JPH11219827A - Coil-type inductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a compact coil-type inductor for accurately operating solder inspection after mounting, and for easily operating detachment or correction after mounting. SOLUTION: A coil-type inductor 11 is constituted of a drum-shaped bobbin 12, a coil 13 wound around the bobbin 12, and a case 15. The dimension of a lower flange part 18 of the bobbin 12 is made almost equal to the dimension of an opening edge face 15a at the lower side of the case 15. A window part 21 is formed on the opening edge face 15a at the lower side of the case 15 for deriving a terminal part 13a of the wire 13 can be derived from the lower flange part 18 of the bobbin 12. A notched part 22 is formed at a position facing the window part 21 of the case 15 at the lower flange part 18 of the bobbin 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wire wound inductor, and more particularly to a wire wound inductor used as a choke coil or a transformer.

[0002]

2. Description of the Related Art FIGS. 5 and 6 show an example of such a conventional wire wound inductor. The wire-wound inductor 1 is a common mode choke coil, and includes a bobbin 2 and a cylindrical case 3. The bobbin 2 is provided with an upper flange 7 and a lower flange 8 at both ends of a columnar body 6. 2 on the torso 6
Two windings 5 are wound. And in FIG.
The lower open end surface of the case 3 is placed on and fixed to the left and right sides of the upper surface 8 a of the lower flange 8 of the bobbin 2. Furthermore, the case 3 and the bobbin 2 are fixed by fixing the upper open end of the case 3 to the outer peripheral surface of the upper flange 7 of the bobbin 2 with an adhesive. The case 3 surrounds the body 6 of the bobbin 2 around which the winding 5 is wound. A terminal electrode 9 is formed on the mounting surface 8b of the lower flange 8 of the bobbin 2. In FIG. 5, each terminal portion 5a of the two windings 5
Are drawn out from the gap between the front side of the lower flange 8 and the case 3 and the gap between the rear side of the lower flange 8 and the case 3 and are electrically connected to the terminal electrodes 9.

[0003]

In the conventional wound-type inductor 1, the terminal 5a of the winding 5 is drawn out from the gap between the case 3 and the lower flange 8 of the bobbin 2.
The dimension of the opening end face of the case 3 must be larger than the dimension of the lower flange 8 so that the terminal 5a does not interfere with the inner peripheral edge of the lower opening of the case 3 or the edge of the lower flange 8. Did not. That is, as shown in FIG. 5, when the dimensions of the lower flange portion 8 are D1 and D2, the dimension L1 of the case 3 is set to a value substantially equal to D1, and the dimension L2 of the case 3 is set to D2.
It is set to a value larger than. For this reason, the conventional wire-wound inductor 1 is excessively large in size by the size of the case 3 protruding from the lower flange portion 8, and it is difficult to reduce the size.

Further, when the wire-wound inductor 1 is mounted on a printed circuit board or the like, the terminal electrode 9 formed on the lower flange 8 is hidden behind the case 3, and solderability between the terminal electrode 9 and the pattern of the printed circuit board is improved. The solder fillet to be confirmed was difficult to see, and the soldering inspection was difficult. In addition, after mounting the wire-wound inductor 1 on a printed circuit board or the like, when there is a case where the wire-wound inductor 1 must be removed from the printed circuit board for repair or repair, when the terminal electrode 9 and the pattern on the printed circuit board are removed. There is also a problem that it is difficult to apply a soldering iron to the solder fillet formed in the above.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a small-sized wire-wound inductor which can reliably perform a soldering inspection after mounting and can be easily removed and modified after mounting.

[0006]

In order to achieve the above object, a wire-wound inductor according to the present invention comprises: (a) a bobbin comprising a body and a flange provided at an end of the body; (B) a winding wound around the body of the bobbin;
(C) a terminal electrode provided on a flange portion of the bobbin for connecting a terminal portion of the winding; and (d) a winding electrode mounted on the flange portion provided with the terminal electrode. (E) the dimension of the flange provided with the terminal electrode is substantially equal to the dimension of the opening end face of the case,
In addition, the case has a window portion for leading out a terminal portion of the winding. Here, for example, the ratio of the dimension of the opening end face of the case to the dimension of the flange provided with the terminal electrode is set to be 0.9 to 1.1.

With the above construction, the dimension of the opening end face of the case is substantially equal to the dimension of the flange provided with the terminal electrode, and is substantially flush with the outer peripheral surface of the case and the terminal electrode provided with the terminal electrode. . Then, the terminal portion of the winding is pulled out from the gap between the window portion and the flange portion of the case, and is connected to the terminal electrode.

In addition, by providing a notch facing the window of the case in the flange provided with the terminal electrode, a gap for drawing out the winding is secured without making the window of the case too large. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a wire wound inductor according to the present invention will be described with reference to the accompanying drawings. In the present embodiment, a common mode choke coil will be described as an example, but it goes without saying that a transformer or an inductor may be used.

One embodiment of a wire wound inductor according to the present invention is shown in FIGS. The wire-wound inductor 11
Is a bobbin 1 having a drum shape, as shown in FIG.
2. Winding 13 and case 15 wound around bobbin 12
It consists of.

The bobbin 12 has a rectangular upper flange portion 17 and a lower flange portion 18 at upper and lower ends of a columnar body portion 16, respectively. Two windings 13 are wound around the body 16 by a single-layer bifilar winding. The flanges 17 and 18 regulate the position of the winding 13 wound around the body 16, and the lower surface 17 a of the upper flange 17 and the upper surface 18 a of the lower flange 18 regulate the position of the winding 13. It is a regulatory aspect. In the present embodiment, in order to improve the releasability from the mold, the flange 17,
On the surfaces 17a, 18a of the taper 18, a tapered portion 14 is provided in a peripheral portion of the body portion 16 (the tapered portion provided on the surface 17a is not shown). The dimension of the upper flange 17 is set smaller than the dimension of the lower flange 18.

Notches 22 are provided on the front side and the back side of the lower flange 18, respectively. This notch 22
Faces a window 21 of a case 15 described later. Window 2
The terminal 13 a of the winding 13 derived from 1 is disposed in the notch 22, so that the angle around the edge of the lower flange 18 becomes gentle. Accordingly, it is possible to suppress damage to the terminal portion 13a due to the edge of the lower flange portion 18, and to smoothly route the terminal portion 13a.

The case 15 has a rectangular cross section having openings on the upper and lower sides. When the dimensions of the lower flange portion 18 of the bobbin 12 are D1 and D2, the dimension L1 of the case 15 is set to a value substantially equal to D1, and the dimension L2 of the case 15 is set to a value substantially equal to D2. As shown in FIG. 2, flat portions on both left and right sides of the upper surface 18 a of the flange portion 18 of the bobbin 12 are provided with a lower open end surface 15 a
Is in contact. The case 15 and the bobbin 12 are fixed by, for example, fixing the upper open end of the case 15 to the outer peripheral surface of the upper flange portion 17 of the bobbin 12 with an adhesive. The case 15 surrounds the body 16 of the bobbin 12 around which the winding 13 is wound. In this embodiment, the ratio of the dimension of the lower opening end face 15a on the lower side of the case 15 to the dimension of the lower flange 18 of the bobbin 12 is set to 0.9 to 1.1. If the dimension of the opening end face 15a of the case 15 is set to less than 90% of the dimension of the lower flange 18, the lower flange 18 protrudes greatly from the outer peripheral surface of the case 15 and is not suitable for miniaturization of the wire wound inductor 11. Because there is.
On the other hand, the dimension of the opening end face 15a of the case 15 is
If the dimension exceeds 110% of the dimension, the terminal electrode 24 provided on the lower flange portion 18 is hidden behind the case 15, and it becomes difficult to visually recognize the terminal electrode 24 when the inductor 11 is viewed from above.

A window 21 is formed on the front side and the back side of the lower opening end face 15a of the case 15 for leading out the terminal portion 13a of the winding 13, respectively. The window 21 faces the notch 22 of the lower flange 18 of the bobbin 12, and the terminal 13 a of the winding 13 is connected to the window 21 of the case 15.
3 is drawn out of a gap 23 formed by the notch 22 of the lower flange 18 of the bobbin 12, and is thermocompression-bonded or soldered to terminal electrodes 24 formed on the lower flange 18 as shown in FIG. And are electrically connected. The terminal electrode 24 is formed from the mounting surface 18b of the lower flange portion 18 to the outer peripheral surface. Bobbin 12 and case 1
5 is molded by a metal mold using, for example, a magnetic material such as ferrite or an insulating material such as a resin. In particular, when the bobbin 12 and the case 15 are formed of a magnetic material,
A wire-wound inductor 11 having a large inductor with high magnetic shielding properties is obtained.

With such a configuration, the dimension of the lower open end face 15a of the case 15 is substantially equal to the dimension of the lower flange portion 18 of the bobbin 12, and the size of the wire-wound inductor 11 can be reduced. In addition, since the outer peripheral surface of the lower flange portion 18 is substantially flush with the outer peripheral surface of the case 15, when the wire-wound inductor 11 is mounted on a printed circuit board or the like, the terminal electrode 24
The solder fillet for confirming the solderability between the circuit board and the pattern of the printed circuit board is not hidden behind the case 15, so that the soldering inspection can be performed reliably. Further, even after the wound inductor 11 has to be removed from the printed board for repair or repair after the wound inductor 11 is mounted on a printed board or the like, even if the terminal electrode 24
A soldering iron can be easily applied to the solder fillet formed between the wire-type inductor and the pattern on the printed circuit board, and the wire-wound inductor 11 can be easily removed and corrected.

Further, in this embodiment, the window portion 21 of the case 15 and the notch portion 22 of the lower flange portion 18 of the bobbin 12 are opposed to each other so that the gap 23 for drawing out the winding 13 is formed.
Is formed. If only the window 21 of the case 15 is sufficient for pulling out the winding 13, the window 21 is sufficient.
When the number 1 is large, the strength of the case 15 is reduced, and the case 15 is easily chipped or cracked. Therefore, a notch portion 22 facing the window portion 21 of the case 15 is provided in the lower flange portion 18 of the bobbin 12, and the winding portion 13 is formed by the window portion 21 and the notch portion 22.
A gap 23 for drawing out the wire 13 is formed, and the gap 23 for drawing out the winding 13 is sufficiently secured without excessively increasing the size of the window 21 of the case 15 to suppress a decrease in the strength of the case 15. Cracks are prevented from occurring. In addition, both ends of the cutout portion 22 of the lower flange 18 may be cut at a right angle, but are cut diagonally in consideration of the strength of the lower flange 18.

Although the basic embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be variously modified within the scope of the invention. For example, the case 15 has a lower opening end surface 15a.
In addition to the window 21 formed on the side, the window 21 may also be formed on the upper opening end face 15b side as shown in FIG. By doing so, the case 15 has no vertical direction, and when manufacturing the wire-wound inductor 11,
There is no need to identify the upper and lower directions of the case 15, and the automation of manufacturing becomes easier. In the embodiment of FIGS. 1 to 3, the notch 22 formed in the lower flange portion 18 of the bobbin 12 may be omitted.

[0018]

As is apparent from the above description, according to the present invention, the dimensions of the opening end face of the case are substantially equal to the dimensions of the flange provided with the terminal electrodes, and the flange provided with the terminal electrodes. Since the outer peripheral surface and the outer peripheral surface of the case are almost flush,
When a wire-wound inductor is mounted on a printed circuit board,
The solder fillet for checking the solderability between the terminal electrode and the pattern of the printed circuit board is not hidden behind the case, so that the soldering inspection can be performed reliably. Also, even after the wound inductor is mounted on a printed circuit board or the like, it may be necessary to remove the wound inductor from the printed circuit board for repair or repair. The soldering iron can be easily applied to the solder fillet, and the wound inductor can be easily removed and corrected.

Further, by providing a notch in the flange provided with the terminal electrode of the bobbin in addition to the window of the case,
It is possible to secure a sufficient space for drawing out the windings without making the window of the case too large, to suppress a decrease in the strength of the case, and to prevent chipping or cracking of the case. And since the angle which the terminal part of a winding goes around the edge of a flange part can be made gentle, while the damage of the terminal part by the edge of a flange part can be reduced, the terminal part of a winding can be routed smoothly. be able to.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a wire wound inductor according to the present invention.

FIG. 2 is a perspective view showing the appearance of the wire-wound inductor shown in FIG.

FIG. 3 is a plan view of a mounting surface of the wire-wound inductor shown in FIG. 1;

FIG. 4 is a perspective view showing a modification of the case.

FIG. 5 is a perspective view showing the appearance of a conventional wire wound inductor.

FIG. 6 is a cross-sectional view showing a configuration of the wire-wound inductor shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Winding type inductor 12 ... Bobbin 13 ... Winding 13a ... Terminal part 15 ... Case 15a, 15b ... Open end surface 16 ... Body 17 ... Upper flange part 18 ... Lower flange part 21 ... Window part 22 ... Notch part 24 ... Terminal electrode

Claims (3)

[Claims] A bobbin comprising a body and a flange provided at an end of the body; a winding wound around the body of the bobbin; and a bobbin provided on the flange of the bobbin. A terminal electrode for connecting a terminal portion of the winding, a case placed on a flange provided with the terminal electrode, a case surrounding a body portion around which the winding is wound, and the terminal electrode is provided. Wherein the dimension of the provided flange is substantially equal to the dimension of the opening end face of the case, and the case has a window for leading out a terminal portion of the winding. . 2. The wire-wound inductor according to claim 1, wherein the flange provided with the terminal electrode has a notch facing a window of the case. 3. The wire-wound inductor according to claim 1, wherein a ratio of a dimension of an opening end face of the case to a dimension of a flange provided with a terminal electrode is 0.9 to 1.1.