JPH0969466A - Monolithic ceramic capacitors - Google Patents

Abstract

(57) [Abstract] [Purpose] Suppresses creeping discharge that occurs on the ceramic surface,
It is an object of the present invention to create a monolithic ceramic capacitor having an improved creeping discharge starting voltage. [Structure] Two first internal electrodes 2a, 2b, 3a, 3
The ceramic green sheet 1 in which b is provided so as to reach the opposite ends, and the ceramic green sheet 1 in which one second internal electrode 4 is provided in the end in a non-contact state
A laminated body in which a plurality of layers are alternately laminated and a first laminated body of the laminated body.
Internal electrodes 2a, 2b, 3a, 3b are provided on the exposed end faces and external electrodes 5a, 5b are provided, and the two first front and back sides are provided.
Since the interval between the internal electrodes 2a and 2b is larger than that between the other two first internal electrodes 3a and 3b, the gradient of the potential on the ceramic surface becomes gentle and the creeping discharge starting voltage improves.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated ceramic capacitor.

[0002]

2. Description of the Related Art Generally, a laminated ceramic capacitor is formed by stacking a ceramic green sheet and a sheet on which an internal electrode paste is printed on the ceramic green sheet, pressurizing the laminated body, and then firing the laminated body to both ends of the sintered body. This is a structure in which an external electrode connected to the internal electrode is provided.

[0003]

The above conventional structure has a problem that the creeping discharge starting voltage is low when used at a high voltage. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and to produce a monolithic ceramic capacitor having an improved creeping discharge starting voltage.

[0004]

In order to achieve this object, the monolithic ceramic capacitor of the present invention is provided on the surface such that the outer sides of the two first internal electrodes reach the opposite ends. A second dielectric layer and a second internal electrode provided on the surface thereof, in which both ends of the second inner electrode are not in contact with the end portions of the second inner electrode.
A plurality of dielectric layers alternately laminated, and an external electrode provided on the exposed end surface of the first internal electrode of the laminated body, and the first first electrode close to the front and back of the first laminated electrode. In at least one of the internal electrodes, the distance between two first internal electrodes facing each other on the same plane is made larger than the distance between the other first internal electrodes.

[0005]

According to this structure, at least one of the first internal electrodes near the front and back of the laminated body has the same distance between two first internal electrodes facing each other on the same plane. Since the gap between the internal electrodes is made larger, the gradient of the potential between the external electrodes on the surface of the laminated body becomes gentle, and as a result, the creeping discharge starting voltage is improved as compared with the conventional case.

[0006]

EXAMPLES Example 1 An example of the present invention will be described below with reference to the drawings.

1, 2, 3 and 4 are cross-sectional views of a monolithic ceramic capacitor according to this embodiment, in which a first internal electrode 2a, 2b, 3 is provided with a ceramic green sheet 1 interposed therebetween.
a and 3b and the second internal electrode 4 are alternately laminated, and external electrodes 5a and 5b are formed on the exposed end faces of the first internal electrodes 2a, 2b, 3a and 3b. In addition, as shown in FIGS. 2 and 4, of the first inner electrodes 2a, 2b, 3a, 3b, two of the first inner electrodes 2a, 2b closest to the front and back of the laminated body.
The distance between the two electrodes is the first internal electrodes 3a, 3b inside the laminated body.
Is larger than the distance between the two electrodes. A method of manufacturing this laminated ceramic capacitor will be described.

First, a dielectric ceramic slurry was formed on a carrier film by a reverse roll coater and dried to form a ceramic green sheet 1. Next, the ceramic green sheet 1 is peeled off from the carrier film, and the internal electrode paste is screen-printed on the ceramic green sheet 1 by printing and drying using the pattern Y shown in FIG. 5 to form the first internal electrodes 2a, 2b. Was formed. Next, the ceramic green sheet 1 was laminated on this, the pattern W of FIG. 6 was shifted in the length direction on this, and the internal electrode paste was printed and dried to form the second internal electrode 4. After that, the ceramic green sheet 1 is laminated on this, the pattern W shown in FIG. 6 is returned to the original position, and the internal electrode paste is printed and dried to form the first internal electrodes 3a and 3b. did. In this way, the patterns W shown in FIG. 6 were alternately shifted in the length direction with the ceramic green sheet 1 sandwiched therebetween, and printing and lamination were repeated until the desired number of layers was obtained. However, the first internal electrode 2
The outermost layer portions of a and 2b were formed using the pattern Y shown in FIG.

Then, a predetermined number of ceramic green sheets 1 on which internal electrodes are not printed are laminated on the front side and the back side of the laminated body as described above to form an ineffective layer, which is pressed and pressed together. A laminated body was obtained. next,
This laminated body is cut, binder-out, and baked, and then the external electrodes 5a and 5b are applied and baked.
Ni plating and Sn-Pb plating were performed on a and 5b to obtain a monolithic ceramic capacitor. This monolithic ceramic capacitor has a capacitance of 100 pF, Q 1200, IR
It was 1 * 10 ¹³ Ω.

The effective layer had a thickness of 90 μm and the ineffective layer had a thickness of 120 μm. Table 1 shows the results of measuring the creeping discharge starting voltage using this multilayer ceramic capacitor.

[0011]

[Table 1]

Further, in this embodiment, the two electrode intervals of the two sets of the first inner electrodes 2a and 2b near the outermost layer and the outermost layer are set to be equal to the two of the first inner electrodes 3a and 3b in the laminated body. Although the distance between the two first inner electrodes 3a, 3b is set to be larger than that of the other first inner electrodes 2a, 2b, one of the pair of the first inner electrodes 2a, 2b is closer to the outermost layer or the outermost layer. Even if the electrode interval is increased, the creeping discharge starting voltage can be improved as compared with the conventional case.

Comparative Example 1 First, a dielectric ceramic slurry was formed on a carrier film by a reverse roll coater and dried to form a ceramic green sheet. Next, the ceramic green sheet is peeled off from the carrier film, the internal electrode paste is printed and dried on the ceramic green sheet by screen printing in the pattern of FIG. 6, the ceramic green sheet is laminated on the ceramic green sheet, and the ceramic green sheet shown in FIG. The internal electrode paste was printed and dried by shifting the pattern in the lengthwise direction. By repeating this process, lamination was performed. The laminated ceramic green sheets were pressed and pressed together to form a laminate. The subsequent steps are the same as in the first embodiment.

The results of measuring the creeping discharge inception voltage using the obtained monolithic ceramic capacitor in the same manner as in Example 1 are shown in (Table 1).

As is clear from this (Table 1), the monolithic ceramic capacitor of the present invention was able to improve the dielectric breakdown voltage.

[0016]

As described above, according to the present invention, at least one of the first internal electrodes near the front and back surfaces of the laminated body has a space between two first internal electrodes facing each other on the same plane as the other internal electrodes. Since the distance between the first internal electrodes is made larger, the gradient of the potential between the external electrodes on the surface of the laminated body becomes gentle,
As a result, the creeping discharge starting voltage is improved as compared with the conventional case.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a monolithic ceramic capacitor according to an embodiment of the present invention.

2 is an A- of the monolithic ceramic capacitor in FIG.
Section A

3 is a B- of the monolithic ceramic capacitor in FIG.
B sectional view

FIG. 4 is a C- of the monolithic ceramic capacitor in FIG.
C cross section

FIG. 5 is a plan view showing an internal electrode printing pattern according to an embodiment of the present invention.

FIG. 6 is a plan view showing an internal electrode printing pattern according to an embodiment of the present invention.

[Explanation of symbols]

 1 Ceramic Green Sheet 2a First Internal Electrode 2b First Internal Electrode 3a First Internal Electrode 3b First Internal Electrode 4 Second Internal Electrode 5a External Electrode 5b External Electrode

Claims (1)

[Claims] 1. A first dielectric layer provided on the surface so that the outer sides of the two first internal electrodes reach the opposite ends, and one second internal electrode on the surface, A laminated body in which a plurality of second dielectric layers each of which is provided in a state where both ends thereof are not in contact with the ends are alternately laminated, and an external surface provided on the exposed end face of the first internal electrode of the laminated body An electrode and at least one of the first inner electrodes near the front and back surfaces of the laminate has a distance between two first inner electrodes facing each other on the same plane, and a distance between the other first inner electrodes. Multilayer ceramic capacitors larger than the spacing of.