JPH08306559A - Coil part - Google Patents

Abstract

PURPOSE: To provide a coil part which is manufactured simply and is miniaturized easily, and still, can be mounted on the surface of a circuit board. CONSTITUTION: A box-form core 21 has opening portions 28 on both its opposite side surfaces, and both its end surfaces and its top and bottom surfaces are closed respectively by end walls 24 and top and bottom walls 23. A winding core portion 25 is formed in the internal place of the core 21 which is present between both its openings 28, and on the side surface of the core 21, electrode portions 22 are formed adjacently to its opening 28. A winding 29 is wound around the winding core portion 25, and drawing-out end portions 26 of the winding 29 are so drawn out from the opening 28 on the side surface of the core 21 as to be connected respectively with the electrode portions 22 by solders 27. The winding core portion 25 and the winding 29 wound around the winding core portion 25 are present in the more inside portion of the core 21 than its opening 28 and they are covered with an insulation material filled into the inner portion of the core 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil component such as a common mode choke coil in which a core is wound.

[0002]

2. Description of the Related Art As shown in FIG. 9, a conventional common mode choke coil has a pair of windings 2 and 2 wound around a core 8 made of ring-shaped ferrite or the like in a toroidal shape. In the common mode choke coil 1, current is passed through the windings 2 and 2 so that magnetic fluxes generated in the core 8 due to the currents flowing through the pair of windings 2 and 2 cancel each other. When such a common mode choke coil 1 is surface-mounted on a circuit board, it can be mounted on the circuit board as it is. However, since the lead-out ends 3 and 3 of the windings 2 and 2 are ends of thin conductive wires, their positions are difficult to determine, and when connecting the windings 2 and 2 to the electrodes on the circuit board, it is necessary to manually Connection is required, and automatic mounting cannot be performed.

Therefore, in order to realize automatic mounting on a circuit board, a base 4 and a case 7 as shown in FIG. 9 are used. The base 4 is made of an insulating material, has projections 6 on its upper surface, and has lead terminals 5 and 5 on both end surfaces. The case 7 has an outer shape corresponding to the shape of the base 4,
It has a box shape with an open bottom. The common mode choke coil 1 is placed on the base 4, and the protrusion 6 of the base 4 is fitted in the inner peripheral hole of the core 8 to form the choke coil 1.
Is fixed on the base 4. The lead-out ends 3 and 3 of the windings 2 and 2 of the common mode choke coil 1 are entwined with the lead terminals 5 and 5 provided on both ends of the base 4 and soldered. Furthermore, by covering the base 4 with the case 7, the common mode choke coil 1 fixed on the base 4 is covered.

By housing the common mode choke coil 1 in the base 4 and the case 7 in this manner, a form similar to a package component can be obtained, and the package can be automatically mounted on a circuit board in the same manner as the package component. become. That is, the common mode choke coil 1 housed in the base 4 and the case 7 is mounted on the circuit board, and the lead terminals 5 and 5 of the base 4 are soldered to the electrodes on the circuit board.

[0005]

However, in the case of packaging such coil components, the base 4 is used.
Since the case 7 is used and the common mode choke coil 1 which is a coil component is incorporated therein, there is a problem that downsizing is difficult and the assembly is troublesome. The present invention has been made in view of the above problems of conventional coil components, and an object of the present invention is to provide a coil component that is easy to manufacture, can be easily miniaturized, and can be surface-mounted on a circuit board.

[0006]

In order to achieve this object, in the present invention, a box-like shape is formed in which both opposing side surfaces 28 are open, and a winding core portion 25 is formed inside the opening portions 28. A specially shaped core 21 having an electrode portion 22 formed on its side surface adjacent to the opening portion 28 is used.
Then, the winding wire 29 is wound around the winding core portion 25, and the lead-out end portion 26 is drawn out from the opening portion 28 on the side surface of the core 21,
A coil component is obtained by connecting to the electrode part 22.

That is, the coil component according to the present invention is a coil component in which the core 21 is provided with the winding wire 29, and has a box shape in which the opening portions 28 are provided on both side surfaces facing each other. Core 2 having a winding core portion 25 formed therein
1, the electrode portion 22 formed on the side surface of the core 21 adjacent to the opening portion 28, and the winding core portion 25, and the lead-out end portion 26 extends from the opening portion 28 on the side surface of the core 21. And a winding wire 29 that is drawn out and connected to the electrode portion 22.

Here, the winding core portion 25 and the winding wire 29 wound around the winding winding core portion 25 are located inside the core 21 with respect to the opening portion 28 of the core 21. 29
Are covered with an insulating material 30 filled inside the core 21. A groove 31 is formed in the electrode portion 22 formed on the side surface of the core 21, and the lead-out end portion 26 of the winding wire 29 is engaged with the groove 31. In the case of a coil component having a pair of windings in opposite directions and having the same number of turns, such as a common mode choke coil, the winding core portion 25 is arranged closer to one electrode 22 side than the center portion of the core 21. There are also cases.

[0009]

In the coil component according to the present invention, the electrode 22 is formed on the side surface of the core 21, and the lead-out end portion 26 of the winding wire 29 wound around the winding core portion 25 of the core 21 is provided on the core 21 itself. Since it is connected to the portion 22, it can be directly manufactured as a packaged coil component without assembling a plurality of members. Therefore, the number of packaging steps can be reduced. Since the electrode 22 is provided on the side surface of the core 21, when the coil component is mounted on the circuit board, the electrode 22 can be easily connected to the electrode on the circuit board.

In the coil component according to the present invention, the winding core portion 25 and the winding wire 29 wound around the winding core portion 25 include the core 21.
When the core portion 25 and the winding wire 29 are covered with the insulating material 30 filled in the core 21, the winding wire 29 is located inside the core 21 from the opening 28. Trouble such as disconnection can be reliably prevented without being exposed to the outside of the core 21. A groove 31 is formed in the electrode portion 22 formed on the side surface of the core 21, and the extraction end portion 26 of the winding wire 29 is engaged with the groove 31 to fix the extraction end portion 26 of the winding wire 29 to the electrode 22. It becomes easier and they can be connected easily.

Further, when all the lead-out ends 26 of the plurality of windings 29 are drawn out from the same side surface of the winding core 25, such as a common mode choke coil, the winding core 25 is formed.
Is at the center of the core 21, the lead-out end 2 of each winding 29 is
There will be a large difference in the length of the electrode 6 up to the electrode 22. On the other hand, when the winding core portion 25 is arranged so as to be biased toward the one electrode 22 side from the central portion of the core 21,
The imbalance in the length of the lead-out end 26 of each winding 29 up to the electrode 22 can be corrected by the bias of the winding core 25.

[0012]

Embodiments of the present invention will now be described specifically and in detail with reference to the drawings. 1 to 4 show an embodiment of the present invention. FIG. 2 shows the core 21 before the winding 29 is applied.
The core 21 has a cubic box shape as a whole. The upper and lower surfaces and both end surfaces of the core 21 are
The core 21 is closed by upper and lower walls 23 and end walls 24, respectively.
An opening 28 is formed only in the central portion of both side surfaces of the core 21, and the opening 28 extends through both side surfaces of the core 21.

A winding core portion 25 is formed inside the upper and lower walls 23 whose upper and lower surfaces are closed, and the width of the winding core portion 25 is
The width is sufficiently narrower than the width of the core 21, and is arranged inside the core 21 from the opening 28. At least the core portion 25 of the core 21 is made of a material having a small magnetic resistance, for example, a soft magnetic material such as ferrite. Of course, the entire core 21 may be formed of a low magnetic resistance material such as ferrite. Further, a conductive paste is applied to both sides of the opening 28 on the side surface of the core 21, and a film-shaped electrode 22 is formed by means such as baking.
Are formed. The surface of the electrode 22 is formed so as to slightly project outward from the side surface of the core 21. In the illustrated embodiment, one electrode 22 is formed on each of both sides of the core 21, and a total of four electrodes 22 are formed.

A conductive wire such as an insulating coated conductive wire is wound around the winding core portion 25 of the core 21 to form a winding 29.
Further, the drawn-out end portion 26 of the winding wire 29 is drawn out from the opening portion 28 of the core 21 to remove the coating on the end of the core 21.
Are connected to the electrodes 22 on both sides with solder 27 or the like. Here, in order to prevent the winding wire 29 from projecting outward from the opening portion 28 of the core 21, the winding core portion 25 is provided inside the inner portion of the core 21 from the opening portion 28 in consideration of the dimensions of the winding wire 29. Keep it.
For example, when the coil component is a common mode choke coil, a pair of winding wires 29 are wound around the winding core portion 25, and their lead-out end portions 26 are drawn out from the opening portion 28 of the core 21 to the electrode 22 side, The electrodes 22 are connected to the respective electrodes 22 with solder 27 or the like.

Further, an insulating resin or the like is injected into the core 21 through the opening 28 and is hardened to form an insulating material 30 as shown in FIG. As a result, the winding wire 29 wound around the winding core portion 25 is covered with the insulating material 30, and only the winding wire 29 is pulled out from the insulating material 20 and is connected to the electrode 22. The coil component is completed through the above steps. The insulating material 30 is
It is preferably formed so as not to project outside the electrode 22.

Such a coil component is mounted on a circuit board (not shown) with the upper and lower walls 23 side facing up or down.
Electrodes are formed in advance on the circuit board so as to correspond to the positions of the electrodes 22 of the core 21, and the electrodes 22 of the coil component mounted thereon are connected to the electrodes of the circuit board by soldering or the like. At this time, the electrodes 22, 22 are formed so as to project from the side surface of the core 21, and the insulating material 30 is formed so as not to project to the outside of the electrodes 22, so that the coil component mounted on the circuit board is formed. The electrode 22 and the electrode on the circuit board can be easily connected by soldering or the like.

Next, the embodiment shown in FIG. 5 will be described. In this embodiment, a groove 31 is provided in the lateral direction of the electrode 22 formed on the side surface of the core 21, and the winding 29 is provided in this groove 31.
Is engaged with the pull-out end portion 26. By this engagement, the lead-out end portion 26 of the winding wire 29 can be temporarily fixed to the electrode 22 before the lead-out end portion 26 is soldered to the electrode 22, so that the lead-out end portion 26 can be easily soldered to the electrode 22. Further, even after soldering, the lead-out end portion 26 does not significantly project from the surface of the electrode 22, so that disconnection or the like is less likely to occur.

Next, the embodiment shown in FIG. 6 will be described. In this embodiment, the winding core portion 25 of the core 21 for winding the winding wire 29 has a columnar shape. In the core 21 according to this embodiment, unlike the winding core portion 25 having a rectangular cross section as shown in FIGS. 2 to 4, the winding wire 29 is not bent at the corners, and the winding wire 29 has a substantially constant pole ratio. Since the winding can be wound, the strength of the winding 29 is not lowered due to partial bending.

Next, the embodiment shown in FIGS. 7 and 8 will be described. In this embodiment, the winding core portion 25 is arranged so as to be offset to the right from the central portion of the core 21 in FIGS. Accordingly, the left end wall 2 in FIGS.
4 is formed wider than the right end wall 24. In this case, the lead-out ends 26 of the pair of windings 29 are connected to the core 2 from the left side in FIGS.
1 is drawn out toward the opening 28 side and soldered to each electrode 22.

For example, as shown in FIG. 4, a pair of windings 2
When 9 is wound symmetrically around the winding core 25, even if the winding core 25 is at the center of the core 21, the lead-out end portions 26 from the respective windings 29 to the electrodes 22 have the same length. But,
As in the example shown in FIG. 7, the extraction end portions 26 of the pair of windings 29 are
Are pulled out from the same side surface of the winding core 25, and the core 2
When soldering to each of the electrodes 22 near the end face of 1,
When the winding core portion 25 is located at the center of the core 21, the lengths of the lead-out end portions 26 of the cores 21 are greatly different. Therefore, when the lead-out end portion 26 is pulled out from the same side surface of the winding core portion 25 in this way, the distances L ₁ and L ₂ from one side surface of the winding core portion 25 to the electrode portions 22 on both sides are made substantially equal. In this case, no significant imbalance occurs in the lengths of the two pull-out end portions 26.

In the above embodiments, the common mode choke coil has been mainly described as an example of the coil component.
The present invention can be applied not only to the common mode choke coil but also to coil components such as a transformer and an inductor. In this case, the electrodes 22 may be provided in the number corresponding to the number of the extraction ends 26 of the winding 29. For example, in the case where there is only one set of the windings 29, the extraction ends 26 have two ends. If it is a book, the number of electrodes 22 may be two. Also,
When some of the lead-out ends 26 can be connected to each other as a common terminal, the electrodes 22 can be shared, and thus the number of the electrodes 22 can be smaller than that of the lead-out ends 26. Furthermore, it is possible to form a composite component such as an LC filter by forming capacitors on the upper and lower surfaces of the core 21, the end faces, and the like, and connecting the capacitors to the coils formed by the winding wires 29.

[0022]

As described above, in the coil component according to the present invention, the number of components is small and the assembling of the components is simple, so that the size can be reduced and the number of manufacturing steps can be reduced. Further, since the electrodes 22 are provided on the side surfaces of the box-shaped core 21, the electrodes can be surface-mounted on the circuit board and the electrodes 22 can be easily connected. As a result, it is possible to obtain a coil component that is inexpensive, smaller, and easy to mount on the circuit board.

[Brief description of drawings]

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

FIG. 2 is a perspective view of a core used in the coil component according to the embodiment.

FIG. 3 is a perspective view of the coil component according to the same embodiment after winding the core and before filling the inside of the core with an insulating material.

4 is a cross-sectional view taken along the line AA in FIG.

FIG. 5 is an external perspective view of a coil component according to another embodiment of the present invention.

FIG. 6 is a perspective view of a core used in a coil component according to another embodiment of the present invention.

FIG. 7 is a cross-sectional plan view of a coil component according to another embodiment of the present invention before being filled with an insulating material.

FIG. 8 is a cross-sectional plan view of a core used in the coil component according to the embodiment.

FIG. 9 is an exploded perspective view of a coil component according to a conventional example.

[Explanation of symbols]

 Reference Signs List 21 core 22 electrode part 23 upper and lower walls of core 24 end wall of core 25 core part of core 26 lead-out end of winding 28 side opening of core 29 winding 30 insulating material 31 groove of electrode part

Claims (5)

[Claims] 1. A coil component formed by winding a winding (29) on a core (21), wherein openings (2) are provided on opposite side surfaces.
8) is provided in the shape of a box, and a core (21) having a winding core (25) formed inside the opening (28) and the opening (28) of the core (21). An electrode portion (22) formed adjacent to the side surface thereof and the winding core portion (25)
And a winding end (26) having a winding (29) connected to the electrode part (22) by being drawn out from an opening (28) on the side surface of the core (21). Coil parts to do. 2. A winding core (25) which is filled in the core (21) and wound around the winding core (25).
The coil component according to claim 1, further comprising an insulating material (30) covering the coil. 3. The winding core (25) and the winding (29) are located inside the core (21) with respect to the opening (28) of the core (21). Coil parts described in. 4. The electrode part (22) is formed with a groove (31) for engaging the extraction end part (26) of the winding wire (29), according to any one of claims 1 to 3. Described coil parts. 5. The winding core part (25) is arranged so as to be biased toward one electrode (22) side from the central part of the core (21), according to any one of claims 1 to 4. Coil parts.