JPS59194416A - Laminated ceramic condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multilayer ceramic capacitor, and particularly to the structure of a dielectric sheet of a multilayer ceramic capacitor. Conventionally, a multilayer ceramic capacitor is manufactured by rotating a ceramic dielectric sheet 1 on which internal electrodes 2 are adhered, as shown in FIG. A plurality of sheets are laminated, and a body sheet 1 is placed on top and bottom of the ceramic layer 1 to serve as a protective layer.
' Laminated multiple sheets and heat-pressed the whole to -i4\,
A ceramic capacitor body 3 as shown in FIG. 2 was obtained,
After firing, external electrodes 4 are formed on both ends of the electrode.

In general, in a multilayer ceramic capacitor having such a conventional structure, as the size and diameter of the capacitor are reduced, the thickness of the ceramic capacitor body 3 is reduced, which inevitably leads to a decrease in mechanical strength. Therefore, there is a problem in the production of capacitors, which leads to a decrease in yield and an increase in costs. Further, there arises the problem that the thermal shock resistance decreases during soldering when mounting on a printed wiring board or the like.

An object of the present invention is to provide a multilayer ceramic capacitor that solves the conventional problems.

According to the present invention, a plurality of dielectric sheets each having a conductive internal electrode formed thereon are alternately formed! In FC multilayer ceramic capacitors, which are made by laminating L layers and then laminating dielectric sheets that serve as protective layers on the top and bottom surfaces and integrating them by thermocompression, fine particles with a high melting point are dispersed in the dielectric sheets that serve as the protective layers. A multilayer ceramic capacitor with characteristics can be obtained.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a plane of the present invention will be described below with reference to the drawings.

FIG. 3 is an exploded perspective view showing the laminated structure of the laminated ceramic capacitor of the present invention. A plurality of dielectric sheets 1 having internal electrodes 2 formed thereon are laminated by rotating them 1800 times so that the end surfaces 2a of the internal electrodes 2 are alternated. Next, one or more dielectric sheets 11' in which fine particles with a high melting point such as sintered alumina are dispersed are laminated on the upper and lower surfaces of the Yc laminated dielectric sheet 1 as described above, and the whole is heated and pressed. Collect,
Unify.

Ceramic capacitor body 1 integrally formed as shown in
In No. 3, as shown in FIG. 4, a large number of fine particles with a high melting point are dispersed in a layer near the surface layer.

Therefore, when this ceramic capacitor element body 13 is fired, in the surface layer where a large number of fine particles with an oblate attraction point are dispersed,
As shown in Fig. 15, the shrinkage 12 in the surface layer is caused by the sintering of the ceramic dielectric powder constituting the dielectric 7-) 11' due to the fine particles 6 intervening at a single point. The shrinkage 11 of the ceramic capacitor body 13 also becomes smaller, compressive stress F is generated in the surface layer of the ceramic capacitor element body 13 after firing, and the mechanical hardness against bending deformation is greater than that of the sub-ramic capacitor element body 3 which has no compressive stress. improves.

As mentioned above, the multilayer ceramic capacitor of the present invention has greater mechanical strength in the same shape than the conventional multilayer ceramic capacitor, so when it is made smaller and thinner, the mechanical strength is higher than that of the conventional multilayer ceramic capacitor. does not decrease,
The manufacturing process will be easy, and the yield will be improved.
This greatly contributes to cost reduction. In addition, we are looking forward to the advantage of being able to make areas smaller and thinner, which was previously impossible.

It goes without saying that the composition, size, etc. of the high-melting-point fine particles mentioned in the present invention should be determined as appropriate depending on the composition of the ceramic dielectric powder used or the desired improvement in the degree of oxidation. Noru.

[Brief explanation of drawings]

Figure 1 is a plan view of a ceramic dielectric sheet with internal electrodes and a ceramic dielectric sheet for a protective layer. Figure 2 is a longitudinal cross-sectional view of a conventional multilayer ceramic capacitor. FIG. 3 is a perspective view showing a laminated structure of a laminated ceramic capacitor according to an embodiment of the present invention. FIG. 4 is a longitudinal sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention. FIG. 5 is a schematic diagram of shrinkage and stress observed in the multilayer ceramic capacitor body of FIG. 4. 1, l', 11'...Ceramic dielectric sheet, 2...Internal electrode, 2a...End face exposed portion of inner 8 electrodes, 3.3'... ...Ceramic capacitor element, 4...External electrode, l, ,
l,...shrinkage, F...compressive stress. Valley 7 Figure z j Figure 2 ? Figure 4 Figure 4 ◇F F Jinko Kuzu Figure 5

Claims (1)

[Claims] In a multilayer seminic capacitor in which a plurality of dielectric sheets on which conductive internal electrodes are formed are alternately laminated, and dielectric sheets serving as protective layers are laminated and integrated on the upper and lower surfaces thereof, the protective layer and A multilayer ceramic capacitor characterized by having fine particles with a high melting point dispersed in a dielectric sheet.