JPS584185Y2 - Multilayer feedthrough capacitor - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a multilayer feedthrough capacitor, and particularly relates to an improvement for widening the range of frequencies that can be used as a filter.

FIG. 1 is a characteristic diagram of the resonant frequency of a conventional multilayer feedthrough capacitor.

As shown here, the conventional laminated feedthrough capacitor is
It has a chevron-shaped characteristic with one peak at a certain value.

Therefore, when this is used in a filter circuit, only a relatively narrow frequency range can be obtained.

However, for example, in the above-mentioned filter circuit,
Broadband may be required.

Furthermore, there may be a need to realize a filter capacitor that has filter characteristics in a plurality of frequency bands that are separated from each other.

That is, they are capacitors having characteristics as shown in FIGS. 2 to 4.

Therefore, the main objective of this invention is to provide a multilayer feedthrough capacitor that can independently satisfy the various demands mentioned above.

In summary, this idea is a feed-through capacitor that has a capacitor section constructed by stacking a plurality of dielectric layers that have a through hole in the center through which the through conductor passes and an electrode on one side. The first group of electrodes are electrically connected, and the second group of electrodes are electrically electrically connected to the grounding fitting, so that a plurality of parallel capacitors are stacked along the length of the through conductor, The plurality of parallel capacitors include at least two different types of capacitors, and the portions forming these different capacitors are located at different positions along the length of the through conductor.

Other objects and features of this invention will become clearer from the detailed description given below with reference to the drawings.
The figure is also a plan view.

First, the basic structure of a multilayer feedthrough capacitor will be described with reference to FIGS. 5 and 6.

The multilayer feedthrough capacitor includes a feedthrough conductor 1 passing on its central axis, a capacitor portion 2 formed around the feedthrough conductor 1, and a grounding metal fitting 3 projecting from the outer periphery of the capacitor portion 2.

In the capacitor portion 2, a plurality of dielectric layers 21 made of, for example, ceramic and extending in a direction intersecting the through conductor 1 are laminated.

Each of the dielectric layers 21 includes a first intermediate electrode 22 extending from its inner edge, and a second intermediate electrode 23 extending from its outer edge. There are some parts that are provided, and these are stacked alternately.

An internal electrode 24 is provided on the inner diameter side of the plurality of dielectric layers stacked in this manner, and an external electrode 25 is provided on the outer diameter side.

A first intermediate electrode 22 is connected to this internal electrode 24,
A second intermediate electrode 23 is connected to the external electrode 25 .

In this way, in the capacitor section 2, unit capacitors are formed between each first intermediate electrode 22 and each second intermediate electrode 23, and these unit capacitors are connected in parallel as a whole. Become.

In this capacitor part 2, solder 4 is provided between the through conductor 1 and the internal electrode 24, and solder 4 is provided between the through conductor 1 and the external electrode 25. , are connected respectively.

In addition to the basic configuration described above, as a characteristic configuration, materials with different dielectric constants are used for each dielectric layer 21.

For example, in FIG. 5, a ceramic material with a high dielectric constant is used in the upper half, and a ceramic material with a low dielectric constant is used in the lower half.

In this way, a portion with a large capacitance and a portion with a small capacitance coexist in one multilayer feedthrough capacitor.

Therefore, the resonance frequency determined by /=L'(2πA) is distributed, for example, as shown by the broken line in FIG. 2, and the overall characteristic has a flat portion as shown by the solid line.

Therefore, if used in a filter circuit, the usable frequency range can be expanded.

In the above embodiment, if the dielectric constants of the ceramic materials constituting each dielectric layer 21 are slightly shifted from each other, each unit capacitor will have a resonant frequency distributed as shown by the broken line in FIG. 3, for example. Therefore, as a whole, it is possible to realize a long characteristic with a fairly flat portion as shown by the solid line.

In the embodiments described above, a generally continuous frequency band was achieved.

However, depending on how the dielectric constant of the ceramic material constituting the dielectric layer 21 is selected, for example, as shown in FIG.
It is also possible to realize a frequency band of

FIG. 7 is a half-assembled sectional view of another embodiment of this invention.

In FIG. 7 and FIGS. 8 to 11, which will be described later, parts corresponding to those shown in FIG. 5 are given the same reference numerals, and the explanation thereof will be omitted.

In the embodiment shown here, the capacitance of each part of the capacitor section 2 is made different from each other, thereby forming parts having mutually different resonant frequencies, as in the above-mentioned embodiments.

Specifically, the intervals between the electrodes 22 and 23 are set to be coarse and fine.

This embodiment can also be modified in the same manner as the above-described embodiment, and has the same effects.

FIG. 8 is a half-assembled sectional view of still another embodiment of this invention.

This embodiment includes a capacitor section 2 having a shape in which truncated cones are connected in reverse, and an external electrode 25 provided on the outer peripheral surface of the capacitor section 2 has an inwardly bent cross-sectional shape.

For this purpose, a grounding fitting 3 is provided via a conductor 5 having a triangular cross section and a band-like shape as a whole.

According to this embodiment, since the areas of the intermediate electrodes 22 and 23 are slightly different from each other, it is possible to obtain an area that is distributed from a portion with a large capacitance and a large residual inductance to a portion with a small capacitance and a small residual inductance. Therefore, the characteristics shown in FIG. 3, for example, can be obtained.

FIG. 9 is a half sectional view of still another embodiment of this invention.

This embodiment includes a capacitor portion 2 having a shape in which a capacitor portion with a relatively small outer diameter is sandwiched between two capacitors with a relatively large outer diameter, and therefore the external electrode 25 has a portion having a rectangular cross section.

For this purpose, a grounding metal fitting 3 is provided via a conductor 5 having a rectangular cross section and an entire band shape.

According to this embodiment, the areas of the electrodes 22 and 23 coexist in a relatively large area and a relatively small area,
Therefore, a portion with a large capacitance and a large residual inductance coexists with a portion with a small capacitance and a small residual inductance.

That is, for example, the characteristics shown in FIG. 2 or FIG. 4 are obtained.

FIG. 10 is a half-ring sectional view of still another embodiment of this invention.

This embodiment corresponds to the container portion 2 in FIG. 9 in which one portion having a relatively large outer diameter is missing.

Furthermore, there is no equivalent to the conductor 5 in FIG. 9, and therefore the grounding fitting 3 is provided in direct contact with the external electrode 25.

According to this embodiment, substantially the same effects as the embodiment shown in FIG. 9 can be achieved.

FIG. 11 is a half-ring sectional view of still another embodiment of this invention.

This embodiment corresponds to one in which one truncated conical portion constituting the container portion 2 in FIG. 8 is omitted.

Furthermore, the grounding fitting 3 is provided in direct contact with the external electrode 25.

According to this embodiment, substantially the same effects as the embodiment shown in FIG. 8 are achieved.

Although various embodiments have been described above, it is also possible to combine these embodiments with each other.

For example, the embodiment shown in FIG. 5 and the embodiment shown in FIG. 7 may be combined, or the embodiment shown in FIG. 5 and FIGS. Can be combined with

In this way, effects can be doubled or unique characteristics can be realized.

As described above, according to this invention, when this multilayer feedthrough capacitor is used in a filter circuit, its usable frequency range is widened, for example, from 10 to 100 G in the SHF band.
It can be extended up to Hz.

Moreover, if the distribution state of the natural resonant frequencies of the plurality of unit capacitors formed in the capacitor section is appropriately selected, an effect as a bandpass filter can be expected.

Further, this multilayer feedthrough capacitor can be used, for example, as a noise filter for a microwave oven or as an EM (electromagnetic interference) filter.

In addition, a multilayer feedthrough capacitor having such characteristics is easy to manufacture because general multilayer capacitor part fabrication technology can be used.

[Brief explanation of the drawing]

1 to 4 are characteristic diagrams of various resonance frequencies, FIG. 5 is a half-ring sectional view of one embodiment of this invention, and FIG. 6 is a plan view. 7 to 11 are half-ring sectional views of other embodiments of this invention. In the figure, 1 is a through conductor, 2 is a capacitor part, 3 is a grounding metal fitting, 21 is a dielectric layer, 22.23 is an intermediate electrode, and 24
25 is an internal electrode, and 25 is an external electrode.

Claims (1)

[Scope of Claim for Utility Model Registration] A laminated feedthrough capacitor comprising a through conductor, a capacitor section provided around the through conductor, and a grounding fitting that extends from the outer periphery of the capacitor section, wherein the capacitor section is formed by stacking a plurality of dielectric layers having a through hole in the center through which the through conductor passes and has an electrode on one side, and the first group of electrodes have a through hole through which the through conductor passes. conductors, and those of the second group of electrodes are connected to the grounding fitting, so that a plurality of parallel capacitors are stacked along the length of the through conductor; A multilayer feedthrough capacitor characterized in that the parallel capacitance includes at least two different types of capacitance, and portions forming such different capacitances are located at different positions along the length direction of the feedthrough conductor.