JPH0666222B2 - Method for manufacturing ceramic laminate - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improvement in a method for producing a ceramic laminate by firing a laminated green chip in which a plurality of ceramic green sheets are laminated, for example, a laminated capacitor and the like. To a method used in the manufacture of ceramic electronic components.

[Conventional technology]

Conventionally, a laminated capacitor is obtained by laminating a plurality of ceramic green sheets coated with an internal electrode paste to obtain a laminated green chip, pressure-bonding the laminated green chips in the thickness direction, and then integrally firing them, after which the internal electrodes are pulled out. It was manufactured by applying an external electrode to the end face.

In the above process, as shown in FIG. 3, when the obtained sintered body 11 is angular, that is, when the portions 11a connecting the respective surfaces of the sintered body are angular, the external electrode is The addition of 12 and 13 becomes insufficient, and the sintered body may be exposed at the angular portion 11a.

Therefore, conventionally, prior to applying the external electrodes 12 and 13,
The corners of the sintered body have been dropped by using a polishing method called so-called barrel processing, in which a large number of sintered bodies are put into a rotating barrel and the rotating barrel is rotated.

[Technical problem to be solved by the invention]

Since a large number of sintered bodies are polished by a rotating barrel, it is possible to remove the angular portion in the conventional method, but the sintered body tends to be chipped or cracked during barrel processing. . As a result, the yield was not sufficient, and a considerable proportion of defective products were generated.

Therefore, an object of the present invention is to provide a method for manufacturing a ceramic laminate that can effectively reduce the occurrence of defective products due to the barrel treatment as described above.

[Means for solving technical problems]

The manufacturing method of the present invention comprises a step of stacking a plurality of ceramic green sheets to prepare a laminated green chip, and the above laminated green chip is put together with an organic powder in a rotary barrel provided with an abrasive on its inner surface. The method is characterized by including a step of rotating and a step of taking out the laminated green chip from the rotating barrel and then sintering it.

[Action]

Prior to sintering, barrel processing is performed on the laminated green chips. Therefore, since barrel polishing is not performed after sintering, chipping, cracks, etc. are unlikely to occur.

Further, since the organic powder is put into the rotary barrel together with the laminated raw chips, the scraps of the laminated raw chips are covered with the organic powder, and the adhesion to the laminated raw chips is prevented.
In addition, since the polishing action is alleviated by the organic powder, the laminated raw chips are prevented from being considerably and sharply polished.

That is, the present invention, the ceramics after sintering is very fragile to impact, and in view of the tendency to cause chipping and cracks, by performing a polishing treatment prior to sintering, it is possible to chamfer the laminate in a short time and It is characterized by performing with high yield.

[Explanation of Examples]

An embodiment of the present invention applied to manufacture of a laminated capacitor will be described below.

First, an electrode paste for forming internal electrodes is applied onto a plurality of ceramic green sheets, laminated, and then pressure-bonded in the thickness direction to obtain a laminated green chip. The step of obtaining the laminated green chip can be performed by a well-known method used in manufacturing a conventional laminated capacitor.

Next, the obtained laminated green chip (not shown) is put into the cylindrical rotary barrel 1 shown in FIGS. 1 and 2.
The rotary barrel 1 is configured to be rotationally driven in the direction of the arrow shown, and is made of a flexible material such as fluororesin.

Further, sandpaper 2 is attached as an abrasive to the inner surface of the rotary barrel 1.

In addition, in the rotating barrel 1, wheat flour 3 as organic powder
Has been thrown in. Rotating barrel 1 prepared in this way
A large number of laminated raw chips are put therein and the rotary barrel 1 is rotated in the direction of the arrow shown.

In this case, as the rotary barrel 1 rotates, the stacked green chips repeatedly contact the sandpaper 2 due to its own weight, and as a result, the stacked green chips are chamfered.

In this embodiment, since the flour 3 is put together with the laminated raw chips, the flour 3 gets into the eyes of the sandpaper 2. Therefore, the polishing action of the sandpaper 2 is buffered by the wheat flour 3 to an appropriate strength. In addition, shavings of raw chips, abrasive grains generated from sandpaper, and the like will be wrapped by the flour 3. Therefore, shavings and abrasive grains of the raw chips do not adhere to the surface of the laminated raw chips, and the possibility that the surface of the laminated raw chips is damaged by these is effectively reduced.

After performing the above rotary barrel treatment, the laminated green chips are taken out from the rotary barrel 1 and each laminated green chip is fired to obtain a sintered body. By this baking, the adhering wheat flour 3 burns and scatters. After that, a pair of external electrodes are applied to the end surface of the sintered body from which the internal electrodes are drawn out by a known external electrode application method, whereby a multilayer capacitor can be obtained.

In the above-described embodiment, prior to sintering, the laminated raw chips are chamfered using the rotary barrel 1 in the state of the laminated raw chips. As a matter of course, the laminated green chip is much more flexible than the ceramics after sintering. Therefore,
Chamfering can be performed in an extremely short time. According to the experiment, when the rotating barrel 1 was rotated at 60 rpm, about 3
While I was able to remove the corner of the laminated raw chip in 0 minutes,
In the conventional method of treating the sintered body with the rotating barrel, the treatment for a long time of 2 hours is required even if the barrel is rotated at 250 rpm.

Further, the ceramics after firing are very weak against mechanical impact, and thus the conventional method was apt to cause chipping and cracks by the barrel treatment after sintering. Therefore, it is possible to effectively prevent the occurrence of chipping and cracks.

In the above embodiment, the sandpaper 2 is attached to the inner surface of the rotary barrel 1 as the abrasive. However, instead of the sandpaper 2, another abrasive may be attached to the inner surface of the barrel 1. Further, the barrel 1 itself may be made of an abrasive material.

Furthermore, although wheat flour 3 was used as the organic powder, other materials than wheat flour can be used as long as they are materials that can enter the eyes of the abrasive, moderately buffer the abrasive action, and trap the shavings of the laminated raw chips. It is also possible to use organic powder.

Furthermore, in the above-mentioned embodiment, the one applied to the manufacturing method of the multilayer capacitor has been described, but the present invention can be applied to the general manufacturing of ceramic multilayer electronic components other than the multilayer capacitor, and the formation of the internal electrode is also possible. It can also be used for manufacturing an integrally fired laminate.

[Effects of the Invention] As described above, according to the present invention, the chamfering is performed by the rotating barrel process in the state of the laminated raw chips. Therefore, the chip can be chamfered in an extremely short time. Not only that, unlike the conventional method, it is not polished in the state of a sintered body, so that it is possible to effectively prevent the occurrence of chipping, cracks, etc., and it is also effective for the generation of microscopic defects such as microcracks. Can be suppressed. Therefore, it is possible to effectively improve the yield of a laminated electronic component such as a laminated capacitor.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a rotary barrel used in an embodiment of the present invention, FIG. 2 is a perspective view of the same, and FIG. 3 is a cross-sectional view of a multilayer capacitor for explaining the problems of the conventional method. . In the figure, 1 is a rotary barrel, 2 is sandpaper as an abrasive, and 3 is wheat flour as an organic powder.

Claims (1)

[Claims] 1. A process of laminating a plurality of ceramic green sheets to prepare a laminated green chip, and placing a plurality of the laminated green chips together with an organic powder in a rotary barrel having an inner surface provided with an abrasive. A method for producing a ceramic laminate, comprising: a step of rotating; and a step of firing the laminated green chip after taking it out of a rotary barrel.