阅读说明：本技术 电子部件 (Electronic component ) 是由 仪武穗 于 2020-09-28 设计创作，主要内容包括：本发明提供单元体与外部电极的底面部之间的密合强度高且安装性优异的电子部件。上述电子部件具备：具有磁性体的单元体,埋设于上述单元体且端部从上述单元体的端面露出的内部电极,以及设置于上述单元体的外表面的外部电极；上述电子部件的上述外部电极具有配置于上述单元体的底面的底面部和延伸配置于与上述单元体的底面垂直相交的上述单元体的端面的端面部,上述端面部与从上述单元体的端面露出的上述内部电极连接,上述底面部包含配置于上述单元体侧的第1底面部和配置于上述第1底面部的外侧的第2底面部,上述第1底面部是含有树脂和导电性填料的树脂电极。(The invention provides an electronic component with high adhesion strength between a unit body and a bottom surface part of an external electrode and excellent installation performance. The electronic component includes: a unit body having a magnetic body, an internal electrode embedded in the unit body and having an end portion exposed from an end surface of the unit body, and an external electrode provided on an outer surface of the unit body; the external electrode of the electronic component includes a bottom surface portion disposed on a bottom surface of the unit body and an end surface portion extended from an end surface of the unit body perpendicularly intersecting the bottom surface of the unit body, the end surface portion being connected to the internal electrode exposed from the end surface of the unit body, the bottom surface portion includes a 1 st bottom surface portion disposed on a side of the unit body and a 2 nd bottom surface portion disposed outside the 1 st bottom surface portion, and the 1 st bottom surface portion is a resin electrode containing a resin and a conductive filler.)

1. An electronic component includes:

a unit body having a magnetic body, wherein,

an internal electrode embedded in the unit body and having an end portion exposed from an end face of the unit body, an

An external electrode disposed on an outer surface of the unit body;

the external electrode has a bottom surface portion disposed on the bottom surface of the unit body and an end surface portion disposed on the end surface of the unit body in an extending manner, the end surface of the unit body perpendicularly intersects with the bottom surface of the unit body,

the end surface portion is connected to the internal electrode exposed from the end surface of the unit cell,

the bottom surface portion includes a 1 st bottom surface portion disposed on the unit body side and a 2 nd bottom surface portion disposed outside the 1 st bottom surface portion,

the No. 1 bottom surface part is a resin electrode containing a resin and a conductive filler.

2. The electronic component according to claim 1, wherein the inner electrode is a coil conductor wound around a winding shaft,

the direction of the winding shaft is perpendicular to the bottom surface of the unit body.

3. The electronic component according to claim 1 or 2, wherein the magnetic body constituting the unit body contains a resin and metal magnetic body particles.

4. The electronic component according to claim 3, wherein the metallic magnetic particles are bonded to the end surface portion by a metallic bond.

5. The electronic component according to any one of claims 1 to 4, wherein the resin electrode contains a thermosetting resin and a metal filler.

6. The electronic component according to claim 5, wherein the thermosetting resin is an epoxy resin, a phenol resin, or an acrylic resin.

7. The electronic component according to claim 5 or 6, wherein an element constituting the metal filler is Cu, Ag, or a combination thereof.

8. The electronic component according to any one of claims 5 to 7, wherein the metal filler is bonded to the 2 nd bottom face portion by a metal bond.

9. The electronic component according to any one of claims 1 to 8, wherein the end surface portion is in direct contact with the unit body.

10. The electronic component according to any one of claims 1 to 9, wherein the 2 nd bottom surface portion is constituted by a plurality of layers.

11. The electronic component according to any one of claims 1 to 10, wherein a surface roughness Ra of the bottom surface portion is smaller than a surface roughness Ra of the end surface portion.

12. The electronic component according to claim 11, wherein the end surface portion has a surface roughness Ra of 6 μm or more.

13. The electronic component according to claim 11 or 12, wherein a surface roughness Ra of the bottom surface portion is 1 μm or more and 5 μm or less.

14. The electronic component according to claim 11 or 12, wherein a surface roughness Ra of the bottom face portion is less than 1 μm.

15. The electronic component according to claim 11, 12 or 14, wherein a surface of the 1 st bottom face portion is coplanar with a bottom face of the unit body.

16. The electronic component according to any one of claims 1 to 15, wherein the external electrode further includes a 1 st side surface portion and a 2 nd side surface portion in addition to the bottom surface portion and the end surface portion, the 1 st side surface portion is disposed so as to extend from a 1 st side surface of the unit body that perpendicularly intersects the bottom surface and the end surface of the unit body, and the 2 nd side surface portion is disposed so as to extend from a 2 nd side surface of the unit body that perpendicularly intersects the bottom surface and the end surface of the unit body and faces the 1 st side surface,

the bottom surface portion has a surface roughness Ra smaller than the surface roughness Ra of the 1 st side surface portion and the 2 nd side surface portion.

17. The electronic component according to any one of claims 1 to 16, wherein the end surface portion is a plated electrode.

18. The electronic component according to any one of claims 1 to 17, wherein the end surface portion and the 2 nd bottom surface portion are composed of the same material.

19. The electronic component according to any one of claims 1 to 18, wherein a portion of the outer surface of the unit cell on which the external electrode is not provided is covered with an insulating film.

20. The electronic component according to claim 19, wherein the insulating film covers an edge portion of the 1 st bottom surface portion.

Technical Field

The present invention relates to an electronic component.

Background

As an electronic component such as an inductor, patent document 1 discloses an electronic component having an outer shape of a rectangular parallelepiped shape or a cubic shape, in which external electrodes having an L-shaped cross section are provided on both opposing end surfaces so as to continuously cover a part of the end surfaces and a part of a bottom surface adjacent to each other with a corner interposed therebetween, and the surface roughness Ra of the end surfaces covered with the external electrodes is 0.5 μm or more.

Further, patent document 1 discloses a method for manufacturing an electronic component, including: the method includes a step of preparing a green laminated ceramic substrate having a predetermined element structure formed therein, a step of forming a plurality of grooves having a roughened inner surface on one surface of the green laminated ceramic substrate in parallel at predetermined intervals, a step of filling the grooves with an external electrode material, a step of forming a plurality of electrode patterns extending along the grooves so as to cover the surfaces of the external electrode material filled in the grooves, a step of dicing the green laminated ceramic substrate along the grooves to form chips, and a step of firing the ceramic chips obtained by forming the green laminated ceramic substrate into chips.

Patent document 1: japanese laid-open patent publication No. 2012-104547

Disclosure of Invention

In the electronic component described in patent document 1, a conductive paste (external electrode material) serving as an end surface portion of the external electrode is provided on each end surface of the unit body, and an electrode pattern serving as a bottom surface portion of the external electrode is provided on a bottom surface of the unit body. When an electronic component is manufactured, the inner surface of the groove formed in the green laminated ceramic substrate is roughened, whereby the interface between the cell body and the external electrode is roughened. This makes it possible to obtain high adhesion strength between the unit cell and the end surface portion of the external electrode.

On the other hand, since the bottom surface of the cell body is not roughened, the adhesion strength between the cell body and the bottom surface portion of the external electrode is insufficient. The thickness of the bottom surface of the unit cell can increase the adhesion strength between the unit cell and the bottom surface of the external electrode, but when the unit cell is mounted on a mounting substrate, problems such as air entrainment may occur in the bottom surface of the external electrode, which may reduce the mountability.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electronic component having high adhesion strength between a unit body and a bottom surface portion of an external electrode and excellent mountability.

The electronic component of the present invention includes: a unit body having a magnetic body, an internal electrode embedded in the unit body and having an end portion exposed from an end surface of the unit body, and an external electrode provided on an outer surface of the unit body; the external electrode has a bottom surface portion disposed on the bottom surface of the unit body and an end surface portion extended from the end surface of the unit body perpendicularly intersecting the bottom surface of the unit body, the end surface portion is connected to the internal electrode exposed from the end surface of the unit body, the bottom surface portion includes a 1 st bottom surface portion disposed on the unit body side and a 2 nd bottom surface portion disposed outside the 1 st bottom surface portion, and the 1 st bottom surface portion is a resin electrode containing a resin and a conductive filler.

According to the present invention, an electronic component having high adhesion strength between the unit body and the bottom surface portion of the external electrode and excellent mountability can be provided.

Drawings

Fig. 1 is a perspective view schematically showing an example of a coil component of the present invention.

Fig. 2 is a perspective view of the coil component shown in fig. 1, with a part of the coil component omitted.

Fig. 3 is a sectional view of the coil component shown in fig. 1.

Fig. 4 is an enlarged sectional view of the vicinity of the bottom surface of the 1 st external electrode.

Description of the symbols

1 coil component (electronic parts)

10 unit body

11 resin

12 metallic magnetic particles

14 1 st end face

15 No. 2 end face

16 bottom surface

17 1 st side

18 upper surface

19 nd side of 2

20 coil conductor (inner electrode)

21 the 1 st end of the coil conductor

22 nd end of coil conductor

31 st external electrode

32 nd 2 nd external electrode

33 bottom surface part

34 end face part

35 No. 1 bottom surface part

36 2 nd bottom surface part

37 resin

38 conductive filler

40 insulating film

Detailed Description

The electronic component of the present invention will be described below. The present invention is not limited to the following configurations, and can be modified as appropriate within a range not departing from the gist of the present invention. In addition, the present invention also includes a configuration in which a plurality of preferable configurations described below are combined.

As one embodiment of the electronic component of the present invention, a coil component in which an internal electrode is a coil conductor will be described as an example. The present invention is not limited to coil components, and can be applied to various electronic components such as inductors that do not include coil conductors as internal electrodes.

Fig. 1 is a perspective view schematically showing a coil component of the present invention. Fig. 2 is a perspective view of the coil component shown in fig. 1, with a part of the coil component omitted. Fig. 3 is a sectional view of the coil component shown in fig. 1.

As shown in fig. 1, 2, and 3, the coil component 1 includes: the unit body 10 includes a magnetic body, a coil conductor 20 embedded in the unit body 10, a 1 st external electrode 31 and a 2 nd external electrode 32 provided on an outer surface of the unit body 10 and electrically connected to the coil conductor 20, and an insulating film 40 provided on the outer surface of the unit body 10. The insulating film 40 may not be provided on the outer surface of the unit cell 10.

The unit body 10 has, for example, a rectangular parallelepiped shape. The unit body 10 has a 1 st end face 14 and a 2 nd end face 15 opposed to each other, and a bottom face 16, a 1 st side face 17, an upper face 18, and a 2 nd side face 19 between the 1 st end face 14 and the 2 nd end face 15. The bottom surface 16, the 1 st side surface 17, the upper surface 18, and the 2 nd side surface 19 are arranged in this order in the circumferential direction. The bottom surface 16 serves as a mounting surface for mounting the coil component 1. The upper surface 18 is opposite the bottom surface 16. The 1 st side 17 and the 2 nd side 19 face each other. The 1 st end surface 14, the 2 nd end surface 15, the 1 st side surface 17 and the 2 nd side surface 19 perpendicularly intersect the bottom surface 16.

The 1 st end portion 21 on one side of the coil conductor 20 is exposed from the 1 st end surface 14 of the unit body 10, and the 2 nd end portion 22 on the other side is exposed from the 2 nd end surface 15 of the unit body 10.

The 1 st external electrode 31 is provided on the 1 st end face 14 side of the unit cell 10. The 1 st external electrode 31 is continuously provided on the 1 st end face 14 of the unit cell 10 and the bottom face 16 on the 1 st end face 14 side. Therefore, the 1 st external electrode 31 has a bottom surface portion 33 disposed on the bottom surface 16 of the unit cell 10 and an end surface portion 34 disposed extending from the 1 st end surface 14 of the unit cell 10. In this manner, the 1 st external electrode 31 is preferably formed in an L shape.

The 2 nd external electrode 32 is provided on the 2 nd end face 15 side of the unit cell 10. The 2 nd external electrode 32 is continuously provided on the 2 nd end face 15 of the unit cell 10 and the bottom face 16 on the 2 nd end face 15 side. Therefore, the 2 nd external electrode 32 has a bottom surface portion 33 disposed on the bottom surface 16 of the unit cell 10 and an end surface portion 34 disposed extending from the 2 nd end surface 15 of the unit cell 10. In this manner, the 2 nd external electrode 32 is preferably formed in an L shape.

The 1 st external electrode 31 may be continuously provided on the 1 st end surface 14, the bottom surface 16, the 1 st side surface 17, and the 2 nd side surface 19 of the unit cell 10. In this case, the 1 st external electrode 31 has a 1 st side surface portion extending from the 1 st side surface 17 of the unit cell 10 and a 2 nd side surface portion extending from the 2 nd side surface 19 of the unit cell 10, in addition to the bottom surface portion 33 and the end surface portion 34. Similarly, the 2 nd external electrode 32 may be continuously provided on the 2 nd end surface 15, the bottom surface 16, the 1 st side surface 17, and the 2 nd side surface 19 of the unit cell 10. In this case, the 2 nd external electrode 32 has a 1 st side surface portion extending from the 1 st side surface 17 of the unit cell 10 and a 2 nd side surface portion extending from the 2 nd side surface 19 of the unit cell 10, in addition to the bottom surface portion 33 and the end surface portion 34. When the 1 st external electrode 31 or the 2 nd external electrode 32 has the 1 st side surface and the 2 nd side surface, the 1 st side surface is preferably connected to the bottom surface 33 and the end surface 34, and the 2 nd side surface is preferably connected to the bottom surface 33 and the end surface 34.

The end surface portion 34 of the 1 st external electrode 31 is connected to the coil conductor 20 exposed from the 1 st end surface 14 of the unit cell 10. Therefore, the 1 st external electrode 31 is electrically connected to the 1 st end portion 21 of the coil conductor 20. Similarly, the end surface portion 34 of the 2 nd external electrode 32 is connected to the coil conductor 20 exposed from the 2 nd end surface 15 of the unit cell 10. Therefore, the 2 nd outer electrode 32 is electrically connected to the 2 nd end portion 22 of the coil conductor 20.

As shown in fig. 3, the bottom surface portion 33 of the 1 st external electrode 31 includes a 1 st bottom surface portion 35 disposed on the unit cell 10 side and a 2 nd bottom surface portion 36 disposed outside the 1 st bottom surface portion 35. Similarly, in the 2 nd external electrode 32, the bottom surface portion 33 includes a 1 st bottom surface portion 35 disposed on the unit cell 10 side and a 2 nd bottom surface portion 36 disposed outside the 1 st bottom surface portion 35.

Fig. 4 is an enlarged sectional view of the vicinity of the bottom surface of the 1 st external electrode. The 1 st bottom surface portion 35 is a resin electrode containing a resin 37 and a conductive filler 38.

The 1 st bottom surface portion 35 as a resin electrode is in contact with the unit body 10 and bites into it. Therefore, the adhesion strength between the unit cell 10 and the bottom surface portion 33 of the external electrode 31 or 32 can be improved. On the other hand, by disposing the 1 st bottom surface portion 35 as a resin electrode between the unit body 10 and the 2 nd bottom surface portion 36, the 2 nd bottom surface portion 36 can be planarized. Therefore, air entrainment and the like generated in the bottom surface portion 33 of the external electrode 31 or 32 when mounted on the mounting substrate are alleviated, and the mounting properties such as solder wettability and mountability can be improved.

Further, the stress applied to the bottom surface portion 33 of the external electrode 31 or 32 is relaxed by the toughness of the resin electrode. In addition, the difference in linear expansion between the unit cell 10 and the bottom surface portion 33 of the external electrode 31 or 32 is alleviated by the resin electrode.

In the external electrode of any one of the 1 st external electrode 31 and the 2 nd external electrode 32, the bottom surface portion 33 may include the 1 st bottom surface portion 35 and the 2 nd bottom surface portion 36, but in the both external electrodes, the bottom surface portion 33 preferably includes the 1 st bottom surface portion 35 and the 2 nd bottom surface portion 36.

The surface roughness of the 1 st bottom surface part 35 on the 2 nd bottom surface part 36 side is preferably smaller than the surface roughness of the 1 st bottom surface part 35 on the unit body 10 side. This makes it possible to easily achieve both the "adhesion strength" and the "planarization".

The surface roughness of the 1 st bottom surface part 35 on the 2 nd bottom surface part 36 side is preferably smaller than the surface roughness of the end surface 14 or 15 of the unit body 10. This makes it easy to make the surface roughness Ra of the bottom surface portion 33 of the external electrode 31 or 32 smaller than the surface roughness Ra of the end surface portion 34 of the external electrode 31 or 32.

The resin electrode contains a resin 37 and a conductive filler 38, and preferably contains a thermosetting resin and a metal filler. By using the resin, the mechanical strength against deflection, bending, dropping, vibration, impact, and the like is improved.

Examples of the thermosetting resin include epoxy resin, phenol resin, and acrylic resin. By using these thermosetting resins, an appropriate linear expansion and curing temperature can be selected.

Examples of the element constituting the metal filler include Cu and Ag. Combinations of these elements are also possible. By using these metal fillers, the difference in resistance with the external electrode can be reduced.

The metal filler is preferably bonded to the 2 nd bottom face portion by a metal bond. In this case, the adhesion strength increases, and the fixing force increases.

The 2 nd bottom surface portion 36 is preferably a plating electrode formed by plating. The 2 nd bottom surface portion 36 can be thinly formed by plating, and therefore, the characteristics can be improved by increasing the size of the unit body 10. Examples of the metal material constituting the plating electrode include Cu, Ni, and Sn.

The 2 nd bottom surface portion 36 may be composed of a plurality of layers. By using a plurality of layers, corrosion resistance, heat resistance, and strength can be improved.

The end surface portion 34 is preferably a plated electrode formed by plating. The end surface portion 34 can be thinly formed by plating, and therefore, the characteristics can be improved by increasing the size of the unit body 10. Examples of the metal material constituting the plating electrode include Cu, Ni, and Sn.

The end surface portion 34 and the 2 nd bottom surface portion 36 are preferably composed of the same material. If the end surface portion 34 and the 2 nd bottom surface portion 36 are made of the same material, the connection between the two is good, and thus the fixing force is increased. The end surface portion 34 may be composed of a plurality of layers.

The end surface portion 34 is preferably in direct contact with the unit cell 10. By bringing the end surface portion 34 into direct contact with the unit cell 10, the adhesion strength between the end surface portion 34 and the unit cell 10 can be improved.

When the 1 st external electrode 31 or the 2 nd external electrode 32 has the 1 st side surface portion and the 2 nd side surface portion described above, the 1 st side surface portion and the 2 nd side surface portion are preferably plated electrodes formed by plating. The end surface portion 34, the 2 nd bottom surface portion 36, the 1 st side surface portion and the 2 nd side surface portion are preferably formed of the same material. The 1 st side surface part and the 2 nd side surface part may be formed of a plurality of layers. In addition, the 1 st side surface portion and the 2 nd side surface portion are preferably in direct contact with the unit body 10.

In the 1 st external electrode 31 or the 2 nd external electrode 32, when the bottom surface portion 33 includes the 1 st bottom surface portion 35 and the 2 nd bottom surface portion 36, the surface roughness Ra of the bottom surface portion 33 is preferably smaller than the surface roughness Ra of the end surface portion 34. Since the surface of the end surface portion 34 is roughened, an anchoring effect is exerted between the end surface portion 34 and the unit cell 10, and thus the adhesion strength between the end surface portion 34 and the unit cell 10 can be improved.

When the surface roughness Ra of the bottom surface portion 33 is smaller than the surface roughness Ra of the end surface portion 34, the surface of the 1 st bottom surface portion 35 is preferably flush with the bottom surface of the unit body 10. In this case, the surface roughness Ra of the bottom surface portion 33 can be reduced. The "flush" may mean that the surface of the 1 st bottom surface portion 35 is not strictly flush with the bottom surface of the unit body 10, and may be deviated from the bottom surface of the unit body 10 by about 0.05 μm, for example.

The surface roughness Ra of the bottom surface part 33 is less than 1 μm if considering mountability. In this case, the surface roughness Ra of the bottom surface 33 is preferably 0.05 μm or more. The surface roughness Ra of the bottom surface portion 33 may be 1 μm or more and 5 μm or less. If the surface roughness Ra of the bottom surface portion 33 is within the above range, air entrainment and the like are less likely to occur during mounting, and a tombstoning phenomenon is less likely to occur. The surface roughness Ra of the bottom surface 33 of the 1 st external electrode 31 and the 2 nd external electrode 32 may be the same or different.

The surface roughness Ra of the end surface portion 34 is preferably 6 μm or more, if the anchoring effect between the end surface portion 34 and the unit body 10 is taken into consideration. If the surface roughness Ra of the end surface portion 34 is in the above range, the anchor effect can be increased. On the other hand, the surface roughness Ra of the end surface portion 34 is preferably 10 μm or less. The surface roughness Ra of the end surface portion 34 of the 1 st external electrode 31 and the 2 nd external electrode 32 may be the same or different.

When the 1 st external electrode 31 or the 2 nd external electrode 32 has the 1 st side surface and the 2 nd side surface, the surface roughness Ra of the bottom surface 33 is preferably smaller than the surface roughness Ra of the 1 st side surface and the 2 nd side surface. This can further improve the adhesion strength between the unit cell 10 and the external electrode 31 or 32. The preferable range of the surface roughness Ra of the 1 st side surface part and the 2 nd side surface part is the same as the preferable range of the surface roughness Ra of the end surface part 34. The surface roughness Ra of the 1 st side surface portion and the 2 nd side surface portion may be the same or different. In the 1 st external electrode 31 and the 2 nd external electrode 32, the surface roughness Ra of the 1 st side surface portion and the 2 nd side surface portion may be the same or different.

In the present specification, the surface roughness Ra is defined by JIS B0601: 2001, the arithmetic average roughness Ra. The surface roughness was measured with a non-contact shape measuring instrument (VK-X200, Keyence) with a cut-off value λ c of 0.8 μm.

As shown in fig. 3, the magnetic material constituting the unit cell 10 preferably contains a resin 11 and metallic magnetic particles 12. By using the resin, the mechanical strength against deflection, bending, dropping, vibration, impact, and the like is improved.

Examples of the resin 11 include thermosetting resins such as polyimide resin and epoxy resin.

The metal constituting the metallic magnetic particles 12 may be Fe, an Fe-containing alloy such as FeSiCr, or both Fe and an Fe-containing alloy. The metallic magnetic particles 12 may contain at least one metal of Pd, Ag, and Cu in addition to Fe or an alloy of Fe. These metals function as plating catalysts that increase the growth rate of plating when the unit is plated. The surfaces of the metallic magnetic particles 12 may be covered with an insulating film.

The metallic magnetic particles 12 are preferably bonded to the end surface portion 34 by a metal bond. In this case, the adhesion strength increases, and the fixing force increases.

The coil conductor 20 includes a conductive material such as Au, Ag, Cu, Pd, Ni, or the like. The surface of the conductive material may be covered with an insulating film.

The coil conductor 20 is wound around the winding shaft. As shown in fig. 2, the winding axis is preferably oriented perpendicular to the bottom surface 16 of the unit body 10. At this time, it is not necessary to additionally secure a space for drawing out to the 1 st end face 14 or the 2 nd end face 15 of the unit body 10, and thus characteristics can be improved by increasing the size of the coil conductor 20 with respect to the unit body 10.

In fig. 2, the coil conductor 20 is spirally wound in 2 steps so that the 1 st end 21 and the 2 nd end 22 are located on the outer periphery. That is, the coil conductor 20 is formed by winding a rectangular wire into an α -winding (outer winding き). However, the shape of the coil conductor 20 is not particularly limited, and the winding method of the coil conductor 20 is also not particularly limited.

When the coil component 1 includes the insulating film 40, the insulating film 40 covers the portions of the outer surface of the unit cell 10 where the 1 st and 2 nd external electrodes 31 and 32 are not provided. That is, the coil component 1 includes the 1 st and 2 nd external electrodes 31 and 32 provided on one part of the outer surface of the unit cell 10, and the insulating film 40 provided on the other part of the outer surface. If the insulating film 40 is provided on the outer surface of the cell body 10 in the portion where the 1 st and 2 nd external electrodes 31 and 32 are not provided, the plating can be prevented from growing greatly beyond the contact region during plating, and the withstand voltage can be improved.

The insulating film 40 and the 1 st external electrode 31 or the 2 nd external electrode 32 may partially overlap. For example, as shown in fig. 4, the insulating film 40 may cover the edge portion of the 1 st bottom surface portion 35. In this case, the peel strength of the 1 st bottom surface portion 35 can be improved.

The insulating film 40 is made of a resin material having high electrical insulation, such as acrylic resin, epoxy resin, or polyimide resin.

The coil component 1 is manufactured, for example, as follows.

First, the coil conductor 20 is provided inside the unit body 10. As one method of embedding the coil conductor 20 in the unit body 10 containing the resin 11 and the metal magnetic particles 12, there is a method of arranging a plurality of winding coils, collectively embedding the winding coils in a sheet containing metal magnetic powder, curing the sheet, and then dicing the sheet into individual pieces (see, for example, japanese patent application laid-open No. 2017-123433). In this method, one surface of a wound coil is embedded and cured together, and then the other surface is embedded, thereby producing a chip inductor.

For example, after one surface of the coil conductor 20 is embedded in a sheet, an Ag resin paste is applied to the other surface of the coil conductor 20 by screen printing and dried, thereby forming a resin electrode. The resin electrode serves as the 1 st bottom surface portion 35 of the 1 st external electrode 31 and the 2 nd external electrode 32. Thereby, the 1 st bottom surface portion 35 is in direct contact with the unit body 10. The other surface of the coil conductor 20 on which the 1 st bottom surface portion 35 is formed is embedded in a sheet, and then is pressed and cured to form a cured product.

Next, the coil conductor 20 is exposed at the 1 st end face 14 and the 2 nd end face 15 of the unit body 10 by dicing and singulation of the mother cured product by a dicer. The insulating film 40 is preferably formed on the outer surface of the unit cell 10 through a barrel polishing process. The insulating film 40 may cover the edge portion of the 1 st bottom surface portion 35 as the resin electrode. For example, in the method described in japanese patent application laid-open No. 2016 and 178282, the insulating film 40 is formed by using the metal magnetic particles 12 of the cell body 10 as nuclei. In fig. 4, the insulating film 40 is in direct contact with the edge portion of the 1 st bottom surface portion 35.

The insulating film 40 on the 1 st end face 14 and the 2 nd end face 15 of the unit 10 are peeled off by the laser beam to expose the metallic magnetic particles 12 (see, for example, international publication No. 2017/135057). Thus, the end surfaces 34 and the 2 nd bottom surfaces 36 of the 1 st external electrode 31 and the 2 nd external electrode 32 are formed. Thereafter, the end surface portion 34 and the 2 nd bottom surface portion 36 are formed by plating. Thus, of the 1 st end face 14 and the 2 nd end face 15 of the unit body 10, the unit body 10 and the coil conductor 20 are in direct contact with the end face portion 34 as the plated electrode. In the above method, the surface roughness Ra of the end surface portion 34 may be 6 μm or more. In addition, the 2 nd bottom surface portion 36 and the end surface portion 34 of the 1 st external electrode 31 and the 2 nd external electrode 32 among the plating electrodes are formed in an L shape integrally.

Through the above operation, the coil component 1 is obtained.

In the above method, the resin electrode to be the 1 st bottom surface portion 35 is formed, and then the other surface of the coil conductor 20 is embedded in the sheet. Therefore, the surface roughness Ra of the bottom surface portion 33 can be made smaller than 1 μm. On the other hand, the other surface of the coil conductor 20 may be embedded in a sheet to form a resin electrode to be the 1 st bottom surface portion 35. At this time, the printing surface of the Ag resin paste is not pressed. Therefore, the surface roughness Ra of the bottom surface portion 33 can be set to 1 μm or more and 5 μm or less. In either case, the 1 st bottom surface portion 35 as the resin electrode is in contact with the unit body 10 and bites into it.

The electronic component of the present invention is not limited to the above-described embodiments, and various applications and modifications can be made within the scope of the present invention with respect to the configuration, manufacturing conditions, and the like of the electronic component such as a coil component.