy and the second energy are combined as processing energy and are concentrated as an impact on a part of the fine part of the groove part 16, which is the part to be processed 19, thereby allowing efficient processing of the part of the fine part. Therefore, even if the molded body 10 is small and lightweight, the inside of the groove part 16 can be properly processed and the burrs 18 can be removed. When the lower surface of the flange part 14a of the molded body 10 is repeatedly at an elevation angle (positive angle) and a depression angle (negative angle) with respect to the horizontal plane in the conveying direction, the position of the contact part is repeatedly at the front part of the groove part 16, which is the part to be processed, and at the rear part of the conveying direction. In this way, the position to be processed is always moving, and as a result, appropriate processing is performed over the entire groove part 16, which is the part to be processed. This will be explained in detail using Figures 4(a) and 4(b).

4(a) and 4(b) are side views explaining the processing by the processing unit 32. As shown in FIG. 4(a) and FIG. 4(b), since the molded body 10 changes its orientation to a vertically downward diagonal direction and a vertically upward diagonal direction, which are different from the conveying direction, the processed parts 19a and 19b are processed while changing the contact angle with the processing unit 32, not at a constant angle. The contact angle can change continuously from a positive angle to a negative angle, and from a negative angle to a positive angle, based on the conveying direction. As shown in FIG. 4(a), the processed part 19a on the front side of the conveying direction of the molded body 10 has a larger contact angle with the processing unit 32 located forward in the conveying direction than the valley when the molded body 10 passes through the valley, and at this time, the processing energy is concentrated and processed. As shown in FIG. 4(b), the contact angle between the processed portion 19b on the rear side of the conveying direction of the molded body 10 and the processing portion 32 located on the rear side of the conveying direction from the valley portion becomes larger when the molded body 10 passes through the valley portion, and at this time, the processing energy is concentrated and processed. In this way, the processed portions 19a and 19b are processed in the up, down, left and right directions while making various contact angles with the processing portion 32, not a constant angle. By repeatedly changing the orientation of this molded body 10, more reliable processing can be performed. In addition, according to this method, two parts of the processed portions 19a and 19b of the molded body 10 can be processed in one process in one processing portion 32. The two processed portions 19a and 19b are the part located on the front side and the part located on the rear side of the conveying direction of the molded body 10 as shown in FIG. 4(a) and FIG. 4(b), so that when the processed portions 19a and 19b are the groove portion 16, both ends of the groove portion 16 are processed. Furthermore, by carrying out processing using this type of movement, the processed parts 19a and 19b can be made rounded.

In step S12, barrel polishing or the like may be performed to process the entire surface of the molded body 10 before or after processing the molded body 10 using the processing device 30. Also, barrel polishing may not be performed in step S12, but may be performed after step S14 described below.

Returning to FIG. 1, after the processing of the molded body 10 is completed, the molded body 10 is subjected to a heat treatment (for example, at about 200° C.) (step S14). This forms a base body made of the molded body 10.

When manufacturing a coil component using the base body formed according to the first embodiment, a conductor with an insulating coating is wound around the shaft portion 12 to form a coil conductor winding portion, the conductor is pulled out from both ends of the winding portion into the groove portion 16, and the conductor is connected to the metal film provided in the groove portion 16 to form an external electrode. This results in a wound coil component.

As described above, according to the manufacturing method of the base body according to the first embodiment, as shown in FIG. 1, a molded body 10 is formed by pressurizing a mixture containing an inorganic powder and a resin (step S10). The groove portion 16, which is the processed portion 19 formed in the molded body 10, is placed on the processing portion 32 so that it is in contact with the processing portion 32, and the molded body 10 is moved in the conveying direction (+X direction) in which the processing portion 32 extends, while repeatedly moving the molded body 10 in a vertically diagonally downward direction and a vertically diagonally upward direction different from the conveying direction (+X direction), thereby processing the groove portion 16 (processed portion 19) (step S12). Thereafter, the molded body 10 is heat-treated (step S14). According to this method, the contact between the processing portion 32 and the groove portion 16 is repeatedly made into a line contact or a point contact, and the processing energy, which is a combination of the first energy generated by the movement of the molded body 10 in the conveying direction (+X direction) and the second energy generated by the movement of the molded body 10 in the vertically diagonally downward direction and the vertically diagonally upward direction, is concentrated at the contact site of the line contact or point contact. That is, the first energy and the second energy are combined as processing energy and are concentrated as an impact on a small portion of the groove portion 16, which is the processed portion 19. Therefore, even if the molded body 10 is small and lightweight, the inside of the groove portion 16 can be properly processed. Therefore, the burrs 18 generated on the inner surface 17 of the groove portion 16 can be removed.

In addition, in this first embodiment, the processing section 32 is a rail section that extends in the conveying direction (+X direction) while repeating valleys and peaks. By using such a processing section 32, it is easy to move the molded body 10 in the conveying direction (+X direction) in which the processing section 32 extends, while repeatedly moving the molded body 10 in a vertically downward and vertically upward diagonal directions that are different from the conveying direction (+X direction).

In the first embodiment, the processed portion 19 of the molded body 10 processed by the processing unit 32 is the groove portion 16, which is a concave portion when the molded body 10 is viewed in cross section in a plane (YZ plane) perpendicular to the conveying direction (+X direction). As electronic components become smaller, the dimensions of the groove portion 16 also become smaller, so in surface processing using barrel polishing, small media that can enter the groove portion 16 are used. For this reason, the weight of the media becomes lighter and the kinetic energy generated becomes smaller, so that the groove portion 16 cannot be properly processed and the burrs 18 cannot be removed. However, by placing the groove portion 16 on the processing unit 32 so that it is in contact with the processing unit 32, and moving the molded body 10 in the conveying direction (+X direction) in which the processing unit 32 extends while repeatedly moving the molded body 10 in a vertically diagonally downward direction and a vertically diagonally upward direction different from the conveying direction (+X direction), the inside of the groove portion 16 can be properly processed as described above, and the burrs 18 generated on the inner surface 17 of the groove portion 16 can be removed.

In addition, in this first embodiment, the width of the upper part of the processing part 32 in a direction (Y axis direction) perpendicular to the conveying direction (+X direction) is smaller than the width between the inner surfaces of the groove part 16 when viewed in cross section on a plane (YZ plane) perpendicular to the conveying direction (+X direction). This allows the upper part of the processing part 32 to be inserted into the groove part 16, and the inside of the groove part 16 can be processed.

In addition, in this first embodiment, the coil conductor wound around the shaft portion 12 is pulled out into the groove portion 16 provided in the flange portion 14a. Since the dimensions of such groove portion 16 are small, even if barrel polishing is performed, the weight of the media becomes lighter and the kinetic energy generated becomes smaller, so that the groove portion 16 may not be properly processed. However, by placing the groove portion 16 on the processing portion 32 so that it is in contact with the processing portion 32, and moving the molding 10 in the conveying direction (+X direction) in which the processing portion 32 extends, while repeatedly moving the molding 10 diagonally downward and upward vertically in a direction different from the conveying direction (+X direction), the inside of the groove portion 16 can be properly processed as described above.

In the first embodiment, the processing unit 32 and the holding unit 34 face each other with a gap 36 therebetween. The processing unit 32 is vibrated to move the molded body 10 in the conveying direction (+X direction). The gap 36 formed between the processing unit 32 and the holding unit 34 makes it easier to independently control the vibrations of the two processing units 32 for moving the molded body 10 in the conveying direction (+X direction). The gap 36 formed between the processing unit 32 and the holding unit 34 also makes it possible to discharge the processing waste generated by the processing unit 32 into the gap 36, thereby preventing the processing waste from adhering to the molded body 10. To facilitate the discharge of the processing waste into the gap 36, air may be sucked from the -Z side of the gap 36.

The processing device for processing the groove portion 16, which is a part of the molded body 10, is not limited to the processing device 30 shown in Figures 3(a) to 3(c), and may be other types. Modified examples of the processing device are shown below.

Figure 5(a) is a top view of processing device 30a of a first modified example according to the first embodiment, Figure 5(b) is a side view seen from direction A in Figure 5(a), and Figure 5(c) is a side view seen from direction B in Figure 5(b). As shown in Figures 5(a) to 5(c), in processing device 30a, no gap is formed between processing section 32 and holding section 34. Processing section 32 may be fixed to the upper surface of holding section 34, or a part of processing section 32 may be embedded in holding section 34, or the embedded part may penetrate holding section 34. The other configurations are the same as those of processing device 30, so description will be omitted.

As in the processing device 30a, the processing part 32 and the holding part 34 are integrated without any gap between them, which increases the holding strength of the processing part 32 by the holding part 34.

6(a) is a top view of the processing device 30b of the second modified example according to the first embodiment, FIG. 6(b) is a side view seen from the A direction of FIG. 6(a), and FIG. 6(c) is a side view seen from the B direction of FIG. 6(b). As shown in FIG. 6(a) to FIG. 6(c), in the processing device 30b, the processing unit 32 and the conveying unit 38 are fixed to the upper surface of the holding unit 34. The conveying unit 38 extends in the X-axis direction while repeating valleys and peaks, similar to the processing unit 32. The conveying unit 38 vibrates to move the molded body 10 in the conveying direction (+X direction) on the processing unit 32. In other words, the molded body 10 moves in the conveying direction (+X direction) on the processing unit 32 due to the vibration of the conveying unit 38. The processing unit 32 vibrates to process the molded body 10. The processing unit 32 may have a larger surface roughness than the conveying unit 38. A gap may be formed between the processing unit 32 and the conveying unit 38. The rest of the configuration is the same as processing device 30, so explanation will be omitted.

As in the processing device 30b, a conveying unit 38 may be provided in addition to the processing unit 32. The conveying unit 38 may be vibrated to move the molded body 10 in the conveying direction (+X direction), and the processing unit 32 may be vibrated to process the inside of the groove portion 16, which is a part of the molded body 10. This allows the conveying unit 38 to vibrate with a vibration suitable for conveying the molded body 10, and the processing unit 32 to vibrate with a vibration suitable for processing the molded body 10, thereby achieving both efficient conveying and processing.

Figure 7(a) is a top view of the processing device 30c of the third modified example according to the first embodiment, Figure 7(b) is a side view seen from the A direction of Figure 7(a), and Figure 7(c) is a side view seen from the B direction of Figure 7(b). Figures 7(a) to 7(c) show the molded body 10 moving on the processing section 32. In the processing device 30b of the second modified example according to the first embodiment described above, both the processing section 32 and the conveying section 38 extend in the X-axis direction while repeating valleys and peaks. In contrast, in the processing device 30c of the third modified example according to the first embodiment, as shown in Figures 7(a) to 7(c), the conveying section 38 extends in the X-axis direction while repeating valleys and peaks, but the processing section 32a extends in the X-axis direction at a constant height. In addition, a gap 36 is formed between the processing section 32a and the conveying section 38.

As in the processing device 30c, the processing section 32a may extend in the X-axis direction at a constant height, and the conveying section 38 may extend in the X-axis direction while repeating valleys and peaks. In this case, by setting the distance between the upper surface of the processing section 32a and the upper surface of the conveying section 38 to an appropriate size, the molded body 10 can be moved in the conveying direction (+X direction) while the valleys and peaks of the conveying section 38 move the molded body 10 diagonally upwards and diagonally downwards.

Figure 8(a) is a top view of the processing device 30d of the fourth modified example according to the first embodiment, and Figure 8(b) is a side view seen from the A direction of Figure 8(a). Figures 8(a) and 8(b) show the molded body 10 moving on the processing unit 32. As shown in Figures 8(a) and 8(b), in the processing device 30d, the processing unit 32 is fixed to the upper surface of the holding unit 34 and extends in the conveying direction (+X direction) while bending in the left-right direction (Y axis direction) when viewed from above. The maximum amplitude value of the part bending in the Y axis direction of the processing unit 32, that is, the distance in the Y axis direction between the part of the processing unit 32 that is bent in the +Y direction to the part of the processing unit 32 that is bent in the -Y direction to the maximum, is set to be smaller than the width of the groove portion 16, which is the opening width of the processed part 19. The other configurations are the same as those of the processing device 30, so a description thereof will be omitted.

As in the processing device 30d, the processing section 32 is bent in the left-right direction (Y-axis direction) when viewed from above, so that the molded body 10 moving on the processing section 32 moves in the conveying direction (+X direction) while repeatedly turning to the right (-Y direction) or left (+Y direction) relative to the processing section 32. Since gravity acts vertically downward on the molded body 10, the force of gravity is also applied when moving left and right, causing the molded body 10 to move in the conveying direction (+X direction) while repeatedly moving horizontally to the right (-Y direction) perpendicular to a vertical direction different from the conveying direction (+X direction) and horizontally to the left (+Y direction) perpendicular to the vertical direction. The posture of the molded body 10 repeatedly tilts left and right relative to the conveying direction (+X direction). That is, the surface including the processed portion 19 of the molded body 10 is repeatedly elevated (positive angle) and depressed (negative angle) with respect to the horizontal plane in the conveying direction, and the molded body 10 is repeatedly turned to the right and left with respect to the conveying direction. As a result, as in the first embodiment, the processing energy, which is a combination of the first energy generated by the movement of the molded body 10 in the conveying direction (+X direction), the second energy generated by the movement of the molded body 10 in the vertically downward and vertically upward diagonal directions, and the third energy generated by the movement of the molded body 10 to the left and right with respect to the conveying direction (+X direction), is locally concentrated in a fine part of the processed portion 19. That is, the first energy, the second energy, and the third energy are combined as processing energy and are concentrated as an impact on a fine part of the processed portion 19. Therefore, even if the molded body 10 is small and lightweight, the processed portion 19 can be appropriately processed and burrs can be removed. When the surface including the processed portion 19 of the molded body 10 is at an elevation angle (positive angle) and a depression angle (negative angle) with respect to the horizontal plane in the conveying direction, and the molded body 10 is repeatedly turned to the right and left in the conveying direction, the position of the contact part is repeatedly at the front part of the surface of the processed portion 19 in the conveying direction and the rear part of the conveying direction, and at the same time, it is repeatedly at the left part of the surface of the processed portion 19 in the conveying direction and the right part of the conveying direction. In this way, the processed position is constantly moving, and as a result, appropriate processing is performed over the entire surface of the processed portion 19. Therefore, the entire inside of the groove portion 16, which is the processed portion 19, can be evenly processed. Therefore, the burrs 18 generated on the inner surface 17 of the groove portion 16 can be effectively removed.

9(a) and 9(b) are top views showing other examples of bending of the processed portion 32. In the bending of FIG. 9(a) and FIG. 9(b), as in the bending of FIG. 8(a), the maximum amplitude value of the portion of the processed portion 32 bent in the Y-axis direction, i.e., the distance in the Y-axis direction between the portion of the processed portion 32 that is bent in the +Y direction to the portion of the processed portion 32 that is bent in the -Y direction to the maximum, is set smaller than the width of the groove portion 16, which is the opening width of the processed portion 19, but in FIG. 9(a) and FIG. 9(b), the maximum amplitude width is shown larger for clarity of the figure. In FIG. 8(a), the processed portion 32 is bent in a triangular wave shape as viewed from above, but as shown in FIG. 9(a), the processed portion 32 may be bent in a sine wave shape as viewed from above. That is, bending of the processed portion 32 in the left-right direction (Y-axis direction) includes bending in a triangular wave shape and bending in a sine wave shape.

In addition, in FIG. 8(a), the interval between the two processed parts 32 is constant in the conveying direction (+X direction), but as shown in FIG. 9(b), the interval between the two processed parts 32 may change in the conveying direction (+X direction). In the case of FIG. 9(b), the processed parts 32 may be sinusoidally curved in a top view. In this way, the width of the processed parts 32 in the Y-axis direction changes in the conveying direction (+X direction), so that the clearance, which is the difference between the width of the processed parts 32 in the Y-axis direction and the opening width of the groove part 16, which is the processed part 19, changes depending on the position in the conveying direction. For this reason, the molded body 10 tends to repeatedly move to the left (+Y direction) or right (-Y direction) relative to the processed parts 32. For this reason, the processed position always moves, and the entire inner surface 17 of the groove part 16, which is the processed part 19, can be evenly processed, and the burrs 18 generated on the inner surface 17 of the groove part 16 can be well removed.

In the first embodiment, the molded body 10 is a drum core, but it may be a T-core or other type.

Second Embodiment
In the first embodiment, the groove 16 provided in the flange 14a is machined. In other words, the groove 16 is the processed part 19. In the second embodiment, the shaft 12 is machined. That is, in the second embodiment, the shaft 12 is the processed part 19. Burrs may also be generated on the side of the shaft 12 due to pressure molding when forming the molded body 10. In the second embodiment, the distance between the flange 14a and the flange 14b (in other words, the axial length of the shaft 12) is 0.5 mm or less.

The flowchart of the method for manufacturing a substrate according to the second embodiment is the same as that shown in FIG. 1 of the first embodiment, and is therefore omitted from the illustration. FIG. 10(a) is a top view showing the processing of the molded body 10 in the second embodiment, FIG. 10(b) is a side view seen from the direction A in FIG. 10(a), and FIG. 10(c) is a side view seen from the direction B in FIG. 10(b). In FIGS. 10(a) and 10(b), the intermediate state of the molded body 10 during its movement is shown by dotted lines. As shown in FIGS. 10(a) to 10(c), the processing device 30e has one processing part 32 fixed to the upper surface of the holding part 34.

The length of the processed portion 32 protruding from the holding portion 34 in the Z-axis direction is longer than the length between the side surfaces of the flanges 14a and 14b and the side surfaces of the shaft portion 12, and the width of the processed portion 32 in the Y-axis direction is smaller than the distance between the flanges 14a and 14b. Therefore, the processed portion 32 can be inserted into the gap between the flanges 14a and 14b. In order to remove burrs generated on the side surfaces of the shaft portion 12, the upper part of the processed portion 32 is inserted into the gap between the flanges 14a and 14b, and the shaft portion 12 is placed so that it is in contact with the processed portion 32. Then, while moving the molded body 10 in the conveying direction (+X direction) in which the processed portion 32 extends, the molded body 10 is repeatedly moved vertically diagonally downward and vertically diagonally upward along the valleys and peaks of the processed portion 32 to process the shaft portion 12. While moving the molded body 10 in the conveying direction (+X direction), the molded body 10 is repeatedly moved in a vertically downward and vertically upward directions different from the conveying direction (+X direction), so that the surface of the processed part of the shaft portion 12 of the molded body 10 is repeatedly tilted downward and upward in the conveying direction with respect to the horizontal plane. That is, the surface of the processed part of the shaft portion 12 of the molded body 10 is repeatedly tilted at an elevation angle (positive angle) and a depression angle (negative angle) with respect to the horizontal plane in the conveying direction. As a result, as in the first embodiment, the processing energy, which is a combination of the first energy generated by the movement of the molded body 10 in the conveying direction (+X direction) and the second energy generated by the movement of the molded body 10 in the vertically downward and vertically upward directions, is locally concentrated on a fine part of the shaft portion 12. That is, both the first energy and the second energy are combined as processing energy and concentrated as an impact on a fine part of the shaft portion 12, which is the processed part 19. Therefore, even if the molded body 10 is small and lightweight, the shaft portion 12 can be properly machined and burrs can be removed. When the surface of the processed portion of the shaft portion 12 of the molded body 10 is repeatedly angled upward (positive angle) and downward (negative angle) with respect to the horizontal plane in the conveying direction, the position of the contact area is repeatedly moved to the front part of the surface of the processed portion of the shaft portion 12 in the conveying direction and then to the rear part of the conveying direction. In this way, the position to be machined is constantly moving, and as a result, proper machining is performed over the entire surface of the processed portion of the shaft portion 12.

In the method for manufacturing a base body according to the second embodiment, a molded body 10 is formed by pressurizing a mixture containing an inorganic powder and a resin. The shaft portion 12, which is the processed portion 19 of the molded body 10, is placed on the processing portion 32 so that it is in contact with the shaft portion 12. The molded body 10 is moved in the conveying direction (+X direction) in which the processing portion 32 extends, while the molded body 10 is repeatedly moved vertically diagonally downward and vertically diagonally upward, which are different from the conveying direction, to process the shaft portion 12 (processed portion 19). The molded body 10 is then heat-treated. According to this method, as in the first embodiment, the contact between the processing portion 32 and the shaft portion 12 is repeatedly made into line contact or point contact, and the processing energy, which is a combination of the first energy generated by the movement of the molded body 10 in the conveying direction (+X direction) and the second energy generated by the movement vertically diagonally downward and vertically diagonally upward, is concentrated at the contact site of the line contact or point contact. That is, the first energy and the second energy are combined as processing energy and are concentrated as an impact on a small portion of the shaft portion 12, which is the processed portion 19. Therefore, even if the molded body 10 is small and lightweight, the shaft portion 12 can be properly processed. Therefore, burrs that have occurred on the side of the shaft portion 12 can be removed.

In addition, in this second embodiment, the processed portion 19 of the molded body 10 processed by the processing unit 32 is the flanges 14a and 14b, which are concave portions when the molded body 10 is viewed in cross section on a plane (YZ plane) perpendicular to the conveying direction (+X direction), and the shaft portion 12 sandwiched between them. As electronic components become smaller, the gap between the flanges 14a and 14b becomes narrower, so that small media that can fit between the flanges 14a and 14b is used in surface processing using barrel polishing. As a result, the weight of the media becomes lighter and the kinetic energy generated becomes smaller, so that the shaft portion 12 cannot be properly processed and burrs cannot be removed, and in particular, when the gap between the flanges 14a and 14b (in other words, the axial length of the shaft portion 12) is 0.5 mm or less, proper processing cannot be performed. However, by placing the shaft portion 12 on the processing portion 32 so that it is in contact with the shaft portion 12, and moving the molded body 10 in the conveying direction (+X direction) in which the processing portion 32 extends, while repeatedly moving the molded body 10 diagonally downward and upward vertically in a direction different from the conveying direction (+X direction), as described above, the shaft portion 12 can be properly processed and burrs can be removed.

11(a) is a top view of the processing device 30f of the first modified example according to the second embodiment, and FIG. 11(b) is a side view seen from the A direction of FIG. 11(a). As shown in FIG. 11(a) and FIG. 11(b), in the processing device 30f, the width of the processing section 32 in the Y-axis direction changes in the conveying direction (+X direction). The maximum value of the width of the processing section 32 in the Y-axis direction is set smaller than the spacing between the flanges 14a and 14b, which is the opening width of the processed section 19. In this way, the width of the processing section 32 in the Y-axis direction changes in the conveying direction (+X direction), so that the clearance, which is the difference between the width of the processing section 32 in the Y-axis direction and the spacing between the flanges 14a and 14b, which is the opening width of the processed section 19, changes depending on the position in the conveying direction. For this reason, the molded body 10 tends to repeatedly move to the left (+Y direction) or right (-Y direction) relative to the processing section 32. In this way, the processing position is always moving, and for the same reason as in the first embodiment, the entire shaft portion 12 can be processed evenly, and burrs that occur on the side surface of the shaft portion 12 can be effectively removed. Note that, even in the first embodiment, the width of the processing portion 32 in the Y-axis direction may change in the transport direction (+X direction).

In the second embodiment, since the molded body 10 moves in the transport direction (+X direction) on one processing section 32, there is a risk that the molded body 10 will lose balance and fall off the processing section 32. Therefore, guide sections may be provided on both sides of the molded body 10 in the Y-axis direction and extending in the X-axis direction along which the processing section 32 extends. This can prevent the molded body 10 from falling off the processing section 32. In the first embodiment, guide sections may be provided on both sides of the molded body 10 in the Y-axis direction. In either embodiment, a guide section may be provided on only one side.

[Third embodiment]
In the first and second embodiments, the case of removing burrs generated on the molded body 10 is shown as an example, but in the third embodiment, an example of forming a rounded edge formed by the side and lower surface of the flange portion 14a of the molded body 10 is shown. That is, in the third embodiment, the edge of the molded body 10 becomes the processed part. The flowchart of the method for manufacturing a base body according to the third embodiment is the same as that of the first embodiment shown in FIG. 1, and therefore is not shown. In the third embodiment, in step S12 of FIG. 1, the surface of the molded body 10 is processed to make the edge of the molded body 10 into a rounded shape. The edge is the boundary between the surfaces of the molded body 10.

The molded body 10 is placed on the processing section 32 of the processing device 30 so that the ridge portion to be processed is in contact with the processing section 32, and while moving the molded body 10 in the conveying direction (+X direction) in which the processing section 32 extends, the molded body 10 is repeatedly moved vertically downward and vertically upward in a direction different from the conveying direction (+X direction). By repeatedly moving the molded body 10 in the conveying direction (+X direction) and vertically downward and vertically upward in a direction different from the conveying direction (+X direction), the attitude of the molded body 10 is such that the surface including the ridge portion of the processed part is repeatedly tilted downward and upward in the conveying direction with respect to the horizontal plane. That is, the surface including the ridge portion of the processed part of the molded body 10 is repeatedly tilted downward and upward in the conveying direction with respect to the horizontal plane in the conveying direction at an elevation angle (positive angle) and a depression angle (negative angle). As a result, the ridgeline portion of the molded body 10 and the processing portion 32 do not form a constant angle, and the contact angle changes repeatedly, so that the ridgeline portion of the molded body 10 can be processed into a rounded shape (R shape). The ridgeline portion to be processed can be placed on the processing portion 32 in any direction, but is preferably placed so as to be perpendicular to the conveying direction (+X direction), i.e., facing the Y direction. By placing it in such a direction, when the face including the ridgeline portion of the processed part is repeatedly tilted downward and upward in the conveying direction with respect to the horizontal plane, the amount of movement when the face including the ridgeline portion of the processed part is at an elevation angle (positive angle) with respect to the horizontal plane in the conveying direction and at a depression angle (negative angle) becomes large, and efficient processing can be performed. In this third embodiment, since the ridgeline portion of the molded body 10 becomes the processed part, the width in the Y direction of the processing portion 32 of the processing device 30 is larger than the width in the Y direction when the molded body 10 is placed on the processing portion 32. Since the molded body 10 is not shaped to hold the processed portion 32, guide portions may be provided on both sides of the molded body 10 in the Y-axis direction and extending in the X-axis direction along which the processed portion 32 extends. This can prevent the molded body 10 from falling off the processed portion 32. In any of the embodiments, the guide portions may be provided on only one side.

12(a) and 12(b) are views of the molded body 10 before surface processing, and 12(c) and 12(d) are views after surface processing. 12(a) and 12(c) are plan views of the molded body 10, 12(b) is a cross-sectional view taken along line A-A in 12(a), and 12(d) is a cross-sectional view taken along line A-A in 12(c). As shown in 12(a) to 12(d), the molded body 10 is placed on the processing section 32 so that the ridge line portion 20, which is the processed portion 19 of the molded body 10, is in contact with the processing section 32, and while moving the molded body 10 in the conveying direction (+X direction) in which the processing section 32 extends, the molded body 10 is repeatedly moved diagonally downward and diagonally upward in a direction different from the conveying direction (+X direction). As in the first and second embodiments, a processing energy obtained by combining a first energy generated by the movement of the molded body 10 in the conveying direction (+X direction) and a second energy generated by the movement in the vertically downward and vertically upward directions is locally concentrated on a fine portion of the ridgeline portion 20, which is the processed portion 19 of the molded body 10. That is, both the first energy and the second energy are combined as processing energy and are concentrated as an impact on a fine portion of the ridgeline portion 20, which is the processed portion 19 of the molded body 10. Therefore, even if the molded body 10 is small and lightweight, the ridgeline portion 20, which is the processed portion 19 of the molded body 10, can be appropriately processed and processed into a rounded shape. When the surface including the ridgeline portion 20, which is the processed portion 19 of the molded body 10, is repeatedly at an elevation angle (positive angle) and a depression angle (negative angle) with respect to the horizontal plane in the conveying direction, the position of the contact portion is repeatedly at the front part in the conveying direction of the surface including the ridgeline portion 20, which is the processed portion 19 of the molded body 10, and at the rear part in the conveying direction. This allows appropriate processing to be performed over the entire surface including the ridgeline portion 20, which is the processed portion 19 of the molded body 10. In particular, when the surface including the ridgeline portion 20 of the processed portion 19 is at an elevation angle (positive angle) with respect to the horizontal plane in the conveying direction, the amount of movement when it is at a depression angle (negative angle) becomes large, and efficient processing can be performed, so that the ridgeline portion 20 of the molded body 10 can be efficiently processed into a rounded shape (R shape).

In the third embodiment, as in the first and second embodiments, the processed portion 32 may extend in the conveying direction (+X direction) while bending in the left-right direction (Y-axis direction) in a top view. The maximum amplitude value of the portion of the processed portion 32 that is bent in the Y-axis direction, i.e., the distance in the Y-axis direction between the portion of the processed portion 32 that is bent in the +Y direction to the portion of the processed portion 32 that is bent in the -Y direction to the maximum, is set smaller than the width of the groove portion 16, which is the opening width of the processed portion 19. For this reason, the molded body 10 tends to repeatedly move to the left (+Y direction) or right (-Y direction) relative to the processed portion 32. In this way, by constantly moving the processed position, the entire processed portion 19 of the molded body 10 can be evenly processed for the same reasons as in the first and second embodiments, and the ridge portion 20, which is the processed portion 19 of the molded body 10, can be processed into a rounded shape (R shape).

In the third embodiment, the burrs 18 generated on the molded body 10 may be removed by the processing section 32, and the ridge line portion 20 of the molded body 10 may be processed by the processing section 32 to give it a rounded shape.

Although the embodiment of the present invention has been described in detail above, the present invention is not limited to such a specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention as described in the claims.

10 Molded object 12 Shaft part 14a, 14b Flange part 16 Groove part 17 Inner surface 18 Burr 19 Processed part 20 Ridge line part 30, 30a, 30b, 30c, 30d, 30e, 30f Processing device 32 Processing part 34 Holding part 36 Gap 38 Transport part

Claims (10)

A step of forming a molded body by pressure molding a mixture containing an inorganic powder and a resin;
a step of placing a processed portion, which is a part of the molded body, on a rail portion , which is a processing portion of a processing device, so that the processed portion is in contact with the rail portion , and while moving the molded body in a conveying direction in which the rail portion extends, repeatedly moving the molded body in a vertically downward diagonal direction and a vertically upward diagonal direction different from the conveying direction, thereby processing the processed portion, which is a part of the molded body;
and heat treating the molded body. The method for manufacturing a base body of a coil component according to claim 1 , wherein the rail portion extends in the conveying direction while alternately having valley portions and peak portions. The method for manufacturing a coil component base body according to claim 2, wherein the rail portion extends in the transport direction while bending left and right when viewed from above. The method for manufacturing a base body of a coil component according to any one of claims 1 to 3, wherein the processed portion, which is a part of the molded body, is a concave portion when the molded body is viewed in cross section on a plane perpendicular to the transport direction. 5. The method for manufacturing a base body of a coil component according to claim 4, wherein a width of the upper portion of the rail portion in a direction perpendicular to the conveying direction is smaller than a width between inner surfaces of the concave portion when viewed in cross section on a plane perpendicular to the conveying direction. The method for manufacturing the base body of a coil component according to claim 4 or 5, wherein the molded body comprises a shaft portion around which the coil conductor is wound, and a flange portion provided at the end of the shaft portion and having the recessed portion from which the coil conductor is pulled out. The method for manufacturing a base body of a coil component according to any one of claims 1 to 3, wherein the processed portion, which is a part of the molded body, is a ridge portion of the molded body. The method for manufacturing a base body of a coil component according to claim 1 , wherein a width of the upper portion of the rail portion in a direction perpendicular to the conveying direction varies in the conveying direction. the processing device includes the rail portion and a holding portion that faces the rail portion across a gap in a direction perpendicular to the transport direction and holds the rail portion ,
The method for manufacturing a base body of a coil component according to claim 1 , wherein the rail portion is vibrated to move the compact in the transport direction. The processing device includes the rail unit and a conveying unit,
The method for manufacturing a base body of a coil component according to any one of claims 1 to 8 , further comprising vibrating the conveying section to move the molded body in the conveying direction and vibrating the rail section to process the processed portion, which is a part of the molded body.

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