JPH0343712Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a multilayer ceramic capacitor block in which a plurality of independent unit multilayer capacitors are contained within an integral multilayer body.

Summary of the invention This invention is based on forming a guard electrode between adjacent unit multilayer capacitors in a multilayer ceramic capacitor block, extending this guard electrode to the outer surface of the multilayer body, and connecting it to earth here. , which aims to reduce the stray capacitance that occurs between adjacent unit multilayer capacitors.

A capacitor block is obtained by assembling a plurality of independently used unit capacitors to form one aggregate. This capacitor block is also called a capacitor network, and is advantageously used in situations where a large number of capacitors are required, such as coupling capacitors in multi-channel digital signal input circuits. In other words, the capacitor block can contribute to overall miniaturization and high-density packaging in such situations.

As one form of such a capacitor block, a unit capacitor is constructed as a multilayer capacitor while using a dielectric material made of ceramic.
There is a multilayer ceramic capacitor block. This multilayer ceramic capacitor block has a plurality of independent unit multilayer capacitors contained within an integral multilayer body, and the external electrodes of each unit multilayer capacitor are formed on the outer surface of the multilayer body. be.

Problems to be Solved by the Invention In order to further reduce the size and increase the density of the multilayer ceramic capacitor block as described above, it is necessary to reduce the distance between the unit multilayer capacitors as much as possible. however,
When the distance between the unit multilayer capacitors is reduced in this way, the stray capacitance between the unit multilayer capacitors increases. In particular, this tendency becomes more pronounced when a unit multilayer capacitor or a capacitor block is constructed using a dielectric material having a high dielectric constant. Therefore, depending on the circuit used, it may not be possible to use a smaller, more dense capacitor block. For example, 0.1μF ~
In the case of a 0.47μF ultra-small capacitor block, the stray capacitance between unit capacitors is about 0.02μF, which is approximately 20%.When this is used to combine multi-channel digital signals, etc., the stray capacitance is large, so The disadvantages were that channel separation deteriorated and crosstalk problems occurred, making it practically unusable.

Therefore, this invention aims to provide a multilayer ceramic capacitor block that can reduce the stray capacitance that occurs between individual unit multilayer capacitors while making it possible to reduce the size and increase the density.

Means for Solving the Problem A plurality of independent unit laminated capacitors each having internal electrodes that overlap each other are included in an integral laminated body, and the external electrodes of each unit laminated capacitor are connected to the laminated body. In the multilayer ceramic capacitor block formed on the outer surface of the capacitor block, the above-mentioned technical problem is solved as follows.

That is, guard electrodes are formed between adjacent unit multilayer capacitors extending to the outer surface of the multilayer body.

Function: By grounding the guard electrode formed to extend to the outer surface of the laminate, the unit laminate capacitors can be shielded from each other, and the generation of stray capacitance can be canceled out.

Embodiment FIG. 1 shows a perspective view of a multilayer ceramic capacitor block (hereinafter simply referred to as "block") 1 which is an embodiment of this invention. This block 1 includes an integral laminate 3 formed by laminating a plurality of ceramic layers, such as ceramic layers 2a to 2e shown as a representative example in FIG.
Inside this multilayer body 3, a plurality of independent unit multilayer capacitors are included. In Figure 1,
The portion surrounded by the dotted line indicated by 4 constitutes one unit multilayer capacitor. External electrodes 5a and 5b of each unit multilayer capacitor 4 are formed on the outer surface of the multilayer body 3.

Each unit multilayer capacitor 4 is made of ceramic layers 2a and 2b or ceramic layers 2d and 2d shown in FIG.
It is constructed by laminating 2e. That is, the ceramic layers 2a, 2b, 2d, and 2e each have the following:
two internal electrodes 6a, 7a, 6b, 7b, 6d,
7d, 6e, and 7e are formed and when they are in a stacked state, the internal electrode 6a is connected to the internal electrode 6b, similarly, 7a is connected to 7b, 6a is connected to 6e, and 7d is connected to 7e.
and each overlaps with the other. Each internal electrode is formed with a lead-out portion 8a, 8b, 9a, 9b extending to the edge of the corresponding ceramic layer. Reference numeral 8a used to indicate these drawers,
8b, 9a, 9b are the respective ceramic layers 2
They are distinguished by their positions in a, 2b, 2d, and 2e.

As shown in FIG. 1, one block 1 includes the following:
For example, ten unit multilayer capacitors 4 are formed in two rows in each row. Guard electrodes, which are a feature of this invention, are formed along the boundary surfaces of these unit multilayer capacitors 4. There are two types of guard electrodes formed in this embodiment. The first is the guard electrode 10 having a wide surface formed on the ceramic layer 2c in FIG.
It is located between adjacent unit multilayer capacitors 4 in the stacking direction, and extends along the layer interface of the multilayer body 3 so as to face the internal electrodes. A lead-out portion 11 is formed in the guard electrode 10 and extends to the edge of the ceramic layer 2c. The second typical example is the ceramic layers 2a, 2b, 2d, 2 in FIG.
A strip-shaped guard electrode 1 formed on e.
2, it is located between unit capacitors 4 adjacent to each other in the direction in which the layer interfaces of the laminate 3 extend, and extends along the same layer interface as the internal electrodes. The guard electrode 12 is formed to extend to both opposing edges of the corresponding ceramic layer.

When ceramic layers are laminated to form a laminate 3 in an arrangement as partially shown in FIG.
The external appearance is shown in a perspective view in Fig. 3. That is, if we pay attention to the upper surface of the laminate 3 in FIG. 3, a plurality of guard electrodes 1
A lead-out portion 8 is provided in each region divided by a band in which the guard electrode 12 is distributed and the guard electrode 12 extends.
a, 8b, 9a, and 9b are distributed in a row. Further, on one side of the laminate 3, the drawer portions 11 are distributed in a row.

As is clear when comparing FIG. 3 with FIG. 1 described above, the external electrodes 5a, 5b are formed to rest on the lead-out portions 8a, 9a, 8b, 9b, respectively. Therefore, the external electrode 5a
For example, the internal electrodes 6a, 6 shown in FIG.
e, 7a, 7e, and the external electrode 5
b is, for example, the internal electrodes 6b, 6d, 7b, 7
electrically connected to d.

The guard electrodes 10 and 12 are grounded, and in order to facilitate these grounding connections, grounding electrodes 13a and 13b as shown in FIG. 1 are formed on the outer surface of the laminate 3. be done. The earth connection electrode 13a is formed to connect the four side surfaces of the laminate 3, and the earth connection electrode 13b
are formed so as to connect the top surface, bottom surface and two side surfaces of the laminate 3. Earth connection electrode 13a
covers the zone where the lead-out portion 11 is exposed and is thereby electrically connected to the guard electrode 10 .
The earth connection electrode 13b rests on the band where the guard electrode 12 is exposed and is electrically connected to the guard electrode 12. Note that the earth connection electrode 13
Since a and 13b intersect with each other, in order to ground the guard electrodes 10 and 12, it is sufficient to connect one of the ground connection electrodes 13a and 13b to ground. Note that the shapes of these earth connection electrodes are completely arbitrary and are not limited to those shown in the drawings.

4 and 5 are for explaining another embodiment of this invention.

As shown in FIG. 4, the block 21 includes a laminated body 22, in which a plurality of unit laminated capacitors as indicated by dotted lines 23 are housed. A portion of the ceramic layers making up the laminate 22 is shown in FIG.

As shown in FIG. 5, the ceramic layer 24a has two internal electrodes 25 arranged in the vertical direction.
a, 26a are formed, and a strip-shaped guard electrode 27 is formed between them. Internal electrode 25
a has a lead-out portion 28a, and the internal electrode 26a has a lead-out portion 29a. Furthermore, the guard electrode 27 extends to both opposing edges of the ceramic layer 24a.

Similarly, the ceramic layers 24b, 24d, 2
Also in 4e, internal electrodes 25b, 26b, 25d, 2
6d, 25e, and 26e are formed, each having a drawer portion. The drawer part is 28a, 28b, 29a, 29b depending on the position from which it is pulled out.
They are distinguished by reference signs, such as Similarly,
Guard electrodes 27 are also formed on the ceramic layers 24b, 24d, and 24c.

A guard electrode 30 having a wide surface is formed on the ceramic layer 24c, and a lead-out portion 31 is provided.

As shown in FIG. 4, external electrodes 32 and 33 and a ground connection electrode 3
4a and 34b are formed. These external electrodes 3
2, 33 and earth connection electrodes 34a, 34b
is shown partially cut away. Therefore,
These electrodes 3 formed on the outer surface of the laminate 22
The state of connection between the electrodes 2, 33, 34a, and 34b and the electrodes formed inside the laminate 22 can be understood by referring to FIG. That is, the external electrode 32 contacts the lead-out portion 28b and is electrically connected to, for example, the internal electrodes 25b and 25d shown in FIG. The external electrode 33 contacts the lead-out portion 29a. The earth connection electrode 34a is the guard electrode 2
7 and is electrically connected. Earth connection electrode 34b
contacts the lead-out portion 31 and is electrically connected to the guard electrode 30 . Note that two types of external electrodes are formed in two rows on the opposite side to the side on which the external electrodes 32 and 33 are formed, and each one is connected to the lead-out part 2.
It is electrically connected to 8a and 29a.

Although this invention has been described above in connection with the illustrated embodiment, the following embodiments are also conceivable as other embodiments.

For example, the number of stacked internal electrodes in each unit multilayer capacitor is completely arbitrary, and the number of stacked internal electrodes may be further increased to increase the capacitance.

It also faces the internal electrodes. The guard electrode with a wide surface (guard electrode 10 or 30) is different from the guard electrode with a strip shape (guard electrode 12 or 2).
In contrast to 7), although the layers were drawn out on different sides of the laminate, they may be drawn out on the same side.

Moreover, the strip-shaped guard electrodes formed extending along the same layer interfaces as the internal electrodes do not have to be formed on all the layers in which the internal electrodes are formed.

In addition, two types of guard electrodes were used: a guard electrode facing the internal electrode and a guard electrode extending along the same layer interface as the internal electrode. Even if it is just that, you can expect the effects of this idea.
In this regard, it should be pointed out that the arrangement of unit multilayer capacitors contained within one multilayer body is arbitrary. That is, in the two illustrated embodiments, the unit multilayer capacitors are arranged in two rows, so that they are adjacent to each other in the stacking direction of the laminates and stacked against each other. It had two aspects: one adjacent to the other in the direction in which the body layer interface extends. However, even if the unit multilayer capacitors are arranged in a line inside the laminate and are adjacent to each other in the stacking direction of the laminate, they are adjacent to each other in the direction in which the layer interfaces of the laminate extend. It may just be something that fits. When unit multilayer capacitors are adjacent to each other in the stacking direction of the laminate, the guard electrode is formed to extend along the interface of the laminate so as to face the internal electrode in the stacking direction of the laminate. It is effective to do so. On the other hand, when unit multilayer capacitors are adjacent to each other in the direction in which the layer interfaces of the laminate extend, the guard electrodes are formed to extend along the same layer interfaces as the internal electrodes. This is effective.

Effects of the invention As described above, according to this invention, a guard electrode is formed between adjacent unit multilayer capacitors, and this guard electrode extends to the outer surface of the laminate and is connected to the ground. , stray capacitance occurring between adjacent unit multilayer capacitors can be reduced as much as possible. Therefore, it is possible to reduce the distance between unit laminated capacitors while preventing the problem of stray capacitance, and it is possible to obtain a laminated ceramic capacitor block suitable for miniaturization and high density.

For example, if the multilayer ceramic capacitor block according to the present invention is used as a coupling capacitor in a multi-channel digital signal input circuit, separation between channels can be improved and crosstalk can be prevented. Therefore, even ultra-small capacitor blocks of, for example, 0.1 μF to 0.47 μF, which could not be used in such situations in the past, can now be used, contributing to high-density packaging.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a multilayer ceramic capacitor block 1 according to an embodiment of this invention. FIG. 2 is an exploded perspective view showing ceramic layers 2a to 2e forming part of the laminate 3 of FIG. 1. FIG. 3 is a perspective view showing a laminate 3 obtained by laminating ceramic layers 2a to 2e shown in FIG. 2. FIG. 4 shows a multilayer ceramic capacitor block 2 according to another embodiment of this invention.
1. FIG. FIG. 5 shows ceramic layers 24a to 2 forming part of the laminate 22 in FIG.
4e is an exploded perspective view. In the figure, 1, 21 are multilayer ceramic capacitor blocks, 2a to 2e, 24a to 24e are ceramic layers, 3, 22 are laminates, 4, 23 are unit multilayer capacitors, 5a, 5b, 32, 33 are external electrodes, 6a , 6b, 6d, 6e, 7a, 7b, 7
d, 7e, 25a, 25b, 25d, 25e, 2
6a, 26b, 26d, 26e are internal electrodes, 1
0, 12, 27, 30 are guard electrodes, 13a, 1
3b, 34a, 34b are earth connection electrodes.

Claims (1)

[Claims for Utility Model Registration] (1) A plurality of independent unit laminated capacitors each having internal electrodes that overlap each other are contained within an integral laminate, and an external electrode of each unit laminated capacitor. What is claimed is: 1. A multilayer ceramic capacitor block in which a guard electrode is formed between adjacent unit multilayer capacitors and extends to the outer surface of the multilayer structure. (2) The unit multilayer capacitors are adjacent to each other in the stacking direction of the laminate, and the guard electrode is arranged along the layer interface of the laminate so as to face the internal electrode in the stacking direction of the laminate. A laminated ceramic capacitor block according to claim 1 of the registered utility model claim. (3) The scope of the utility model registration claim, in which the unit multilayer capacitors are adjacent to each other in the direction in which the layer interfaces of the laminate extend, and the guard electrodes extend along the same layer interfaces as the internal electrodes. 2. The multilayer ceramic capacitor block according to item 1.