JPH10177932A - Manufacture of laminated ceramic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen an occurrence rate of a short circuit in the manufacture of a laminated ceramic capacitor by a method wherein a specific amount of soluble acrylic polymer is added to a mixed solvent of solvent naphtha and dialkyl ketone for the formation of dielectric slurry, and the dielectric slurry is applied onto a support and dried up into an electrode-buried ceramic green sheet, and the ceramic green sheet formed on the support is bonded to another ceramic green sheet by thermocompression, and the support is separated off from the sheets. SOLUTION: 0.01 to 10wt.% of soluble acrylic polymer is added to a mixed solvent of solvent naphtha and dialkyl ketone for the formation of dielectric slurry, and the dielectric slurry is applied onto a dry support where a dry electrode is provided and dried out for the formation of an electrode-buried ceramic green sheet. Then, the electrode-buried ceramic green sheet stuck to the support is bonded to another ceramic green sheet or another electrode by thermocompression, and then only the support is separated off, whereby the electrode-buried ceramic green sheet is transferred onto another ceramic green sheet or another electrode. By this setup, the surface of a ceramic green sheet is flattened with acrylic polymer, and the occurrence rate of a short circuit can be lessened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer ceramic capacitor widely used for electric products such as a video tape recorder, a liquid crystal television receiver, and OA equipment.

[0002]

2. Description of the Related Art In recent years, the demand for multilayer ceramic capacitors has been increasing more and more in order to satisfy the demand for lighter, thinner and smaller, and various technical problems to be improved have been clarified accordingly. A mere reduction in area directly leads to a decrease in electric capacity. Therefore, it is necessary to increase the capacitance at the same time as reducing the size of the multilayer ceramic capacitor.

As a method of increasing the capacitance of a multilayer ceramic capacitor, it has been considered to reduce the thickness of a dielectric layer in addition to increasing the dielectric constant of a dielectric. As one of the methods of thinning, without peeling the electrode-embedded ceramic raw sheet from the support, after thermocompression bonding on another ceramic raw sheet or another electrode, only the support is peeled off. A method of transferring the electrode-embedded ceramic raw sheet onto the other ceramic raw sheet or another electrode has been considered.

[0004]

However, such a conventional method has a problem that the short-circuit rate is high.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a method of manufacturing a multilayer ceramic capacitor with a reduced short-circuit rate.

[0006]

In order to solve this problem, the present invention provides an acrylic polymer dissolved in a mixed solvent of solvent naphtha and dialkyl ketone on a support on which a dried electrode is formed. A dielectric slurry having a content of not less than 01% by weight and not more than 10% by weight is applied and dried to prepare an electrode-embedded ceramic raw sheet. After thermocompression bonding on a sheet or another electrode, only the support is peeled off, and the electrode-embedded ceramic raw sheet is transferred onto another ceramic raw sheet or another electrode.

According to this method, the dispersibility is improved and the leveling property is improved by adding the acrylic polymer to the dielectric slurry. Since the thin portion of the wire is reduced, the short circuit is reduced.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION According to the first aspect of the present invention, an acrylic polymer dissolved in a mixed solvent of solvent naphtha and dialkyl ketone is added to a support on which a dried electrode is formed. A dielectric slurry containing from 01% by weight to 10% by weight is applied and dried to form a ceramic raw sheet with embedded electrodes, and then the raw ceramic sheet with embedded electrodes is separated from the support without peeling off from the support. Alternatively, after thermocompression bonding on another electrode, only the support is peeled off, and the electrode-embedded ceramic raw sheet is transferred onto another ceramic raw sheet or another electrode. The raw sheet surface is flattened and short-circuit can be reduced.

Hereinafter, an embodiment of the present invention will be described. First, electrode printing will be described. Add butyl carbitol to palladium ink so as to have an appropriate viscosity,
Stir well. Using a polyethylene terephthalate film (PET film) as a base film, the above-mentioned electrode ink was continuously printed thereon at regular intervals by a screen printing method, and dried at 100 ° C.

Next, how to make a dielectric slurry will be described. A barium titanate-based dielectric powder was added to a vehicle comprising a binder, a plasticizer, a dispersant, and a solvent, and the mixture was stirred well, and roll kneading was repeated four times with a three-roll mill. In addition, 0.01% by weight of an acrylic polymer dissolved in a mixed solvent of solvent naphtha and dialkyl ketone
More than 10% by weight or less was added and stirred well to obtain a dielectric slurry.

Next, a dielectric slurry was printed by a screen printing method on the base film on which the dried electrodes were formed, and dried at 100 ° C. to produce a ceramic sheet with embedded electrodes.

Next, after the electrode-embedded ceramic raw sheet or the ceramic raw sheet is thermocompressed onto another ceramic raw sheet or another electrode without peeling from the base film, only the base film is peeled off. By repeating this process, lamination was performed.

Next, cutting, binder-out and baking are performed, and then external electrodes are applied and baked, and Ni plating,
Sn-Pb plating was performed to obtain a multilayer ceramic capacitor.

Next, an experiment was conducted to clarify the relationship between the amount of the acrylic polymer dissolved in the mixed solvent of solvent naphtha and dialkyl ketone and the short-circuit rate. Here, the experiment was performed with the effective dielectric layer being 140 layers. The results are shown in (Table 1). The measurement of the short-circuit rate is data for 200 samples. Solvent naphtha,
The amount of the acrylic polymer dissolved in the mixed solvent of the dialkyl ketone was represented by% by weight, with the dielectric slurry before addition being 100% by weight.

[0015]

[Table 1]

As shown in Table 1, the short-circuit rate is reduced by adding 0.01% by weight or more of an acrylic polymer dissolved in a solvent mixture of solvent naphtha and dialkyl ketone. However, when the content exceeds 12.0% by weight, the transferability deteriorates.

[0017]

As described above, according to the present invention, it is possible to obtain the effect that the unevenness of the surface of the ceramic green sheet is reduced, flattened, and the short circuit is reduced.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Mahito Omiya 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] An acrylic polymer dissolved in a mixed solvent of solvent naphtha and dialkyl ketone is present in an amount of 0.01% by weight or more on a support on which a dried electrode is formed.
A dielectric slurry containing 0% by weight or less is applied and dried to produce a ceramic raw sheet with embedded electrodes, and then the raw ceramic sheet with embedded electrodes is separated from the support without peeling off the raw ceramic sheet or other electrodes. A method of manufacturing a laminated ceramic capacitor, wherein only the support is peeled off after thermocompression bonding, and the ceramic raw sheet with embedded electrodes is transferred onto another ceramic raw sheet or another electrode.