JP2022109327A - Coil component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil component that can prevent the occurrence of peeling on an interface between a coil conductor and resin in a magnetic substance part due to heating during mounting.

SOLUTION: A coil component 10 according to the present invention comprises: an element assembly 12 including a coil conductor 16 that is formed by winding a lead wire 16a covered by an insulating film 18 and a magnetic substance part 14 containing metal magnetic body particles 14a and resin; and an external electrode 40 that is arranged on a surface of the element assembly 12 while being electrically connected with exposure surfaces of lead-out parts 22a, 22b of the coil conductor 16 exposed to the surface of the element assembly 12. The metal magnetic body particles 14a are arranged in concave parts 28 formed on surfaces of the lead wire 16a in the lead-out parts 22a, 22b of the coil conductor 16.

SELECTED DRAWING: Figure 5

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to coil components.

A conventional coil component has a magnetic body part made of metal magnetic particles and resin, a coil conductor is embedded inside the magnetic body part, and the end of the coil conductor is on the surface of the magnetic body part. An extracted coil component is disclosed (see, for example, US Pat.

JP 2019-080073

In the coil component disclosed in Patent Document 1, the surface of the coil conductor is coated with a film for insulation. When a coil component having such a coil conductor is mounted on a mounting board using solder by reflow, the coil component may expand due to heating or the like at that time. When the coil component expands, the difference in the coefficient of thermal expansion between the coil conductor and the resin in the magnetic body (generally, the resin is larger) causes a deviation at the interface between the coil conductor and the resin in the magnetic body. There was a possibility that peeling might occur.

SUMMARY OF THE INVENTION Therefore, it is a primary object of the present invention to provide a coil component that can suppress the occurrence of peeling at the interface between the coil conductor and the resin in the magnetic body due to heating during mounting.

A coil component according to the present invention includes a base body including a coil conductor formed of a conductive wire coated with an insulating film, a magnetic body portion containing metal magnetic particles and a resin, and a lead-out portion of the coil conductor. and an external electrode disposed on the surface of the element body electrically connected to the exposed surface exposed on the surface of the element body of the coil component, wherein , a coil component in which metal magnetic particles are arranged.

In the coil component according to the present invention, the surface of the lead-out portion of the coil conductor has concave portions, and the metal magnetic particles contained in the magnetic portion are arranged in the concave portions. On the other hand, the generation of the anchor effect can improve the bonding strength between the magnetic portion and the coil conductor.

According to the present invention, it is possible to provide a coil component that can suppress the occurrence of delamination at the interface between the coil conductor and the resin in the magnetic body due to heating during mounting.

The above object, other objects, features and advantages of the present invention will become more apparent from the following description of the mode for carrying out the invention with reference to the drawings.

1 is an external perspective view schematically showing an embodiment of a coil component of the present invention; FIG. 2 is a see-through perspective view of a magnetic body portion in which a coil conductor is embedded in the coil component shown in FIG. 1; FIG. FIG. 2 is a cross-sectional view taken along line III-III of FIG. 1 showing the coil component according to the present invention; FIG. 2 is a cross-sectional view taken along line IV-IV in FIG. 1 showing the coil component according to the present invention; FIG. 4 is a see-through perspective view showing a first modification of the base body of the coil component according to the embodiment of the invention; (a) is a see-through perspective view showing a second modification of the base body of the coil component according to the embodiment of the present invention, and (b) is a see-through perspective view seen from a direction different from (a). (a) is a cross-sectional view taken along line VV in FIG. 1 showing a coil component according to the present invention, and (b) is an enlarged cross-sectional view of part a. FIG. 10 is an enlarged cross-sectional view showing a first modification of the structure around the lead-out portion of the coil conductor; FIG. 11 is an enlarged cross-sectional view showing a second modification of the structure around the lead-out portion of the coil conductor; FIG. 11 is an enlarged cross-sectional view showing a third modification of the structure around the lead-out portion of the coil conductor; (a) is an enlarged cross-sectional view showing a fourth modification of the structure around the lead-out portion of the coil conductor, and (b) is an enlarged cross-sectional view showing the lead-out portion of the coil conductor viewed from the end face side of the element body, excluding external electrodes; is an enlarged view showing a fourth modification of the structure of . FIG. 4 is a manufacturing process diagram showing an embodiment of manufacturing a first molded body in the coil component manufacturing method. FIG. 4 is a manufacturing process diagram showing an embodiment of manufacturing an aggregate base in a method of manufacturing a coil component.

1. Coil Component Hereinafter, the coil component of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an external perspective view schematically showing an embodiment of a coil component according to the invention. FIG. 2 is a see-through perspective view of a magnetic body portion in which a coil conductor is embedded in the coil component shown in FIG. 1; FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1 showing the coil component according to the invention. 4 is a cross-sectional view taken along line IV-IV in FIG. 1 showing the coil component according to the present invention; FIG. FIG. 5 is a see-through perspective view showing a first modification of the base body of the coil component according to the embodiment of the invention. FIG. 6(a) is a see-through perspective view showing a second modification of the base body of the coil component according to the embodiment of the present invention, and FIG. 6(b) is a see-through perspective view from a direction different from (a). It is a diagram. FIG. 7(a) is a cross-sectional view taken along the line VV in FIG. 1 showing the coil component according to the present invention, and FIG. 7(b) is an enlarged cross-sectional view of the part a.

The coil component 10 has a rectangular parallelepiped element body 12 and external electrodes 40 .

(A) Element Body The element body 12 has a magnetic body portion 14 and a coil conductor 16 embedded in the magnetic body portion 14 . The element body 12 has a first main surface 12a and a second main surface 12b facing in the pressing direction x, and a first side surface 12c and a second side surface facing in the width direction y perpendicular to the pressing direction x. 12d, and a first end face 12e and a second end face 12f facing each other in a length direction z perpendicular to the pressing direction x and width direction y. The dimensions of the element body 12 are not particularly limited.

(B) Magnetic Portion The magnetic portion 14 includes metal magnetic particles and a resin material.

The resin material is not particularly limited, but examples thereof include thermosetting resins and organic materials such as epoxy resins, phenol resins, polyester resins, polyimide resins, and polyolefin resins. The number of resin materials may be one, or two or more.

The metal magnetic particles preferably include first metal magnetic particles and second metal magnetic particles.

The first metal magnetic particles have an average particle size of 10 μm or more. Also, the first magnetic particles preferably have an average particle size of 200 μm or less, more preferably 100 μm or less, and even more preferably 80 μm or less. By setting the average particle size of the first metal magnetic particles to 10 μm or more, the magnetic properties of the magnetic portion are improved.

The average particle size of the second metal magnetic particles is smaller than the average particle size of the first metal magnetic particles. The second metal magnetic particles have an average particle size of 5 μm or less. Since the average particle size of the second metal magnetic particles is smaller than the average particle size of the first metal magnetic particles, the packing property of the metal magnetic particles in the magnetic portion 14 is further improved. Therefore, the magnetic properties of the coil component 10 can be improved.

Here, the average particle size means an average particle size D50 (particle size equivalent to 50% cumulative percentage based on volume). The average particle diameter D50 can be measured, for example, with a dynamic light scattering particle size analyzer (UPA manufactured by Nikkiso Co., Ltd.).

The first metal magnetic particles and the second metal magnetic particles are not particularly limited, but examples thereof include iron, cobalt, nickel, gadolinium, or alloys containing one or more of these. Preferably, the first metal magnetic particles and the second metal magnetic particles are iron or an iron alloy. Examples of iron alloys include, but are not particularly limited to, Fe--Si, Fe--Si--Cr, Fe--Ni, and Fe--Si--Al. The first metal magnetic particles and the second metal magnetic particles may be of one kind or two or more kinds.

The surfaces of the first metal magnetic particles and the second metal magnetic particles may be covered with an insulating coating. By covering the surfaces of the metal magnetic particles with an insulating coating, the specific resistance inside the magnetic body portion 14 can be increased. In addition, since the surface of the metal magnetic particles is insulated by the insulating film, short-circuit failure with the coil conductor 16 can be suppressed.

Materials for the insulating coating include oxides of silicon, phosphate glass, bismuth glass, and the like. In particular, an insulating coating made of zinc phosphate glass mechanochemically treated on metal magnetic particles is preferable.

The thickness of the insulating coating is not particularly limited, but may be preferably 5 nm or more and 500 nm or less, more preferably 5 nm or more and 100 nm or less, still more preferably 10 nm or more and 100 nm or less. By increasing the thickness of the insulating coating, the specific resistance of the magnetic body portion 14 can be increased. Further, by reducing the thickness of the insulating coating, the amount of metal magnetic particles in the magnetic body portion 14 can be increased, and the magnetic properties of the magnetic body portion 14 are improved.

The content of the first metal magnetic particles and the second metal magnetic particles in the magnetic portion 14 is preferably 50% by volume or more, more preferably 60% by volume or more, and further It is preferably at least 70% by volume. By setting the contents of the first metal magnetic particles and the contents of the second metal magnetic particles within such ranges, the magnetic properties of the coil component of the present invention are improved. In addition, the content of the first metal magnetic particles and the second metal magnetic particles is preferably 99% by volume or less, more preferably 95% by volume or less, and still more preferably 90% by volume of the entire magnetic body portion 14. % by volume or less. By setting the contents of the first metal magnetic particles and the contents of the second metal magnetic particles within such ranges, the specific resistance of the magnetic body portion 14 can be further increased.

A region adjacent to the coil conductor 16 in the surface portion of the magnetic body portion 14 may be removed. By removing the magnetic body portion 14 in the region adjacent to the coil conductor 16, the gap between the magnetic body portion 14 and the coil conductor 16 becomes larger, making it easier for the media to enter during the barrel plating process. A plated film is formed over a wider area of . This is expected to improve joint strength and reduce DC resistance.

(C) Coil conductor The coil conductor 16 includes a winding portion 20 formed by winding a conductive wire containing a conductive material in a coil shape, and a first lead-out portion 22a drawn out to one side of the winding portion 20. and a second lead-out portion 22 b that is led out to the other side of the winding portion 20 .
The winding portion 20 is formed by being wound in two stages. The coil conductor 16 is formed by winding a flat conductor wire in an α winding shape. The dimension of the rectangular conductor in the width direction y is 15 μm or more and 200 μm or less, and the dimension in the pressure direction x is 50 μm or more and 500 μm.
The first lead-out portion 22a is exposed from the first end surface 12e of the element body 12 and the first exposed portion 24a is disposed thereon, and the second lead-out portion 22b is exposed from the second end surface 12f of the element body 12. Then, the second exposed portion 24b is arranged.

Here, a first modification of the base body 12 of the coil component 10 according to the embodiment of the invention is shown.
FIG. 5 is a see-through perspective view showing a first modification of the base body of the coil component according to the embodiment of the invention.

The element body 112 has a magnetic body portion 114 and a coil conductor 116 embedded in the magnetic body portion 114 . The element body 112 has a first main surface 112a and a second main surface 112b facing in the height direction x, and a first side surface 112c and a second side surface facing in the width direction y orthogonal to the height direction x. 112d, and a first end face 112e and a second end face 112f facing each other in a length direction z orthogonal to the height direction x and width direction y.

The coil conductor 116 includes a winding portion 120 formed by winding a conductive wire containing a conductive material in a coil shape, a first lead-out portion 122 a drawn out to one side of the winding portion 120 , and the other side of the winding portion 120 . and a second drawer portion 122b that is drawn out to the side.
The first lead-out portion 122a is led out to the first main surface 112a of the element body 112 to be exposed, and the first exposed portion 124a is disposed thereon. A second exposed portion 124b is arranged to be exposed from the surface 112a.

Also, a second modification of the element body 12 of the coil component 10 according to the embodiment of the present invention is shown.
FIG. 6(a) is a see-through perspective view showing a second modification of the base body of the coil component according to the embodiment of the present invention, and FIG. 6(b) is a see-through perspective view from a direction different from (a). It is a diagram.

As shown in FIGS. 6A and 6B , the element body 212 includes a magnetic body portion 214 and a coil conductor 216 embedded in the magnetic body portion 214 . The magnetic body part 214 has a first magnetic body part 214 a arranged inside the base body 212 and a second magnetic body part 214 b covering the first magnetic body part 214 a and the coil conductor 216 .
The element body 212 is formed in a substantially rectangular parallelepiped shape, and has a first main surface 212a and a second main surface 212b facing in the height direction x and a first main surface 212b facing in the width direction y orthogonal to the height direction x. It has a side surface 212c and a second side surface 212d, and a first end surface 212e and a second end surface 212f facing each other in a length direction z orthogonal to the height direction x and width direction y.

The coil conductor 216 is disposed on one side of the first magnetic body portion 214a, and is formed by winding a conductive wire containing a conductive material in a coil shape. It has a first lead-out portion 222 a that is led out and a second lead-out portion 222 b that is led out to the other side of the winding portion 220 . The first lead-out portion 222a is led out to the first end surface 212e side of the second main surface 212b of the element body 212 and exposed, and the second lead-out portion 222b extends from the second main surface 212b of the element body 212. 212b is pulled out and exposed on the second end face 12f side.
In this manner, the first lead-out portion 222a may be formed and arranged on the second main surface 212b of the element body 212, and the second lead-out portion 222b may be formed on the second main surface 212b of the element body 212. 212b may be formed and disposed.

The coil conductor 16 is composed of a conducting wire 16a such as a metal wire or wire. The conductive material of the coil conductor 16 is not particularly limited, but examples thereof include Ag, Au, Cu, Pd, and Ni. Preferably, the conductive material includes copper. The number of conductive materials may be one, or two or more.

An insulating film 18 is formed on the surface of the conducting wire 16a forming the coil conductor 16 by covering it with an insulating material. By coating the conductive wire 16a forming the coil conductor 16 with an insulating material, the insulation between the wound coil conductors 16 and between the coil conductor 16 and the magnetic body portion 14 can be ensured.
The insulating film 18 is not formed on the first exposed portion 24a and the second exposed portion 24b of the conductor wire 16a forming the coil conductor 16, respectively. Therefore, it is easy to form the external electrodes 40 by plating. Also, the resistance value in the electrical connection between the coil conductor 16 and the external electrode 40 can be made smaller.

The insulating material of the insulating film 18 is not particularly limited, but examples thereof include polyurethane resin, polyester resin, epoxy resin, and polyamide-imide resin. Preferably, the insulating film 18 is made of polyamide-imide resin.

The thickness of the insulating film 18 is preferably 2 μm or more and 10 μm or less.

As shown in FIG. 7B, a plurality of concave portions 28 are formed on a surface 26a1 on the first main surface 12a side and a surface 26a2 on the second main surface 12b side of the first lead-out portion 22a of the conductor 16a of the coil conductor 16. are formed respectively. Metal magnetic particles 14 a and insulating film 18 are arranged in these concave portions 28 . Alternatively, only the metal magnetic particles 14a are arranged in the concave portions 28 . At this time, when the metal magnetic particles 14a are arranged in the concave portions 28, the metal magnetic particles 14a are formed on the surface 26a1 of the first lead-out portion 22a on the side of the first main surface 12a and on the side of the second main surface 12b. It may or may not penetrate the insulating film 18 formed on the surface 26a2.
Similarly, a plurality of recesses 28 are formed on a surface 26b1 of the first main surface 12a and a surface 26b2 on the second main surface side of the second lead-out portion 22b of the conductor 16a in the coil conductor 16, respectively. Metal magnetic particles 14 a and insulating film 18 are arranged in these concave portions 28 . Alternatively, only the metal magnetic particles 14a are arranged in the concave portions 28 . At this time, when the metal magnetic particles 14a are arranged in the concave portions 28, the metal magnetic particles 14a are formed on the surface 26b1 of the second lead-out portion 22b on the side of the first main surface 12a and on the side of the second main surface 12b. It may or may not penetrate the insulating film 18 formed on the surface 26b2.

Moreover, it is preferable that the insulating film 18 is not disposed on exposed portions (exposed surfaces) of the first exposed portion 24a and the second exposed portion 24b of the coil conductor 16 on both end surfaces 12e and 12f of the element body 12. . Thereby, the coil conductor 16 and the external electrode 40 can be directly electrically connected, so that the electrical connection resistance between the coil conductor 16 and the external electrode 40 can be reduced.

Furthermore, in the metal magnetic particles 14 a that are in contact with the external electrodes 40 , the average thickness of the insulating coatings that are in contact with the external electrodes 40 is preferably smaller than the average thickness of the insulating coatings that are not in contact with the external electrodes 40 . As a result, when the external electrodes 40 are formed by plating, the first lead-out portion 22a and the second lead-out portion 22b of the coil conductor 16 exposed at the first end surface 12e and the second end surface 12f of the base body 12 are The metal magnetic particles 14a located in the periphery can be intensively energized to grow the plating.

The structure around the exposed surface of the lead-out portion of the coil conductor 16 exposed on the surface of the element body 12 may be configured as described below.

FIG. 8 is an enlarged cross-sectional view showing a first modification of the structure around the lead-out portion of the coil conductor 16. As shown in FIG.
As shown in FIG. 8, in the first lead-out portion 22a and the second lead-out portion 22b of the coil conductor 16, an insulating film removed portion 30 having no insulating film 18 toward both end surfaces 12e and 12f of the element body 12 is removed. is formed. A plurality of recesses 28 are formed in a surface 26a1 on the first main surface 12a side and a surface 26a2 on the second main surface 12b side of the first lead-out portion 22a of the coil conductor 16. Magnetic particles 14a are arranged. Similarly, a plurality of recesses 28 are formed in a surface 26b1 on the first main surface 12a side and a surface 26b2 on the second main surface 12b side of the second lead-out portion 22b of the coil conductor 16. , metal magnetic particles 14a are arranged. Therefore, the metal magnetic particles 14 a are directly arranged in the recess 28 without penetrating the insulating film 18 in the insulating film-removed portion 30 .
As described above, the insulating film 18 acts as a cushion when forming the concave portion 28 on the surface of the coil conductor 16 with the metal magnetic particles 14a. By removing the film 18, the recess 28 can be easily formed in the surface of the coil conductor 16. FIG.
Moreover, it is preferable that a part of the external electrode 40 is arranged in the insulating film removed portion 30 . Thereby, the bonding strength between the coil conductor 16 and the external electrode 40 can be further improved.

FIG. 9 is an enlarged cross-sectional view showing a second modification of the structure around the lead-out portion of the coil conductor 16. As shown in FIG.
In the second modification around the lead-out portion of the coil conductor 16, as shown in FIG. An insulating film removed portion 30 having no insulating film 18 is formed toward both end faces 12e and 12f of the element body 12 in 22a and the second lead-out portion 22b. Further, minute irregularities 32 are formed on the surfaces of the exposed portions of the first exposed portion 24a and the second exposed portion 24b of the coil conductor 16 on both end faces 12e and 12f of the element body 12, respectively. As a result, the contact surface area between the coil conductor 16 and the external electrode 40 can be increased, so that the bonding strength between the coil conductor 16 and the external electrode 40 can be further improved.

FIG. 10 is an enlarged cross-sectional view showing a third modification of the structure around the lead-out portion of the coil conductor 16. As shown in FIG.
In the third modification around the lead-out portion of the coil conductor 16, as shown in FIG. An insulating film removed portion 30 having no insulating film 18 is formed toward both end faces 12e and 12f of the element body 12 in 22a and the second lead-out portion 22b. Further, recesses 34 are formed in the element body 12 around the exposed portions on both end surfaces 12e and 12f of the element body 12 of the first exposed portion 24a and the second exposed portion 24b of the coil conductor 16. . In the recessed portion 34, the average distance between the coil conductor 16 and the magnetic body portion 14 increases in the direction in which the first lead-out portion 22a and the second lead-out portion 22bd of the coil conductor 16 are led out to the end surfaces 12e and 12f. It is formed to be As a result, the external electrode 40 fills the recesses 34 formed in the periphery of the exposed portions of the first exposed portion 24a and the second exposed portion 24b of the coil conductor 16 on both end surfaces 12e and 12f of the element body 12. Since the coil conductors 16 and the external electrodes 40 can be arranged in such a manner that the coil conductors 16 and the external electrodes 40 are arranged in such a manner that the bonding strength is increased.

FIG. 11 is an enlarged cross-sectional view showing a fourth modification of the structure around the lead-out portion of the coil conductor 16. As shown in FIG.
In the fourth modified example of the periphery of the lead-out portion of the coil conductor 16, as shown in FIG. An insulating film removed portion 30 having no insulating film 18 is formed toward both end faces 12e and 12f of the element body 12 in 22a and the second lead-out portion 22b. Furthermore, the surfaces of both end surfaces 12e and 12f of the element body 12, and the exposed portions of the first exposed portion 24a and the second exposed portion 24b of the coil conductor 16 on both end surfaces 12e and 12f of the element body 12 (exposed surfaces ) in the pressing direction x, a groove portion 36 is formed with a predetermined width in the width direction y. The depth of the groove 36 with respect to the element body 12 is preferably 5 μm or more and 100 μm or less. As a result, the external electrodes 40 are exposed on both end surfaces 12e and 12f of the element body 12 and on both end surfaces 12e and 12f of the first exposed portion 24a and the second exposed portion 24b of the coil conductor 16. Since it can be arranged so as to fill the grooves 36 formed on the surface (exposed surface), the bonding strength between the coil conductor 16 and the external electrode 40 can be further improved.

7 to 11, the lead portions 22a and 22b of the coil conductor 16 are led out to both end faces 12e and 12f. Although the exposed structure has been described, it is not limited to this. As shown in FIG. The structure around the exposed surfaces where the lead portions 222a and 222b are exposed on the side of the second principal surface 212b may also have the same structure.

(D) External Electrodes External electrodes 40 are arranged on the first end face 12e side and the second end face 12f side of the element body 12 . The external electrode 40 has a first external electrode 40a and a second external electrode 40b.

The first external electrode 40a is arranged on the surface of the first end face 12e of the base body 12. As shown in FIG. The first external electrode 40a extends from the first end surface 12e to partially cover the first main surface 12a, the second main surface 12b, the first side surface 12c, and the second side surface 12d. It may be formed so as to cover the first end surface 12e and extends from the second main surface 12b to cover a part of each of the first end surface 12e and the second main surface 12b. may Further, as shown in FIG. 5, when the first lead-out portion 122a of the coil conductor 116 is exposed from the first main surface 112a, the first external electrode 40a partially covers the first main surface 112a. You may form so that it may cover. Furthermore, as shown in FIG. 6, when the first lead-out portion 222a of the coil conductor 216 is formed and exposed from the second main surface 212b, the first external electrode 40a is formed on the second main surface 212b. 212b may be formed so as to cover a portion thereof. In this case, the first external electrode 40 a is electrically connected to the first lead-out portion 22 a of the coil conductor 16 .
The second external electrode 40b is arranged on the surface of the second end face 12f of the base body 12. As shown in FIG. The second external electrode 40b extends from the second end surface 12f to partially cover the first main surface 12a, the second main surface 12b, the first side surface 12c, and the second side surface 12d. It may be formed so as to cover the second end surface 12f and extends from the second main surface 12b to cover a part of each of the second end surface 12f and the second main surface 12b. may Further, as shown in FIG. 5, when the second lead-out portion 122b of the coil conductor 116 is exposed from the first main surface 112a, the second external electrode 40b partially covers the first main surface 112a. You may form so that it may cover. Furthermore, as shown in FIG. 6, when the second lead-out portion 222b of the coil conductor 216 is formed and exposed from the second main surface 212b, the second external electrode 40b is formed on the second main surface 212b. 212b may be formed so as to cover a portion thereof. In this case, the second external electrode 40b is electrically connected to the second lead-out portion 22b of the coil conductor 16. As shown in FIG.

The thickness of each of the first external electrode 40a and the second external electrode 40b is not particularly limited, but can be, for example, 1 μm or more and 50 μm or less, preferably 5 μm or more and 20 μm or less.

The first external electrode 40a includes a first base electrode layer 42a and a first plated layer 44a disposed on the surface of the first base electrode layer 42a. Similarly, the second external electrode 40b includes a second base electrode layer 42b and a second plated layer 44b arranged on the surface of the second base electrode layer 42b.

The first base electrode layer 42 a is arranged on the surface of the first end surface 12 e of the element body 12 . Note that the first base electrode layer 42a extends from the first end surface 12e to form part of each of the first main surface 12a, the second main surface 12b, the first side surface 12c and the second side surface 12d. , or may extend from the first end face 12e and cover a part of each of the second main faces 12b. Moreover, as shown in FIG. 5, when the first lead-out portion 122a of the coil conductor 116 is exposed from the first main surface 112a, the first base electrode layer 42a is formed on the first main surface 112a. You may form so that a part may be covered. Furthermore, as shown in FIG. 6, when the first lead-out portion 222a of the coil conductor 216 is formed and exposed from the second main surface 212b, the first base electrode layer 42a is formed on the second main surface 212b. may be formed so as to cover a part of the
Also, the second base electrode layer 42b is arranged on the surface of the first end surface 12e of the element body 12 . The second base electrode layer 42b extends from the first end surface 12e to part of each of the first main surface 12a, the second main surface 12b, the first side surface 12c and the second side surface 12d. or extend from the second end surface 12f to cover a part of the second main surface 12b. Further, as shown in FIG. 5, when the second lead-out portion 122b of the coil conductor 116 is exposed from the first main surface 112a, the second base electrode layer 42b is part of the first main surface 112a. may be formed to cover the Furthermore, as shown in FIG. 6, when the second lead-out portion 222b of the coil conductor 216 is formed to be exposed from the second main surface 212b, the second base electrode layer 42b is formed on the second main surface 212b. may be formed so as to cover a part of the

The first base electrode layer 42a and the second base electrode layer 42b are made of a conductive material, preferably one or more metal materials selected from Au, Ag, Pd, Ni and Cu. The first base electrode layer 42a and the second base electrode layer 42b may each be formed as a plated electrode, or may be formed by applying a conductive paste or by sputtering.

The average thickness of the first base electrode layer 42a and the second base electrode layer 42b is, for example, 10 μm.

The first plated layer 44a is arranged to cover the first base electrode layer 42a. Specifically, the first plated layer 44a is arranged so as to cover the first base electrode layer 42a arranged on the first end surface 12e, and extends from the first end surface 12e to form the first electrode layer 44a. It may be arranged so as to cover the surface of the first base electrode layer 42a arranged on the main surface 12a, the second main surface 12b, the first side surface 12c and the second side surface 12d. It may be arranged so as to cover the first base electrode layer 42a extending from 12e and arranged so as to cover a part of the second main surface 12b. Moreover, as shown in FIG. 5, when the first lead-out portion 122a of the coil conductor 116 is exposed from the first main surface 112a, the first plated layer 44a is arranged on the first main surface 112a. It may be formed to cover the first base electrode layer 42a. Furthermore, when the first lead-out portion 222a of the coil conductor 216 is formed and directly led out to the second main surface 212b as shown in FIG. It may be formed to cover 42a.
The second plated layer 44b is arranged to cover the second base electrode layer 42b. Specifically, the second plated layer 44b is arranged so as to cover the second base electrode layer 42b arranged on the second end surface 12f, extends from the second end surface 12f, and forms the first electrode layer 44b. It may be arranged so as to cover the surface of the second base electrode layer 42b arranged on the main surface 12a, the second main surface 12b, the first side surface 12c and the second side surface 12d, and the second end surface. It may be arranged so as to cover the second base electrode layer 42b extending from 12f and arranged so as to cover a part of the second main surface 12b. Moreover, as shown in FIG. 5, when the second lead-out portion 122b of the coil conductor 116 is exposed from the first main surface 112a, the second plating layer 44b is arranged on the first main surface 112a. It may be formed to cover the second base electrode layer 42b. Furthermore, as shown in FIG. 6, when the second lead-out portion 222b of the coil conductor 216 is formed and directly led out to the second main surface 212b, the second base electrode arranged on the second main surface 212b It may be formed to cover the layer 42b.

The metal material of the first plating layer 44a and the second plating layer 44b includes, for example, at least one selected from Cu, Ni, Ag, Sn, Pd, Ag—Pd alloy, Au, and the like.

The first plating layer 44a and the second plating layer 44b may be formed in multiple layers.
The first plating layer 44a has a two-layer structure of a first Ni plating layer 46a and a first Sn plating layer 48a on the surface of the first Ni plating layer 46a. The second plating layer 44b has a two-layer structure of a second Ni plating layer 46b and a second Sn plating layer 48b on the surface of the second Ni plating layer 46b.

The average thickness of the first Ni plating layer 46a and the second Ni plating layer 46b is, for example, 5 μm.
Also, the average thickness of the first Sn-plated layer 48a and the second Sn-plated layer 48b is, for example, 10 μm.

The first external electrode 40a and the second external electrode 40b may be provided with the following configuration.
For example, the first base electrode layer 42a and the second base electrode layer 42b may be Ag-containing resin electrodes, or may be composed of a sputtered Ag layer, a Cu sputtered layer, or a Ti sputtered layer. Glass frit may be contained when the first base electrode layer 42a and the second base electrode layer 42b are composed of Ag-containing resin electrodes. Further, when the first base electrode layer 42a and the second base electrode layer 42b are formed by sputtering, a Cu sputter layer may be formed on the Ti sputter layer.
Further, the outermost layers of the first plating layer 44a and the second plating layer 44b may be composed only of the Sn plating layers 48a and 48b.
Further, an Ag plating layer or a Ni plating layer may be formed on the base body 12 without forming the first base electrode layer 42a and the second base electrode layer 42b.

(E) Protective Layer In the present embodiment, the protective layer 50 includes the first exposed portion 24a exposed on the first end surface 12e of the element body 12 and the second exposed portion 24b exposed on the second end surface 12f. It is provided on the surface of the base body 12 except for the . The protective layer 50 is made of, for example, a highly electrically insulating resin material such as acrylic resin, epoxy resin, or polyimide. In addition, although the protective layer 50 is provided in the present invention, it is not limited to this and may not necessarily be provided.

Assuming that the dimension in the length direction z of the coil component 10 is the L dimension, the L dimension is preferably 1.0 mm or more and 12.0 mm or less. Assuming that the dimension of the coil component 10 in the width direction y is the W dimension, the W dimension is preferably 0.5 mm or more and 12.0 mm or less. The dimension T of the coil component 10 in the pressing direction x is preferably 0.5 mm or more and 6.0 mm or less.

2. Method for Manufacturing Coil Component Next, a method for manufacturing the coil component will be described.

(A) Preparation of Metal Magnetic Particles First, metal magnetic particles are prepared. Here, the metal magnetic particles are not particularly limited. A soft magnetic material powder can be used. Also, the material form of the metal magnetic particles is preferably amorphous with good soft magnetic properties, but is not particularly limited, and may be crystalline.

Although the average particle size of the metal magnetic particles is not particularly limited, it is preferable to use two or more kinds of metal magnetic particles having different average particle sizes. That is, the metal magnetic particles are dispersed in the resin material. Therefore, from the viewpoint of improving the filling efficiency of the metal magnetic particles, for example, the first metal magnetic particles having an average particle size of 10 μm or more and 40 μm or less and the second metal magnetic particles having an average particle size of 1 μm or more and 20 μm or less It is preferred to use metallic magnetic particles having a different average particle size than the magnetic particles.

(B) Formation of insulating coating Next, the surfaces of the metal magnetic particles are coated with an insulating coating. Here, when the insulating coating is formed by a mechanical method, the metal magnetic particles and the insulating material powder are placed in a rotating container, and the particles are combined by a mechanochemical treatment, thereby insulating the surface of the magnetic powder. A coating can be applied.

(C) Fabrication of Magnetic Sheet Next, a resin material is prepared. The resin material is not particularly limited, and for example, epoxy resin, phenol resin, polyester resin, polyimide resin, polyolefin resin, etc. can be used.

Subsequently, metal magnetic particles coated with an insulating film and other filler components (glass material, ceramic powder, ferrite powder, etc.) are mixed with a resin material to form a slurry, which is then molded using a doctor blade method or the like. It is processed and then dried to produce a magnetic sheet having a thickness of 50 μm or more and 300 μm or less in which the filler component is dispersed in the resin material.

(D) Fabrication of Aggregate Substrate Next, an α-turn-shaped coil conductor 16 made of a rectangular wire coated with an insulating film 18 and made of Cu wire is prepared. If necessary, the insulating film 18 in a region of 50 μm from the end of the coil conductor 16 is removed with nippers. As a result, an insulating film-removed portion 30, which is a portion not covered with the insulating film 18, is formed in an annular shape with the extending direction of the coil conductor 16 as the central axis. The insulating film 18 can be removed by burning off by heating, or by dissolving with a chemical solution or laser. At this time, recesses 28 may be provided in advance in the first lead-out portion 22 a and the second lead-out portion 22 b of the coil conductor 16 .

Subsequently, the element body 12 in which the coil conductor 16 is embedded is manufactured.

FIG. 12 is a manufacturing process diagram showing an embodiment of manufacturing the first compact in the coil component manufacturing method. FIG. 13 is a manufacturing process diagram showing an embodiment of manufacturing an aggregate substrate in a method of manufacturing a coil component.

First, as shown in FIG. 12(a), a first mold 60 is prepared, and coil conductors 16 are arranged on the first mold 60 in a matrix.

Next, as shown in FIG. 12(b), a first magnetic sheet 70a of a mixture containing first metal magnetic particles, second metal magnetic particles and a resin material is placed on these coil conductors 16. , and then, as shown in FIG. 12(c), a second mold 62 is arranged on the upper surface side of the first magnetic sheet 70a. Then, as shown in FIG. 12(d), the first magnetic sheet 70a is sandwiched between the coil conductor 16 on the first die 60 and the second die 62 to perform primary press molding. By this primary press molding, at least a portion of the coil conductor 16 is embedded in the sheet, and the interior of the coil conductor 16 is filled with the mixture to produce the first compact 72 .

Next, as shown in FIG. 13A, the first molded body 72 embedded with the coil conductor 16 obtained by primary press molding is removed from the second mold 62, and the first molded body 72 is removed. The first molding 72 is placed on the first mold 60 by turning it over. Then, another second magnetic sheet 70b is overlaid on the surface where the coil conductor 16 is exposed. Next, as shown in FIG. 13(b), a third mold 64 is arranged on the upper surface side of the second magnetic sheet 70b. Then, as shown in FIG. 13(c), the second magnetic sheet 70b is sandwiched between the first molded body 72 on the first mold 60 and the third mold 64, and secondary pressing is performed. conduct.

The third mold 64 has projections 64a and 64b at portions corresponding to the drawers. At the time of secondary pressing, the protrusions 64a and 64b can apply more pressure to the periphery of the lead-out portion via the second magnetic sheet. As a result, in the secondary press shown in FIG. 13(c), the metal magnetic particles 14a and the insulating film 18 are pressed on the surface of the first lead-out portion 22a and the surface of the second lead-out portion 22b of the coil conductor 16. can let you in.
In the secondary pressing, the metal magnetic particles can be arranged so as to be embedded by adjusting the pressure at the time of pressurization or by providing concave portions in advance on the surface of the lead portion.

Subsequently, after the secondary pressing, as shown in FIG. 13(d), the third mold 64 is removed, and the entire coil conductor 16 is formed into the first magnetic sheet 70a and the second magnetic sheet 70b. An aggregate base (second compact) 74 embedded therein is produced.

(E) Fabrication of base body Next, the first mold 60 and the third mold 64 are separated, and as shown in FIG. Using a tool, the aggregate substrate 74 is cut along the cutting lines into individual pieces, whereby the first exposed portion 24a and the second exposed portion 24b of the coil conductor 16 are exposed from both end surfaces of the element body 12. The element body 12 in which the coil conductor 16 is embedded is produced as described above. Dividing the aggregate base 74 into the individual elements 12 can be performed using a dicing blade, various laser devices, a dicer, various cutting tools, and metal molds. In a preferred embodiment, the cut surface of each blank 12 is barrel polished.

Next, a protective layer 50 is formed on the entire surface of the element obtained above. The protective layer 50 can be formed by electrodeposition coating, a spray method, a dipping method, or the like.

By irradiating a laser around the locations where the first exposed portion 24a and the second exposed portion 24b are arranged in the coil conductor 16 of the element body 12 coated with the protective layer 50 obtained above, the coil conductor 16 Insulating film 18 around locations where first exposed portion 24a and second exposed portion 24b are arranged, insulating film covering metal magnetic particles 14a and metal magnetic particles 14a, and protective layer 50 are removed. and melt the metal magnetic particles 14a. As for the method of removing the protective layer 50, blasting, polishing, or the like can be used instead of laser irradiation.

(F) Formation of External Electrodes Next, a first external electrode 40a is formed on the first end surface 12e of the element body 12, and a second external electrode 40b is formed on the second end surface 12f.

First, the element body 12 is plated with Cu by electrolytic barrel plating to form a base electrode layer. Subsequently, a Ni plating layer is formed on the surface of the underlying electrode layer by Ni plating, and a Sn plating layer is further formed by Sn plating to form the external electrodes 40 . As a result, the first exposed portion 24a of the coil conductor 16 is electrically connected to the first external electrode 40a, and the second exposed portion 24b of the coil conductor 16 is electrically connected to the second external electrode 40b. Connected.

The coil component 10 is manufactured as described above.

The metal magnetic particles 14a of the magnetic portion 14 may be arranged in recesses formed on the surface of the conductor wire 16a in the winding portion 20 of the coil conductor 16 inside the element body 12 .

By arranging the metal magnetic particles 14a of the magnetic body portion 14 in the concave portions 28 formed on the surface of the first exposed portion 24a and the surface of the second exposed portion 24b of the coil conductor 16 from which the insulating film 18 has been removed, The bonding strength between the magnetic portion 14 and the coil conductor 16 can be improved by the anchor effect caused by the metal magnetic particles 14a.
Moreover, since the coil conductor 16 and the external electrode 40 are directly joined, the contact resistance can be reduced.

As described above, the embodiments of the present invention are disclosed in the above description, but the present invention is not limited thereto.
That is, without departing from the scope of the technical idea and purpose of the present invention, various modifications can be made to the above-described embodiments in terms of mechanism, shape, material, quantity, position, arrangement, etc. and they are included in the present invention.

10 coil component 12, 112, 212 element body 12a, 112a, 212a first main surface 12b, 112b, 212b second main surface 12c, 112c, 212c first side surface 12d, 112d, 212d second side surface 12e, 112e, 212e first end face 12f, 112f, 212f second end face 14, 114, 214 magnetic body part 14a metal magnetic particle 16, 116, 216 coil conductor 18 insulating film 20, 120, 220 winding part 22a, 122a , 222a first lead portions 22b, 122b, 222b second lead portions 24a, 124a first exposed portions 24b, 124b second exposed portions 26a1, 26b1 first surfaces 26a2, 26b2 second surfaces 28 recesses 30 Insulating film removed portion 32 Concavo-convex portion 34 Recessed portion 36 Groove portion 40 External electrode 40a First external electrode 40b Second external electrode 42a First base electrode layer 42b Second base electrode layer 44a First plated layer 44b Second plating layer 46a first Ni plating layer 46b second Ni plating layer 48a first Sn plating layer 48b second Sn plating layer 50 protective layer 60 first mold 62 second mold 64 third Metal molds 64a, 64b Protrusions 70a First magnetic sheet 70b Second magnetic sheet 72 First molded body 74 Assembled substrate x Pressure direction (height direction)
y width direction z length direction

Claims (14)

a coil conductor formed of a conductive wire covered with an insulating film;
a magnetic body portion containing metal magnetic particles and a resin;
and a body with
an external electrode disposed on the surface of the element body and electrically connected to an exposed surface of the lead-out portion of the coil conductor exposed on the surface of the element body;
A coil component comprising
A coil component, wherein the metal magnetic particles are arranged in a recess on the surface of the lead wire of the lead-out portion of the coil conductor. An insulating film removal portion not having the insulating film is provided at the lead-out portion of the coil conductor,
2. The coil component according to claim 1, wherein said insulating film-removed portion has said recess, and said metal magnetic particles are arranged in said recess. 3. The coil component according to claim 2, wherein said insulating film-removed portion and said external electrode are directly connected. 4. The coil component according to claim 1, wherein said metal magnetic particles are coated with an insulating coating. In the metal magnetic particles that are in contact with the external electrode, the average thickness of the insulating coating that is in contact with the external electrode is thinner than the average thickness of the insulating coating that is not in contact with the external electrode. 5. The coil component according to claim 4. 6. The coil component according to any one of claims 1 to 5, wherein the exposed surface has uneven portions. The base body around the exposed surface has a recessed portion such that the average distance between the coil conductor and the magnetic body portion increases in the direction in which the coil conductor is pulled out to the surface of the base body. The coil component according to any one of claims 1 to 6, characterized by: characterized in that the exposed surface has a groove with a depth of 5 μm or more and 100 μm or less,
The coil component according to any one of claims 1 to 7. 9. The coil component according to claim 1, wherein said external electrodes are plated electrodes. The metal magnetic particles include first metal magnetic particles and second metal magnetic particles,
The average particle size of the second metal magnetic particles is smaller than the average particle size of the first metal magnetic particles,
10. The coil component according to claim 1, wherein said first metal magnetic particles have an average particle size of 10 [mu]m or more and 40 [mu]m or less. 11. The coil component according to claim 10, wherein said second metal magnetic particles have an average particle diameter of 5 [mu]m or less. 12. The coil component according to claim 10, wherein said second metal magnetic particles have an average particle size of 1 [mu]m or more. 2. The coil component according to claim 1, wherein said metal magnetic particles are arranged in said recess via said insulating film. 2. The coil component according to claim 1, wherein said metal magnetic particles penetrate said insulating film and are arranged in said recess.

Images