JP2003318036A - Coil component and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coil component that can suppress the cracking of a core with closed magnetic circuit caused by temperature changes when the component is used or manufactured, and to provide a method of manufacturing the component. <P>SOLUTION: This coil component is constituted by bonding and fixing two split cores to each other by applying an adhesive even to the boundary faces 13 of the split cores so that the split cores may form a cylindrical shape and, at the same time, disposing the adhesive 15 in a gap section 14. The adhesive 15 is composed of a thixotropic material having a coefficient of liner expansion which is close to those of the spit cores and applied to the boundary faces 13 of the split cores so that the applied extent (H) of the adhesive 15 in the facing direction of the boundary faces 13 may become larger than that (W) of the adhesive 15 in the widthwise direction of the faces 13. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil component used in various electronic devices and the like and a method for manufacturing the same.

[0002]

2. Description of the Related Art A conventional coil component will be described below with reference to the drawings.

FIG. 11 is a perspective view of a conventional coil component, FIG.
2 is a sectional view of the coil component.

11 and 12, a conventional coil component is a closed magnetic circuit core 3 formed by combining two split cores, an E-shaped core 1 and an I-shaped core 2, and one of the closed magnetic circuit cores 3. And a coil portion 4 arranged on the magnetic leg.
The one magnetic leg is provided so that the boundary surface 7 between the middle leg portion 5 of the E-shaped core 1 and the central portion 6 of the I-shaped core 2 faces each other through the void portion 8. An adhesive 9 is applied to the boundary surface 7 between the middle leg 5 of the first I-shaped core 2 and the center 6 of the I-shaped core 2 to bond and fix the two split cores. This adhesive 9
The dimension (W) of the boundary surface 7 of the split core in the facing direction is smaller than the dimension (W) of the boundary surface 7 of the split core, and
It protrudes from the space 8 in the width direction of the split core.

[0005]

The conventional coil component is
It is mainly used as a DC-DC choke coil (driving frequency is 200 to 300 kHz) for driving a CPU (central processing unit) mounted in a computer or the like.
The input current of the DC-DC choke is increasing as the frequency of the CPU exceeds the limit.

In general, when the input current to the coil component increases, the facing distance of one magnetic leg in the above conventional coil component is increased, and the gap 8 is formed so that the dimension (H) in the facing direction is increased. The closed magnetic circuit core 3 for a large current input
In addition to suppressing the saturation of the noise, the beat is remarkably generated. Therefore, it is necessary to apply an adhesive to the boundary surface to suppress the beat.

However, in the above-mentioned conventional structure, when the adhesive 9 is applied to the boundary surface 7 having a large opposed dimension (H), the amount of the adhesive 9 applied must be increased, and the coil component is used. A stress is likely to be generated between the adhesive 9 and the closed magnetic circuit core 3 due to a temperature change at the time of manufacturing or manufacturing, and the fragile portion of the closed magnetic circuit core 3 (in the case of an E-shaped core, the vicinity of the root of the middle leg portion). There was a problem that the division) was broken.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a coil component in which cracking of the closed magnetic circuit core due to temperature change during use or manufacturing is suppressed and a manufacturing method thereof.

[0009]

In order to achieve the above object, the present invention has the following constitution.

In the invention according to claim 1 of the present invention, in particular, the one magnetic leg is provided so that the boundary surfaces of the two split cores face each other with a gap therebetween, and the boundary surface of the two split cores. An adhesive is applied to the two cores to bond and fix the two divided cores, and the adhesive is arranged inside the void.

Generally, the larger the adhesive area between the adhesive and the split core, the greater the stress due to the temperature change. However, in the above construction, the contact area between the adhesive and the split core is inside the void. Since it is limited to the corresponding part,
It is possible to suppress the generation of stress even when the boundary surface between the two split cores in one magnetic leg is separated from each other without causing stress more than necessary.

Therefore, cracking of the closed magnetic circuit core due to temperature change can be suppressed.

According to a second aspect of the present invention, in particular, the adhesive has a configuration in which the dimension of the boundary surface of the split core in the opposing direction is larger than the dimension of the boundary surface of the split core in the width direction.

With the above structure, it is possible to suppress the generation of stress even if the distance between the boundary surfaces of the two split cores in one magnetic leg is large.

According to a third aspect of the present invention, in particular, the linear expansion coefficient of the adhesive and the linear expansion coefficient of the split cores are the same.

With the above structure, since the linear expansion coefficients are the same, it is possible to suppress the stress caused by the temperature change.

The invention according to claim 4 of the present invention is particularly configured such that the adhesive has a thixotropic property.

With the above structure, the adhesive can be easily placed inside the void.

According to a fifth aspect of the present invention, the adhesive has a cylindrical shape.

With the above structure, it is possible to suppress the generation of stress even if the distance between the boundary surfaces of the two split cores in one magnetic leg is large.

According to a sixth aspect of the present invention, in particular, the adhesive has a drum-shaped configuration in which the center of the cylinder is constricted.

With the above structure, it is possible to suppress the occurrence of stress even if the distance between the boundary surfaces of the two split cores in one magnetic leg is large.

In the invention according to claim 7 of the present invention, in particular, the adhesive has an elliptical shape.

With the above structure, even if the distance between the boundary surfaces of the two split cores in one magnetic leg is long, the generation of stress can be suppressed.

In the invention according to claim 8 of the present invention, in particular, the closed magnetic circuit core has one of two split cores which is an E-shaped core and the other which is an I-shaped core. It is formed by combining with the I-shaped core,
The middle leg portion of the I-shaped core and the central portion of the I-shaped core are opposed to each other with a gap therebetween as a boundary surface, and the adhesive is provided in the gap portion.

With the above structure, the use of the E-shaped core and the I-shaped core makes it possible to suppress the generation of stress even if the distance between the boundary surfaces of the two split cores in one magnetic leg is large.

The invention according to claim 9 of the present invention is the invention according to claim 8.
In the invention described above, in particular, the adhesive has a triangular pyramid shape with the end side of the middle leg of the E-shaped core as the bottom side and the center side of the I-shaped core as the apex.

With the above structure, the use of the E-shaped core and the I-shaped core makes it possible to suppress the generation of stress even if the distance between the boundary surfaces of the two split cores in one magnetic leg is large.

The invention according to claim 10 of the present invention is
A taper portion is provided at the end portion of the middle leg portion of the E-shaped core, and an adhesive is applied to the tip of the end portion excluding the taper portion.

With the above configuration, the use of two E-shaped cores makes it possible to suppress the generation of stress even if the distance between the boundary surfaces of the two split cores in one magnetic leg is large.

The invention according to claim 11 of the present invention is
The closed magnetic circuit core is formed by combining two split cores each having an E-shaped core, and the ends of the middle legs of the two E-shaped cores are opposed to each other with a gap therebetween as a boundary surface. The adhesive is provided in the void.

With the above structure, the use of two E-shaped cores makes it possible to suppress the generation of stress even if the distance between the boundary surfaces of the two split cores in one magnetic leg is large.

The invention according to claim 12 of the present invention is
A taper portion is provided at the end portion of the middle leg portion of the E-shaped core, and an adhesive is applied to the tip of the end portion excluding the taper portion.

With the above structure, the adhesive can be applied only to the tip of the end of the middle leg excluding the tapered portion, and the position of the taper portion determines the position where the adhesive is applied to the end of the middle leg. Can be adjusted. As a result, the closer the application position of the adhesive is to the center of the end of the middle leg, the smaller the stress applied to the root of the middle leg, and the occurrence of stress can be suppressed.

The invention according to claim 13 of the present invention is particularly
An adhesive is applied to the boundary surface between the two split cores, and the adhesive is placed inside the void to provide an adhesive step of adhesively fixing the two split cores.

With the above structure, the contact area between the adhesive and the split cores is limited to the portion corresponding to the inside of the void portion, stress is not generated more than necessary, and the boundary surface between the two split cores in one magnetic leg is reduced. It is possible to manufacture a coil component that suppresses the generation of stress even if the distance is large.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION The invention described in all the claims of the present invention will be described below with reference to the drawings by using one embodiment.

FIG. 1 is a sectional view of a coil component according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the coil component, FIG. 3 is a front side perspective view of the coil component, and FIG. It is a rear side perspective view.

1 to 4, a coil component according to an embodiment of the present invention includes a closed magnetic circuit core 11 formed by combining two split cores, and a coil arranged on one magnetic leg of the closed magnetic circuit core 11. The one magnetic leg is provided so that the boundary surface 13 of the two split cores faces each other via the void portion 14. An adhesive 15 is applied and fixed to the split core and the coil portion 12.

An adhesive 15 is applied to the boundary surface 13 between the two split cores so as to form a cylindrical shape, and the two split cores are bonded and fixed together. The adhesive 15 is arranged inside the void portion 14. . The adhesive 15 is made of a material having a thixotropy property of a linear expansion coefficient close to that of the split core, and the adhesive 15 has a width direction dimension (W) larger than that of the split core boundary surface 13. The coating is performed so that the dimension (H) in the facing direction is increased.

One of the two split cores is an E-shaped core 1.
6 and the other is an I-shaped core 17, and the E-shaped core 16 and the I-shaped core 17 are combined to form an end portion of the middle leg portion 18 of the E-shaped core 16 and the center of the I-shaped core 17. The closed magnetic circuit core 11 is formed with the portion 19 and the boundary surface 13 as boundaries. A terminal for connecting to the coil portion 12 is attached to the I-shaped core 17, and the coil portion 1
2 and the I-shaped core 17 are fixed by applying an adhesive 15.

In the method for manufacturing the coil component, the closed magnetic circuit core 11 is formed by combining the two split cores so that the boundary surface 13 of the two split cores faces each other with the gap 14 in one magnetic leg. The method includes a path core 11 forming step and a coil portion 12 arranging step of arranging the coil portion 12 on one magnetic leg of the closed magnetic circuit core 11.

An adhesive 15 is applied to the boundary surface 13 between the two split cores, and the adhesive 15 is positioned inside the void portion 14 to provide an adhesive process for adhesively fixing the two split cores. ing.

According to the above construction, the adhesive 15 is generally used.
Although the stress due to temperature change tends to increase as the contact area between the core and the split core increases, the contact area between the adhesive 15 and the split core is limited to the portion corresponding to the inside of the void portion 14. , No more stress than necessary.

That is, even if the distance between the boundary surfaces 13 of the two split cores in one magnetic leg is long, the generation of stress can be suppressed, so that cracking of the closed magnetic circuit core 11 due to temperature change can be suppressed. In particular, one of the two split cores is E
When the letter-shaped core 16 is used and the other is the I-shaped core 17, the end portion of the middle leg portion 18 of the E-shaped core 16 and the central portion 19 of the I-shaped core 17 are used as the boundary surface 13 with each other and the adhesive 15 may be applied.

Since the adhesive 15 has a cylindrical shape and has a dimension (H) in the facing direction of the boundary surface 13 of the split core larger than a dimension (W) in the width direction of the boundary surface 13 of the split core, Generation of stress can be suppressed even if the distance between the boundary surfaces 13 of the two split cores in one magnetic leg is large.

Further, since the linear expansion coefficient of the adhesive 15 is the same as the linear expansion coefficient of the split core, it is possible to further suppress the stress caused by the temperature change.

Further, since the adhesive 15 has a thixotropic property, it becomes easy to dispose the adhesive 15 inside the void portion 14.

According to the above manufacturing method, a coil component having the above effects can be manufactured.

As described above, according to the present embodiment, even if the distance between the boundary surfaces 13 of the two split cores in one magnetic leg is long, the generation of stress is suppressed, and the closed magnetic circuit core 11 due to the temperature change is closed. It is possible to suppress cracking.

Although the two split cores are the E-shaped core 16 and the I-shaped core 17 in this embodiment, the two E-shaped cores 16 may be combined.

Although the adhesive 15 has a cylindrical shape, it has an elliptical shape as shown in FIG. 5, a drum shape with a constricted center of the cylinder as shown in FIG. 6, and an I-shape as shown in FIG. A triangular pyramid shape having the central portion 19 side of the core 17 as an apex, or an opposite inverted triangular pyramid shape as shown in FIG. 8 may be used.

It is preferable that the adhesive 15 has a dimension (H) in the facing direction larger than the dimension (W) in the width direction, but even if the dimension (W) in the width direction is larger than the dimension (H) in the facing direction. Good. For example, as shown in FIG. 9, the inverted triangular pyramid-shaped adhesive 15 may have a flat inverted triangular pyramid shape in which the dimension (H) in the facing direction and the dimension (W) in the width direction are about 1: 3.

Further, in order to apply the adhesive 15, as shown in FIG.
It is better to provide a taper portion 20 at the end portion of the middle leg portion 18 of the E-shaped core 16 as shown in 0 and apply the adhesive 15 to the tip of the end portion excluding the taper portion 20.

[0055]

As described above, according to the present invention, since the contact area between the adhesive and the split core is limited to the portion corresponding to the inner side of the void portion, stress is not generated more than necessary, and Even if the distance between the boundary surfaces of the two split cores in the magnetic leg is long, the generation of stress can be suppressed.

As a result, it is possible to provide a coil component in which cracking of the closed magnetic circuit core due to temperature change is suppressed and a method for manufacturing the same.

[Brief description of drawings]

FIG. 1 is a sectional view of a coil component according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the same.

FIG. 3 is a front perspective view of the same.

FIG. 4 is a rear perspective view of the same.

FIG. 5 is a sectional view of a coil component coated with the same elliptical adhesive.

FIG. 6 is a cross-sectional view of a coil component to which the same drum-shaped adhesive is applied.

FIG. 7 is a sectional view of a coil component coated with the same triangular-pyramidal adhesive.

FIG. 8 is a cross-sectional view of a coil component coated with an adhesive in the shape of an inverted triangular pyramid.

FIG. 9 is a cross-sectional view of a coil component coated with the same flat inverted triangular pyramid adhesive.

FIG. 10 is a sectional view of a coil component in which a taper portion is provided on a middle leg portion of the E-shaped core.

FIG. 11 is a perspective view of a conventional coil component.

FIG. 12 is a sectional view of the same.

[Explanation of symbols]

11 Closed magnetic circuit core 12 coil part 13 Boundary 14 Void 15 Adhesive 16 E-shaped core 17 I-shaped core 18 Middle leg 19 central part

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Keiichi Nakatani             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Yu Yoshihara             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd.

Claims (13)

[Claims] 1. A closed magnetic circuit core formed by combining two split cores, and a coil portion arranged on one magnetic leg of the closed magnetic circuit core, wherein the one magnetic leg is a boundary surface between the two split cores. Are provided so as to face each other through a void, and an adhesive is applied to the boundary surface of the two split cores to bond and fix the two split cores, and the adhesive is applied to the inside of the void. Placed coil parts. 2. The coil component according to claim 1, wherein the adhesive has a dimension in the facing direction of the boundary surface of the split core larger than a dimension in the width direction of the boundary surface of the split core. 3. The coil component according to claim 1, wherein the linear expansion coefficient of the adhesive and the linear expansion coefficient of the split core are the same. 4. The coil component according to claim 1, wherein the adhesive has a thixotropic property. 5. The coil component according to claim 2, wherein the adhesive has a cylindrical shape. 6. The coil component according to claim 2, wherein the adhesive has a drum shape in which the center of the cylinder is constricted. 7. The coil component according to claim 2, wherein the adhesive has an elliptical shape. 8. The closed magnetic circuit core is formed by combining one of the two split cores with an E-shaped core and the other with an I-shaped core, and combining the E-shaped core with the I-shaped core. And an end portion of the middle leg of the E-shaped core and a central portion of the I-shaped core are opposed to each other via a void as boundary surfaces, and the adhesive is provided in the void. The coil component according to item 1. 9. The coil component according to claim 8, wherein the adhesive has a triangular pyramid shape with the end side of the middle leg of the E-shaped core as the bottom side and the center side of the I-shaped core as the apex. . 10. The coil component according to claim 8, wherein a taper portion is provided at an end portion of the middle leg portion of the E-shaped core, and an adhesive is applied to a tip of the end portion excluding the taper portion. 11. The closed magnetic circuit core is formed by combining two split cores each formed of an E-shaped core, and a void is formed with the ends of the middle legs of the two E-shaped cores as boundary surfaces with each other. The coil component according to claim 1, wherein the coil component is opposed to each other and the adhesive is provided in the void. 12. The coil component according to claim 11, wherein a taper portion is provided at an end portion of the middle leg portion of the E-shaped core, and an adhesive is applied to a tip of the end portion excluding the taper portion. 13. A closed magnetic circuit core forming step of forming a closed magnetic circuit core by combining the two divided cores so that the boundary surfaces of the two divided cores face each other with a gap in one magnetic leg, and the closed magnetic circuit core. A coil portion arranging step of arranging a coil portion on one magnetic leg of the road core, and applying an adhesive to a boundary surface between the two split cores, and arranging the adhesive inside the void portion. And a method of manufacturing a coil component, which comprises a bonding step of bonding and fixing the two divided cores.