JPH0429531Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a chip-type inductor provided with conductive terminals at both ends.

[Conventional technology]

Chip-shaped inductors have metal electrode terminals at both ends of a drum-shaped core for connection to electrodes on a wiring board. However, when the electrode terminals are brought into close contact with both ends of the core, a magnetic path passing through the conductive terminals is formed. Therefore, there is a problem in that eddy current loss occurs and the Q value decreases.

For this reason, conventional methods have been proposed in which cap-shaped conductive terminals are fitted into both ends of the core via a space, or disc-shaped conductive terminals are attached to both ends of the core via spacers. However, with these means, other problems arise, such as difficulty in connecting the coil lead wire to the conductive terminal, or difficulty in supplying parts.

Therefore, in order to solve this problem, the third
A chip-type inductor as shown in the figure has been proposed (Utility Model Publication No. 60-25870). That is, the lead wires 2, 2 are made to protrude from both ends of the core 1, and the coil 4 is connected to the lead wires 2, 2.
Tie the terminal parts 4a, 4a together and solder them. Further, substantially disc-shaped conductive terminals 7, 7 are fitted into the ends of the lead wires 2, 2 to conductively fix them, and recesses 7a, 7a provided at the centers of the conductive terminals 7, 7 are fitted.
The terminal portions 4a, 4a of the coil 4 are housed in the coil 4, and the space between them is covered with an insulating coating 6.

[Problem that the invention attempts to solve]

However, the conventional chip type inductor shown in FIG. 3 has the following problems.

First, the coil 4 is made of a very thin metal wire of about 0.01 to 0.1 mm, so it is extremely weak. However, in the above chip type inductor, the conductive terminals 7,
When fitting 7 or during subsequent handling, the external force applied to the conductive terminals 7, 7 tends to directly reach the end portions 4a, 4a of the coil 4, which is likely to break.

Secondly, since the gap between the conductive terminals 7, 7 and the core 1 is very narrow, the insulation coating 6 cannot easily wrap around the gap, and the protection and insulation of the terminal portions 4a, 4a of the coil 4 tend to be incomplete.

Thirdly, since the inner surfaces of the conductive terminals 7, 7 are almost entirely covered with the insulating coating 6, the insulating coating 6 may get in the way when soldering them to the electrodes b, b of the wiring board a. This makes it difficult for the solders c, c to wrap around the inner surfaces of the conductive terminals 7, 7. For this reason, it is difficult to obtain sufficient soldering strength.

This idea was made to solve the above-mentioned problems with conventional chip-type inductors.
Disconnection of the coil lead wire is unlikely to occur, and the coil lead wire is completely protected and insulated by the insulation coating.
It is an object of the present invention to provide a chip-type inductor that can provide a good soldering condition.

[Means for solving problems]

The structure of the present invention will be explained with reference to the reference numerals in FIGS. 1 and 2. The chip-type inductor according to the present invention includes a drum-shaped core 11,
lead wires 12, 12 fixed to both ends of the core 11, and terminal portions 14a, 1 formed on the winding portion of the core 11;
4a is wound around the lead wires 12, 12 and is conductively fixed; and the lead wires 12, 12.
A nearly disk-shaped conductive terminal 1 conductively fixed to the tip of the
7, 17, from the core 11 to the terminal portions 14a, 1 of the coil 14.
A spindle-shaped insulating sheath 16 with tapered ends is formed by covering the part up to the lead wire where the insulating sheath 16 is wrapped with an insulating material. A conductive terminal 17,1 is attached to the tip to a position that touches both ends of the insulation coating 16.
7 is fitted and conductively fixed.

[Effect]

In the chip-type inductor according to this invention, since the conductive terminals 17, 17 are fitted on the outside of the insulating coating 16, which covers the part up to the lead wire around which the terminal parts 14a, 14a of the coil 14 are wound, the conductive terminals 17, 17 are fitted. It is possible to reliably cover with the insulating coating 16 up to the lead wire portion where the wires 14a are entwined. In addition, since the conductive terminals 17, 17 are fitted into the tips of the lead wires 12, 12 to a position where both ends are tapered and hit both ends of the spindle-shaped insulating coating 16,
Most of the conductive terminals 17, 17 are exposed, with only a portion near the center hitting the tip of the thin insulation coating 16.

Further, the conductive terminals 17, 17 at both ends are connected to the coil 1.
4, but the tip of the insulating coating 16 is interposed between them. Therefore, the external force applied to the conductive terminals 17, 17 is temporarily buffered by the insulation coating 16, and the terminal portion 14
It does not directly extend to a and 14a.

〔Example〕

Next, examples and preferred embodiments of this invention will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, the core 11 is made of a soft magnetic material such as a sintered body of ferrite, and consists of flange portions 11b at both ends, and an intermediate portion 11a which is tapered one step between the flanges 11b. Attachment holes 11c, 11c for the lead wires 12, 12 are provided on both end surfaces, and the lead wires 12, 12 are fitted into the mounting holes 11c, 11c, and the adhesive 13,
Fix it at 13. As the adhesives 13, 13, epoxy resin adhesives and the like are often used.

A coil 14 is wound around the middle part of the core 11,
Both ends thereof are pulled out to both ends of the core 11 beyond the flange portions 11b, 11b. Then, the terminal portions 14a, 14a are tied around the lead wires 12, 12, and soldered to ensure a secure connection.

Further, the core 11 and its coil 14 to its terminal portions 14a, 14a are covered with an insulating coating 16. This insulating coating 16 is generally coated with uncured insulating resin, and is applied from the coil 14 to its terminal portion 1.
It is provided by a method such as applying it to the parts up to 4a and 14a and then curing it. As a result, the insulating coating 16 has a spindle shape, with the end portions covering the lead wires 12, 12 being thinner and the portion covering the core 11 being thicker. In this case, the leading ends of the lead wires 12, 12 are not covered, but are left partially protruding from the insulation coating 16.

Then, substantially disc-shaped conductive terminals 17, 17 are fitted into the tips of the protruding lead wires 12, 12, and are conductively fixed by solders 18, 18 or the like. In addition to the solders 18, 18, fixing means such as welding or conductive adhesive may also be used. Note that the terminal portions of the lead wires 12, 12 protruding from the conductive terminals 17, 17 are cut off, and the conductive terminals 1
Align it almost with the end faces of 7 and 17.

This chip-type inductor is constructed by connecting conductive terminals 17, 17 at both ends to electrodes b, b of wiring board a with solders c, c, as in the conventional one.
It is mounted on the wiring board a.

FIG. 2 shows various embodiments of the conductive terminals 17, 17.

a and b connect the conductive terminals 17, 17 to the lead wires 12,
It is of a type that can be inserted from 12 terminals. That is, a has a through hole 20 in the center of the disc-shaped conductive terminals 17, 17, and the lead wire 1 is inserted here.
Insert the tips of 2 and 12. In addition, b is a disc-shaped conductive terminal 17, 17 with three radial cuts 21, 21, 21 radially extending from the center thereof.
Lead wires 12, 12 are fitted at the tips of protrusions 22, 22, 22 between 1, 21, 21 and temporarily fixed.

C to e connect the conductive terminals 17, 17 to the lead wires 12,
It is of the type that is fitted from the side of 12. That is, in c, a single notch 23 is provided that opens from the center of the disc-shaped conductive terminals 17, 17 to the circumferential surface, and along this, the conductive terminals 17, 1 are inserted from the side of the lead wires 12, 12.
Insert 7. d is basically the same as c above, but several concave and convex lines are provided on both main surfaces parallel to the notch 23. As a result, the conductive terminal 17 can be inserted into the lead wires 12, 12 by mechanical means such as an automatic insertion machine.
When fitting 17, its direction can be controlled.
Furthermore, the adhesion of solder c and c to the end face also improves. e
A boss-shaped lead wire support part 24 is provided at the center of the ring-shaped conductive terminals 17, 17, one of which is opened in the radial direction to form an insertion opening 25, and both sides of the lead wire support part 24 are provided with spring properties. . The lead wires 12, 12 are inserted into the insertion opening 25 against the elasticity of the conductive terminals 17, 17.
Then, fit it into the lead wire support part 24.

In either case, it goes without saying that the conductive terminals 17, 17 are conductively fixed to the lead wires 12, 12 by solders 18, 18 or the like.

[Effect of idea]

As explained above, according to this invention, the following effects can be obtained.

First, in the chip-type inductor according to this invention, since the coil 14 to its terminal portions 14a, 14a are reliably covered with the insulation coating 16, high protection and insulation functions can be obtained.

Second, the conductive terminals 17, 17 do not come into direct contact with the terminal portions 14a, 14a of the coil 14, and the insulating coating 16 between them serves as a so-called buffer material. Therefore, the external force applied to the conductive terminals 17, 17 when fitting the conductive terminals 17, 17 or handling them afterwards does not directly reach the terminal portions 14a, 14a of the coil 14.
Problems such as disconnection are less likely to occur.

Thirdly, only a portion of the inner surface of the conductive terminals 17, 17 near the center contacts the insulation coating 16. Therefore, the solder c, c wraps around the inner surfaces of the conductive terminals 17, 17 well, and high soldering strength can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal side view showing an embodiment of this invention, Fig. 2 is an exploded perspective view showing various embodiments of the conductive terminal in the same embodiment, and Fig. 3 is a conventional example of a chip-type inductor. FIG. DESCRIPTION OF SYMBOLS 11... Core, 12... Lead wire, 14... Coil, 14a... Terminal part of coil, 16... Insulating coating, 17... Conductive terminal.

Claims (1)

[Scope of utility model registration request] A drum-shaped core 11, lead wires 12, 12 fixed to both ends of the core 11, and end portions 14a, 14a formed at the winding portion of the core 11 and entwined with the lead wires 12, 12. In a chip-type inductor consisting of a coil 14 that is conductively fixed and substantially disc-shaped conductive terminals 17, 17 that are conductively fixed to the ends of the lead wires 12, 12, the core 11
The part from the end portions 14a of the coil 14 to the lead wires around which the terminal portions 14a are wound is covered with an insulating material,
A spindle-shaped insulating sheath 16 tapered at both ends is formed, and conductive terminals 17, 17 are fitted into the tips of the lead wires 12, 12 protruding from both ends of the insulating sheath 16 to positions that touch both ends of the insulating sheath 16. A chip-shaped inductor characterized by being conductively fixed.