WO2023188683A1

WO2023188683A1 - Electronic component and production method for same

Info

Publication number: WO2023188683A1
Application number: PCT/JP2023/000464
Authority: WO
Inventors: 大輔大塚; 祥文間木
Original assignee: 株式会社村田製作所
Priority date: 2022-03-28
Filing date: 2023-01-11
Publication date: 2023-10-05
Also published as: JPWO2023188683A1

Abstract

The present invention provides an electronic component that is capable of reducing stress applied to an element due to flexibility in a substrate, while suppressing an increase in direct current resistance. The electronic component comprises an element and an external electrode provided to the element, wherein: the element is provided with a first end surface, a second end surface that is opposite from the first end surface, and a bottom surface that is perpendicular to the first end surface and the second end surface; the external electrode is provided with a first external electrode that is provided to the first end surface side and a second external electrode that is provided to the second end surface side; the first external electrode is provided with a metal electrode that is provided to at least a part of the bottom surface and a resin electrode that covers a part of the portion of the metal electrode which is provided to the bottom surface; and on the bottom surface, the metal electrode has an exposed portion that is exposed from the resin electrode.

Description

Electronic components and their manufacturing methods

The present invention relates to an electronic component and a method for manufacturing the same.

Conventionally, as a coil component, there is one described in Japanese Unexamined Patent Publication No. 2021-40160 (Patent Document 1). This coil component includes an element body and an external electrode provided on the surface of the element body. The external electrode includes a metal electrode and a resin electrode that covers the entire surface of the metal electrode. At this time, in consideration of the increase in direct current resistance, the resin electrode is provided so that the end portion is thick and the other portions are thinner. Thereby, stress is relaxed and crack generation is suppressed.

Japanese Patent Application Publication No. 2021-40160

However, in the above-mentioned coil component, the high resistance resin electrode covers the entire surface of the metal electrode, so the effect of reducing DC resistance is insufficient. In addition, in coil components, it is difficult to specify in detail the path through which direct current flows, and it is difficult to reduce direct current resistance by adjusting the thickness of the resin electrode.

An object of the present disclosure is to provide an electronic component that can reduce deflection stress while suppressing an increase in DC resistance, and a method for manufacturing the same.

In order to solve the above problems, an electronic component that is one aspect of the present disclosure includes:
The element body and
an external electrode provided on the element body,
The element body is
a first end surface;
a second end face opposite to the first end face;
a bottom surface perpendicular to the first end surface and the second end surface,
The external electrode is
a first external electrode provided on the first end surface side;
a second external electrode provided on the second end surface side,
The first external electrode is
a metal electrode provided on at least a portion of the bottom surface;
a resin electrode that covers a part of the bottom surface of the metal electrode,
On the bottom surface, the metal electrode has an exposed portion exposed from the resin electrode.

The exposed portion of the metal electrode is the portion of the metal electrode that is not covered by the resin electrode. The exposed portion includes not only the portion exposed to the outside of the metal electrode, but also the portion covered with a member other than the resin electrode, such as a metal film or a plating layer.

According to the embodiment, only a part of the metal electrode provided on the bottom surface is covered with the resin electrode, so when electronic components are mounted on the bottom surface side, an increase in DC resistance due to the provision of the resin electrode can be avoided. The stress applied to the element body due to the deflection of the substrate (hereinafter referred to as deflection stress) can be reduced while suppressing the stress.

In one embodiment, the electronic component further includes a plating layer that covers at least a portion of the first external electrode on the bottom surface.

According to the embodiment, when electronic components are mounted on the bottom surface side, the electronic components are soldered through the plating layer, so that adhesiveness is improved. Furthermore, the plating layer suppresses solder from corroding into the electronic component.

In one aspect, a direction in which the first end surface and the second end surface face each other is an L direction, and
The direction perpendicular to the L direction on the bottom surface is defined as the W direction,
On the bottom surface,
The exposed portion and the resin electrode are arranged side by side in the W direction.

According to the embodiment, the deflection stress is further reduced.

In one aspect, a direction in which the first end surface and the second end surface face each other is an L direction, and
The direction perpendicular to the L direction on the bottom surface is defined as the W direction,
The exposed portions are provided at both ends of the bottom surface in the W direction.

In one aspect, a direction in which the first end surface and the second end surface face each other is an L direction, and
The direction perpendicular to the L direction on the bottom surface is defined as the W direction,
On the bottom surface,
The resin electrodes are provided so as to sandwich the exposed portion from both sides in the W direction.

According to the embodiment, the number of current paths that do not involve resin electrodes can be increased, and an increase in DC resistance can be further suppressed.

In one aspect, in the bottom surface,
The maximum width of the resin electrode in the W direction is wider than the maximum width of the exposed portion adjacent to the resin electrode in the W direction.

According to the embodiment, the deflection stress is further reduced.

In one aspect, in the bottom surface,
The maximum width of the exposed portion sandwiched between the two resin electrodes is 10 μm or more and 160 μm or less.

According to the embodiment, it is easy to balance the effect of reducing deflection stress and the effect of suppressing increase in DC resistance.

In one aspect,
In the first external electrode,
The metal electrode is further provided on a portion of at least one of the first end face and the second end face,
The resin electrode further covers a part of the portion provided on at least one of the first end surface and the second end surface of the metal electrode.

According to the embodiment, the deflection stress is further reduced.

In one aspect,
The direction in which the first end surface and the second end surface face each other is an L direction,
A direction perpendicular to the L direction on the bottom surface is a W direction, and
A direction perpendicular to both the L direction and the W direction is the T direction,
In the first external electrode,
The resin electrode provided on a portion of at least one of the first end surface and the second end surface is 1 of the height of the element body in the T direction from the bottom surface side of the end surface on which the resin electrode is provided. /2 is provided in the area.

According to the embodiment, when electronic components are mounted on the bottom surface side, the direct current resistance can be further reduced while maintaining the effect of reducing deflection stress.

In one aspect,
The direction in which the first end surface and the second end surface face each other is an L direction,
A direction perpendicular to the L direction on the bottom surface is a W direction, and
A direction perpendicular to both the L direction and the W direction is the T direction,
The resin electrode provided on the bottom surface protrudes outward in the T direction from the surface of the metal electrode provided on the bottom surface.

According to the embodiment, when electronic components are mounted on the bottom surface side, solder can penetrate into the unevenness formed by the resin electrodes, and the connection strength between the circuit board and the electronic components can be improved. The plated layer also becomes difficult to peel off because the solder can penetrate into the unevenness formed by the resin electrode.

In one embodiment, the electronic component further includes a metal film that covers at least an exposed portion of the metal electrode exposed from the resin electrode.

In one embodiment, at least on the bottom surface, the surface of the resin electrode and the surface of the metal film are flush with each other.

According to the embodiment, when electronic components are mounted on the bottom surface side, positional displacement and tilting of the electronic components are reduced, and the electronic components are mounted with high precision.

In one aspect, the resin electrode provided on the bottom surface is symmetrical with respect to a straight line passing through the center of the bottom surface and extending in the L direction, which is a direction in which the first end surface and the second end surface face each other. be.
In one embodiment, the resin electrode provided on the bottom surface has a uniform thickness.

According to the embodiment, when electronic components are mounted on the bottom surface side, wobbling and tilting of the electronic components are reduced.

In one aspect,
The direction in which the first end surface and the second end surface face each other is an L direction,
A direction perpendicular to the L direction on the bottom surface is a W direction, and
A direction perpendicular to both the L direction and the W direction is the T direction,
In a cross section parallel to the TW plane formed by the straight line extending in the W direction and the straight line extending in the T direction and cutting the resin electrode,
The width of the first surface of the resin electrode provided on the bottom surface on the metal electrode side is narrower than the width of the second surface of the resin electrode on the opposite side to the first surface.

According to the embodiment, peeling of the plating layer from the contact portion between the metal electrode and the resin electrode is suppressed. In addition, the anchor effect acts to improve the bonding strength between the circuit board and the electronic component by solder.

In one embodiment, the electronic component may further include a coil provided inside the element body. The coil, the first external electrode, and the second external electrode are electrically connected.

According to the embodiment, since an increase in direct current resistance is suppressed, it is possible to reduce deflection stress while suppressing heat generation etc. even in a coil component through which a large current can flow.

Further, a method for manufacturing an electronic component, which is one aspect of the present disclosure, includes:
preparing an element body including a first end surface, a second end surface opposite to the first end surface, and a bottom surface perpendicular to the first end surface and the second end surface;
providing a first external electrode on the first end surface side;
a step of providing a second external electrode on the second end surface side; the step of providing the first external electrode;
forming a metal electrode on at least a portion of the bottom surface on the first end surface side;
forming a resin electrode that covers a part of the bottom surface of the metal electrode;
In the step of forming the resin electrode, an exposed portion of the metal electrode exposed from the resin electrode is formed.

According to the embodiment, in an electronic component including a metal electrode and a resin electrode, an exposed portion of the metal electrode that is exposed from the resin electrode can be formed.

The step of forming the resin electrode includes:
applying a conductive resin composition containing a photosensitive resin to at least a portion of the bottom surface of the metal electrode;
irradiating a part of the applied resin composition with laser light;
After the step of irradiating, the method may further include a step of removing the part or remainder of the resin composition.

According to the embodiment, a resin electrode with a desired shape and thickness can be formed with high precision.

After the step of forming the resin electrode,
The method may further include a step of forming a metal film that covers at least an exposed portion of the metal electrode exposed from the resin electrode.

According to the embodiment, an electronic component with lower DC resistance can be obtained.

According to the electronic component that is one aspect of the present disclosure, stress applied to the element body due to deflection of the substrate can be reduced while suppressing an increase in DC resistance.

It is a perspective view showing a 1st embodiment of a coil component. 2 is a sectional view taken along line XX in FIG. 1. FIG. 2 is a sectional view taken along YY line in FIG. 1. FIG. FIG. 3 is an exploded plan view of the coil component. FIG. 2 is a perspective view showing a coil component soldered to a pad provided on a circuit board. FIG. 2 is a cross-sectional view corresponding to the YY cross-sectional view of FIG. 1, showing a modification of the first embodiment of the coil component. FIG. 2 is a cross-sectional view corresponding to the YY cross-sectional view of FIG. 1, showing another modification of the first embodiment of the coil component. FIG. 2 is a cross-sectional view corresponding to the YY cross-sectional view of FIG. 1, showing still another modification of the first embodiment of the coil component. FIG. 3 is a perspective view showing a comparative coil component. FIG. 7 is a perspective view showing another comparative coil component. It is a perspective view showing a 2nd embodiment of a coil component. It is a perspective view which shows 3rd Embodiment of a coil component. It is a perspective view which shows 4th Embodiment of a coil component. It is a perspective view showing a 5th embodiment of a coil component. It is a perspective view showing a 6th embodiment of a coil component. It is a perspective view which shows the other modification of 6th Embodiment of a coil component. It is a perspective view showing still another modification of a 6th embodiment of a coil component. It is a perspective view showing a 7th embodiment of a coil component. It is a perspective view which shows 8th Embodiment of a coil component.

Hereinafter, an electronic component that is one aspect of the present disclosure will be described in detail using illustrated embodiments. Some of the drawings are schematic and may not reflect actual dimensions or proportions.

[First embodiment]
≪Configuration≫
FIG. 1 is a perspective view showing a first embodiment of a coil component, in which resin electrodes are hatched for convenience. FIG. 2A is a cross-sectional view taken along the line XX in FIG. 1, and is an LT cross-sectional view in which the resin electrode is cut. FIG. 2B is a YY cross-sectional view of FIG. 1, and a TW cross-sectional view of the resin electrode. FIG. 3 is an exploded plan view of the coil component, showing the view along the T direction from the bottom to the top. In FIG. 3, external electrodes are omitted for convenience.

The L direction is the length direction of the coil component 1, the W direction is the width direction of the coil component 1, and the T direction is the height direction of the coil component 1. Hereinafter, the forward direction of the T direction will be referred to as the upper side, and the opposite direction of the T direction will also be referred to as the lower side. The LT cross-sectional view shown in FIG. 2A is obtained by cutting the resin electrode along a plane parallel to a plane formed by a straight line extending in the L direction and a straight line extending in the T direction. The TW cross section shown in FIG. 2B is obtained by cutting the resin electrode along a plane parallel to a plane formed by a straight line extending in the T direction and a straight line extending in the W direction.

As shown in FIGS. 1, 2A, 2B, and 3, the coil component 1 includes an element body 10, a coil 20 provided inside the element body 10, and a coil 20 provided on the surface of the element body 10. The first external electrode 30A and the second external electrode 30B are electrically connected to the external electrode 20.

The coil component 1 is electrically connected to wiring on a circuit board (not shown) via first and second

external electrodes

30A and 30B. The coil component 1 is used, for example, as a noise removal filter, and is used in electronic devices such as personal computers, DVD players, digital cameras, TVs, mobile phones, and car electronics.

The coil 20 includes a plurality of coil wirings 22 stacked along the T direction, a via wiring 24 extending along the T direction and connecting adjacent coil wirings 22 in the T direction, and a coil wiring 22 in the top layer. The first lead-out conductor 23A is connected to the coil wiring 22 in the lowest layer, and the second lead-out conductor 23B is connected to the coil wiring 22 in the lowest layer.

Each coil wiring 22 is provided in each of the plurality of magnetic layers 21 except for the uppermost magnetic layer 21 and the lowermost magnetic layer 21. Each coil wiring 22 is wound along a plane parallel to the WL plane, arranged side by side in the T direction, and electrically connected in series to form a spiral. Each coil wiring 22 is wound with less than one turn. The via wiring 24 penetrates the magnetic layer 21 in the T direction. Coil wires 22 adjacent in the T direction are electrically connected in series via via wires 24 .

The first lead-out conductor 23A extends linearly from the end of the uppermost coil wiring 22 opposite to the end to which the via wiring 24 is connected to the first end surface 15A of the element body 10. The first lead-out conductor 23A is exposed from the first end surface 15A and electrically connected to the first external electrode 30A. The second lead conductor 23B extends linearly from the end of the lowest layer coil wiring 22 opposite to the end to which the via wiring 24 is connected to the second end surface 15B of the element body 10. The second lead conductor 23B is exposed from the second end surface 15B and electrically connected to the second external electrode 30B.

The coil wiring 22 and the first and second lead-out

conductors

23A and 23B are made of a conductive material such as Ag or Cu, for example. Neither the coil wiring 22 nor the first and second lead-out

conductors

23A and 23B are formed in the magnetic layer 21 disposed at the outermost position in the T direction of the laminate.

The number of layers of coil wiring 22 is not particularly limited. By firing this laminate, a coil 20 forming a spiral along the T direction is obtained. The number of stacked magnetic layers 21 disposed at the outermost position in the T direction of the laminate, that is, the magnetic layers 21 in which neither the coil wiring 22 nor the first or second lead-out

conductors

23A, 23B are formed, is also not particularly limited. , each may have two or more layers.

The element body 10 is formed into a substantially rectangular parallelepiped shape. The surface of the element body 10 includes a first end surface 15A, a second end surface 15B opposite to the first end surface 15A, a bottom surface 16 perpendicular to the first and second end surfaces 15A and 15B, and a top surface 17 opposite to the bottom surface 16. and a first side surface 18A and a second side surface 18B, which are located between the first end surface 15A and the second end surface 15B, and other than the bottom surface 16 and the top surface 17.

The expression that the bottom surface 16 is perpendicular to the first and second end surfaces 15A and 15B means that the angle formed by the bottom surface 16 and the first and second end surfaces 15A and 15B is 80° or more and 100° or less.

The first end surface 15A and the second end surface 15B face each other in the L direction. The bottom surface 16 and the top surface 17 face each other in the T direction. The first side surface 18A and the second side surface 18B face each other in the W direction.

Specifically, the L direction is a direction perpendicular to the first end surface 15A and the second end surface 15B. Specifically, the W direction is a direction perpendicular to the first side surface 18A and the second side surface 18B. The W direction is perpendicular to the L direction on the bottom surface. The W direction is also perpendicular to the L direction and parallel to the mounting surface (typically, the bottom surface 16) of the coil component 1. Specifically, the T direction is a direction perpendicular to the bottom surface 16 and the top surface 17. The T direction is orthogonal to the L direction and the W direction.

The bottom surface 16 is an area that is visible when the element body 10 is viewed from below. The bottom surface 16 is located between the first end surface 15A and the second end surface 15B, and is continuous with both the first end surface 15A and the second end surface 15B. The top surface 17 is an area that is visible when the element body 10 is viewed from above. In the illustrated example, the bottom surface 16 and the top surface 17 each have curved surface portions at the end portions on the first and second end surfaces 15A and 15B and on the first and second side surfaces 18A and 18B. The first side surface 18A is an area excluding the bottom surface 16 and the top surface 17 from the area visible when the element body 10 is viewed from the W direction. The second side surface 18B is also similar to the first side surface 18A. In the illustrated example, the first and second side surfaces 18A and 18B each have a curved surface portion at the end on the side of the first and second end surfaces 15A and 15B. The first end surface 15A is an area obtained by excluding the bottom surface 16, the top surface 17, and the two

side surfaces

18A and 18B from the region visible when the element body 10 is viewed from the L direction. The second end surface 15B is also similar to the first end surface 15A.

The height T of the element body 10 is the distance from the lowest end of the bottom surface 16 to the highest end of the top surface 17 along the T direction.

The element body 10 is provided with at least a first external electrode 30A and a second external electrode 30B. The first external electrode 30A is provided on the first end surface 15A side, and the second external electrode 30B is provided on the second end surface 15B side.

The first external electrode 30A includes a metal electrode 31 provided on at least a portion of the bottom surface, and a resin electrode 32 covering a portion of the portion provided on the bottom surface of the metal electrode 31. The metal electrode 31 is further provided on a portion of at least one of the first end surfaces 15A. The resin electrode 32 further covers a portion of the portion provided on at least one of the first end surfaces 15A of the metal electrode 31. The first external electrode 30A is electrically connected to one end of the coil 20.

The second external electrode 30B includes a metal electrode 31 provided on at least a portion of the bottom surface, and a resin electrode 32 covering a portion of the portion provided on the bottom surface of the metal electrode 31. The metal electrode 31 is further provided on a portion of at least one of the second end surfaces 15B. The resin electrode 32 further covers a portion of the portion provided on at least one of the second end surfaces 15B of the metal electrode 31. The second external electrode 30B is electrically connected to the other end of the coil 20.

The first external electrode 30A and the second external electrode 30B have plane symmetry with respect to the TW cross section passing through the center of the element body 10, and point symmetry with respect to the center of the element body 10.

Hereinafter, the configuration of the first external electrode 30A will be explained. The description regarding the first external electrode 30A can be applied to the second external electrode 30B by replacing the first end surface 15A with the second end surface 15B.

<Configuration of first external electrode>
The first external electrode 30A is a metal electrode 31 that covers the entire surface of the first end surface 15A, and the respective ends of the bottom surface 16, the top surface 17, the first side surface 18A, and the second side surface 18B on the first end surface 15A side; A resin electrode 32 covering a part of the metal electrode 31 is also provided.

The metal electrode 31 has a first exposed portion 311, a second exposed portion 312, and a third exposed portion 313. The resin electrode 32 has a first resin electrode 321 and a second resin electrode 322.

FIG. 4 shows a perspective view of a coil component soldered to a pad provided on a circuit board. As shown in FIG. 4, the coil component 1 is soldered to a pad 6 placed on a circuit board (not shown), with the bottom surface 16 serving as a mounting surface. For example, the current flows from the circuit board through the first external electrode 30A of the coil component 1, the coil 20, and the second external electrode 30B in this order. At this time, it was found that the current density was higher on the bottom surface 16 side than on the first end surface 15A side. Therefore, since the metal electrode 31 has the first, second, and third

exposed portions

311, 312, and 313 exposed from the resin electrode 32 at least on the bottom surface 16, the metal electrode 31 has the first, second, and third

exposed portions

311, 312, and 313 exposed from the resin electrode 32. An increase in DC resistance is more effectively suppressed.

Further, as shown in FIG. 4, when the coil component 1 is soldered to the circuit board on the first and second end surfaces 15A and 15B of the bottom surface 16, the deflection stress is applied to the first and second end surfaces of the bottom surface 16. It acts in a direction to bend the element body 10 in the T direction with the 15A and 15B sides as starting points. Therefore, by providing the first and

second resin electrodes

321 and 322 on the bottom surface 16, the deflection stress can be more effectively reduced.

That is, by providing the first and

second resin electrodes

321 and 322 on at least the bottom surface 16 and providing the first, second and third

exposed portions

311, 312 and 313 on the bottom surface 16, the first and

second resin electrodes

321 and 322 are provided on the bottom surface 16. Flexural stress can be effectively reduced while suppressing an increase in DC resistance due to the provision of

electrodes

321 and 322.

The first and

second resin electrodes

321 and 322 prevent cracking of the element body 10 due to the difference in thermal expansion between the element body 10 and the metal electrode 31, and cracking of the element body 10 due to the difference in thermal expansion between the solder and the element body 10 after mounting. Cracking can also be suppressed.

The metal electrode 31 is obtained, for example, by firing a conductive paste containing conductive particles such as Ag powder and glass. The metal electrode 31 is also called a base electrode and is directly connected to the coil 20. The metal electrode 31 is usually formed of the same material as the coil wiring 22 and the first and

second lead conductors

23A and 23B.

The thickness of the metal electrode 31 is, for example, 1 μm or more and 100 μm or less, and may be 5 μm or more and 80 μm or less. The thickness of the metal electrode 31 is the thickness at approximately the center of the metal electrode 31.

The approximate center of the metal electrode 31 is the center of the metal electrode 31 in the W direction in the TW cross section that bisects the metal electrode 31 provided on the bottom surface 16 or the top surface 17 of the first external electrode 30A in the L direction, or , is the center of the metal electrode 31 in the T direction in the LT cross section that bisects the metal electrode 31 provided on the first end surface 15A of the first external electrode 30A in the W direction. The thickness of the metal electrode 31 can be measured using an image taken with a scanning electron microscope (SEM) of the above-mentioned TW cross section or LT cross section exposed by polishing the coil component 1.

The metal electrode 31 in the first external electrode 30A and the metal electrode 31 in the second external electrode 30B may be the same or different in material and thickness.

The resin electrode 32 contains organic matter and has electrical conductivity. The resin electrode 32 is formed of, for example, a resin composition containing conductive particles such as Ag powder and a photosensitive resin.

The thickness of the resin electrode 32 is, for example, 1 μm or more and 100 μm or less, and may be 5 μm or more and 20 μm or less. The thickness of the resin electrode 32 is the thickness at approximately the center of the resin electrode 32.

The approximate center of the resin electrode 32 refers to the W direction of the resin electrode 32 in the TW cross section that bisects any one resin electrode 32 provided on the bottom surface 16 or the top surface 17 of the first external electrode 30A in the L direction. or the center of the resin electrode 32 in the T direction in the LT cross section that bisects any one resin electrode 32 provided on the first end surface 15A of the first external electrode 30A in the W direction. The thickness of the resin electrode 32 can be measured using a SEM image of the above-mentioned TW cross section or LT cross section exposed by polishing the coil component 1.

The thickness of the resin electrode 32 is uniform. In particular, when the thickness of the resin electrode 32 provided on the bottom surface 16 is uniform, wobbling and tilting of the coil component 1 can be suppressed when the coil component 1 is mounted on the bottom surface 16.

Uniform thickness means that the thickness of any one resin electrode 32 on any surface is within ±20% of the thickness at the end with respect to the thickness at approximately the center. The end of the resin electrode 32 refers to the middle (the above resin (equivalent to the approximate center of the electrode 32), or at three points that divide the resin electrode 32 into four equal parts in the T direction in the above LT cross section used to determine the approximate center of the resin electrode 32. This is one of the points excluding the middle (corresponding to the approximate center of the resin electrode 32 described above).

When a plurality of resin electrodes 32 are provided on the same surface, the material and thickness of the plurality of resin electrodes 32 may be the same or different. In this embodiment, the thickness of the first resin electrode 321 and the second resin electrode 322 is the same on any surface and the same on all surfaces.

The plurality of resin electrodes 32 having the same thickness on any plane means that the thickness of any one resin electrode 32 on that plane is within ±20% of the average thickness of the plurality of resin electrodes 32 on that plane. Say something.

The coil component 1 may include a plating layer 40 on the bottom surface 16 that covers at least a portion of the first external electrode 30A. The plating layer 40 is not directly connected to the coil 20, but is connected to the coil 20 via the first, second, and third

exposed portions

311, 312, 313 and/or the first and

second resin electrodes

321, 322. 1 is electrically connected to the external electrode 30A. The plating layer 40 is usually formed of a different material from the coil wiring 22 and the first and second lead-out

conductors

23A and 23B. The plating layer 40 is a thin metal film formed by surface treatment (typically, wet plating).

The metals included in the plating layer 40 are, for example, nickel and tin. The plating layer 40 may be one layer, or may be two or more layers. The plating layer 40 may have a laminated structure of a nickel plating layer and a tin plating layer. The thickness of each plating layer 40 is not particularly limited, and is, for example, 2 μm or more and 15 μm or less.

In FIG. 2A, the plating layer 40 is shown by a two-dot chain line. In FIG. 2A, the plating layer 40 covers the entire first external electrode 30A and is electrically connected to the first external electrode 30A. Therefore, due to the plating layer 40, the current that tends to concentrate on the bottom surface 16 side also flows on the first end surface 15A side, and flows to the circuit board via the solder fillet, for example. This further reduces the influence of increased DC resistance due to the provision of the first and

second resin electrodes

321 and 322. The plating layer 40 may cover only a portion of the first external electrode 30A.

<Detailed configuration of first external electrode>
Hereinafter, the resin electrode 32 and metal electrode 31 of the first external electrode 30A will be explained in detail.
The resin electrode 32 has two strip-shaped first and

second resin electrodes

321 and 322. The strip-shaped first and

second resin electrodes

321 and 322 each extend continuously in the L direction on the bottom surface 16, in the T direction on the first end surface 15A, and in the L direction on the top surface 17, in this order. . The first resin electrode 321 and the second resin electrode 322 are arranged side by side in the W direction with an interval between them.

The metal electrode 31 has first, second, and third

exposed portions

311, 312, and 313 exposed from the resin electrode 32. The first exposed portion 311 includes an end portion of the first side surface 18A on the first end surface 15A side, an end portion of the bottom surface 16 on the first end surface 15A side and on the first side surface 18A side, and a first end portion of the top surface 17 on the first end surface 15A side. They are located at an end on the end surface 15A side and on the first side surface 18A side, and at an end portion of the first end surface 15A on the first side surface 18A side. The second exposed portion 312 is located between the first resin electrode 321 and the second resin electrode 322, and is located in the L direction on the bottom surface 16, in the T direction on the first end surface 15A, and in the L direction on the top surface 17. It is a band-like shape that extends continuously in this order. The third exposed portion 313 includes an end portion of the second side surface 18B on the first end surface 15A side, an end portion of the bottom surface 16 on the first end surface 15A side and on the second side surface 18B side, and a first end portion of the top surface 17. It is located at the end on the end surface 15A side and on the second side surface 18B side, and at the end on the second side surface 18B side of the first end surface 15A.

The first exposed portion 311, the first resin electrode 321, the second exposed portion 312, the second resin electrode 322, and the third exposed portion 313 are arranged so that the resin electrode and the exposed portion are arranged in the W direction in this order from the first side surface 18A side. They are placed side by side, alternating.

By providing the first and

second resin electrodes

321 and 322 in a band shape from the bottom surface 16 to the top surface 17, the effect of reducing deflection stress becomes greater. Furthermore, by providing the second exposed portion 312 between the first resin electrode 321 and the second resin electrode 322, an increase in DC resistance can be more easily suppressed. In addition, since the first exposed portion 311 and the third exposed portion 313 are provided on the first and second side surfaces 18A and 18B of the element body 10, respectively, an increase in DC resistance is further suppressed.

Since the first and

second resin electrodes

321 and 322 are also provided on the first end surface 15A, when the coil component 1 is mounted with the bottom surface 16 as the mounting surface, as shown in FIG. will also be more likely to be suppressed. The fillet of the solder 5 is usually formed to cover at least a portion of the first external electrode 30A on the first end surface 15A. The first and

second resin electrodes

321 and 322 can suppress cracking of the solder 5 due to the difference in thermal expansion between the solder 5 and the element body 10.

The first resin electrode 321 and the second resin electrode 322 are provided in plane symmetry with respect to the LT cross section passing through the center of the element body 10. Thereby, wobbling and tilting of the coil component 1 during mounting can be easily suppressed.

The first, second, and third

exposed portions

311, 312, and 313 are a first metal portion 3101 provided on the bottom surface 16, a second metal portion 3102 provided on the first end surface 15A, and a second metal portion 3102 provided on the top surface 17, respectively. A third metal portion 3103 provided therein. The first and third

exposed portions

311 and 313 are also provided on the first end surface 15A side of the first and second side surfaces 18A and 18B, respectively. The first and

second resin electrodes

321 and 322 each include a first resin portion 3201 provided on the bottom surface 16, a second resin portion 3202 provided on the first end surface 15A, and a third resin portion provided on the top surface 17. A resin portion 3203 is provided. In the first external electrode 30A in FIG. 2A, the boundary between the first resin part 3201 and the second resin part 3202 and the boundary between the second resin part 3202 and the third resin part 3203 are shown by broken lines, respectively.

(First metal part and first resin part)
The first metal portion 3101 and the first resin portion 3201 will be described below.
Three first metal portions 3101 are provided. The three first metal portions 3101 are part of the first, second, and third

exposed portions

311, 312, and 313, respectively. Two first resin portions 3201 are provided. The two first resin portions 3201 are part of the first and

second resin electrodes

321 and 322, respectively. On the bottom surface 16, the first metal portions 3101 and the first resin portions 3201 are arranged alternately in the W direction. Two of the first metal parts 3101 are provided at both ends of the bottom surface 16 in the W direction.

The fact that the first metal portions 3101 and the first resin portions 3201 are arranged alternately in the W direction means that the boundary line BL _B between the first metal portions 3101 and the first resin portions 3201 is along the L direction. In other words, it is. The expression that the boundary line BL _B is along the L direction means that the acute angle θ between the boundary line BL _B and the L direction is 0° or more and 30° or less. The boundary line _BLB may be a straight line, may include a curved portion, or may be meandering. When the boundary line between the first metal portion 3101 and the first resin portion 3201 is curved or meandering on the bottom surface 16, a straight line connecting both ends of the boundary line is defined as the boundary line BL _B. In FIG. 1, a boundary line _BLB on the top surface 17 is shown for convenience. The boundary line BL _B on the bottom surface 16 is also shown in the same way as the boundary line BL _B on the top surface 17 in FIG.

The two first resin portions 3201 are provided symmetrically with respect to a straight line passing through the center of the bottom surface 16 and extending in the L direction. This suppresses wobbling and tilting of the coil component 1 mounted on the bottom surface 16.

In the first external electrode 30A, the total coverage of the first resin portion 3201 is approximately 50%. The coverage of the first resin portion 3201 is not particularly limited, and may be appropriately set in consideration of the balance between the effect of suppressing increase in resistance and the effect of reducing deflection stress. The coverage of the first resin portion 3201 may be 30% or more and 70% or less. When the coverage of the first resin portion 3201 is 50% or more, the effect of reducing deflection stress can be particularly improved. The coverage rate of the first resin portion 3201 is determined by dividing the total area of the first resin portion 3201 by the total area of all the first resin portions 3201 and all the first metal portions 3101 in the first external electrode 30A. Calculated by

The maximum width Wb of the first resin portion 3201 in the W direction is wider than the maximum width Wa1 of the first metal portion 3101 adjacent to the first resin portion 3201 in the W direction. This further reduces the deflection stress mentioned above. In the coil component 1, the ratio of the maximum width Wb of the first resin portion 3201 to the maximum width Wa1 of the first metal portion 3101: Wb/Wa1 is approximately 1.7. The Wb/Wa1 may be greater than 1 and less than or equal to 5, and may be greater than or equal to 1.2 and less than or equal to 4.5.

The maximum width Wa1 is the maximum length in the W direction of the first metal portion 3101 adjacent to the first resin portion 3201 in the projection view of the bottom surface 16. When there are two first metal parts 3101 adjacent to the first resin part 3201, the maximum width Wa of each first metal part 3101 is calculated, and the larger one is set as Wa1.

The maximum width Wb is the maximum length of the first resin portion 3201 in the W direction in the projection view of the bottom surface 16.

The maximum width Wa2 of the first metal portion 3101 sandwiched between two adjacent first resin portions 3201 is approximately 110 μm. Thereby, the coverage rate of the first resin portion 3201 can be easily adjusted. The maximum width Wa2 may be 10 μm or more and 160 μm or less, and may be 10 μm or more and 120 μm or less.

The maximum width Wa2 is the maximum length in the W direction of the first metal portion 3101 sandwiched between two adjacent first resin portions 3201 in the projection view of the bottom surface 16. When there are two first metal parts 3101 sandwiched between two adjacent first resin parts 3201, the maximum width Wa of each first metal part 3101 is calculated, and the larger one is set as Wa2. The maximum widths Wa1 and Wa2 may be the same.

(Second metal part and second resin part)
Next, the second metal portion 3102 and the second resin portion 3202 will be explained.
Three second metal parts 3102 are provided. The three second metal portions 3102 are part of the first, second, and third

exposed portions

311, 312, and 313, respectively. Two second resin portions 3202 are provided. The two second resin portions 3202 are part of the first and

second resin electrodes

321 and 322, respectively. On the first end surface 15A, the second metal portions 3102 and the second resin portions 3202 are arranged alternately in the W direction. Two of the second metal parts 3102 are provided at both ends of the first end surface 15A in the W direction.

The fact that the second metal portion 3102 and the second resin portion 3202 are arranged alternately in the W direction means that the boundary line BL _t between the second metal portion 3102 and the second resin portion 3202 is It can be said that there is. The expression that the boundary line BL _t is along the T direction means that the acute angle θ between the boundary line BL _t and the T direction is 0° or more and 30° or less. The boundary line _BLt may be a straight line, may include a curved portion, or may meander. In the first end surface 15A, when the boundary line between the first metal portion 3101 and the first resin portion 3201 is curved or meandering, a straight line connecting both ends of the boundary line is defined as the boundary line BL _t .

Both of the two second resin portions 3202 are provided extending from the bottom surface 16 side to the top surface 17 side of the first end surface 15A. The second resin portions 3202 may each be provided in an area up to 1/2 of the height of the element body 10 from the bottom surface 16 side of the first end surface 15A. Each of the second resin portions 3202 may be provided in an area up to 1/3 of the height of the element body 10 from the bottom surface 16 side of the first end surface 15A. Each of the second resin portions 3202 may be provided in an area up to 1/6 of the height of the element body 10 from the bottom surface 16 side of the first end surface 15A.

In the first external electrode 30A, the total coverage of the second resin portion 3202 is approximately 50%. The coverage rate of the second resin portion 3202 is not particularly limited, and may be appropriately set in consideration of the balance between the effect of suppressing increase in resistance and the effect of reducing deflection stress. The coverage of the second resin portion 3202 may be 30% or more and 70% or less. When the coverage of the second resin portion 3202 is 50% or more, the effect of reducing deflection stress can be particularly improved. The coverage rate of the second resin portion 3202 is calculated in the same manner as the first resin portion 3201.

The maximum width Wb of the second resin portion 3202 in the W direction is wider than the maximum width Wa1 of the second metal portion 3102 adjacent to the second resin portion 3202 in the W direction. This further reduces the deflection stress mentioned above. In the coil component 1, the ratio of the maximum width Wb of the second metal portion 3102 to the maximum width Wa1 of the second metal portion 3102: Wb/Wa1 is approximately 1.7. The Wb/Wa1 may be greater than 1 and less than or equal to 5, and may be greater than or equal to 1.2 and less than or equal to 4.5. The maximum width Wa1 of the second metal portion 3102 is calculated in the same manner as the first metal portion 3101. The maximum width Wb of the second resin portion 3202 is calculated in the same manner as the first resin portion 3201.

The maximum width Wa2 of the second metal portion 3102 sandwiched between two adjacent second resin portions 3202 is approximately 110 μm. The maximum width Wa2 may be 10 μm or more and 160 μm or less, and may be 10 μm or more and 120 μm or less. The maximum width Wa2 of the second metal portion 3102 is calculated in the same manner as the first metal portion 3101. The maximum widths Wa1, Wa2, and Wb at the first end surface 15A are shown similarly to the maximum widths Wa1, Wa2, and Wb at the bottom surface 16 in FIG. 2B.

The two second resin portions 3202 are provided symmetrically with respect to a straight line passing through the center of the first end surface 15A and extending in the T direction. The arrangement of the two second resin portions 3202 is also point symmetrical with respect to the center of the first end surface 15A.

(Third metal part and third resin part)
Next, the third metal portion 3103 and the third resin portion 3203 will be explained.
Three third metal portions 3103 are provided. The three third metal portions 3103 are part of the first, second, and third

exposed portions

311, 312, and 313, respectively. Two third resin portions 3203 are provided. The two third resin portions 3203 are part of the first and

second resin electrodes

321 and 322, respectively. On the top surface 17, the third metal portions 3103 and the third resin portions 3203 are arranged alternately in the W direction. Two of the third metal parts 3103 are provided at both ends of the top surface 17 in the W direction.

The shape, arrangement, coverage, size, etc. of the third resin portion 3203 on the top surface 17 are the same as those of the first resin portion 3201 on the bottom surface 16.

FIG. 5 shows a modification. FIG. 5 is a diagram of a modified example of the coil component cut along a plane corresponding to the YY cross section of FIG.
As shown in FIG. 5, the first and

second resin electrodes

321 and 322 protrude outward in the T direction from the surface of the metal electrode 31 on which the resin electrodes are provided. In particular, it is desirable that irregularities be formed on the bottom surface 16 by the first and

second resin electrodes

321 and 322. Accordingly, during mounting, the solder enters so as to reduce the step difference between the first and

second resin electrodes

321, 322 and the metal electrode 31, so that the connection strength between the circuit board and the coil component 1 can be improved. In addition, the plating layer 40 covering the first external electrode 30A becomes difficult to peel off.

FIG. 6 shows another modification. FIG. 6 is a diagram illustrating a coil component according to another modified example, cut along a plane corresponding to the YY cross section in FIG.
When the first and

second resin electrodes

321 and 322 protrude outward in the T direction from the surface of the metal electrode 31 on which the resin electrodes are provided, as shown in FIG. 2. The metal film 41 may be provided to cover the third

exposed portions

311, 312, and 313. The metal film 41 is formed of a metal material such as Ag. Thereby, the DC resistance increased by the resin electrode 32 can be reduced without changing the size of the coil component 1.

The metal film 41 does not contain organic matter and has conductivity. Metal film 41 is not directly connected to coil 20. The metal film 41 is electrically connected to the coil 20 via the first, second, and third

exposed portions

311, 312, and 313, and serves as an electrode. Hereinafter, the metal electrode 31, the resin electrode 32, and the metal film 41 may be collectively referred to as a first external electrode 30A. The metal film 41 is usually formed of the same material as the coil wiring 22, the first and

second lead conductors

23A, 23B, and the metal electrode 31. The metal film 41 is usually formed by a method different from that of the plating layer 40 (eg, the same method as the metal electrode or a dry plating method).

The metal film 41 may further cover the first and

second resin electrodes

321 and 322. In this case, the metal film 41 can be further electrically connected to the first external electrode 30A via the first and

second resin electrodes

321 and 322.

The metal film 41 is arranged so as to fill the steps between the first and

second resin electrodes

321 and 322 and the first, second and third

exposed portions

311, 312 and 313, so that the metal film 41 covers at least the first and

second resin electrodes

321 and 322 on the bottom surface 16. The surfaces of the two

resin electrodes

321 and 322 and the surface of the metal film 41 may be flush with each other. This reduces wobbling and tilting of the coil component 1 during mounting.

Whether or not the surfaces of the first and

second resin electrodes

321, 322 and the surface of the metal film 41 on the bottom surface 16 are flush with each other can be determined by polishing the coil component 1. This can be confirmed from the enlarged photograph of the TW cross section at (locations). A plurality of TW cross sections can be obtained in the process of polishing the coil component 1 in the L direction. In the above enlarged photograph, find the maximum value of the difference between the distance from the surface of the bottom surface 16 to the surfaces of the first and

second resin electrodes

321, 322 and the distance from the surface of the bottom surface 16 to the surface of the metal film 41. . The above maximum value is calculated for each enlarged photo, and the average value of these values is determined. If this average value is 5 μm or less, it can be said that the surfaces of the first and

second resin electrodes

321, 322 and the surface of the metal film 41 on the bottom surface 16 are flush with each other. The magnification of the enlarged photograph is, for example, 50 times or more and 300 times or less.

By forming the metal electrode 31 in an uneven shape and providing the first and

second resin electrodes

321 and 322 in the recessed portions of the metal electrode 31, the surfaces of the first, second and third

exposed portions

311, 312, 313 and The surfaces of the first and

second resin electrodes

321 and 322 may be flush with each other.

By partially thickening the plating layer 40, the steps between the first and

second resin electrodes

321, 322 and the first, second, and third

exposed portions

311, 312, 313 are filled, and the plating layer 40 is thickened. The surface may be smoothed.

FIG. 7 shows yet another modification. FIG. 7 is a diagram illustrating a coil component according to yet another modification, cut along a plane corresponding to the YY cross section of FIG.
As shown in FIG. 7, in the TW cross section, the length (width) in the W direction of the first surface X on the metal electrode 31 side of the first and

second resin electrodes

321, 322 is The width may be narrower than the width of the second surface Y on the opposite side from X. In other words, the widths of the first and

second resin electrodes

321 and 322 in the TW cross section may become narrower toward the metal electrode 31 in a stepwise or linear manner. Thereby, peeling of the plating layer 40 from the contact portion between the metal electrode 31 and the first and

second resin electrodes

321 and 322 is suppressed. In particular, when the first and

second resin electrodes

321 and 322 have the above-mentioned cross-sectional shapes on the bottom surface 16, an anchor effect acts, and the strength of the solder bond between the circuit board and the coil component 1 is also improved. .

In the TW cross section, the acute angle (hereinafter referred to as taper angle θ) formed by at least one side surface of the first and

second resin electrodes

321, 322 and the metal electrode 31 is, for example, 60° or more and less than 90°. The taper angle θ can also be measured using a SEM image of the TW cross section, as described above.

≪Manufacturing method≫
The coil component 1 includes a step of preparing an element body 10 including a first end surface 15A, a second end surface 15B opposite to the first end surface 15A, and a bottom surface 16 perpendicular to the first end surface 15A and the second end surface 15B. , manufactured by a method comprising a step of forming a metal electrode 31 on at least a part of the bottom surface 16, and a step of forming a resin electrode 32 covering a part of the part provided on the bottom surface 16 of the metal electrode 31. Ru. In the step of forming the resin electrode, first, second, and third

exposed portions

311, 312, and 313 of the metal electrode 31 exposed from the resin electrode 32 are formed on the bottom surface 16.

<Preparation of the elementary body>
In this embodiment, an element body 10 and a coil 20 provided inside the element body 10 are prepared.
First, a plurality of magnetic layers 21 on which coil wiring 22 is formed are stacked so as to be sandwiched between two or more magnetic layers 21 on which coil wiring 22 is not formed. A magnetic layer 21 including a first lead-out conductor 23A or a second lead-out conductor 23B is arranged at the outermost end of the plurality of magnetic layers 21 on which the coil wiring 22 is formed. Next, this laminate is fired. In this way, the element body 10 and the coil 20 provided inside the element body 10 are obtained. The firing temperature is not particularly limited, and may be appropriately set in consideration of the type of material used. The configurations of the coil 20 and the element body 10 are as shown in FIG. 2A.

The magnetic layer 21 is obtained by forming a paste containing a magnetic material into a sheet shape. Examples of the magnetic material include Ni--Cu--Zn based ferrite materials. Ni-Cu-Zn based ferrite materials include, for example, Fe in terms of Fe ₂ O ₃ of 40 mol% or more and 49.5 mol% or less, Zn in terms of ZnO of 2 mol% or more and 35 mol% or less, and Cu in terms of CuO. It contains 6 mol% or more and 13 mol% or less, and 10 mol% or more and 45 mol% or less when converted to NiO. The magnetic material may contain additives and unavoidable impurities as necessary. Examples of additives include Mn ₃ O ₄ , Co ₃ O ₄ , SnO ₂ , Bi ₂ O ₃ and SiO ₂ .

Specifically, the magnetic layer 21 is manufactured as follows. First, Fe ₂ O ₃ , ZnO, CuO, and NiO are weighed to have a predetermined composition. These and pure water are placed in a ball mill along with PSZ (partially stabilized zirconia) media, and wet-mixed and pulverized for 4 to 8 hours. Thereafter, water is evaporated and dried, and calcined at a temperature of 700° C. or more and 800° C. or less for 2 to 5 hours. As a result, a Ni--Cu--Zn based ferrite material (magnetic material) is obtained.

The obtained magnetic material, an organic binder such as polyvinyl butyral, an organic solvent such as ethanol or toluene, and a plasticizer are placed in a ball mill together with PSZ media and further mixed. Next, the obtained mixture is formed into a sheet having a thickness of 5 μm or more and 30 μm or less by a doctor blade method or the like. Thereafter, the magnetic layer 21 is obtained by punching this sheet into a predetermined shape (typically a rectangle).

Via holes are formed at predetermined locations in the produced magnetic layer 21, for example, by laser irradiation.

Separately, a conductive paste containing a conductive material (typically, Ag powder) as a main component is prepared. In addition to the conductive material, the conductive paste may contain a solvent, a resin, a dispersant, and the like. This conductive paste is applied to the magnetic layer 21 in which via holes are formed, for example, by screen printing. As a result, the via hole is filled with the conductive paste, and the coil wiring 22 and the first and

second lead conductors

23A and 23B are formed in the magnetic layer 21.

Subsequently, the plurality of produced magnetic layers 21 are laminated in a predetermined order and bonded by thermocompression to produce a laminated block. Next, the laminated block is cut into pieces using a dicer or the like. The individual pieces are fired in a firing furnace at a temperature of 900° C. or higher and 920° C. or lower for 2 to 4 hours. The resulting sintered body is placed in a rotating barrel machine along with media and rotated to polish the edges and corners of the sintered body. As a result, the element body 10 and the coil 20 are obtained.

<Formation of first and second external electrodes>
Next, a first external electrode 30A is provided on the first end surface 15A side of the element body 10, and a second external electrode 30B is provided on the second end surface 15B side. The step of providing the first external electrode 30A includes forming the metal electrode 31 on at least a portion of the bottom surface 16 on the first end surface 15A side, and covering a portion of the portion of the metal electrode 31 provided on the bottom surface 16. A step of forming a resin electrode 32 is provided. In the step of forming the resin electrode 32, first, second, and third

exposed portions

311, 312, and 313 of the metal electrode 31 exposed from the resin electrode 32 are formed. The second external electrode 30B is provided in the same manner as the first external electrode 30A.

<Formation of metal electrode>
The metal electrodes 31 are formed at two locations on the first end surface 15A side and the second end surface 15B side of the element body 10. The metal electrode 31 on the first end surface 15A side is provided on the entire surface of the first end surface 15A, and on each end of the bottom surface 16, the top surface 17, the first side surface 18A, and the second side surface 18B on the first end surface 15A side. It will be done. The metal electrode 31 on the second end surface 15B side is provided on the entire surface of the second end surface 15B, and on each end of the bottom surface 16, the top surface 17, the first side surface 18A, and the second side surface 18B on the second end surface 15B side. It will be done. Each metal electrode 31 is directly connected to the coil 20.

The metal electrode 31 is formed, for example, by applying a conductive paste containing conductive particles such as Ag powder and glass to a predetermined location of the element body 10 and firing it at a temperature of 750° C. or more and 850° C. or less. The coating method is not particularly limited, and may be, for example, a dipping method or a screen printing method. By firing, the conductive particles are sintered and a metal layer is formed. The firing temperature is not particularly limited, and may be appropriately set in consideration of the type of material used.

<Formation of resin electrode>
Subsequently, a resin electrode 32 is formed to cover a portion of the metal electrode 31. For example, the resin electrode 32 includes a step of applying a conductive composition containing a photosensitive resin to at least a portion of the metal electrode 31 formed on the bottom surface 16, and a step of applying a laser beam to a portion of the applied resin composition. and a step of removing the part or remainder of the resin composition after the irradiation step. As a result, first, second, and third

exposed portions

311, 312, and 313 of the metal electrode 31 exposed from the resin electrode 32 are formed on the bottom surface 16, and the first and second external electrodes 30A according to the present embodiment are formed. , 30B are obtained.

The photosensitive resin may be a positive type that is decomposed by laser light, or a negative type that is polymerized or crosslinked by laser light. When using a positive photosensitive resin, the portion exposed to laser light is removed by a removal process. When using a negative photosensitive resin, the portions not exposed to laser light are removed by a removal process. A mask may be used during laser beam irradiation. The laser light is partially blocked by the mask.

By employing the photolithography method using laser light, the resin electrode 32 can be formed in a desired shape and thickness with higher precision than the screen printing method. For example, the maximum width Wa of the second exposed portion 312 sandwiched between the first resin electrode 321 and the second resin electrode 322 can be set to 10 μm or more and 160 μm or less. Alternatively, the maximum width Wb of the first resin electrode 321 and the second resin electrode 322 can be set to 10 μm or more and 160 μm or less. Furthermore, the thickness of the resin electrode 32 can be made uniform. In the screen printing method, it is generally difficult to make the maximum width Wa or Wb within 80 μm because it is affected by the elongation of the screen plate and the viscosity of the resin composition.

According to the photolithography method using laser light, the degree of polymerization or crosslinking of the photosensitive resin can be controlled arbitrarily. Therefore, as shown in FIG. 7, in the TW cross section, the width of the first surface X of the first and

second resin electrodes

321, 322 on the metal electrode 31 side is It can be made narrower than the width of the second surface Y. For example, when using a negative photosensitive resin, the degree of polymerization or crosslinking of the photosensitive resin can be reduced by lowering the laser beam irradiation intensity or reducing the number of irradiations. The widths of the first and

second resin electrodes

321 and 322 can be narrowed stepwise or linearly toward the metal electrode 31.

The conductive resin composition further includes conductive particles. Examples of the conductive particles include Ag powder. The conductive resin composition may further contain a solvent and a dispersant.

Specifically, the resin composition contains 60% by mass to 85% by mass of Ag powder, 2% by mass to 20% by mass of epoxy resin (for example, bisphenol A epoxy resin), and organic solvent (for example, diethylene glycol monomer). butyl ether) from 10% by mass to 20% by mass. The resin composition further contains a thermosetting resin (e.g., phenol resin), a silane coupling agent (e.g., 3-glycidoxypropyltrimethoxysilane), and a curing agent (e.g., imidazole compound) in an amount of 1% by mass or less. may be included. During application, a paste obtained by mixing 100% by mass of the resin composition with 10% by mass of photosensitive varnish may be used.

When using a negative-type epoxy resin as the photosensitive resin, the portion where the resin electrode 32 is to be provided is irradiated with laser light. Thereafter, the part coated with the resin composition is immersed in a developer. The epoxy resin that has not been irradiated with the laser beam is dissolved in the developer and removed. On the other hand, the exposed epoxy resin is cured and remains. Finally, the resin electrode 32 is formed by heat treatment at 230° C. for about 1 hour.

<Formation of metal film>
After forming the metal electrode 31 and before or after forming the resin electrode 32, a step of forming the metal film 41 may be performed.

The metal film 41 may be formed using the same method and material as the metal electrode 31, for example, before forming the resin electrode 32. Specifically, before forming the resin electrode 32, the metal film 41 is coated with a conductive material (typically Specifically, it is formed by applying a conductive paste containing Ag powder as a main component and firing at a temperature of 750° C. or more and 850° C. or less. The firing for forming the metal electrode 31 and the firing for forming the metal film 41 may be performed simultaneously.

The metal film 41 may be formed, for example, by sputtering after the resin electrode 32 is formed. Specifically, the metal film 41 is formed at least on the first, second, and third

exposed portions

311, 312, and 313 of the metal electrode 31 by sputtering using Ag as a target.

<Formation of plating layer>
After the step of forming the resin electrode 32 and after the step of forming the metal film 41, which is performed as necessary, a plating layer 40 is formed to cover at least a portion of the first and second

external electrodes

30A and 30B. You may carry out a process. The plated layer 40 is typically formed by wet plating. The wet plating method is not particularly limited, and may be an electrolytic plating method or an electroless plating method. The step of forming the plating layer 40 is performed multiple times as necessary. The plating layer is formed in order of a Ni plating layer and a Sn plating layer, for example, by electrolytic plating.

≪Evaluation≫
The coil component 1 according to this embodiment was evaluated by simulation. The size, number, arrangement, etc. of the resin electrodes 32 of the coil component 1 are as shown in FIG. The coil component 1 used in the simulation was further provided with a metal film 41 covering the first, second, and third

exposed portions

311, 312, and 313. The coil component 1 has a length (L) of 1.6 mm, a width (W) of 0.8 mm, and a height (T) of 0.8 mm. As shown in FIG. 4, the coil component 1 has the bottom surface 16 of the coil component 1 used as the mounting surface, and a pad 6 placed near the center of a substrate (thickness 1.6 mm), not shown, on the bottom surface 16. It is assumed that the second end faces 15A and 15B are soldered. Femtet (registered trademark) manufactured by Murata Software Co., Ltd. was used for the simulation.

<Deflection stress>
In the evaluation of deflection stress, the composition and physical property values of each member were set as shown in Table 1. The deflection test was conducted as follows. The board is supported from below at two locations (distance between fulcrums: 90 mm) so that the surface on which the coil component 1 is mounted is the bottom surface. A load was applied to approximately the center of the substrate from above to below using a presser at a speed of 0.08 mm/sec. The stress applied to the coil component 1 when the amount of deflection of the board was 5 mm was obtained as the deflection stress.

<Resistance value>
In evaluating the resistance value, the composition and physical property values of each member were set as shown in Table 2. As the resistance value, the DC resistance value between the first and second end faces 15A, 15B of the coil component 1 and the surface of the pad 6 was obtained.

A coil component 2A and a coil component 2B were prepared for comparison. The comparative coil component 2A has an element body and a metal electrode having the same configuration as the coil component 1, except that it does not have the resin electrode 32 and has a metal film 41 that covers the entire surface of the metal electrode 31. Comparative coil component 2B has the same element body and metal electrode as coil component 1, except that it has a metal film 41 that covers the entire surface of the metal electrode 31 and a resin electrode 32 that covers the entire surface of the metal film 41. ing. FIG. 8 is a perspective view showing a comparative coil component 2A. FIG. 9 is a perspective view showing a comparative coil component 2B.

Since the comparative coil component 2B has the resin electrode 32 covering the entire surface of the metal film 41, its deflection stress is reduced by 73.6% compared to the comparative coil component 2A. On the other hand, the resistance value of the comparative coil component 2B increases by 66.6%.

On the other hand, since the coil component 1 according to the present embodiment has the first, second, and third

exposed portions

311, 312, and 313 at least on the bottom surface 16, the resistance value increase rate remains at 21.4%. On the other hand, the bending stress is reduced by 53.5% due to the band-shaped first and

second resin electrodes

321 and 322. In this manner, the coil component according to the present embodiment can effectively reduce deflection stress while suppressing an increase in resistance.

[Second embodiment]
FIG. 10 is a perspective view showing a second embodiment of the coil component, and corresponds to FIG. 1 of the first embodiment. The second embodiment differs from the first embodiment in the size, number, and arrangement of resin electrodes. This different configuration will be explained below. The configuration of the second embodiment other than the size, number, and arrangement of the resin electrodes is the same as the first embodiment, so a description thereof will be omitted. In the second embodiment, the same reference numerals as those in the first embodiment have the same configurations as in the first embodiment, so a description thereof will be omitted. In the second embodiment, the manufacturing method is the same as that in the first embodiment, so a description thereof will be omitted.

The configuration of the first external electrode 30A of the coil component 1A of the second embodiment will be described below. The configuration of the second external electrode 30B is also similar.
The resin electrode 32 has a single strip shape. The resin electrode 32 extends continuously in the L direction on the bottom surface 16, in the T direction on the first end surface 15A, and in the L direction on the top surface 17 in this order.

The metal electrode 31 has first and second exposed

portions

311 and 312 exposed from the resin electrode 32. The first exposed portion 311 includes an end portion of the first side surface 18A on the first end surface 15A side, an end portion of the bottom surface 16 on the first end surface 15A side and on the first side surface 18A side, and a first end portion of the top surface 17 on the first end surface 15A side. They are located at an end on the end surface 15A side and on the first side surface 18A side, and at an end portion of the first end surface 15A on the first side surface 18A side. The second exposed portion 312 includes an end portion of the second side surface 18B on the first end surface 15A side, an end portion of the bottom surface 16 on the first end surface 15A side and on the second side surface 18B side, and a first end portion of the top surface 17. It is located at the end on the end surface 15A side and on the second side surface 18B side, and at the end on the second side surface 18B side of the first end surface 15A.

The first exposed portion 311, the resin electrode 32, and the second exposed portion 312 are arranged in this order in the W direction from the first side surface 18A side. The first and second exposed

portions

311 and 312 are provided on the first and second side surfaces 18A and 18B of the element body 10, respectively.

The coverage of the resin electrode 32 on the bottom surface 16, top surface 17, and first end surface 15A is approximately 40%, respectively. In each of the above surfaces, the ratio of the maximum width Wb to the maximum width Wa1: Wb/Wa1 is greater than 1. Specifically, the ratio: Wb/Wa1 is about 1.4.

≪Evaluation≫
The coil component 1A was evaluated by simulation in the same manner as in the first embodiment. The coil component 1A includes one strip-shaped resin electrode 32 provided approximately at the center of the first external electrode 30A in the W direction, and a metal film 41 covering the first and second exposed

portions

311 and 312. It has an element body and a metal electrode having the same configuration as the coil component 1 except for the following.

Since the coil component 1A according to this embodiment has the first and second exposed

portions

311 and 312 at least on the bottom surface 16, its resistance value increase rate is 15.6% compared to the coil component 2A in the above comparison. stay. On the other hand, the bending stress of the coil component 1A is reduced by 34.6% due to the band-shaped resin electrode 32.

[Third embodiment]
FIG. 11 is a perspective view showing a third embodiment of the coil component, and corresponds to FIG. 1 of the first embodiment. The third embodiment differs from the first embodiment in the size, number, and arrangement of resin electrodes. This different configuration will be explained below. The configuration of the third embodiment other than the size, number, and arrangement of the resin electrodes is the same as the first embodiment, so a description thereof will be omitted. In the third embodiment, the same reference numerals as those in the first embodiment have the same configurations as in the first embodiment, so a description thereof will be omitted. In the third embodiment, the manufacturing method is the same as that in the first embodiment, so the description thereof will be omitted.

The configuration of the first external electrode 30A of the coil component 1B of the third embodiment will be described below. The configuration of the second external electrode 30B is also similar.
The resin electrode 32 has a single strip shape. The resin electrode 32 extends continuously in the L direction on the bottom surface 16, in the T direction on the first end surface 15A, and in the L direction on the top surface 17 in this order.

The metal electrode 31 has first and second exposed

portions

The coverage rate of the resin electrode 32 on the bottom surface 16, top surface 17, and first end surface 15A is about 67%, respectively. In each of the above surfaces, the ratio of the maximum width Wb to the maximum width Wa1: Wb/Wa1 is greater than 1. Specifically, the ratio: Wb/Wa1 is about 4.3.

≪Evaluation≫
The coil component 1B was evaluated by simulation in the same manner as in the first embodiment. The coil component 1B includes one wide band-shaped resin electrode 32 provided approximately at the center of the first external electrode 30A in the W direction, and a metal film covering the first and second exposed

portions

311 and 312. 41, the element body and metal electrodes have the same configuration as the coil component 1.

Since the coil component 1B according to this embodiment has the first and second exposed

portions

311 and 312 at least on the bottom surface 16, its resistance value increase rate is 30.0% compared to the coil component 2A of the above comparison. stay. On the other hand, the bending stress of the coil component 1B is reduced by 65.7% due to the wide band-shaped resin electrode 32.

[Fourth embodiment]
FIG. 12 is a perspective view showing a fourth embodiment of the coil component, and corresponds to FIG. 1 of the first embodiment. The fourth embodiment differs from the first embodiment in the size of the resin electrode. This different configuration will be explained below. The configuration of the fourth embodiment other than the size of the resin electrode is the same as the first embodiment, so a description thereof will be omitted. In the fourth embodiment, the same reference numerals as those in the first embodiment have the same configurations as in the first embodiment, so a description thereof will be omitted. In the fourth embodiment, the manufacturing method is the same as that in the first embodiment, so the description thereof will be omitted.

The configuration of the first external electrode 30A of the coil component 1C of the fourth embodiment will be described below. The configuration of the second external electrode 30B is also similar.
The resin electrode 32 has two strip-shaped first and

second resin electrodes

321 and 322. The first and

second resin electrodes

321 and 322 extend continuously in the L direction on the bottom surface 16, in the T direction on the first end surface 15A, and in the L direction on the top surface 17, respectively, in this order. The first resin electrode 321 and the second resin electrode 322 are arranged side by side in the W direction with an interval between them.

The metal electrode 31 has first, second, and third

exposed portions

The first exposed portion 311, the first resin electrode 321, the second exposed portion 312, the second resin electrode 322, and the third exposed portion 313 are arranged in this order in the W direction from the first side surface 18A side.

The coverage of the resin electrode 32 on the bottom surface 16, top surface 17, and first end surface 15A is about 26%, respectively. In each of the above surfaces, the ratio of the maximum width Wb to the maximum width Wa1: Wb/Wa1 is 1 or less. Specifically, the ratio: Wb/Wa1 is about 0.45. When the ratio: Wb/Wa1 is 1 or less, the effect of suppressing an increase in resistance is particularly likely to be improved. The maximum width Wa2 of the second exposed portion 312 sandwiched between the two adjacent first and

second resin electrodes

321 and 322 is approximately 104 μm.

≪Evaluation≫
The coil component 1C was evaluated by simulation in the same manner as in the first embodiment. The coil component 1C has the same configuration as the coil component 1 except that the width of the strip-shaped resin electrode 32 is narrow and that it has a metal film 41 that covers the first, second, and third

exposed portions

311, 312, and 313. It has an element body and a metal electrode.

Since the coil component 1C according to this embodiment has the first, second, and third

exposed portions

311, 312, and 313 on at least the bottom surface 16, its resistance value increase rate is lower than that of the coil component 2A in the above comparison. It remains at 8.9%. On the other hand, the deflection stress of the coil component 1C is reduced by 23.1% due to the first and

second resin electrodes

321 and 322.

[Fifth embodiment]
FIG. 13 is a perspective view showing a fifth embodiment of the coil component, and corresponds to FIG. 1 of the first embodiment. The fifth embodiment differs from the first embodiment in the size, number, and arrangement of resin electrodes. This different configuration will be explained below. The configuration of the fifth embodiment other than the size, number, and arrangement of the resin electrodes is the same as the first embodiment, so a description thereof will be omitted. In the fifth embodiment, the same reference numerals as in the first embodiment have the same configurations as in the first embodiment, so the explanation thereof will be omitted. In the fifth embodiment, the manufacturing method is the same as that in the first embodiment, so the description thereof will be omitted.

The configuration of the first external electrode 30A of the coil component 1D of the fifth embodiment will be described below. The configuration of the second external electrode 30B is also similar.
The metal electrode 31 has strip-shaped first and second exposed

portions

311 and 312 exposed from the resin electrode 32 in order from the first side surface 18A side. The two strip-shaped first and second exposed

portions

311 and 312 extend continuously in the L direction on the bottom surface 16, in the T direction on the first end surface 15A, and in the L direction on the top surface 17, respectively, in this order. are doing. The first exposed portion 311 and the second exposed portion 312 are arranged side by side in the W direction with an interval between them.

The resin electrode 32 has first, second, and

third resin electrodes

321, 322, and 323. The first resin electrode 321 is connected to an end portion of the first side surface 18A on the first end surface 15A side, an end portion of the bottom surface 16 on the first end surface 15A side and on the first side surface 18A side, and a first end portion of the top surface 17 on the first end surface 15A side. It is provided at an end portion on the end surface 15A side and on the first side surface 18A side, and an end portion on the first side surface 18A side of the first end surface 15A. The second resin electrode 322 is located between the first exposed portion 311 and the second exposed portion 312, and is located in the L direction on the bottom surface 16, in the T direction on the first end surface 15A, and in the L direction on the top surface 17. It is a band-like shape that extends continuously in this order. The third resin electrode 323 is connected to an end portion of the second side surface 18B on the first end surface 15A side, an end portion of the bottom surface 16 on the first end surface 15A side and on the second side surface 18B side, and a first end portion of the top surface 17. It is provided at an end on the end surface 15A side and on the second side surface 18B side, and an end portion on the second side surface 18B side of the first end surface 15A.

The first resin electrode 321, the first exposed portion 311, the second resin electrode 322, the second exposed portion 312, and the third resin electrode 323 are arranged in this order in the W direction from the first side surface 18A side. The first and

third resin electrodes

321 and 323 are provided on the first and second side surfaces 18A and 18B of the element body 10, respectively.

The coverage of the resin electrode 32 on the bottom surface 16, top surface 17, and first end surface 15A is approximately 70%, respectively. In each of the above surfaces, the ratio of the maximum width Wb to the maximum width Wa1: Wb/Wa1 is greater than 1. Specifically, the ratio: Wb/Wa1 is about 2.0. A first exposed portion 311 sandwiched between two adjacent first and

second resin electrodes

321 and 322, and a second exposed portion 312 sandwiched between two adjacent second and

third resin electrodes

322 and 323. The maximum width Wa2 is approximately 104 μm in both cases.

≪Evaluation≫
The coil component 1D was evaluated by simulation in the same manner as in the first embodiment. In the coil component 1D, a band-shaped second resin electrode 322 is provided approximately at the center of the first external electrode 30A in the W direction, and the first and

third resin electrodes

321 and 323 are provided in the W direction of the first external electrode 30A. It has an element body and metal electrodes having the same configuration as the coil component 1, except that it is provided at both ends of the coil component 1, and has a metal film 41 that covers the first and second exposed

portions

311, 312. There is.

Since the coil component 1D according to the present embodiment has the first and second exposed

portions

311 and 312 at least on the bottom surface 16, its resistance value increase rate is 41.1% compared to the coil component 2A of the above comparison. stay. On the other hand, the deflection stress of the coil component 1D is reduced by 48.4% due to the first, second, and

third resin electrodes

321, 322, and 323.

[Sixth embodiment]
FIG. 14 is a perspective view showing a sixth embodiment of the coil component, and corresponds to FIG. 1 of the first embodiment. The sixth embodiment differs from the first embodiment in the size, number, and arrangement of resin electrodes. 15A and 15B are perspective views showing a modification of the sixth embodiment. The modification shown in FIGS. 15A and 15B differs from the sixth embodiment in the arrangement of resin electrodes on each end surface. These different configurations will be explained below. The configuration of the sixth embodiment other than the size, number, and arrangement of the resin electrodes is the same as the first embodiment, so a description thereof will be omitted. In the sixth embodiment, the same reference numerals as those in the first embodiment have the same configurations as in the first embodiment, so a description thereof will be omitted. In the sixth embodiment, the manufacturing method is the same as that in the first embodiment, so a description thereof will be omitted.

The configuration of the first external electrode 30A of the coil component 1E of the sixth embodiment will be described below. The configuration of the second external electrode 30B is also similar.
The metal electrode 31 has strip-shaped first, second, and third

exposed portions

311, 312, and 313 exposed from the resin electrode 32 in order from the first side surface 18A side. The three strip-shaped first, second, and third

exposed portions

311, 312, and 313 are arranged in the L direction on the bottom surface 16, in the T direction on the first end surface 15A, and in the L direction on the top surface 17 in this order. extends continuously. The first exposed portion 311, the second exposed portion 312, and the third exposed portion 313 are arranged side by side in the W direction with an interval between them.

The resin electrode 32 has first, second, third, and

fourth resin electrodes

321, 322, 323, and 324. The first resin electrode 321 is connected to an end portion of the first side surface 18A on the first end surface 15A side, an end portion of the bottom surface 16 on the first end surface 15A side and on the first side surface 18A side, and a first end portion of the top surface 17 on the first end surface 15A side. It is provided at an end portion on the end surface 15A side and on the first side surface 18A side, and an end portion on the first side surface 18A side of the first end surface 15A. The second resin electrode 322 is located between the first exposed portion 311 and the second exposed portion 312, and extends in the L direction on the bottom surface 16, in the T direction on the first end surface 15A, and in the L direction on the top surface 17. , in a band shape that extends continuously in this order. The third resin electrode 323 is located between the second exposed portion 312 and the third exposed portion 313, and extends in the L direction on the bottom surface 16, in the T direction on the first end surface 15A, and in the L direction on the top surface 17. , in a band shape that extends continuously in this order. The fourth resin electrode 324 is connected to an end portion of the second side surface 18B on the first end surface 15A side, an end portion of the bottom surface 16 on the first end surface 15A side and on the second side surface 18B side, and a first end portion of the top surface 17. It is provided at an end on the end surface 15A side and on the second side surface 18B side, and an end portion on the second side surface 18B side of the first end surface 15A.

The first resin electrode 321, the first exposed portion 311, the second resin electrode 322, the second exposed portion 312, the third resin electrode 323, the third exposed portion 313, and the fourth resin electrode 324 are arranged from the first side surface 18A side, They are arranged in this order in the W direction. The first and

fourth resin electrodes

321 and 324 are provided on the first and second side surfaces 18A and 18B of the element body 10, respectively.

The coverage of the resin electrode 32 on the bottom surface 16, top surface 17, and first end surface 15A is approximately 55%, respectively. In each of the above surfaces, the ratio of the maximum width Wb to the maximum width Wa1: Wb/Wa1 is 1 or less. Specifically, the ratio: Wb/Wa1 is about 1.0. A first exposed portion 311 sandwiched between two adjacent first and

second resin electrodes

321 and 322, a second exposed portion 312 sandwiched between two adjacent second and

third resin electrodes

322 and 323, and an adjacent The maximum width Wa2 of the second exposed portion 312 sandwiched between the two matching third and

fourth resin electrodes

323 and 324 is approximately 110 μm.

(Modified example)
FIG. 15A shows a coil component 1Ea as a modification of this embodiment. In the coil component 1Ea, the first, second, third, and

fourth resin electrodes

321, 322, 323, and 324 are all located at 1/1/2 of the height T of the element body 10 from the bottom surface 16 side of each

end surface

15A, 15B. It is provided in areas up to 6. The first exposed portion 311 is one continuous region of the metal electrode 31 other than the first, second, third, and

fourth resin electrodes

321, 322, 323, and 324.

FIG. 15B shows a coil component 1Eb of a modification of this embodiment. In the coil component 1Eb, the first, second, third, and

fourth resin electrodes

end surface

15A, 15B. It is provided in areas up to 3. The first exposed portion 311 is one continuous region of the metal electrode 31 other than the first, second, third, and

fourth resin electrodes

321, 322, 323, and 324.

Even in these modifications, the above-mentioned effect of reducing deflection stress can be obtained.

≪Evaluation≫
Coil components 1E, 1Ea, and 1Eb were evaluated by simulation in the same manner as in the first embodiment. In the coil component 1E, band-shaped second and

third resin electrodes

322 and 323 are provided near the center of the first external electrode 30A in the W direction, and first and

fourth resin electrodes

321 and 324 are provided in the first external electrode 30A. The same configuration as the coil component 1 except that it is provided at both ends of the electrode 30A in the W direction and has a metal film 41 that covers the first, second, and third

exposed portions

311, 312, and 313. It has an element body and a metal electrode.

In the coil component 1Ea, the first, second, third, and

fourth resin electrodes

end surface

15A, 15B. The element body and the metal electrode have the same configuration as the coil component 1 except that the coil component 1 is provided in the region up to 6 and has the metal film 41 that covers the first exposed portion 311.

In the coil component 1Eb, the first, second, third, and

fourth resin electrodes

321, 322, 323, and 324 are all located at 1/1 of the height T of the element body 10 from the bottom surface 16 side of each

end surface

15A, 15B. The element body and the metal electrode have the same configuration as the coil component 1 except that the coil component 1 is provided in the region up to 3 and has the metal film 41 that covers the first exposed portion 311.

Since the coil component 1E according to the present embodiment has first, second, and third

exposed portions

311, 312, and 313 on at least the bottom surface 16, its resistance value increase rate is lower than that of the coil component 2A in the above comparison. The increase remains at 31.0%. On the other hand, the deflection stress is reduced by 30.8% due to the first, second, third, and

fourth resin electrodes

321, 322, 323, and 324. Since the coil component 1Ea according to the present embodiment also has the first exposed portion 311 at least on the bottom surface 16, its resistance value remains at an increase of 23.7%. On the other hand, the deflection stress is reduced by 32.6% due to the first, second, third, and

fourth resin electrodes

321, 322, 323, and 324. Since the coil component 1Eb according to the present embodiment also has the first exposed portion 311 at least on the bottom surface 16, the rate of increase in resistance value remains at 30.1%. On the other hand, the deflection stress is reduced by 31.3% due to the first, second, third, and

fourth resin electrodes

321, 322, 323, and 324.

[Seventh embodiment]
FIG. 16 is a perspective view showing a seventh embodiment of the coil component, and corresponds to FIG. 1 of the first embodiment. The seventh embodiment differs from the first embodiment in the size, number, and arrangement of resin electrodes. This different configuration will be explained below. The structure of the seventh embodiment other than the size, number, and arrangement of the resin electrodes is the same as the first embodiment, so the description thereof will be omitted. In the seventh embodiment, the same reference numerals as those in the first embodiment have the same configurations as in the first embodiment, so the description thereof will be omitted. In the seventh embodiment, the manufacturing method is the same as that in the first embodiment, so the description thereof will be omitted.

The configuration of the first external electrode 30A of the coil component 1F of the seventh embodiment will be described below. The configuration of the second external electrode 30B is also similar.
The metal electrode 31 has strip-shaped first and second exposed

portions

The resin electrode 32 has first, second, and

third resin electrodes

The coverage of the resin electrode 32 on the bottom surface 16, top surface 17, and first end surface 15A is approximately 45%, respectively. In each of the above surfaces, the ratio of the maximum width Wb to the maximum width Wa1: Wb/Wa1 is 1 or less. Specifically, the ratio: Wb/Wa1 is about 0.6. A first exposed portion 311 sandwiched between two adjacent first and

second resin electrodes

third resin electrodes

322 and 323. The maximum width Wa2 is approximately 210 μm. This embodiment in which the coverage is less than 50% and the ratio: Wb/Wa is 1 or less is particularly effective in suppressing an increase in resistance.

≪Evaluation≫
The coil component 1F was evaluated by simulation in the same manner as in the first embodiment. In the coil component 1F, a band-shaped second resin electrode 322 is provided approximately in the center of the first external electrode 30A in the W direction, and the first and

third resin electrodes

portions

311, 312. There is.

Since the coil component 1F according to the present embodiment has the first and second exposed

portions

311 and 312 at least on the bottom surface 16, the resistance value increases only by 24.3% compared to the coil component 2A of the above comparison. .

[Eighth embodiment]
FIG. 17 is a perspective view showing the eighth embodiment of the coil component, and corresponds to FIG. 1 of the first embodiment. The eighth embodiment differs from the first embodiment in the size and arrangement of the resin electrodes. This different configuration will be explained below. The structure of the eighth embodiment other than the size and arrangement of the resin electrodes is the same as that of the first embodiment, so a description thereof will be omitted. In the eighth embodiment, the same reference numerals as those in the first embodiment have the same configurations as in the first embodiment, so a description thereof will be omitted. In the eighth embodiment, the manufacturing method is the same as that in the first embodiment, so the description thereof will be omitted.

The configuration of the first external electrode 30A of the coil component 1G of the eighth embodiment will be described below. The configuration of the second external electrode 30B is also similar.
The metal electrode has one strip-shaped first exposed portion 311 . The first exposed portion 311 extends continuously in the L direction on the bottom surface 16, in the T direction on the first end surface 15A, and in the L direction on the top surface 17 in this order.

The resin electrode 32 has first and

second resin electrodes

321 and 322. The first resin electrode 321 is connected to an end portion of the first side surface 18A on the first end surface 15A side, an end portion of the bottom surface 16 on the first end surface 15A side and on the first side surface 18A side, and a first end portion of the top surface 17 on the first end surface 15A side. It is provided at an end portion on the end surface 15A side and on the first side surface 18A side, and an end portion on the first side surface 18A side of the first end surface 15A. The second resin electrode 322 is connected to an end portion of the second side surface 18B on the first end surface 15A side, an end portion of the bottom surface 16 on the first end surface 15A side and on the second side surface 18B side, and a first end portion of the top surface 17. It is provided at an end on the end surface 15A side and on the second side surface 18B side, and an end portion on the second side surface 18B side of the first end surface 15A.

The first resin electrode 321, the first exposed portion 311, and the second resin electrode 322 are arranged in this order in the W direction from the first side surface 18A side. The first and second resin electrodes 322 are provided on the first and second side surfaces 18A and 18B of the element body 10, respectively.

The coverage of the resin electrode 32 on the bottom surface 16, top surface 17, and first end surface 15A is about 30%, respectively. In each of the above surfaces, the ratio of the maximum width Wb to the maximum width Wa1: Wb/Wa1 is 1 or less. Specifically, the ratio: Wb/Wa1 is about 0.2. The maximum width Wa2 of the first exposed portion 311 sandwiched between two adjacent first and

second resin electrodes

321 and 322 is approximately 540 μm. This embodiment is also particularly effective in suppressing an increase in resistance.

≪Evaluation≫
The coil component 1G was evaluated by simulation in the same manner as in the first embodiment. The coil component 1G includes first and

second resin electrodes

321 and 322 provided at both ends of the first external electrode 30A in the W direction, and a metal film 41 that covers the first exposed portion 311. Other than this, it has an element body and metal electrodes having the same configuration as the coil component 1.

Since the coil component 1G according to the present embodiment has the first exposed portion 311 at least on the bottom surface 16, its resistance value increase rate remains at 18.3%.

The present disclosure is not limited to the above-described embodiments, and design changes can be made without departing from the gist of the present disclosure. For example, the features of the first to eighth embodiments may be combined in various ways. The number, arrangement, and size of resin electrodes can be changed in design.

In the first to eighth embodiments, a coil component was described as an example of an electronic component, but the electronic component according to the present disclosure is not limited to a coil component.
The electronic component according to the present disclosure may be an active component or a passive component other than a coil component. Active components refer to components that amplify, rectify, or convert supplied power. Examples of active components include transistors and various sensors. Passive components are components that consume, store, or emit supplied power, but do not perform active operations such as amplification and rectification. Passive components include, for example, resistors, capacitors, and thermistors in addition to coil components.

The arrangement of the metal electrodes 31 is not limited to the above embodiment.
The metal electrode 31 may be provided only on the bottom surface 16, or may have an L-shape extending from the first end surface 15A or the second end surface 15B to the bottom surface 16.

The arrangement of the resin electrodes 32 is not limited to the above embodiment.
The resin electrode 32 may be provided only on the bottom surface 16, or may have an L-shape extending from the first end surface 15A or the second end surface 15B to the bottom surface 16.

The resin electrode 32 may cover the entire surface of the metal electrode 31 provided on the first and second end faces 15A and 15B. The resin electrode 32 may cover the entire surface of the metal electrode 31 provided on the top surface 17.

The shape, arrangement, coverage, size, etc. of the resin electrode 32 on the top surface 17 may be the same as or different from the resin electrode 32 on the bottom surface 16.

The number of resin electrodes 32 is not limited to the above embodiment.
At least one resin electrode 32 may be provided on the bottom surface 16.

The thickness of the resin electrode 32 is not limited to the above embodiment.
The thickness of the resin electrode 32 may be uniform or non-uniform.
The thickness of the resin electrode 32 on each surface may be the same or different. The thicknesses of the plurality of resin electrodes 32 provided on the same surface may be the same or different.

The shape, number, arrangement, coverage, size, etc. of the resin electrodes 32 provided on the first end surface 15A side of the bottom surface 16 are the same as those of the resin electrodes 32 provided on the second end surface 15B side of the bottom surface 16. It's okay to be different.

The shape, number, arrangement, coverage, size, etc. of the resin electrodes 32 provided on the first end surface 15A may be the same as or different from those of the resin electrodes 32 provided on the second end surface 15B.

The shape, number, arrangement, coverage, size, etc. of the resin electrodes 32 provided on the first end surface 15A side of the top surface 17 are the same as those of the resin electrodes 32 provided on the second end surface 15B side of the top surface 17. and may be different.

The shape of the element body 10 is not limited to the above-described embodiment.
The bottom surface 16 does not need to be continuous with both the first end surface 15A and the second end surface 15B. The bottom surface 16 may be divided into, for example, a first bottom surface that continues only to the first end surface 15A and a second bottom surface that continues only to the second end surface 15B.

The arrangement of the exposed portion and the resin electrode 32 is not limited to the above embodiment.
In at least a part of the region of the bottom surface 16 where the metal electrode 31 is provided, the exposed portion and the resin electrode 32 may be arranged side by side in the W direction. For example, in a part of the region of the bottom surface 16 where the metal electrode 31 is provided, only an exposed portion may be provided from one end of the bottom surface 16 in the W direction to the other end. In a part of the region of the bottom surface 16 where the metal electrode 31 is provided, only the resin electrode 32 may be provided from one end of the bottom surface 16 in the W direction to the other end.

This application claims priority based on Japanese Patent Application No. 2022-051695 filed in Japan on March 28, 2022, and the entire content thereof is incorporated herein by reference.

1,1A to 1G, 1Ea, 1Eb Coil parts 10 Element body 15A First end surface 15B Second end surface 16 Bottom surface 17 Top surface 18A First side surface 18B Second side surface 20 Coil 21 Magnetic layer 22 Coil wiring 23A First lead-out conductor 23B No. 2 lead-out conductor 24 Via wiring 30A First external electrode 30B Second external electrode 31 Metal electrode 311 First exposed portion 312 Second exposed portion 313 Third exposed portion 3101 First metal portion 3102 Second metal portion 3103 Third metal portion 32 Resin electrode 321 First resin electrode 322 Second resin electrode 323 Third resin electrode 324 Fourth resin electrode 3201 First resin part 3202 Second resin part 3203 Third resin part 40 Plating layer 41

Metal film

2A, 2B Comparative coil parts 5 Solder 6 Pad

Claims

The element body and
an external electrode provided on the element body,
The element body is
a first end surface;
a second end face opposite to the first end face;
a bottom surface perpendicular to the first end surface and the second end surface,
The external electrode is
a first external electrode provided on the first end surface side;
a second external electrode provided on the second end surface side,
The first external electrode is
a metal electrode provided on at least a portion of the bottom surface;
a resin electrode that covers a part of the bottom surface of the metal electrode,
In the electronic component, the metal electrode has an exposed portion exposed from the resin electrode on the bottom surface.
The electronic component according to claim 1, further comprising a plating layer covering at least a portion of the first external electrode on the bottom surface.
A direction in which the first end surface and the second end surface face each other is an L direction, and
The direction perpendicular to the L direction on the bottom surface is defined as the W direction,
On the bottom surface,
The electronic component according to claim 1 or 2, wherein the exposed portion and the resin electrode are arranged side by side in the W direction.
A direction in which the first end surface and the second end surface face each other is an L direction, and
The direction perpendicular to the L direction on the bottom surface is defined as the W direction,
The electronic component according to any one of claims 1 to 3, wherein the exposed portions are provided at both ends of the bottom surface in the W direction.
A direction in which the first end surface and the second end surface face each other is an L direction, and
The direction perpendicular to the L direction on the bottom surface is defined as the W direction,
On the bottom surface,
The electronic component according to claim 1, wherein the resin electrodes are provided to sandwich the exposed portion from both sides in the W direction.
On the bottom surface,
The electronic component according to any one of claims 3 to 5, wherein the maximum width of the resin electrode in the W direction is wider than the maximum width in the W direction of the exposed portion adjacent to the resin electrode.
On the bottom surface,
The electronic component according to any one of claims 3 to 6, wherein the maximum width of the exposed portion sandwiched between the two resin electrodes is 10 μm or more and 160 μm or less.
In the first external electrode,
The metal electrode is further provided on a portion of at least one of the first end face and the second end face,
8. The electronic component according to claim 1, wherein the resin electrode further covers a part of a portion provided on at least one of the first end surface and the second end surface of the metal electrode.
The direction in which the first end surface and the second end surface face each other is an L direction,
A direction perpendicular to the L direction on the bottom surface is a W direction, and
A direction perpendicular to both the L direction and the W direction is the T direction,
In the first external electrode,
The resin electrode provided on a portion of at least one of the first end surface and the second end surface is 1 of the height of the element body in the T direction from the bottom surface side of the end surface on which the resin electrode is provided. The electronic component according to claim 8, wherein the electronic component is provided in an area up to /2.
The direction in which the first end surface and the second end surface face each other is an L direction,
A direction perpendicular to the L direction on the bottom surface is a W direction, and
A direction perpendicular to both the L direction and the W direction is the T direction,
The resin electrode provided on the bottom surface projects outward in the T direction from the surface of the metal electrode provided on the bottom surface, according to any one of claims 1 to 9. electronic components.
The electronic component according to any one of claims 1 to 10, further comprising a metal film that covers at least an exposed portion of the metal electrode exposed from the resin electrode.
The electronic component according to claim 11, wherein the surface of the resin electrode and the surface of the metal film are flush with each other at least on the bottom surface.
The resin electrode provided on the bottom surface is symmetrical with respect to a straight line passing through the center of the bottom surface and extending in the L direction, which is a direction in which the first end surface and the second end surface face each other. The electronic component according to any one of 1 to 12.
The electronic component according to any one of claims 1 to 13, wherein the resin electrode provided on the bottom surface has a uniform thickness.
The direction in which the first end surface and the second end surface face each other is an L direction,
A direction perpendicular to the L direction on the bottom surface is a W direction, and
A direction perpendicular to both the L direction and the W direction is the T direction,
In a cross section parallel to the TW plane formed by the straight line extending in the W direction and the straight line extending in the T direction and cutting the resin electrode,
The width of the first surface on the metal electrode side of the resin electrode provided on the bottom surface is narrower than the width of the second surface of the resin electrode on the opposite side from the first surface. Electronic components described in item (1) above.
Furthermore, a coil provided inside the element body is provided,
The electronic component according to claim 1, wherein the coil, the first external electrode, and the second external electrode are electrically connected to each other.
preparing an element body including a first end surface, a second end surface opposite to the first end surface, and a bottom surface perpendicular to the first end surface and the second end surface;
providing a first external electrode on the first end surface side;
a step of providing a second external electrode on the second end surface side; the step of providing the first external electrode;
forming a metal electrode on at least a portion of the bottom surface on the first end surface side;
forming a resin electrode that covers a part of the bottom surface of the metal electrode;
In the method of manufacturing an electronic component, in the step of forming the resin electrode, an exposed portion of the metal electrode exposed from the resin electrode is formed.
The step of forming the resin electrode includes:
applying a conductive resin composition containing a photosensitive resin to at least a portion of the bottom surface of the metal electrode;
irradiating a part of the applied resin composition with laser light;
18. The method for manufacturing an electronic component according to claim 17, further comprising a step of removing the part or remainder of the resin composition after the irradiation step.
After the step of forming the resin electrode,
The method for manufacturing an electronic component according to claim 17 or 18, further comprising the step of forming a metal film that covers at least the exposed portion of the metal electrode.