JPS62567B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a multilayer ceramic capacitor.

Conventionally, this type of laminated ceramic capacitor has a cross section shown in Fig. 1, in which a required number of blank ceramic sheets 2 without electrodes are stacked on top and bottom of a laminated block of ceramic sheets 1 with electrodes formed on their surfaces, and laminated under pressure. It had become For this reason, where the electrodes overlap, the thickness overlaps and the applied pressure is directly transmitted, increasing the density, but in the areas where the electrodes do not exist, the pressure is absorbed by the electrodes, so the density remains low. It was layered. This non-uniformity in laminated density is caused by the fact that when a laminated ceramic block is pressure-pressed and then cut into capacitor chips, the strength is weak in the low-density areas where no electrodes are present, and the pressure of the cutting blade is also a factor. There are disadvantages such as large displacement,
This caused cracks and electrode peeling. That is, as shown in the partially enlarged view of FIG. 3, in the low-density parts of the ceramic laminated block where sufficient pressure has not been applied, the cracks 6 and electrodes 10 may bend sharply due to the pressure applied by the cutting blade during cutting. A peeling portion 5 of the electrode occurs due to the strain.
These defective areas either recover to some extent during the ceramic sintering process at high temperatures, or they do not recover to the normal state before the defect occurred, and the remaining small defective areas may be damaged when a load is applied to the multilayer ceramic capacitor during use. As a result of the growth, insulation deterioration and short circuit accidents were caused.

An object of the present invention is to provide a method for manufacturing a laminated ceramic capacitor which eliminates these drawbacks, has no internal cracks or minute gaps, has high density, and has good moisture resistance.

According to the present invention, a method for manufacturing a ceramic capacitor includes laminating a plurality of first ceramic sheets having electrodes formed on their surfaces and then cutting the sheets.
A method for manufacturing a multilayer ceramic capacitor is provided, characterized in that a second ceramic sheet is prepared in advance and the thickness of the portion corresponding to the electrode portion is smaller than that of the other region, and the second ceramic sheet is laminated together with the first ceramic sheet. It will be done.

According to the present invention, the density of the laminated ceramic block can be made uniform and the reliability and quality can be improved. That is, according to the present invention, when the ceramic sheets having electrodes formed on their surfaces are laminated under pressure, the thickness is adjusted using another ceramic sheet, and the thickness is added by a cutting blade in order to obtain a laminated block of uniform density. It has the advantage that it can be cut into capacitor chips without causing defects such as bending of the ceramic sheet or distortion of the electrodes because it generates a suitable resistance against pressure.

An embodiment of the present invention will be described in detail below with reference to FIGS. 4 and 5.

FIG. 4 is a sectional view showing an embodiment of the present invention.
1 is applied to a ceramic thin film of 10 μm to 50 μm formed from slurry by the doctor blade method etc.
A ceramic sheet is prepared by printing a Pd paste electrode 10, 12 is a blank sheet on which no electrode is formed, 13 is a ceramic sheet with a recessed portion in the thickness corresponding to the electrode 10, and this is, for example, a blank sheet. It is obtained by heating the sheet to about 100° C. and selectively pressing the recessed portions with a mold rod. When such a structure is heated to 100-150℃, pressurized at a pressure of about 150Kg/ ^cm2 for 15 minutes, then held at a temperature of 80-100℃ and cut with a razor-like thin blade under pressure. As shown in Fig. 5, due to the effect of uniform pressure, the amount of displacement and distortion caused by the cutting blade becomes extremely small. Here, the ceramic thin film has elasticity and flexibility to the extent that it can be bent like a plastic plate.

Furthermore, even in the high-temperature sintering process, capacitor chips with uniform density do not cause warping of the ceramic sheet due to reaction shrinkage, and an extremely good laminated ceramic sintered body can be obtained. The thickness and number of layers of the ceramic sheet 13 shown in FIGS. 4 and 5 can be selected to the optimum value according to the thickness of the electrode, and the density in the stacking direction can be made uniform at the insertion point. It may be located on the top layer, middle layer, or bottom layer, as long as it is possible.

As explained above, according to the present invention, defects such as cracks and electrode peeling in ceramic sheets when cutting into capacitor chips can be eliminated. As a result, it is possible to produce highly reliable multilayer ceramic capacitors with improved moisture resistance and no insulation deterioration or short-circuit accidents, and the defect rate in the manufacturing process has also been significantly improved, making it possible to supply inexpensive capacitors.

[Brief explanation of the drawing]

FIGS. 1, 2, and 3 are a cross-sectional view, a diagram showing a method of cutting into chips, and a partial cross-sectional view, respectively, of a conventional multilayer ceramic capacitor.
4 and 5 are cross-sectional views of a multilayer ceramic capacitor which is an embodiment of the present invention. Codes in the figure, 1, 11: ceramic sheet,
2, 12: Blank sheet, 13: Ate sheet,
10: electrode, 5: peeling part of electrode, 6: crack part.

Claims (1)

[Claims] 1. A method for manufacturing a ceramic capacitor in which a plurality of first ceramic sheets having electrodes formed on their surfaces are laminated and then cut.
1. A method for producing a multilayer ceramic capacitor, which comprises preparing a ceramic sheet in advance and laminating it together with a first ceramic sheet.