阅读说明：本技术 线圈部件及其制造方法 (Coil component and method for manufacturing same ) 是由 森长哲也 于 2018-10-23 设计创作，主要内容包括：本发明提供一体构造的绕线型的线圈部件,其无论对于螺旋状导线和端子电极这样的电气元件,还是对于环状的芯体,都不存在担心可靠性的接合部分。线圈部件(1)具备：一体构造的芯体(2),将至少一部分设为卷芯部(5),为具有贯通孔(10)的环状,由非导电性材料构成；以及一体构造的线圈导体(3),具有配置为绕卷芯部(5)呈螺旋状延伸的螺旋状导线(11)、和分别形成于螺旋状导线(11)的两端部的第一和第二端子电极(12、13)。经过如下工序制造线圈部件(1)：使用3D打印机对芯体(2)、线圈导体(3)以及形状保持部件(4)进行三维造型,形状保持部件(4)是用于保持芯体(2)的规定上述贯通孔(10)的壁面的形状是部件。(The invention provides a winding type coil component with an integrated structure, which has no joint part with reliability worry for electric elements such as a spiral lead and a terminal electrode and a ring-shaped core body. A coil component (1) is provided with: a core (2) of an integral structure, at least a part of which is a winding core (5), which is annular with a through hole (10), and which is made of a non-conductive material; and an integrally structured coil conductor (3) having a helical lead wire (11) disposed to extend in a helical manner around the winding core (5), and first and second terminal electrodes (12, 13) formed on both ends of the helical lead wire (11), respectively. A coil component (1) is produced by the following steps: a core (2), a coil conductor (3), and a shape-retaining member (4) are three-dimensionally molded using a 3D printer, and the shape-retaining member (4) is a member that defines a wall surface of the through-hole (10) for retaining the core (2).)

1. A coil component, comprising:

a core body of an integral structure, at least a part of which is a winding core portion, which is annular with a through hole, and which is made of a non-conductive material; and

the coil conductor has a helical lead wire disposed to extend helically around the winding core, and a first terminal electrode and a second terminal electrode formed on both ends of the helical lead wire.

2. The coil component of claim 1,

the core is made of a magnetic body to form a completely closed magnetic circuit.

3. The coil component of claim 1 or 2, wherein,

the core body includes, in addition to the winding core portion:

a drum portion having first and second flange portions provided at first and second ends of the winding core portion on opposite sides thereof, respectively; and

a plate-like portion that is integrated with the drum-like portion and that is provided so as to straddle between the first flange portion and the second flange portion while forming the through hole and in a state of facing the core portion,

the spiral lead is integrated with the winding core, and the first terminal electrode and the second terminal electrode are integrated with the first flange portion and the second flange portion, respectively.

4. The coil component of claim 3,

the shape-retaining member is made of an electrically insulating material filled at least between the winding core and the plate-like portion, and at least a portion of the spiral lead located between the winding core and the plate-like portion is embedded in the shape-retaining member.

5. The coil component of claim 4, wherein,

the shape retaining member is composed of glass.

6. The coil component of claim 4 or 5, wherein,

the shape retaining member is provided so as to cover the spiral-shaped wire, the winding core portion, and portions of the first terminal electrode and the second terminal electrode.

7. The coil component according to any one of claims 1 to 6, wherein,

the helical wire is circular in cross section.

8. The coil component according to any one of claims 1 to 7, wherein,

the first terminal electrode and the second terminal electrode each have a shape that cannot pass through the through hole of the core.

9. A method for manufacturing a coil component, wherein the coil component comprises:

a core body of an integral structure, at least a part of which is a winding core portion, which is annular with a through hole, and which is made of a non-conductive material; and

a coil conductor having an integral structure, the coil conductor including a spiral conductor wire arranged to extend spirally around the winding core, and a first terminal electrode and a second terminal electrode formed at both ends of the spiral conductor wire,

the method for manufacturing a coil component includes the following three-dimensional modeling step:

the core, the coil conductor, and a shape holding member for holding a shape of a wall surface defining the through hole of the core are three-dimensionally molded using a 3D printer.

10. The coil component manufacturing method according to claim 9, wherein,

in the three-dimensional modeling step, an inkjet discharge type 3D printer is used as the 3D printer, and the following steps are performed: molding the core with a solution containing a powder of a non-conductive material; molding the coil conductor with a solution containing conductive metal powder; and molding the shape retaining member with a solution containing an electrically insulating material powder,

further comprises the following firing step: firing the core, the coil conductor, and the shape retaining member, which are molded by the 3D printer.

11. The coil component manufacturing method according to claim 9, wherein,

in the three-dimensional modeling step, an inkjet discharge type 3D printer is used as the 3D printer, and the following steps are performed: molding the core with a solution containing a powder of a non-conductive material; molding the coil conductor with a solution containing conductive metal powder; and molding the shape retaining member with a solution containing a resin,

further comprises the following firing step: firing the core, the coil conductor, and the shape retaining member that are molded by the 3D printer,

the firing step includes a step of firing the shape retaining member.

12. The coil component manufacturing method according to claim 10 or 11, wherein,

a solution containing a magnetic material powder is used as the solution containing the non-conductive material powder, a solution containing a copper powder or a solution containing a silver powder is used as the solution containing the conductive metal powder, and a solution containing a glass powder, a solution containing an alumina powder, or a solution containing a zirconia powder is used as the solution containing the electrically insulating material powder.

Technical Field

The present invention relates to a coil component and a method for manufacturing the same, and more particularly to a coil component including a coil conductor wound around a core and a method for manufacturing the same.

Background

For example, in a toroidal coil having a structure in which a conductive wire is spirally wound around a ring-shaped core made of a magnetic material, the ring-shaped core and the spiral conductive wire form a cross-linked structure. In the toroidal coil, magnetic flux is enclosed within a ring-shaped core while passing through the core, thereby forming a closed magnetic circuit. Therefore, the magnetic flux inside the core is not affected by the change in the state outside the core, and there is almost no magnetic flux outside the core.

Since the loop coil has a small magnetic resistance of the magnetic path, when compared with a coil of the hollow core type or the open magnetic path type in which the number of turns of the wire is the same, the core cross-sectional area is the same, and the magnetic path length is the same, a larger amount of magnetic flux can be generated, and a larger inductance value can be realized.

On the other hand, in order to manufacture the toroidal coil, it is necessary to perform a step of winding a wire spirally around at least a part of the annular core as a winding core. In this case, since the winding core is provided by at least a part of the annular core, the process of passing the wire through the through hole of the core for every 1 turn must be repeated. However, it is difficult to mechanize this process, and complicated manual work is usually required.

As a method capable of avoiding such complicated manual work, there are, for example, the techniques described in japanese patent laid-open No. 2001-68364 (patent document 1) and the techniques described in japanese patent laid-open No. 8-203762 (patent document 2).

Patent document 1 describes the following method: a ring coil is manufactured by preparing a split body obtained by splitting an annular core, bending a cylindrical coil in which a wire is wound in a spiral shape in advance into an annular shape, inserting the split core into a hollow portion of the cylindrical coil, and then joining split surfaces of the core with an adhesive.

Patent document 2 describes a method for manufacturing a toroidal coil, which comprises: a helical lead is realized by alternately connecting a plurality of conductors in an inverted U shape and a plurality of conductor films on a wiring substrate, a ring-shaped core is arranged on the wiring substrate in a state of being aligned with the conductor films, and then, in order to realize the helical lead, the plurality of conductors in the inverted U shape are arranged so as to straddle the core, and the plurality of conductors in the inverted U shape and the plurality of conductor films on the wiring substrate are joined by welding.

Patent document 1: japanese patent laid-open No. 2001 and 68364

Patent document 2: japanese laid-open patent publication No. 8-203762

However, the technique described in patent document 1 and the technique described in patent document 2 both have problems to be solved.

First, both the technique described in patent document 1 and the technique described in patent document 2 have the following problems: the number of processes for manufacturing the toroidal coil is larger than that of a manual work of passing the wire through the through hole of the core every 1 turn. In the technique described in patent document 1, at least a step of adhering the split surfaces of the core to each other must be added. In the technique described in patent document 2, at least a step of soldering a plurality of conductors in an inverted U shape to a plurality of conductor films on a wiring board must be added.

In both the technique described in patent document 1 and the technique described in patent document 2, a bonding step such as adhesion or welding cannot be avoided in order to obtain a toroidal coil. Therefore, reliability at the joint portion is concerned as compared with the integrated article. In particular, in the technique described in patent document 1, if the core itself, which is a main part of the coil component, is broken, there is a great problem that the core is originally broken. Further, even if the core itself is not broken, there is a problem that the inductance obtaining efficiency is lowered due to leakage of magnetic flux at the joint portion of the core. On the other hand, the technique described in patent document 2 cannot ignore the fatal problem of disconnection of a spiral lead wire composed of a plurality of conductors in an inverted U shape and a plurality of conductor films on a wiring board.

In general, in a surface-mount type coil component, a terminal electrode is provided along the surface of a core, and each end of a spiral wire is joined to the terminal electrode. In this case, the spiral lead and the terminal electrode are separate bodies, and reliability at the joint portion is concerned.

Further, as the miniaturization of coil components has progressed, the market has demanded, for example, a length dimension of 1mm or less. However, in the conventional toroidal coil having such a size, it is necessary to wind the toroidal core, but it is impossible to wind the toroidal core. In manual work, winding is not possible at all, and even if an automatic winding machine is used, such a small automatic winding machine does not exist. This is because, although there is a limit to mechanical miniaturization, the main reason is that the strength of the wound wire is insufficient (there is no toughness).

Disclosure of Invention

Accordingly, an object of the present invention is to provide a winding type coil component having no joint portion where reliability is concerned, in both an electric element such as a spiral lead and a terminal electrode and a ring-shaped core.

Another object of the present invention is to provide a method for easily manufacturing a coil component which has no joint portion where reliability is concerned and can be miniaturized to a length dimension of, for example, 1mm or less.

The present invention is directed to a winding type coil component including an annular core.

The coil component according to the present invention is characterized by comprising:

a core body of an integral structure, at least a part of which is a winding core portion, which is annular with a through hole, and which is made of a non-conductive material; and

the coil conductor has a helical lead wire disposed to extend in a helical manner around a winding core, and first and second terminal electrodes formed on both ends of the helical lead wire.

According to the present invention, since the core and the coil conductor having the spiral lead and the terminal electrode are of a linked structure and are each of an integral structure, there is no joint portion where there is a concern that the characteristics are degraded and the reliability is deteriorated.

Preferably, the core is made of a magnetic material and forms a completely closed magnetic circuit. With this configuration, a high inductance value can be obtained in the coil component.

In the present invention, it is preferable that the core body further includes, in addition to the winding core portion: a drum portion having a first flange portion and a second flange portion provided at a first end and a second end of the winding core portion, respectively, on opposite sides of the winding core portion; and a plate-like portion that is integrated with the drum-like portion and that is disposed across between the first flange portion and the second flange portion in a state of facing the core portion while forming the through hole. The spiral lead is integrated with the winding core, and the first terminal electrode and the second terminal electrode are integrated with the first flange portion and the second flange portion, respectively. With this configuration, the coil component can be formed in a form suitable for surface mounting.

In the preferred embodiment, it is more preferable that the shape-retaining member is made of an electrically insulating material filled at least between the winding core and the plate-like portion, and at least a portion of the spiral lead located between the winding core and the plate-like portion is embedded in the shape-retaining member. In this configuration, the shape retaining member functions to retain the shape of the wall surface of the core body defining the through hole. Therefore, the space between the winding core portion and the plate-like portion is filled with the shape retaining member, and therefore the strength of the coil component can be increased.

Preferably, the shape retaining member is made of glass. The glass is relatively inexpensive, and the shape retaining member made of glass does not adversely affect the electrical characteristics of the coil member.

The shape retaining member may be provided so as to cover the spiral lead, the winding core, and a portion of each of the first terminal electrode and the second terminal electrode. According to this configuration, since the shape retaining member covers a main portion of the coil component including the spiral wire, the environmental resistance of the coil component can be improved.

In the present invention, the spiral wire is preferably circular in cross section. According to this structure, the parasitic capacitance generated between adjacent turns of the helical wire can be reduced.

In the present invention, it is preferable that the first and second terminal electrodes each have a shape of a through hole that cannot pass through the core. According to this configuration, the reliability of electrical connection and mechanical fixation with the mounting substrate in the mounted state of the coil component can be improved. This preferred structure is a characteristic structure that can be realized by the following manufacturing method.

The present invention is also directed to a method of manufacturing a coil component, the coil component including: a core body of an integral structure, at least a part of which is a winding core portion, which is annular with a through hole, and which is made of a non-conductive material; and an integrally structured coil conductor having a spiral wire arranged to extend spirally around the winding core, and a first terminal electrode and a second terminal electrode formed on both ends of the spiral wire, respectively.

The method for manufacturing a coil component according to the present invention includes: the core, the coil conductor, and a shape holding member for holding the shape of the wall surface defining the through hole of the core are three-dimensionally molded using a 3D printer. The three-dimensional modeling is performed using a 3D printer, thereby enabling the core and the coil conductor, more specifically, the winding core portion of the interlinked structure and the helical wire to be integrally modeled. In addition, the shape holding member can perform three-dimensional modeling of the core and the coil conductor while holding the shape of the through hole.

In the above three-dimensional modeling step, an inkjet discharge type 3D printer is preferably used as the 3D printer, and the following three-dimensional modeling step is preferably performed: molding the core body by using a solution containing non-conductive material powder; molding the coil conductor by using a solution containing conductive metal powder; and molding the shape retaining member with a solution containing an electrically insulating material powder. The manufacturing method further includes the steps of: the core, the coil conductor, and the shape retaining member molded by the 3D printer are fired.

In addition to the preferred embodiment described above, the three-dimensional modeling step may be performed by using an inkjet discharge type 3D printer as the 3D printer, and performing the following steps: molding the core body by using a solution containing non-conductive material powder; molding the coil conductor by using a solution containing conductive metal powder; and molding the shape retaining member with a solution containing a resin. The manufacturing method further includes the following firing step: the core, the coil conductor, and the shape retaining member molded by the 3D printer may be fired, or the shape retaining member may be burned out in the firing step.

In the above preferred embodiments, it is more preferable that a solution containing a magnetic powder is used as the solution containing the non-conductive material powder, a solution containing a copper powder or a solution containing a silver powder is used as the solution containing the conductive metal powder, and a solution containing a glass powder, a solution containing an alumina powder or a solution containing a zirconia powder having a low dielectric constant is used as the solution containing the electrically insulating material powder.

According to the coil component of the present invention, since the coil component is integrally structured with both the annular core and the coil conductor having the spiral lead and the terminal electrode, there is no joint portion where reliability is concerned. Therefore, the coil component having high reliability can be obtained both electrically and mechanically.

According to the method of manufacturing a coil component of the present invention, the coil component is manufactured through a three-dimensional molding process using a 3D printer, and the coil component is configured such that the annular core and the coil conductor having the spiral lead and the terminal electrode are of a linked structure and are each of an integral structure. Therefore, it is possible to easily manufacture a coil component which is formed without a joint portion where reliability is concerned and which is miniaturized in a length dimension of, for example, 1mm or less.

Drawings

Fig. 1 is a perspective view showing an external appearance of a coil component 1 according to an embodiment of the present invention.

Fig. 2 is a front view of the coil component 1 shown in fig. 1.

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

Fig. 4 is a right side view of the coil component 1 shown in fig. 1.

Fig. 5 is a diagram for explaining a method of manufacturing the coil component 1 shown in fig. 1, and is a front view showing the shaped object 16a immediately after three-dimensional shaping is started using a 3D printer.

Fig. 6 is a front view showing a shaped object 16b obtained by continuing three-dimensional shaping from the state shown in fig. 5.

Fig. 7 is a front view showing a shaped object 16c obtained by further continuing the three-dimensional shaping from the state shown in fig. 6.

Fig. 8 is an enlarged cross-sectional view of a part of the shaped object 16c shown in fig. 7.

Fig. 9 is a front view showing a shaped object 16d obtained by further continuing the three-dimensional shaping from the state shown in fig. 7.

Fig. 10 is a front view showing a shaped object 16e obtained by further continuing the three-dimensional shaping from the state shown in fig. 9.

Fig. 11 is a front view showing a shaped object 16f obtained by further continuing the three-dimensional shaping from the state shown in fig. 10.

Fig. 12 is a front view showing a shaped object 16g obtained by further continuing the three-dimensional shaping from the state shown in fig. 11 and completing the shaping.

Fig. 13 (a) shows inductance characteristics of a coil component according to an example of the present invention, and (B) shows inductance characteristics of a coil component according to a comparative example outside the scope of the present invention.

Detailed Description

A structure of a coil component 1 according to an embodiment of the present invention will be described with reference to fig. 1 to 4. The illustrated coil component 1 is a component constituting a single coil, for example.

The coil component 1 includes a core 2, a coil conductor 3, and a shape retaining member 4. In fig. 1 to 4, the shape retaining member 4 is a transparent member and is shown by a dashed-dotted line.

The core 2 is made of a non-conductive material, but is preferably made of a magnetic material such as ferrite or a metallic magnetic material. However, the core 2 may be made of a non-magnetic material such as alumina. The core 2 includes a drum portion 8, and the drum portion 8 includes a winding core 5 having a rectangular cross section, and first and second flange portions 6, 7 provided at first and second ends of the winding core 5 opposite to each other, respectively, and a plate-like portion 9 provided so as to straddle between the first and second flange portions 6, 7. The plate-like portion 9 is opposed to the winding core 5.

When the core 2 is made of a magnetic material, a completely closed magnetic circuit is formed, and the core is an integral structure. Namely, the drum portion 8 and the plate portion 9 are integrated. The core body 2 has a through hole 10 formed between the winding core 5 and the plate-like portion 9 facing each other, and is formed in a ring shape as a whole.

The coil conductor 3 includes a spiral wire 11 arranged to extend spirally around the winding core 5, and first and second terminal electrodes 12, 13 formed at both ends of the spiral wire 11, respectively. More specifically, the first and second terminal electrodes 12 and 13 are formed with connection pieces 14 and 15, respectively, which extend into the through-hole 10, and both ends of the spiral wire 11 are connected to the connection pieces 14 and 15, respectively. The coil conductor 3 is an integral structure. Therefore, the spiral lead wire 11 and the first and second terminal electrodes 12 and 13 are integrated.

The spiral conductor 11 is preferably circular in cross section (see fig. 8). According to this structure, the parasitic capacitance generated between adjacent turns of the spiral wire 11 can be reduced. In order to improve the reliability of electrical connection and mechanical fixation to the mounting board in the mounted state of the coil component 1, the first and second terminal electrodes 12 and 13 need to have a size equal to or larger than a predetermined size. In this embodiment, the first and second terminal electrodes 12 and 13 each have a shape that cannot pass through the through hole 10 of the core 2, and for example, the first and second terminal electrodes 12 and 13 each have a size larger than the through hole 10. This structure is a characteristic structure that can be realized by the manufacturing method described later.

The shape holding member 4 holds the shape of the wall surface of the predetermined through hole 10 of the core 2, and is filled at least between the core portion 5 and the plate-like portion 9. Therefore, at least a portion of the spiral wire 11 located between the winding core 5 and the plate-like portion 9 is embedded in the shape retaining member 4. In this way, if the space between the winding core portion 5 and the plate-like portion 9 is filled with the shape retaining member 4, the strength of the coil component 1 can be increased. The shape retaining member 4 has an important function of enabling three-dimensional modeling using a 3D printer, which is performed in a manufacturing method described later.

The shape retaining member 4 is made of an electrically insulating material such as glass, alumina, or zirconia. Among them, the shape retaining member 4 is preferably made of glass. This is because glass is relatively inexpensive, and the shape retaining member 4 made of glass does not adversely affect the electrical characteristics of the coil member 1.

In this embodiment, the shape retaining member 4 is provided so as to cover a portion of each of the spiral lead wire 11, the winding core 5, and the first and second terminal electrodes 12 and 13. According to this configuration, since the shape retaining member 4 covers the main portion of the coil component 1 including the spiral wire 11, the environmental resistance of the coil component 1 can be improved.

Next, an advantageous method for manufacturing the coil component 1 will be described with reference to fig. 5 to 12.

The manufacturing method described here is characterized in that the core 2, the coil conductor 3, and the shape retaining member 4 are three-dimensionally molded using a 3D printer. By three-dimensional modeling using a 3D printer, the core 2 and the coil conductor 3 of the interlinked structure can be integrally modeled.

Fig. 12 shows a shaped object 16g obtained by turning the coil component 1 shown in fig. 2 upside down. By sequentially performing the steps described below, a shaped object 16g shown in fig. 12 can be obtained.

First, as shown in fig. 5, a build table 17 is prepared, and three-dimensional build using a 3D printer is started on the build table 17. Immediately after the three-dimensional modeling is started, a modeled object 16a to be a part of the shape retaining member 4 is obtained on the modeling table 17.

Then, the three-dimensional modeling is continued. As the time for continuing the three-dimensional modeling elapses, shaped objects 16b, 16c, 16d, 16e, 16f, and 16g shown in fig. 6, 7, 9, 10, 11, and 12, respectively, are sequentially generated.

In fig. 6, as the height of the portion to be the shape retaining member 4 increases, a shaped object 16b is generated, and the shaped object 16b has a portion to be a part of the spiral wire 11 in the coil conductor 3.

Next, in fig. 7, as the height of each portion to be the shape retaining member 4 and the spiral wire 11 increases, a shaped object 16c is produced, and the shaped object 16c has a portion to be a part of the core portion 5 and a portion of each of the first and second flange portions 6 and 7 in the core body 2.

Here, referring to fig. 8 showing a cross-sectional view of a part of the shaped object 16c in an enlarged manner, it can be seen that the spiral lead wire 11 has a circular cross section, is embedded in the shape holding member 4, and is in contact with the core portion 5. Fig. 8 also shows that a predetermined space is provided between adjacent turns of the spiral conductor wire 11, and these spaces are filled with the shape retaining member 4. In addition, depending on the resolution of the 3D printer used, the cross-sectional shape of the spiral conductor 11 may not draw a clear circular contour as shown in fig. 8, but may be a jagged contour.

Next, in fig. 9, as the height of each portion to be a part of each of the shape retaining member 4, the spiral lead wire 11, and the first and second flange portions 6 and 7 further increases, a shaped object 16d is produced, and the shaped object 16d has a portion to be a part of each of the first and second terminal electrodes 12 and 13 in the coil conductor 3. In this shaped object 16d, the shaping of the roll core 5 is completed. In addition, the first and second terminal electrodes 12, 13 are shaped together with the first and second flanges 6, 7, respectively, and thus are integrated with the first and second flanges 6, 7.

Next, in fig. 10, a shaped object 16e is obtained, and the height of the shaped object 16e is further increased by the portions to be part of the first and second flange portions 6 and 7 and the first and second terminal electrodes 12 and 13. In the shaped object 16e, the shape holding member 4 and the spiral wire 11 are shaped.

Next, in fig. 11, as the height of the portion to be a part of each of the first and second flange portions 6 and 7 and the first and second terminal electrodes 12 and 13 further increases, a shaped object 16f is produced, which starts shaping the plate-like portion 9 in the core 2. Here, although the through hole 10 is formed between the winding core 5 and the plate-like portion 9, it should be noted that the shape of the plate-like portion 9 by the 3D printer can be made because the through hole 10 is filled with the shape retaining member 4.

Next, in fig. 12, the shaping of the first and second flange portions 6, 7, the first and second terminal electrodes 12, 13, and the plate-shaped portion 9 is completed, and a shaped object 16g including all the elements included in the coil component 1 shown in fig. 2 is produced.

As described above, the three-dimensional modeling by the 3D printer is completed.

In the three-dimensional modeling step, an inkjet discharge type 3D printer is preferably used as the 3D printer. In the inkjet ejection type 3D printer, the core 2 is molded with a solution containing a non-conductive material powder, the coil conductor 3 is molded with a solution containing a conductive metal powder, and the shape holding member 4 is molded with a solution containing an electrically insulating material powder. Then, the core 2, the coil conductor 3, and the shape retaining member 4, which are molded by the inkjet 3D printer, are further fired. Thereby, the coil component 1 is completed.

In the above molding step, more specifically, a solution containing a magnetic material powder, more preferably a solution containing a ferrite powder or a solution containing a metallic magnetic material powder is used, a solution containing a copper powder or a solution containing a silver powder is used as the solution containing a non-conductive material powder, and a solution containing a glass powder, a solution containing an alumina powder or a solution containing a zirconia powder having a low dielectric constant is used as the solution containing an electrically insulating material powder. When a solution containing copper powder is used as the solution containing conductive metal powder, the firing step is preferably performed in a reducing gas.

The step of firing the core 2, the coil conductor 3, and the shape retaining member 4 is usually performed after the shaping of the core 2, the coil conductor 3, and the shape retaining member 4 is completed, but instead of this, firing with a laser, for example, may be applied simultaneously with the shaping of the core 2, the coil conductor 3, and the shape retaining member 4. This latter firing method is particularly suitable in the case of using a solution containing copper powder as the solution containing conductive metal powder.

In the above-described embodiment, the coil component 1 as a product includes the shape retaining member 4, but the shape retaining member 4 may not be present in the coil component as a product.

That is, in the three-dimensional molding step, the core 2 is molded with a solution containing a non-conductive material powder, and the coil conductor 3 is molded with a solution containing a conductive metal powder, while the shape retaining member 4 is molded with a solution containing a resin. Further, the core 2, the coil conductor 3, and the shape retaining member 4 molded by the 3D printer are fired, and in this firing step, the shape retaining member 4 is burned out, so that the core can be prevented from remaining in the coil component as a product.

According to the three-dimensional modeling using the 3D printer described above, the design of the coil component as a product can be easily changed as described below by merely changing the program.

For example, in the illustrated embodiment, the spiral conductor 11 is formed by single-layer winding, but the spiral conductor may be formed by multi-layer winding having two or more layers. In the multilayer winding, one or more spiral wires may be used. Therefore, the coil component may be a common mode choke coil, a transformer, or the like, in addition to a single coil. In addition, the spiral wire 11 may be wound around the plate-like portion 9

In the illustrated embodiment, the coil component 1 includes two terminal electrodes 12 and 13, but may include four terminal electrodes, six terminal electrodes, and the terminal electrodes may be arranged asymmetrically. The shape, size, and arrangement of the terminal electrode can also be freely changed.

In addition, the shape of the core can be freely changed. For example, it is also easy to form the core in a conical shape.

Further, the size of the coil component or the size of each element provided in the coil component can be freely changed.

Further, the plurality of coil components can be molded at the same time. In this case, the coil components to be molded simultaneously may be all of the same type or different types.

In fig. 13, inductance characteristics of the coil component according to the example of the present invention and the coil component according to the comparative example outside the scope of the present invention are compared. In fig. 13, (a) shows inductance characteristics of the coil component according to the example, and (B) shows inductance characteristics of the coil component according to the comparative example.