JPH09180958A - Multilayer ceramic capacitor structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance multilayered ceramic capacitors in uniformity of capacitance in 5 manufacturing process. SOLUTION: A narrowed part 12a' is provided to an inner electrode 12a on each of first ceramic sheets 11a corresponding to the tip of an inner electrode 12b on each of second ceramic sheets 11b, and a narrowed part 12b' is provided to the inner electrode 12b corresponding to the tip of the inner electrode 12a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a laminated ceramic capacitor formed by laminating and integrating a plurality of ceramic sheets having internal electrodes formed on their surfaces.

[0002]

2. Description of the Related Art Generally, this type of multilayer ceramic capacitor is well known in the prior art and, as shown in FIGS. 9 to 11, has an internal electrode 2a formed on its surface so as to extend to one edge 1a '. The first ceramic sheet piece 1a,
A plurality of second ceramic sheet pieces 1b each having an internal electrode 2b formed to extend to one end edge 1b 'on the surface thereof are alternately laminated so that one end edges 1a' and 1b 'thereof are opposite to each other. After that, it is integrated into one chip body 3, and each of the left and right end surfaces 3a and 3b of the chip piece 3 has a terminal electrode 4a electrically connected to the internal electrode 2a of each of the first ceramic sheet pieces 1a, and The internal electrodes 2b of each of the second ceramic sheet pieces 1b and the terminal electrodes 4b that are electrically connected to each other are formed by applying a conductive pace. Note that reference numeral 15
Shows a ceramic sheet piece for a cover.

In this case, in the conventional multilayer ceramic capacitor, the internal electrode 2a in each of the first ceramic sheet pieces 1a has the same width dimension W1 over the entire length thereof and the internal electrode 2b in each of the second ceramic sheet pieces 1b. Is set to have the same width W2 over its entire length, and these are appropriately overlapped at a portion having a length L, so that the capacitance of the capacitor is set by the area at the portion having the overlapping length L.

Further, in manufacturing the multilayer ceramic capacitor having the above-mentioned structure, the conventional method is disclosed in, for example, Japanese Patent Laid-Open No.
As described in Japanese Patent No. 12817, a ceramic green sheet in which a large number of ceramic sheet pieces are integrally connected is prepared, and a conductive paste is applied to the surface of the ceramic green sheet by screen printing. A method is adopted in which the capacitors are put on and then dried, then a plurality of these ceramic green sheets are laminated and integrated, and then cut into individual capacitors.

[0005]

By the way, between the internal electrode 2a in each first ceramic sheet piece 1a and the internal electrode 2b in each second ceramic sheet piece 1b,
Print misalignment that occurs when screen-printing a conductive paste for the ceramic green sheet, and
Due to the stacking deviation that occurs when stacking a plurality of ceramic green sheets, a relative deviation inevitably exists in both the length direction and the width direction. For these internal electrodes 2
The area of the overlapping portion of a and 2b increases or decreases, and the capacitance value of each capacitor changes.

Therefore, conventionally, with respect to the relative displacement in the width direction of the two directions, the width dimension W1 of the internal electrode 2a of the first ceramic sheet piece 1a is set to the second width.
By making the width of the ceramic sheet piece 1b larger than the width W2 of the internal electrode 2b, the area of the overlapping portion does not increase or decrease. However, with respect to the relative displacement in the length direction of the two directions, the internal electrode 2a in each first ceramic sheet piece 1a and the internal electrode 2b in each second ceramic sheet piece 1b have the same width over their entire length. Since the size remains the same, the area in the overlapping portion greatly increases or decreases.

Therefore, in the structure of the conventional multilayer ceramic capacitor, there is a problem that the rate of occurrence of defective products becomes high because of large variation in the capacitance value among the multilayer ceramic capacitors during the manufacture thereof.
SUMMARY OF THE INVENTION It is a technical object of the present invention to provide a structure in a multilayer ceramic capacitor that does not cause such a problem.

[0008]

In order to achieve this technical object, the present invention provides a "first ceramic sheet piece having an internal electrode formed on the surface so as to extend to one edge, and the internal electrode on one edge. A second ceramic sheet piece formed so as to extend up to, and alternately laminated and integrated so that one end edges thereof are opposite to each other, and an internal electrode in the first ceramic sheet piece is provided. At least a portion corresponding to the tip of the internal electrode in the second ceramic sheet piece, and at least a portion of the internal electrode in the second ceramic sheet piece corresponding to the tip of the internal electrode in the first ceramic sheet piece. Is partially formed in the narrow portion. "

[0009]

As described above, at least a portion of the internal electrodes of the first ceramic sheet piece that corresponds to the tip of the internal electrode of the second ceramic sheet piece, and at least the internal electrode of the second ceramic sheet piece. By forming each of the portions corresponding to the tips of the internal electrodes in the first ceramic sheet piece partially in the narrow width portion, the internal electrodes in the first ceramic sheet piece and the internal electrodes in the second ceramic sheet piece are formed. Due to the relative displacement in the length direction between the internal electrodes, the tips of the internal electrodes are displaced in the length direction in the narrow portion of the internal electrodes. The rate at which the area in the overlapping portion of changes with the relative deviation in the length direction,
The width of each internal electrode can be made smaller than in the conventional case where the width is the same.

Therefore, according to the present invention, when manufacturing a monolithic ceramic capacitor, it is possible to reduce variations in capacitance value among the monolithic ceramic capacitors, and to significantly reduce the rate of defective products.
Further, as in “claim 2”, the width dimension of the internal electrode in the first ceramic sheet piece is made larger than the width dimension of the internal electrode in the second ceramic sheet piece, so that the width direction of each internal electrode is reduced. Since it is possible to prevent the area in the overlapping portion from increasing or decreasing with respect to the relative deviation, it is possible to further reduce the defective product generation rate.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings of FIGS. In this figure, reference numeral 11a indicates a first ceramic sheet piece having an internal electrode 12a formed on the surface so as to extend to one end edge 11a '.
Reference numeral 11b denotes an inner electrode 12b on the surface at one end edge 11b '.
Reference numeral 15 denotes a second ceramic sheet piece formed so as to extend to, and reference numeral 15 denotes a ceramic sheet piece for a cover.

In this case, the first ceramic sheet piece 1
The width dimension W1 of the internal electrode 12a in 1a is
The width is larger than the width W2 of the internal electrode 12b in the ceramic sheet piece 11b. The first ceramic sheet piece 11a and the second ceramic sheet piece 1
A plurality of sheets 1b, one edge 11a ', 11
Alternately laminated so that b'is opposite to each other.
After stacking the ceramic sheets 15 for the cover, they are integrated into one chip body 13, and the left and right end surfaces 13a and 13b of the chip piece 13 are electrically connected to the internal electrodes 12a of the first ceramic sheet pieces 11a. A terminal electrode 14a that is electrically connected to the internal electrode 12b of each of the second ceramic sheet pieces 11b is formed.

In this case, according to the present invention, of the internal electrodes 12a of each of the first ceramic sheet pieces 11a, the portion corresponding to the tip of the internal electrode 12b of the second ceramic sheet piece 11b is inserted into the left and right sides thereof. By providing the portions 16a and 16b, the dimension W1 'is partially provided.
Of the internal electrodes 12b of the second ceramic sheet pieces 11b among the internal electrodes 12a of the first ceramic sheet pieces 11a.
Insert the part corresponding to the tip of the
7a and 17b are provided, and the narrow portion 1 having the dimension W2 'is partially provided.
2b '.

In this way, each first ceramic sheet piece 1
A portion of the internal electrode 12a in 1a corresponding to the tip of the internal electrode 12b in the second ceramic sheet piece 11b is partially formed in the narrow portion 12a ', while each second
Of the internal electrodes 12b in the ceramic sheet piece 11b, the internal electrodes 12 in the first ceramic sheet piece 11a
By forming a portion corresponding to the tip of a in the narrow portion 12b ', the internal electrode 12a in the first ceramic sheet piece 11a and the second ceramic sheet piece 11 are formed.
In FIG. 5, the internal electrode 12b in FIG. 5b is relatively displaced in the length direction so that the overlapping dimension L increases to L ', as shown by the chain double-dashed line in FIG. As shown by the dashed line, in any case where the overlapping dimension L is relatively deviated so as to be reduced to L ″, the tips of the internal electrodes 12a, 12b are Narrow part 12 of 12b
Since the portions a'and 12b 'are displaced in the longitudinal direction, the ratio of the area change in the overlapping portion of the internal electrodes 12a and 12b due to the relative displacement in the longitudinal direction is As described above, the width of each internal electrode can be made smaller than in the case where the width is the same over the entire length.

In this case, the narrow portion 12
The width dimensions W1 ', W2' in a ', 12b' are set to the second
By making the width dimension W2 of the internal electrode 12b to be half, the ratio of the area of the overlapping portion of the internal electrodes 12a and 12b that changes due to the relative displacement in the length direction is halved as compared with the conventional case. It is possible.

Further, the width W1 of the internal electrode 12a in the first ceramic sheet piece 11a is made larger than the width W2 of the internal electrode 12b in the second ceramic sheet piece 11b, so that the width of each internal electrode 12a, 12b is increased. The area in the overlapping portion does not increase or decrease with respect to the relative deviation in the direction. In the above description, the inner electrodes 12a of the first ceramic sheet piece 11a and the inner electrodes 12b of the second ceramic sheet piece 11b are provided with the indented portions 16a, 16b, 17a, 17b on both left and right sides. As a result, the internal electrodes 12a, 12b are partially connected to the narrow portion 12
The case of forming a'and 12b 'is shown, but the present invention is
Not limited to this, as shown in FIG. 6, by providing the penetration portions 16a and 17a only on one side of both the internal electrode 12a of the first ceramic sheet piece 11a and the internal electrode 12b of the second ceramic sheet piece 11b. , The inner electrodes 12a and 12b are partially formed in the narrow portion 12
a ', 12b', or, as shown in FIGS. 7 and 8, each internal electrode 12a, 1b.
The narrow portions 12a 'and 12b' in 2b are connected to the end faces 11a 'and 11 in the ceramic sheet pieces 11a and 11b.
It may be configured to extend to b '.

In this case, as described above, the internal electrodes 12a and 12b are inserted into the internal portions 16a and 16b.
In the case where the narrow electrodes 12a 'and 12b' are partially formed by providing b, 17a and 17b, the internal electrodes 12a and 12b are connected to the left and right end surfaces 13a and 13b of the chip piece 13, respectively. Since it is wide in
When the terminal electrodes 14a and 14b are formed on the left and right end surfaces 13a and 13b of the chip piece 13, the respective terminal electrodes 1
There is an advantage in that the certainty of electrically connecting 4a, 14b to each of the internal electrodes 12a, 12b is higher than that in the case of the configuration as shown in FIGS. 7 and 8.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view of a multilayer ceramic capacitor according to the present invention.

FIG. 2 is a plan sectional view taken along line II-II of FIG.

FIG. 3 is an exploded perspective view of a multilayer ceramic capacitor according to the present invention.

FIG. 4 is an enlarged plan view.

FIG. 5 is an enlarged plan view.

FIG. 6 is a perspective view showing another example of the present invention.

FIG. 7 is a perspective view showing another example of the present invention.

FIG. 8 is a perspective view showing another example of the present invention.

FIG. 9 is a vertical sectional front view of a conventional multilayer ceramic capacitor.

10 is a plan sectional view taken along line XX of FIG.

FIG. 11 is an exploded perspective view of a conventional multilayer ceramic capacitor.

[Explanation of symbols]

11a 1st ceramic sheet piece 11b 2nd ceramic sheet piece 12a, 12b Internal electrode 12a ', 12b' Narrow part 13 Chip body 14a, 14b Terminal electrode

Claims (2)

[Claims] 1. A first ceramic sheet piece having an internal electrode formed on its surface so as to extend to one end edge, and a second ceramic sheet piece having an internal electrode formed on its surface extending to one end edge. In a multilayer ceramic capacitor that is alternately laminated and integrated so that one end edges thereof are opposite to each other, it corresponds to at least a tip of an internal electrode in the second ceramic sheet piece among internal electrodes in the first ceramic sheet piece. And a part of each of the internal electrodes of the second ceramic sheet piece corresponding to the tip of the internal electrode of the first ceramic sheet piece is partially formed in a narrow portion. Type ceramic capacitor structure. 2. A first ceramic sheet piece having an internal electrode formed on the surface so as to extend to one edge, and a second ceramic sheet piece having an internal electrode formed on the surface so as to extend to one edge. In a monolithic ceramic capacitor which is alternately laminated and integrated so that one end edges thereof are opposite to each other, the width dimension of the internal electrode in the first ceramic sheet piece is smaller than the width dimension of the internal electrode in the second ceramic capacitor. While increasing at least a portion of the internal electrodes of the first ceramic sheet piece that corresponds to at least the tip of the internal electrode of the second ceramic sheet piece, and at least the first electrode of the internal electrodes of the second ceramic sheet piece. Width of each part of the ceramic sheet piece that corresponds to the tip of the internal electrode Structure of the multilayer ceramic capacitor, characterized in that formed on the section.