JPH05205966A - Multilayer capacitor - Google Patents

Abstract

PURPOSE:To enable a multilayer capacitor to be increased in electric resonant frequency and decreased in equivalent series resistance by a method wherein two kinds of insulating sheets, where a region on which no electrode is located is provided inside electrodes, are superposed to form a multilayer body, and the same electrodes are connected to each other through a lead-out electrode which penetrates the region of the multilayer body where no electrode is located. CONSTITUTION:Two kinds of ceramic green sheets, where regions 13 and 14 on which no electrode is located are provided at different points inside electrodes 11 and 12, are alternately superposed as many as required and burned as pressed into a multilayer body 19. Through-holes 20 and 21 are provided to the laminate 19 vertically penetrating the regions 13 and 14 where no electrode is provided. The through-holes 20 and 21 connect the same electrodes 11 and 12 together to serve as the lead-out parts of them, but both the through- holes 20 and 21 are formed inside the electrodes 11 and 12, so that the electrodes 11 and 12 substantially have no lead-out part. Therefore, inductance and resistance accompanying lead-out electrodes are hardly generated, and by this setup, a multilayer capacitor can be increased in resonant frequency and decreased in equivalent series resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer capacitor having a high electric resonance frequency and a low equivalent series resistance.

[0002]

2. Description of the Related Art In a conventional multilayer capacitor A, as shown in FIG. 6, a plurality of ceramic green sheets 2 each having a rectangular electrode 1 provided on one surface thereof so as to reach one end thereof are arranged on the opposite side from which the electrodes 1 are taken out. Alternately, the ceramic green sheets 3 and 4 are stacked one above the other and pressed to sinter them, and at the same time, external electrodes 5 and 6 are provided at both ends as shown in FIG. 6 has a structure in which electrodes 6 are alternately connected.

By the way, the above multilayer capacitor A
As shown in FIG. 8, the portion where the electrodes 1 face each other substantially forms a capacitor, and the portion where the electrodes 1 face each other is electrically connected to the external electrode at a position away from the facing portion. The part between the part reaching from the external electrode to the external electrode is the extraction electrode 7.

[0004]

As described above, the electrode 1
If the extraction electrode 7 exists in the lead electrode 7, as shown in the equivalent circuit of FIG. 8, inductance and resistance are generated in the extraction electrode 7, the electric resonance frequency is low, and the equivalent series resistance (E
There is a problem in that SR) becomes a large capacitor, making it difficult to use in a high frequency band.

Therefore, an object of the present invention is to provide a multilayer capacitor which is constructed so that the extraction electrode is taken out from the inside of the electrode and which has a high electric resonance frequency and a low equivalent series resistance.

[0006]

In order to solve the above problems, the present invention stacks at least two kinds of insulating sheets in which regions without electrodes are formed at different positions inside electrodes provided on the surface. A laminated body is formed by using a structure in which the same electrodes are connected to each other with lead-out electrodes of through holes or via holes provided so as to penetrate through the area of the laminated body where there is no electrode, and the laminated body is drawn out of the laminated body. It was done.

[0007]

[Operation] At least two kinds of insulating sheets in which regions without electrodes are formed at different positions inside the electrodes are stacked to form a laminated body, and the same electrode is formed by the extraction electrode penetrating the region without electrodes in the laminated body. Since they are connected to each other, the extraction electrode can be taken out from the electrode, and there is practically no electrode extraction part, and since there is no electrode extraction part, the electrical resonance frequency is high and the equivalent series resistance It is a low multilayer capacitor.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. 1 to 5 of the accompanying drawings.

As shown in FIG. 1, there are no electrodes 13 and 1 inside the circular patterns of electrodes 11 and 12 provided on the surface.
Prepare two kinds of ceramic green sheets 15 and 16 in which 4 is formed at different positions, stack the required number of these ceramic green sheets 15 and 16 alternately, and stack the ceramic green sheets 17 and 18 on the upper and lower sides. The laminate 19 is formed by pressurizing and firing.

The laminated body 19 is provided with through holes 20 and 21 vertically penetrating the portions 13 and 14 of the electrodes 11 and 12 where there is no electrode, as shown in FIG.

The through holes 20 and 21 have a diameter slightly smaller than that of the regions 13 and 14 having no electrode, and the region 1 described above is used.
It is provided so as to penetrate through the centers of the electrodes 3 and 14, so that both through holes 20 and 21 are formed in the regions 13 and 1 without electrodes.
4 does not conduct with the electrode, and one through hole 20 penetrates the electrode 12 and the other through hole 21 penetrates the electrode 11, and at this penetrating portion, the electrodes 11 and 12 are electrically connected. Will be connected.

Therefore, the through-holes 20 and 21 are formed by connecting the same electrodes 11 and 12 to each other.
Both of the through holes 20 and 21 can be used as external electrodes for connecting to the circuit board at the portions that are drawn out of the laminated body 19.

As described above, both through holes 20 and 21 are provided.
Is a lead-out portion for both electrodes 11, 12, but by forming both through-holes 20, 21 inside the electrodes 11, 12, it is possible to connect to the external electrode at the shortest distance, and substantially the lead-out portion is formed. Is almost gone.

That is, the distance from each part of the electrodes 11, 12 to the through holes 20, 21 can be suppressed within the range of l ₁ to l ₂ , so that the two through holes 20 and 21 are located at the centers of the electrodes 11, 12. It is preferable to provide the regions 13 and 14 without electrodes so that they can be formed as close as possible.

Next, FIG. 2 shows a ceramic green sheet 1.
Electrodes 11 and 12 provided on 5a and 16a are formed in a square shape, and electrode-free regions 13 and 14 are provided on different positions of both electrodes 11 and 12, respectively.
1 shows an example of forming a multilayer capacitor by stacking in the same manner as in FIG.

When the electrodes 11 and 12 are square like this example, the distances from the through holes to the four corners of the electrodes are larger than those of the circular electrodes, and the characteristics are slightly degraded by that amount, but the circular electrodes are Compared with the above, when taking the same area, there is an advantage that the planar shape of the multilayer capacitor can be downsized.

In any of the examples, as shown in FIG. 4, the electrodes 11 and 12 may be connected to each other and the laminated body 19 may be drawn out through the via holes 22 and 23. In this case, the laminated bodies are laminated. In the electrode land on the back of the body 19,
The bumps 24 and 25 may be formed to facilitate mounting on the circuit board. Further, three or more types of sheets may be provided to provide regions having no electrodes at different positions.

The multilayer capacitor of the present invention has the above-mentioned structure, and as shown in FIGS.
Through hole 20 for connecting 12 and drawing out
21 or the via holes 22 and 23 are taken out of the electrodes 11 and 12, so that there is almost no lead-out electrode, and accordingly, the generation of inductance and resistance due to the lead-out electrode is small, which causes resonance. The frequency is high and the equivalent series resistance (ESR) is low.

By the way, Table 1 shows the results of measuring the characteristics of the conventional multilayer capacitor shown in FIG. 7 and the multilayer capacitor of the present invention shown in FIGS. 1 and 2.

[0020]

[Table 1]

As is clear from the above measurement results, the multilayer capacitor of the present invention has a significantly higher resonance frequency and a smaller equivalent series resistance than the conventional multilayer capacitor.

Further, in the multilayer capacitor of the present invention, since the characteristics differ depending on the shape of the electrode, the electrode shape may be selected from both aspects of characteristics and size.

Further, in order to take advantage of the characteristic that the resonance frequency is high and the equivalent series resistance is low, as shown in FIG. 5, a component 26 such as a capacitor or a resistor is mounted on the electrode portion drawn out on the surface of the multilayer capacitor, and the multilayer capacitor is laminated. You may use a capacitor as a board | substrate of a module etc.

[0024]

As described above, according to the present invention, the connection of the internal electrodes in the multilayer capacitor and the extraction to the outside are performed from the inside of the internal electrodes, so that the external electrodes are close to the internal electrodes forming the capacitor, There is an effect that there is almost no extraction electrode, the electric resonance frequency is high, and the equivalent series resistance is low.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing patterns of a ceramic green sheet and electrodes that form a multilayer capacitor.

FIG. 2 is an exploded perspective view showing an example in which the same electrode pattern is different.

FIG. 3 is a vertical sectional view of a multilayer capacitor.

FIG. 4 is a vertical sectional view of a multilayer capacitor using a via hole.

FIG. 5 is a vertical cross-sectional view using a multilayer capacitor as a module substrate.

FIG. 6 is an exploded perspective view showing a conventional multilayer capacitor.

FIG. 7 is a vertical sectional view showing a conventional multilayer capacitor.

FIG. 8 is an equivalent circuit diagram of the above.

[Explanation of symbols]

11,12 Electrodes 13,14 Areas without electrodes 15,15a, 16,16a Ceramic green sheet 17,18 Ceramic green sheet 19 Laminated body 20,21 Through hole 22,23 Via hole

Claims (1)

[Claims] 1. A laminated body is formed by stacking at least two kinds of insulating sheets each having an electrodeless region formed at different positions inside an electrode provided on a surface thereof to form a laminated body. A multilayer capacitor, wherein the same electrodes are connected to each other by lead-out electrodes of through-holes or via-holes provided so as to penetrate and are led out to the outside of the laminated body.