JP2613473B2 - Method for producing dielectric ceramic sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a dielectric ceramic sheet used for a multilayer ceramic capacitor, a multilayer piezoelectric actuator, and the like, and more particularly to a method for manufacturing a green sheet.

[Conventional technology]

Conventionally, the production of a green sheet for making a dielectric ceramic sheet includes a dielectric ceramic powder, a binder,
It is formed by a process of forming a slurry composed of a dispersant, a solvent, a plasticizer and the like on a base film having a polyester film surface coated with silicone by using a doctor blade method or the like, and drying the film. However, when this method is used, the binder is formed in a layer on the entire surface of the silicone-coated base film, so that there is a problem that it is difficult to peel off the film from the base film. Therefore, even a film formed with great care cannot be used because it cannot be peeled off from the base film, or even if it is peeled off, it is not perfect and has defects. This tends to become more pronounced as the film becomes thinner, and the development and manufacturing method of a coating material that is easy to peel off is being studied.

[Problems to be solved by the invention]

In order to solve the above-mentioned problem, the present invention coats a dielectric ceramic powder in an island shape with a very small thickness in advance so that the film is easily peeled off on the base film, and then coats it with a conventional method. By the method of forming a slurry of
An object of the present invention is to provide a manufacturing method capable of obtaining a green sheet that can be easily peeled. That is, it is an object of the present invention to provide a method of manufacturing a dielectric ceramic sheet by using a green sheet that can be easily peeled and can provide a highly reliable product when used for a multilayer ceramic capacitor or the like without film cracking and cutting. .

B. Configuration of the Invention [Means for Solving the Problems] The present invention, when producing a dielectric ceramic sheet used for a multilayer ceramic capacitor and the like, a slurry containing a dielectric ceramic powder, a binder, a dispersant, etc. was silicone-coated. In the method of forming a film on the base film, a dielectric ceramic powder of the same material as that contained in the dielectric ceramic sheet is coated on the base film in advance, and the slurry is formed on the base film, An object of the present invention is to provide a method for manufacturing a dielectric ceramic sheet in which a green sheet is easily peeled and a film is not broken.

[Action]

In producing a green sheet of a dielectric ceramic sheet, a powder of the same material as the dielectric to be formed is applied in an island shape on a base film serving as a base, and then a slurry is applied to form a film. Of the green sheet and the base film is reduced, and the adhesive strength between the green sheet and the base film is reduced, and the green sheet is easily peeled.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which (a) is a cross-sectional view in which a dielectric ceramic powder 1 is coated in an island shape on a base film 5 before forming a green sheet of a dielectric ceramic sheet, and (b). FIG. 3A is a cross-sectional view illustrating a state where a film is formed on the base film in FIG.

A ceramic powder 1 made of barium titanate as a dielectric material. A fine powder having an average particle size of about 0.5 μm is formed into an island shape with a thickness of about 4 μm and a base film 5 covering about 30% of the surface.
Attached on top (see FIG. 1 (a)). The method of attaching is to collect only the features by the air classification method in order to utilize the static electricity charged on the base film, bring the powder close to the base film, and adsorb the barium titanate powder on the base film in an island shape. A slurry consisting of barium titanate powder, polyvinyl butyral (PVB, binder), ethyl cellosolve (solvent), and butyl carbitol (BPBG, plasticizer) was applied to this base film by the doctor blade method.
Form a film to a thickness of 20 μm. Further, the film is peeled off from the base film, and an internal electrode for manufacturing a multilayer ceramic capacitor is printed on the green sheet. Then lamination,
A multilayer ceramic capacitor was prepared by performing hot pressing, cutting, binder removal, sintering, and attaching external electrodes. Green sheet used in this example and the above-mentioned conventional method (see FIG. 1)
Table 1 shows the characteristics of the multilayer ceramic capacitor including the green sheets prepared in the above and the dielectric ceramic sheets prepared from the respective green sheets.

As shown in the results of Table 1, the method of the present invention has a peel strength of
It was reduced to 1/2, and no defects were found in the peeled film. Also, it can be seen that the failure rate of the completed capacitor is improved as compared with the conventional method.

C. Effects of the Invention [Effects of the Invention] A highly reliable derivative ceramic sheet that can be easily peeled off by the method of the present invention can be provided, and an economical multilayer capacitor and actuator can be provided.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, in which (a) is a cross-sectional view in which a dielectric ceramic powder is coated in an island shape on a base film before a green sheet of the dielectric ceramic sheet is prepared,
FIG. 2B is a cross-sectional view showing a state where the film is formed on the base film of FIG. FIG. 2 shows a state of forming a green sheet of a conventional dielectric ceramic sheet, (a) is a cross-sectional view of a base film,
(B) is a cross-sectional view showing a state where the film is formed on the base film, and a right end of the figure is a state where the film is partially peeled. 1 ... ceramic powder, 2 ... binder, 3 ... pores, 4
… Green sheet, 5… Base film.

Claims (1)

(57) [Claims] 1. A method of forming a dielectric ceramic sheet for use in a multilayer ceramic capacitor or the like, comprising forming a slurry containing a ceramic powder of a dielectric substance, a binder, a dispersant, and the like on a silicon-coated base film. A method of manufacturing a dielectric ceramic sheet, comprising: coating a dielectric ceramic powder of the same material as that contained in a body ceramic sheet on a base film in advance; and forming the slurry on the base film.