JP2886005B2 - LC filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LC filter as a noise suppression component used in various electronic devices.

[0002]

2. Description of the Related Art As conventional LC filters using a conductive plate, those shown in FIGS. 10 and 11 have been developed.

As shown in FIG. 10, reference numeral 1 denotes a hoop material of a conductive plate made of an iron alloy, copper, a copper alloy or the like, and a feed hole 2 is provided on one side of the hoop material 1. In this hoop material 1, an inductance portion 3 is continuously formed by punching. The inductance portion 3 includes terminal portions 4a and 4b which are connected to the hoop material 1 at a constant interval, and meandering portions 5a and 5b formed continuously from the tips of the terminal portions 4a and 4b. Parts 5a, 5
The coupling portion 6 is configured by a connecting portion 6 for connecting the leading ends of the electrodes b and an electrode portion 7 protruding toward the hoop material 1 in the middle of the connecting portion 6. The hoop material 1 corresponding to the electrode portion 7 is also provided with a terminal portion 8 protruding toward the electrode portion 7.

[0006] Next, as shown in FIG. 11, the tip portions of the electrode portion 7 and the terminal portion 8 are bent downward in an L-shape, and a chip capacitor 9 is arranged at this portion and connected by soldering or the like. The exterior 10 is formed entirely using a resin material mixed with magnetic powder,
An LC filter was formed.

[0005]

In the above-described LC filter, since the inductance portion 3 is completely molded with the resin material sheath 10 mixed with magnetic powder, the inductance magnetic coupling increases and the attenuation is deteriorated. At the same time, since the chip capacitor 9 is also molded with the outer package 10, an eddy current is generated in the chip capacitor 9 to increase the loss (tan δ) of the capacitor and deteriorate the trap attenuation.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides two meandering inductance elements formed by punching a conductive plate, a capacitor provided between the inductance elements, and two capacitors. An exterior in which the inductance element is molded with a resin material mixed with magnetic powder , the inductance element is provided with a terminal at one end, and a connection is provided at the other end to connect the two inductance elements, and the connection is Along with integrally providing the electrode portion, a capacitor terminal portion is provided at a position facing the electrode portion, a through hole for mounting a capacitor is provided on the exterior, and a part of the electrode portion and the capacitor terminal portion is The capacitor is inserted into the through-hole, and the electrodes at both ends of the capacitor are connected to the through-hole. The electrode portion exposed and to a portion of the capacitor terminal portion is in contact configuration.

[0007]

With the above construction, by providing a through hole between the two inductance elements, the magnetic resistance becomes higher than the periphery of the inductance, thereby preventing the passage of magnetic flux. As a result, the coupling between the inductances becomes coarse, Since the capacitor is also mounted in the through hole, the generation of the eddy current as described above is eliminated, and an increase in loss can be prevented.

In addition, since the capacitor is inserted into the through hole, the solder connection between the capacitor electrode and a part of the capacitor terminal can be easily checked from the side opposite to the mounting direction of the capacitor. Connection reliability can be improved.

Furthermore, the capacitor can be mounted after the outer casing is formed, the capacitor can be replaced without being destroyed by the influence of the pressure at the time of forming the outer casing, and the electrode portion and the capacitor can be replaced when the capacitor is replaced. Terminal
Without some is deformed, it is possible to securely hold the capacitor.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an LC filter according to the present invention will be described below with reference to FIGS.

First, in FIGS. 1 to 3, an iron alloy, copper,
A meandering two inductance elements 11 formed by punching from a conductive plate made of a copper alloy, a terminal section 12 integrally formed at one end thereof, and a connection section 13 connecting the two inductance elements 11 thereto, It comprises an electrode portion 14 protruding downward from the connecting portion 13 and an independent substantially L-shaped capacitor terminal portion 15. The capacitor terminal section 15 is composed of a capacitor connection section 15a and a board connection section 15b.

Such two inductance elements 1
1, terminal part 12, connecting part 13, capacitor terminal part 15
Is molded with a sheath 17 made of a resin material mixed with magnetic powder such as ferrite, and a space 16 for mounting a capacitor is formed in a portion of the sheath 17 located between the inductance elements 11.

The space 16 is formed by a through hole. The space 16 has an electrode portion 14 provided in the connecting portion 13 and a capacitor connecting portion 1 of the capacitor terminal portion 15.
5a is exposed.

Further, at the lower part of the exterior 17, the tip of the terminal portion 12 and the board connecting portion 15b of the capacitor terminal portion 15 are exposed, and are configured to be surface-mounted on a printed board or the like.

The outer casing 17 is made of, for example, 75 to 95% by weight of ferrite magnetic powder and 5 to 25% by weight of a polyphenylene sulfide resin.

Then, after forming the exterior 17 in the gap 16, a chip capacitor 18 is inserted, and the electrodes 19 at both ends of the chip capacitor 18 are exposed in the gap 16 and the capacitor terminal section. After being brought into contact with the 15 capacitor connection portions 15a, the contact portions are connected and fixed with solder or the like.

In the above description, FIG. 1 is a perspective view of the exterior 17 seen through, FIG. 2 is a perspective view of the completed state, FIG.
Shows the same front view.

With such a configuration, the gap 16 is formed between the inductance elements 11 in the resin material exterior 17 mixed with magnetic powder, so that the magnetic coupling between the inductance elements 11 , And as a result, the attenuation of the LC filter does not deteriorate as shown in FIG. In FIG. 4, the solid line shows the characteristic of the conventional LC filter, and the broken line shows the characteristic of the attenuation of the LC filter of the embodiment of the present invention.

Also, since the chip capacitor 18 is configured to be incorporated into the space 16 of the exterior 17 later,
Since a gap is always generated between the chip capacitor 18 and the outer case 17, a current flows through the chip capacitor 18 and no current is generated any more, which may increase the loss (tan δ) of the capacitor and deteriorate the trap attenuation. Can be prevented.

Next, an embodiment for stabilizing the mounting of the chip capacitor 18 will be described.

In the embodiment shown in FIG. 5, the positioning projection 20 is provided on the electrode portion 14 exposed in the space 16 formed by the through hole formed in the exterior 17 and the capacitor connecting portion 15a of the capacitor terminal portion 15. As a configuration for engaging with both end surfaces of the capacitor 18, a configuration for mounting the chip capacitor 18 and increasing a connection area by soldering to improve a mounting strength of the chip capacitor 18 can also be adopted.

In the embodiment shown in FIG. 6, the electrode portion 14 exposed in the gap portion 16 and the capacitor connecting portion 15a of the capacitor terminal portion 15 are made of elastic material and are inserted by the chip capacitor 18 to be inserted. It is also possible to adopt a configuration in which the chip capacitor 18 is elastically bent and elastically clamps the chip capacitor 18.

Further, as shown in FIG. 7, the gap 16 is formed so that the cross-sectional dimension of the gap 16 is gradually reduced from the capacitor insertion side, so that the chip capacitor 18 can be easily inserted. Capacitor connection 15a
, The chip capacitor 18 may be press-fitted and held in the gap 16.

As shown in FIG. 8, a rib 21 is formed on the side of the gap 16 so that the chip capacitor 18 is held by the rib 21 when the chip capacitor 18 is pressed into the gap 16. It can also be.

In the above embodiment, the terminal plate 12, the inductance element 11, the connecting portion 13,
Although the formation of the electrode portion 14 and the capacitor terminal portion 15 has been described, as shown in FIG. 9, the inductance element 11 is formed by winding a conductive wire such as copper, and both ends of the conductor are connected to the terminal portion 12. What is connected to the connecting portion 13 by welding or the like may be formed so that the exterior 17 has the void portion 16.

In the embodiment shown in FIGS.
The inductance portion and the capacitor terminal portion 15 are kept in a state where the electrode portion 14 and the capacitor terminal portion 15 are connected to each other until the exterior 17 is formed, and after the exterior 17 is formed, the electrode portion 14 is cut off. It can be separated into the capacitor terminal section 15, which is advantageous in fixing the inductance section and the capacitor terminal section 15 with a molding die.

[0027]

As described above, the LC filter of the present invention is
Since the exterior is formed so that a through hole for mounting a capacitor is formed between the inductance elements, the magnetic coupling between the inductance elements is suppressed and the attenuation is not deteriorated, and the capacitor is also mounted in the through hole of the exterior. Therefore, characteristics can be stabilized without generating eddy current in the capacitor, increasing loss and deteriorating trap attenuation in a high frequency region.

Further, since the capacitor is inserted into the through hole, the solder connection between the capacitor electrode and a part of the capacitor terminal can be easily checked from the side opposite to the mounting direction of the capacitor. Connection reliability can be improved.

Furthermore, the capacitor can be mounted after the outer casing is formed, the capacitor can be replaced without being damaged by the influence of the pressure at the time of forming the outer casing, and the electrode portion and the capacitor can be replaced when the capacitor is replaced. Terminal
Without some is deformed, it is possible to securely hold the capacitor.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of an LC filter according to the present invention.

FIG. 2 is a perspective view of the same.

FIG. 3 is a front view of the same.

FIG. 4 is a diagram showing attenuation characteristics of the present invention and a conventional LC filter.

FIG. 5 is a sectional view of another embodiment of the present invention.

FIG. 6 is a sectional view of still another embodiment.

FIG. 7 is a sectional view of still another embodiment.

FIG. 8 is a front view of still another embodiment.

FIG. 9 is a perspective perspective view of still another embodiment.

FIG. 10 is a plan view showing a part of a manufacturing process of a conventional LC filter.

FIG. 11 is a perspective view of the conventional LC filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Inductance element 12 Terminal part 13 Connecting part 14 Electrode part 15 Terminal part for capacitors 16 Air gap part 17 Exterior 18 Chip capacitor

 ──────────────────────────────────────────────────の Continued on the front page (72) Yoshinobu Nakajima 1006 Kadoma Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References Japanese Utility Model 1-97616 (JP, U) Japanese Utility Model 62-62424 (JP, U)

Claims (5)

(57) [Claims] 1. A meandering two inductance element formed by punching from a conductive plate, a capacitor provided between the inductance elements, and an exterior formed by molding the two inductance elements with a resin material mixed with magnetic powder. A terminal portion is provided at one end of the inductance element, and a connection portion for connecting the two inductance elements is provided at the other end, and the connection portion is provided integrally with an electrode portion, and is provided at a position facing the electrode portion. A capacitor terminal portion is provided, a through hole for mounting a capacitor is provided on the exterior, and a part of the electrode portion and the capacitor terminal portion is exposed in the through hole. Inserting the capacitor and exposing the electrodes at both ends of the capacitor to the through hole of the electrode portion and the capacitor terminal portion . Contact with the LC filter and a portion. 2. The LC filter according to claim 1, wherein positioning projections are provided at a part of the electrode part and the capacitor terminal part which are exposed in the through hole to engage with both ends of the capacitor. Wherein at least one of a portion of the electrode portion and the capacitor terminal portion exposed in the through hole is made of resilient metal, according to claim 1, wherein the capacitor has to be resiliently clamped to be inserted LC filter. 4. A through-hole, LC filter according to claim 1 wherein the smaller the size of gradually through-hole cross-section from the insertion side of the capacitor. 5. The LC filter according to claim 1, wherein a rib for holding the capacitor is provided on an inner wall of the through hole.