JPH01189216A - Lc filter - Google Patents

Abstract

PURPOSE:To compose an LC filter in relation to a connector pin by penetrating- inserting the connector pin into a through hole formed to a ceramic laminated body and making the connector pin into a condition to be electrically connected to the electrode of one side formed on an exposed surface. CONSTITUTION:The LC filter has a dielectric part 1 and a magnetic substance 2 to be unified in a layered condition, and at least the dielectric part 1 is equipped with a ceramic laminated body 4 to form an exposed surface 3. An opening 5 of one side is located on the exposed surface 3, simultaneously, plural through holes 6 to commonly penetrate the dielectric part 1 and magnetic substance 2 are formed, and a connector pin 7 is penetrating-inserted. In the surrounding area of the opening 5. An electrode 8 of one side of a capacitor is formed in a loop shape, it is connected with the connector pin 7 by a solder 9, an electrode 10 of the other side is formed on an interface between the dielectric part 1 and magnetic substance 2 except for the surrounding area of the through hole 6, and it is made into the electrode at a grounding side. Thus, an L type filter equipped with one capacitor C1-n and one inductor L1-n, respectively, can be composed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an LC filter in which a capacitor and an inductor are formed in association with one connector pin, and in particular, an LC filter that can be built into a connector, The present invention also relates to a high frequency filter that is effective in removing high frequency noise.

[Prior art and its problems] Conventionally, as a structure for incorporating a high-frequency filter into a connector, a configuration was adopted in which, for example, a feedthrough capacitor or a feedthrough inductor was used, and a connector pin was passed through each of these feedthrough components. .

However, with this structure, it is necessary to attach the penetrating parts to each connector pin one by one, which increases the number of manufacturing steps, and accordingly increases the manufacturing cost.

Furthermore, in order to obtain a sufficient noise removal effect as a high frequency filter, both a capacitor and an inductor are required, but usually only one of a feedthrough capacitor or a feedthrough inductor is attached to one connector pin. Therefore, there was a problem in that the noise removal effect was inferior to that of an LC filter made up of discrete circuit components.

It is also possible to incorporate both a capacitor and an inductor in connection with one connector pin, but in this case, the structure of the capacitor and/or inductor becomes complex and requires more manufacturing steps. Therefore, the problem arises that the production cost becomes even higher.

Therefore, the present invention forms a capacitor and an inductor in connection with one connector pin, which has an excellent noise removal effect, reduces the manufacturing process, and can be advantageously incorporated into the connector. It attempts to provide a filter.

[Means for Solving the Problems] In order to solve the above-mentioned technical problems, the LC filter according to the present invention is characterized by having the following configuration.

In other words, at least one layer is integrated while forming a layer.
The ceramic laminate has at least one dielectric portion and at least one magnetic portion, with at least the dielectric portion forming an exposed surface.

The ceramic laminate includes at least one opening, one of which is located on the exposed surface of the dielectric portion, and which extends through both the dielectric portion and the magnetic portion in common.
Through-holes are formed, and connector pins are inserted into the through-holes.

One electrode of a capacitor is formed on the exposed surface in a region surrounding the one opening so as to be electrically connected to the connector pin.

On the other hand, the other electrode of the capacitor is opposed to the one electrode with the dielectric constituting the dielectric portion interposed therebetween, and is formed excluding the area around the through hole, and the other electrode serves as a ground side electrode of the ceramic. It is drawn out to the outer surface of the laminate.

[Function] In this invention, among the capacitor and inductor constituting the LC filter, the capacitor has one electrode that is electrically connected to the connector pin on the exposed surface of the dielectric portion, and a dielectric portion that is connected to the one electrode. It is formed between the other electrode and the opposite electrode, sandwiching the constituent dielectric material therebetween. On the other hand, the inductor is formed at the portion where the connector pin passes through the magnetic material portion.

[Effects of the Invention] According to the present invention, simply inserting the connector pin into the through hole formed in the ceramic laminate and electrically connecting the connector pin to one electrode formed on the exposed surface. Then, an LC filter consisting of a capacitor and an inductor can be constructed in association with this connector pin. For example, a ceramic laminate can be used as a mechanical retaining member for a connector pin while providing the retaining member with functions as a capacitor and an inductor. Therefore, it is possible to obtain an LC filter that can be advantageously built into the connector.

Therefore, according to the LC filter according to the present invention, it is possible to have a larger insertion loss at high frequencies than a filter composed of only either a capacitor or an inductor, and therefore, a greater noise removal effect can be expected. be able to.

The present invention includes a plurality of connector pins, a plurality of the one electrodes are formed in a state that is electrically independent from each other in relation to each of the plurality of connector pins, and the other electrode is connected to the plurality of one electrodes. It has a particularly remarkable effect when it is formed so that it faces in common with the two. That is, by simply attaching a plurality of connector pins to one ceramic laminate as desired, all of these connector pins can be given the function of a high frequency filter.

Furthermore, in this invention, by appropriately selecting the dielectric material constituting the dielectric part and the magnetic material constituting the magnetic part, the dielectric part and the magnetic part can be integrated into one body by co-firing the ceramic laminate. It can be composed of

[Description of Embodiment] FIG. 1 is a sectional view showing an enlarged main part of an embodiment of the present invention. Further, FIG. 2 is an equivalent circuit diagram of an LC filter obtained by the structure shown in FIG. 1.

Referring to FIG. 1, the LC filter has a dielectric portion 1 and a magnetic portion 2 that are integrated while forming a layered structure, and at least the dielectric portion 1 is made of a ceramic material forming an exposed surface 3. A laminate 4 is provided. The ceramic laminate 4 has a plate shape as a whole, and FIG. 1 shows a cross section cut in the thickness direction.

A plurality of through holes 6 are formed in the ceramic laminate 4, with one opening 5 located on the exposed surface 3 of the dielectric portion 1 and penetrating both the dielectric portion 1 and the magnetic portion 2 in common. There is. A connector pin 7 is inserted into each through hole 6 .

One electrode 8 of a capacitor is formed on the exposed surface 3 of the dielectric portion 1 and in the area surrounding the one opening 5 . This one electrode 8 has, for example, an annular planar shape. Connector pin 7 and one electrode 8 are electrically connected by solder 9, for example. In addition, connector pin 7
The ceramic laminate 4 is assembled by soldering as described above.
However, it is also in a mechanically held state.

The other electrode 10 of the capacitor is formed to face the one electrode 8 with the dielectric constituting the dielectric portion 1 in between. In this embodiment, the other electrode 10 is located so as to extend on the interface between the dielectric portion 1 and the magnetic portion 2, and is formed except for the area around the through hole 6.

Note that a plurality of one electrodes 8 are formed electrically independent from each other in relation to each of the plurality of connector pins 7, but the other electrode 10 is common to the plurality of one electrodes 8. They are formed to face each other. On the other hand, the electrode 10 is
Since it is used as a ground-side electrode, it is drawn out to the outer surface of the ceramic laminate 4, as shown and explained later.

According to the configuration shown in FIG. 1, as shown in FIG. 2, each connector pin 7-1. 7-2. ..., one capacitor C1, C2, ... in relation to 7-0.

Cn and one inductor Ll, L2. ..., Ln
An L-type filter is constructed. That is,
For example, in connection with connector pin 7-1 shown in FIG. 2, capacitor C1 is formed between one electrode 8 and the other electrode 10 in FIG. 1, and inductor L1 is formed between connector pin 7-1 in FIG. 7 is formed in a portion penetrating the magnetic material portion 2.

Next, a specific example of the method for manufacturing the LC filter shown in FIGS. 1 and 2 will be described with reference to FIGS. 3 to 7.

First, as a dielectric material constituting the dielectric portion 1, Pb
A composite perovskite is selected, e.g.
0.5Pb(Fe1/2Nb1/2)Oa + 0.5
P b (F e l/2 T a 1/2 ) O
A material having the composition a is used. On the other hand, as the magnetic material constituting the magnetic part 2, a Ni-Zn ferrite is selected, for example, 0.17NiO+0
．． 32ZnO+0105CuO+0°48Fez o3
A composition having the following composition is used. Approximately 10% by weight of an organic resin binder was added to each of these raw materials, and a dielectric green sheet 11 and a magnetic green sheet 12 each having a thickness of several tens of μm were prepared by the doctor blade method, as shown in FIG. And pile up. That is, the dielectric portion 1 described above is formed by a plurality of dielectric green sheets 11, and the magnetic portion 2 is formed by a plurality of magnetic green sheets 12.

As shown in FIG. 3, the other electrode 10 described above is formed on the lowest dielectric green sheet lla among the dielectric green sheets 11 stacked in plurality.

Note that the other electrode 10 is formed by printing a conductive paste mainly composed of silver. The planar shape of the electrode 10 is shown in FIG. As shown in FIG. 4, the electrode 10 has, for example, a circular defect portion 13 corresponding to a portion where the through hole 6 will be formed later and its surrounding area. Furthermore, as can be seen from the outline of the dielectric green sheet lla indicated by the dotted line, the electrode 10 is
A pull-out portion 14 is provided that extends to the edge of the dielectric green sheet 11a.

After a plurality of dielectric green sheets 11 and magnetic green sheets 12 are stacked in a vertical relationship as shown in FIG. 3, they are pressure-formed using a press. As a result, as shown in FIG. 5, a ceramic laminate 4 consisting of one dielectric portion 1 and one magnetic portion 2 is obtained.

Then, a through hole 6 for inserting the connector pin 7 is formed by, for example, a drill. Each through hole 6 passes through both the dielectric portion 1 and the magnetic portion 2 in common.

The ceramic laminate 4 shown in FIG. 5 is in an unfired state. Therefore, by firing this at, for example, 1000° C. for 2 hours, the dielectric portion 1 and the magnetic portion 2 are sintered together.

As shown in FIG. 6, on the exposed surface 3 of the dielectric portion 1 in the ceramic laminate 4 integrated by co-firing in this manner, the aforementioned one electrode 8, which has an annular shape, for example, is formed. That is, this electrode 8 is formed in the area surrounding one opening 5 of the through hole 6 .

On the other hand, as shown in FIG. 7, an external ground electrode 15 is formed on the side surface of the ceramic laminate 4 at a portion where the lead portion 14 of the electrode 10 described above is exposed. Therefore, the external ground electrode 15 is electrically connected to the electrode 10. In addition, electrode 8 and external earth electrode 1
Both electrodes 8 and 5 are formed by applying a conductive paste mainly composed of silver and then baking, but both electrodes 8 and 15 can be baked at the same time.

Each through hole 6 of the ceramic laminate 4 in the state shown in FIG.
As shown in FIG. 1, if the connector pins 7 are inserted into the respective terminals, and the connector pins 7 and the electrodes 8 are electrically connected by solder 9, the structure shown in FIG. An L-type LC filter having an equivalent circuit as shown in FIG. 2 is obtained.

Note that the external ground electrode 15 may be formed at another position on the ceramic laminate 4, instead of at the position shown in FIG.

In the embodiment described above, the other electrode 10 serving as the earth side electrode was formed so as to extend on the interface between the dielectric part 1 and the magnetic part 2. For example, as shown in FIG.
It may also be formed inside the dielectric portion 1.

FIG. 9 is a diagram for explaining still another embodiment of the present invention, and corresponds to FIG. 1 described above. In this embodiment, a ceramic laminate 4a is composed of one magnetic material portion 2 and two dielectric material portions 1 and 21 located on both sides thereof. That is, as shown in FIG. A configuration related to the dielectric portion 21 is added to the embodiment described above.

Therefore, the reference numerals used in the embodiment shown in FIG. The configuration related to the portion 21 will be mainly explained.

Referring to FIG. 9, on the exposed surface 23 of the dielectric portion 21 and in the area surrounding the other opening 25 of the through hole 6, one electrode 28 of another capacitor is connected to the aforementioned electrode 8. are provided in a similar manner. This electrode 28 is connected to the solder 2
It is electrically connected to the connector pin 7 by 9.

On the other hand, the other electrode 30, which is paired with the electrode 28 to form a capacitor, is formed to extend on the interface between the dielectric portion 21 and the magnetic portion 2. The other electrode 30 is formed to have substantially the same shape as the other electrode 10 described above.

Therefore, according to the structure shown in FIG. 9, the π-type LC filter as shown in FIG.
-2. ..., 7-n. That is, connector pin 7-1. 7-2. ..., 7-n
associated with each of the first capacitors CI, C2,
..., Cn, second capacitor C'1. C'
2. ..., C nl and inductor Ll,
L2. ..., Ln are formed, respectively.

FIG. 11 illustrates the state in which green sheets are stacked to obtain the structure shown in FIG. 9, and is a diagram corresponding to FIG. 3 described above. In order to obtain the dielectric part 21, a plurality of dielectric green sheets 3 are further placed below the magnetic part 2.
1 is stacked.

Of these dielectric green sheets 31, on one side of the dielectric green sheet 31a located at the top,
The other electrode 30 described above is formed.

Several dielectric green sheets 11 shown in FIG.
When the magnetic green sheets 12 and dielectric green sheets 31 are stacked and pressurized, a ceramic is formed in which the dielectric parts 1 and 21 are located on both sides of one magnetic part 2, respectively, as shown in FIG. A laminate 4a is obtained. Similarly to the embodiment described above, the dielectric portion 1,
A through hole 6 is formed by a drill or the like so as to commonly penetrate through the magnetic body portion 21 and the magnetic body portion 2. These dielectric parts 1 and 21 and magnetic part 2 are integrated by simultaneous firing.

FIG. 13 is a diagram corresponding to the above-mentioned FIG. 7, and when the external earth electrode 15 is formed on the side surface of the ceramic laminate 4, it functions to lead out the electrodes 10 and 30 in common.

In FIG. 14, similar to the relationship between FIG. 8 and FIG. 3 described above, the stacking state of FIG.
and 30 are formed inside each corresponding dielectric portion 1 and 21.

Although this invention has been described above in connection with several illustrated embodiments, various other modifications are possible within the scope of this invention.

For example, in the illustrated embodiment, a single ceramic laminate is penetrated by a plurality of connector pins; however, even if there is only one pin, this would be beyond the scope of the present invention. isn't it.

In addition, in the illustrated embodiment, the dielectric portion and the magnetic portion were integrated by simultaneous firing to form a ceramic laminate, but the ceramic laminate consists of dielectric portions obtained by firing each separately. The structure may be constructed by bonding the magnetic material portion and the magnetic material portion together later.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an enlarged main part of an embodiment of the present invention. FIG. 2 is an equivalent circuit diagram of the LC filter shown in FIG. 1. FIG. 3 is a perspective view illustrating the lamination mode of the dielectric green sheet 11 and the magnetic green sheet 12 to obtain the ceramic laminate 4 shown in FIG. 1. FIG. 4 is a plan view showing the shape of the electrode 10 formed on the dielectric green sheet 11a shown in FIG. FIG. 5 is a perspective view showing the ceramic laminate 4 in a state in which the through holes 6 are formed after the dielectric green sheet 11 and the magnetic green sheet 12 shown in FIG. 3 are laminated. FIG. 6 is a plan view of a state in which an electrode 8 is subsequently formed on the exposed surface 3 of the dielectric portion 1 of the ceramic laminate 4. As shown in FIG. FIG. 7 is a perspective view of the ceramic laminate 4 in which an external earth electrode 15 is further formed. FIG. 8 is a diagram corresponding to FIG. 3 for explaining another embodiment of the present invention. FIG. 9 is a diagram corresponding to FIG. 1 for explaining still another embodiment of the present invention. Figure 10 shows the 9th
FIG. 3 is an equivalent circuit diagram of the LC filter shown in the figure. FIGS. 11, 12, and 13 are diagrams for explaining the embodiment of FIG. 9, and correspond to FIGS. 3, 5, and 7, respectively. FIG. 14 is a diagram corresponding to FIG. 11 for explaining still another embodiment of the present invention. In the figure, 1.21 is a dielectric part, 2 is a magnetic part,
3.23 is an exposed surface, 4 and 4a are ceramic laminates, and 5.
25 is an opening, 6 is a through hole, 7.7-1+ 7-2.7
n is the connector pin, 8.28 is one electrode, 9.29
is solder, 10.30 is the other electrode, 11. lla, 31,
31a is a dielectric green sheet, 12 is a magnetic green sheet, 13 is a defective part, 14 is a lead-out part, 15 is an external earth electrode, CI, C2, Cn, C' 1. C'2.
C' n is a capacitor, Ll, L2 . Ln is an inductor. Patent Applicant Murata Manufacturing Co., Ltd. Patent Attorney Kube Fukami'□'~°゛-1゛1 (and 2 others > -” !4 Figure 3

Claims (7)

[Claims] (1) A ceramic laminate having at least one dielectric portion and at least one magnetic portion integrated in a layered manner, and at least the dielectric portion forming an exposed surface; At least one through hole is formed in the ceramic laminate, one opening of which is located on the exposed surface of the dielectric part, and which commonly penetrates both the dielectric part and the magnetic part, A connector pin is inserted into the through hole, one electrode of a capacitor is formed on the exposed surface in a region surrounding the one opening, and the other electrode of the capacitor is formed to be electrically connected to the connector pin. The other electrode faces the one electrode with the dielectric constituting the dielectric part sandwiched therebetween, and is formed excluding the area around the through hole, and the other electrode serves as a grounding electrode on the outer surface of the ceramic laminate. LC filter pulled out. (2) The LC filter according to claim 1, wherein the ceramic laminate is formed by integrating the dielectric portion and the magnetic portion by co-firing. (3) The LC filter according to claim 2, wherein the dielectric portion is made of a Pb-based composite perovskite. (4) The LC filter according to claim 2 or 3, wherein the magnetic material portion is made of Ni-Zn ferrite. (5) A plurality of the connector pins are provided, a plurality of the one electrodes are formed in relation to each of the plurality of connector pins and are electrically independent from each other, and the other electrode is a plurality of the one electrodes. The LC filter according to any one of claims 1 to 4, which is formed so as to commonly face one electrode of the LC filter. (6) The LC filter according to any one of claims 1 to 5, wherein the ceramic laminate includes one dielectric portion and one magnetic portion. (7) According to any one of claims 1 to 5, the ceramic laminate is composed of one magnetic part and two dielectric parts located on both sides of the magnetic part. LC filter as described.