JPS6039910A - Chip type noise elimination filter - Google Patents

Abstract

PURPOSE:To obtain a chip type noise elimination filter mounted directly on a printed board or the like by allowing a ferrite board to act like an inductance to a conductive path assembled between the flat ferrite boards. CONSTITUTION:Electrodes 14a, 14b of a chip capacitor 14 are soldered respectively to a wide part 13a of a middle part of the conductive path 13 and an earth electrode 17a. The other ferrite board 12 having a concaved part (not shown) to which the capacitor 14 is inserted is bonded to the major plane where the conductive path 13 of the ferrite board 11 and the earth electrode 17a are formed. Through the constitution above, the ferrite boards 11, 12 act like inductances L15 and L16 to a part reaching the wide part 13a from an input terminal 15 of the conductive path 13 and a part reaching an output terminal 16 from the wide part 13a, the L15 and the L16 are connected respectively between the input terminal 15 and the wide part 13a and between the output terminal 16 and the wide part 13a, and the chip type noise elimination filter where the capacitor 14 is connected between the wide part 13a and the earth terminal 17 is obtained.

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a chip-type noise removal filter, and more specifically, the present invention relates to a chip-type noise removal filter, and more specifically, it is made into a chip by giving two flat ferrite plates an inductance function and a case function. This invention relates to a chip-type noise removal filter.

(Prior Art) Conventionally, as shown in FIG. 1, a noise removal filter has been constructed using a disk-shaped capacitor 1 having a hole in the center, and cylindrical ferrite beads 2.3 on both sides of the capacitor 1. The capacitor 1 and the ferrite bead 2.3 are arranged coaxially, and the through terminal 4 is passed through the capacitor 1 and the ferrite bead 2.3, and the whole is housed inside a cylindrical metal case 5. It is generally known that electrodes 1a and 1b are soldered to a metal case 5 and a through terminal 4, respectively, and the metal case 5 is filled with resin 6.

(8P; As shown in Figure 2, inductances L2 and L3 are formed by ferrite beads 2 and 3 in the middle of the through terminal 4, and between these inductances L2 and L3, the through terminal 4 However, since the noise filter shown in Figure 1 is a through type, it is difficult to attach the noise filter to a printed circuit board, and the shape is also awkward. However, it was difficult to implement small, high-density electronics that required a noise filter.

(Object of the Invention) The present invention has been made in consideration of the above-mentioned conventional noise filter, and its purpose is to incorporate a conductive path and a capacitor between two flat ferrite plates.
In step 7, by making the ferrite plate act as an inductance for the conductive path and also function as a case for a noise filter, the conductive path and the ground electrode are drawn out of the ferrite plate, resulting in an inexpensive chip type that can be mounted on a printed circuit board, etc. To obtain a noise removal filter (Structure of the invention) For this reason, the present invention provides a conductive path made of a metal plate on one main surface of a flat ferrite plate, and a conductive path made of a metal plate in the middle of the conductive path and the above-mentioned ferrite plate. A chip capacitor is connected between the ground electrode provided on the plate, another ferrite plate is bonded to the main surface of the ferrite plate, and both ends of the conductive path and the ground electrode are connected to the input terminal, the output terminal, and the ground electrode, respectively. It is characterized in that it can be drawn out to the outside of the two ferrite plates as a ground terminal.

(Example) Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In FIGS. 3 and 4, 11.12 is a ferrite plate, 1]d! 14 is a chip capacitor; 15 is an input terminal; 16 is an output terminal; 17 is a ground terminal; Among the plates 11 and 12, one main surface of one of the ferrite plates 11 is provided with four parts 18 for inserting conductive paths, as shown in FIG.
is formed and C is formed.

Both ends of the conductive path insertion recess 18 are located on one side of the main surface of the ferrite plate 11, and the both ends and the middle part are formed 11 times wider than the other parts.

On the main surface of the ferrite plate 11, a ground electrode insertion recess 19 is also formed between both ends of the conductive path insertion recess 18.

A conductive path 13, which is made by punching a metal plate made of copper or the like with good conductivity into a shape matching the four conductive path insertion parts 18, is inserted into the recess 18 as shown in FIG. An input terminal 15 and an output terminal 16 forming extensions of both ends of the conductive path 13 are bent onto one end surface and the other main surface of the ferrite plate 11, respectively.

Similarly, the ground electrode insertion recess 19 has a plate-shaped ground electrode 17. a is inserted and bent onto one end surface and the other main surface of the Cadaferrite plate 11, and a ground terminal 17 forming an extension of the ground electrode 17a.

A chip capacitor 14 is connected to the wide part 13a of the middle part of the conductive path 13 and the ground electrode 17H, respectively. [Pole 14a and 14b are soldered.

Conductive path 13 of ferrite plate 11 and earth conductor 4% 1
The above-mentioned chip capacitor 1 is mounted on the main surface on the side where 7 H is formed.
Another ferrite plate 12 having a recess (not shown) into which the ferrite plate 4 is inserted is bonded with an adhesive or the like.

If the above is done, as can be seen from FIG. The ferrite plates 11 and 12 act with inductance L15 and Li2 on the input terminal 15 and the input terminal 15, as shown in FIG. connected between the wide part 13a and between the output terminal 16 and the wide part 13a,
A chip-type noise removal filter in which a chip capacitor 14 is connected between the wide portion 13a and the ground terminal 17 can be obtained.

In addition, in the above embodiment, the ferrite plates 11 and 1
The slits lla and 12'a formed in 2 are
This is to ensure that the magnetic flux contributing to the inductances 1.15 and 16 is as large as possible. That is, if it is assumed that magnetic flux 31, 32 is running around the conductive paths 13, 13 inside the ferrite plates 11 and 12, as shown in FIG. Among the magnetic fluxes 31 running, the magnetic flux 31a running on the outermost side goes around inside the ferrite plate 11.12 due to the slits 11a and 12a, and of the magnetic flux 32 running on the other conductive path 13, the ferrite Board 1
The magnetic flux 32a running on the outermost side of 1.12 also flows through the slit 11a.
, 12a, these magnetic fluxes 31a, 32a go around inside the ferrite plates 11, 12, and these magnetic fluxes 31a, 32a connect to the four electric circuits 13.
．． After reaching between the conductive paths 13 and 13 and reinforcing each other, the conductive paths 13 and 13 enter the respective conductive paths 13 and 13.

Even when the directions of the magnetic fluxes 31 and 32 are opposite to the above, the same relationship as above can be obtained.

Therefore, the 1'-fields 31a and 32a are not weakened by interference with other magnetic fluxes 32 and 31, and act on the conductive path 13.13, increasing the inductance.

In the above embodiment, the input terminal 15. Output terminal 1
6 and the ground terminal 17 may be drawn out only to one end surface of the ferrite plate 11, as shown in FIG.

Next, other embodiments of the present invention are shown in FIGS. 9, 10, and 11.
and FIG. 12.

The noise removal filter shown in FIG. 9 is similar to that shown in FIGS.
In the noise removal filter shown in the figure, the input terminal 15 and the output terminal 16 are respectively drawn out to two opposite end faces different from the lead-out end face of the ground terminal 17 of the ferrite plate 11.

In addition, the noise removal filter shown in FIG.
While soldering the conductive path 13 located between the 2nd and 7th elite plates 11 and the electrode 14b of the chip capacitor 14, the earth? [Pole 17a and electrode 1 of chip capacitor 14]
4a and soldered together.

The noise removal filters described above in FIGS. 9 and 10 each have an equivalent circuit shown in FIG. 6.

On the other hand, the noise removal filter shown in FIG. 11 is the noise removal filter explained in FIGS. 3 and 4, in which chip capacitors 24a and 24b are connected between each end of the conductive path 13 and the ground electrode 17a. As shown in FIG.
and 12 are connected, and chip capacitors 24a and 24b are connected between input terminal 15 and ground terminal 17 and between output terminal 16 and ground terminal 17, respectively.

Further, the noise removal filter shown in FIG. 12 is different from the chip capacitors 24a and 2 of the noise removal filter in FIG.
4b, the chip capacitor 24a is removed, and as shown in FIG. 14, it has an equivalent circuit in which the chip capacitor 24a is removed from the equivalent circuit of FIG.

It should be noted that the above-mentioned embodiments of the present invention are not intended to limit the present invention. In particular, the conductive paths and terminals shown in each embodiment may be in the form of a film rather than a plate, and their shapes may be arbitrary. Furthermore, the shape of the chip capacitor and its connection method are also arbitrary.

(Effects of the Invention) As is clear from the detailed description above, the present invention has the following effects:
The ferrite plate acts as an inductance for the conductive path built between the flat ferrite plates, and also functions as a case for the noise removal filter, eliminating the need for a metal case like in conventional noise removal filters, reducing the number of parts to 13. It is possible to obtain a chip-type noise removal filter that can be directly mounted on an inexpensive printed circuit board or the like, and does not require processes such as resin filling.

[Brief explanation of the drawing]

Figure 1 is a 11 cross-sectional view of a conventional noise removal filter;
The figure is an equivalent circuit diagram of the noise removal filter shown in FIG. 1, @3 is a perspective view of an embodiment of the noise removal filter according to the present invention, and FIG.
Figure 5 is a perspective view of the ferrite plate on the conductive path formation side of the noise removal filter in Figure 3, Figure 6 is an equivalent circuit diagram of the noise removal filter in Figure 3, and Figure 7 is an explanation of the operating functions of the ferrite plate. 8, 9 and 10 are respectively perspective views of modified examples of the noise removal filter shown in FIG. The perspective view of the embodiment, FIGS. 13 and 14, are equivalent circuit diagrams of the chip type noise removal filters shown in FIGS. 11 and 12, respectively. 11.12... Ferrite plate, 13... Conductive path, 14
...Chip capacitor, 14a, 14b...Electric Th
, 15...input terminal, 16...output terminal, 17...
・Earth terminal, 17a...Earth electrode. Patent Applicant Murata Manufacturing Co., Ltd. representative, Physician Aoyama Aoyama and 2 others Figure 1 Figure 2 Figure 70

Claims (1)

[Claims] (1) Four electrical paths made of a metal plate are arranged on one main surface of a flat ferrite plate, and a chip-shaped capacitor is connected between the conductive path and a ground electrode provided on the ferrite plate, Another ferrite plate is joined to the main surface of the 7-elite plate, and both ends of the conductive path and the ground electrode are drawn out to the outside of the two ferrite plates as an input terminal, an output terminal, and a ground terminal, respectively. A chip-type noise removal filter featuring: