JPH03105905A - Manufacture of laminated ceramic capacitor - Google Patents

Abstract

PURPOSE:To obtain a homogeneous green sheet having a uniform thickness for the title capacitor by printing a ceramic film having the same thickness as that printed electrode films have between the electrode films and forming a ceramic layer after making the front thickness of the green sheet uniform. CONSTITUTION:Paste for continuously forming internal electrodes 1 on a rolled substrate film 3 is screen printed. Then ceramic paste 2 for forming a dielectric layer between internal electrode 1 patterns by the same printing method so that used for the internal electrode 1 patterns is printed on the part of the roll, where the internal electrodes 1 are not printed, after accurate positioning is made by using the guide hole of the film 3. After printing the paste 2, a film is formed on the printed surface from ceramic slurry 8. Thereafter, the sheet is cut into pieces after the sheet is dried and subject to punching, overlapping, and thermocompression fixing and external electrodes are formed for each piece. Then each piece is calcined through a binder removing end calcining processes, and thus, the laminated ceramic capacitor of this invention is obtained.

Description

[Detailed description of the invention] a. Object of the Invention [Field of Industrial Application] The present invention relates to a method for manufacturing a multilayer ceramic capacitor, and particularly to a method for manufacturing a green sheet of ceramic layers on which internal electrodes are printed.

[Conventional technology]

Conventionally, the manufacturing method for green sheets used in multilayer ceramic capacitors is to print electrode films on green sheets. However, because the thickness of the electrode layers varies depending on the location, green sheets are punched out and laminated. When the electrodes are separated and sintered, delamination or defects containing such delamination are likely to occur, and short circuits between opposing electrodes are often caused. In order to prevent these drawbacks, methods such as the transfer method, in which electrodes are printed on a base film in advance and then ceramic slurry is deposited, are being considered; The drawback is that uniform film formation cannot be achieved. These drawbacks are fatal when attempting to further reduce the thickness of the dielectric layer to achieve high capacity and miniaturization.

[Problem to be solved by the invention]

The present invention eliminates the above-mentioned drawbacks, and in the production of green sheets for multilayer ceramic capacitors, the electrodes are placed between the printed electrode films so that the thickness of the electrode film does not affect the formation of the ceramic layer. By printing a ceramic film with the same thickness as the film to make the thickness uniform over the entire green sheet part, and then forming a ceramic layer, we can provide a homogeneous green sheet with a uniform thickness. The present invention aims to provide a method for manufacturing a highly reliable multilayer ceramic capacitor even with a thin film.

B. Structure of the Invention [Means for Solving the Problems] The present invention provides a method for manufacturing a green sheet in the manufacturing process of a multilayer ceramic capacitor, after printing a paste for a conductive film that will become an internal electrode on a base film. Print with ceramic paste on the parts of the base film other than the printed film for internal electrodes under conditions that the thickness is about the same as the thickness of the printed film, and then form the ceramic layer using the thick film deposition method. As a result, it is possible to manufacture a green sheet with processed internal electrodes that does not cause any difference in the thickness of the electrode part, and by manufacturing a multilayer ceramic capacitor using this green sheet, it is extremely reliable and can be used to make capacitors thinner and larger in capacity. The present invention provides a method for manufacturing multilayer ceramic capacitors that can be used in various ways.

That is, the present invention provides a conductive film paste for forming internal electrodes on a polyester film as a base material when manufacturing a green sheet of a ceramic layer that constitutes one layer of a ceramic capacitor in a method for manufacturing a multilayer ceramic capacitor. After printing on a predetermined internal electrode pattern, a ceramic paste with approximately the same thickness as the conductive film paste is printed on areas other than the internal electrode pattern, and then a thick film of ceramic slurry is applied on the printed area. The present invention provides a method for manufacturing a multilayer ceramic capacitor characterized by manufacturing a green sheet for a multilayer ceramic capacitor by forming a film.

[Effect]

In order to manufacture green sheets processed with electrode films for multilayer ceramic capacitors in a homogeneous state with uniform thickness, the internal electrode films are processed on the base film in advance by a printing method, and the gaps are filled with ceramic paste using a printing method. After filling with a film and forming a flat layer, a ceramic layer is deposited on the entire surface.
By creating and laminating flat, homogeneous green sheets, highly reliable multilayer ceramic capacitors with less delamination and insulation defects can be manufactured.

〔Example〕

Embodiments of the present invention will be described using the drawings.

1 to 3 are an external perspective view and a cross-sectional view illustrating the manufacturing procedure of a green sheet of a ceramic layer used in a multilayer ceramic capacitor.

In this example, it is necessary to obtain positional accuracy between the printing of the electrode paste and the printing of the ceramic paste from the viewpoint of mass production. layer or 2
A 50μ wave is used, and a guide hole 7 for printing positioning is provided at the edge of the film.

As shown in FIG. 1, a conductive film paste for forming internal electrodes 1 is continuously screen printed on the base film 3 wound into a roll. After printing, the base film 3 is continuously dried with hot air from a dryer 6 and wound up into a roll.

During printing, the positioning guide hole 7 provided in the base film was used to accurately position the base film 3 for printing.

Next, as shown in FIG. 2, this roll is printed with ceramic paste 2 for forming a dielectric layer between the patterns of the internal electrodes 1 using the same printing method as the pattern of the internal electrodes. By using the guide holes in the base film 3 to accurately position and print on the areas where the internal electrodes are not printed, the ceramic paste can be accurately applied to the areas where the internal electrodes are not printed. Since it can be printed, it can be printed without any gaps or overlaps in areas where there is no internal electrode pattern. After printing, it is continuously dried in the same way as the internal electrode pattern, and then
Wind up into a roll.

Subsequently, as shown in FIG. 3, ceramic slurry 8 is spread over the printed surface to a thickness of 10 to 50 microns. In the example, a green sheet on which a ceramic layer 5 of about 14 .mu.m was formed was prepared by a doctor blade method. As with general multilayer ceramic capacitors, this sheet was dried, punched, stacked, thermo-compressed, cut into individual pieces, removed from the binder, and fired to form external electrodes and baked to create a product. Table 1 shows the results of life tests and internal observations of the multilayer ceramic capacitors manufactured in this way and the multilayer ceramic capacitors manufactured by the conventional method.

As can be seen from Table 1 in the margin below, the reliability improvement effect of the present invention was confirmed. According to the manufacturing method of the present invention, delamination defects and insulation defects are greatly improved, and reliability is improved.

C. Effects of the Invention [Effects of the Invention] As described above, according to the present invention, it is possible to provide a highly reliable multilayer ceramic capacitor that is less prone to delamination even in a high-capacity compact structure with a very narrow distance between internal electrodes. .

[Brief explanation of drawings]

Fig. 1 is an external perspective view for explaining an embodiment of the present invention, and shows a state in which internal electrodes are formed in fixed positions by printing internal electrode paste on a base film using guide holes. Figure 2 is a cross-sectional view of the base film with ceramic paste embedded in the gaps between the printed internal electrodes shown in Figure 1 using a printing method.6 Figure 3 is a cross-sectional view of the printed internal electrodes shown in Figure 2. FIG. 2 is a cross-sectional view illustrating a state in which a ceramic layer is formed by a doctor blade method on a base film flatly embedded with ceramic paste. 1... Internal electrode, 2... Ceramic paste, 3...
... Base film, 4... Blade, 5... Ceramic layer, 6... Dryer, 7... Guide hole, 8... Ceramic slurry Fig. 1 6

Claims (1)

[Claims] 1. In a manufacturing method for a multilayer ceramic capacitor, when manufacturing a green sheet for a ceramic layer that constitutes one layer of a ceramic capacitor, a conductive film paste for forming internal electrodes is applied to a polyester film as a base material in a predetermined internal electrode pattern. After printing, a ceramic paste with approximately the same thickness as the conductive film paste is printed on areas other than the internal electrode pattern, and then a thick film is formed using ceramic slurry on the printed area to form a laminated layer. A method for manufacturing a multilayer ceramic capacitor, characterized by manufacturing a green sheet for a ceramic capacitor.