JPS6258130B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a multilayer capacitor with excellent manufacturing efficiency.

Conventionally, a typical example of a method for manufacturing a multilayer capacitor is to apply electrodes 12 to a green sheet 11 of ceramic or the like, as shown in FIGS. The electrodes 12 are stacked and pressed together so that the electrodes 12 are led out from opposite ends, and then fired, and then an external electrode 13 is attached to each lead-out end of the electrode 12. However, in multilayer capacitors manufactured in this way,
Since the predetermined electrodes 12 are applied exclusively to the green sheet 11 by printing, the green sheet may be stretched or damaged due to the pressure applied during printing, resulting in poor dimensional accuracy and poor stability. This caused chipping, which significantly reduced manufacturing efficiency and yield. Furthermore, the green sheet was prone to elongation and breakage during handling during the processing process. This made it impossible to print fine figures.
Furthermore, when applying electrodes directly onto the green sheet, depending on the combination of the binder in the green sheet and the varnish in the electrode material, the electrode may diffuse into the green sheet, reducing its insulation resistance value. There was also a risk that reliability would deteriorate.

Therefore, the present invention aims to provide a manufacturing method whose main purpose is to obtain a multilayer capacitor with excellent manufacturing efficiency and stable characteristics.

To summarize the present invention, as a green sheet,
The method uses a plastic film with an electrode formed on one side and a green film formed on the other side. Other objects and features of the invention will become apparent from the embodiments described below with reference to the drawings. Although this embodiment shows the case where a plurality of multilayer capacitors are obtained at the same time, it is of course not prohibited to manufacture them one by one.

What is shown in FIG. 3 is a plan view of the green sheet 1 used in the present invention, and FIG. 4 is a sectional view of the same side.
In both figures, 2 is a plastic film made of polyethylene, polypropylene, etc., and on one surface of this film 2, a plurality of electrodes 3 are provided in a grid pattern by, for example, printing. film 2
On the other side, a green film 4 is applied to almost the entire surface by, for example, a doctor blade method or a spray method. In this case, the green film 4 must be applied so that it faces all the electrodes 3 with the plastic film 1 in between. Further, an electrode 3 and a green film 4 are provided on both sides of the plastic film 2.
Although either may be applied first, it is preferable that the electrode 3 is applied and dried first, and then the green film 4 is applied and dried. In the figure, reference numeral 5 denotes holes formed at both ends of the plastic film 2 and used for positioning, feeding, etc.

A plurality of green sheets 1 formed in this manner are prepared, and then these are stacked and pressed together as shown in FIG. 5. That is, they are stacked so that the 4 surfaces of the green film of the second layer green sheet 1 are in contact with the electrode 3 surface of the first layer green sheet 1 (the same applies hereinafter). In this case, the electrodes 2 which are superimposed on each other with the green film 4 interposed therebetween must be alternately shifted slightly in the left and right directions in the figure. This is the same as when manufacturing a normal multilayer capacitor.

Next, the items stacked in this way are placed in the fifth
It is cut at the positions indicated by arrows in the figure to obtain an independent laminate 6 as shown in FIG. As can be seen from this laminate 6, the buried electrodes 3 are alternately led out to the opposite end faces.

Next, this laminate 6 is fired, and then the electrode 3
An external electrode 7 is provided to each lead-out portion of the seventh
A multilayer capacitor as shown in the figure is obtained. What is characteristic here is that the plastic film 2 of the green sheet 1 shown in FIG. 3 is burned out when the laminate 6 is fired.
Since the laminate 6 is usually fired at a high temperature of 800° C. or higher, the plastic film 2 will be burned away before the temperature reaches such a high temperature. By burning out the plastic film 2, the laminate 6
At first glance, it seems that voids are formed in the green film 4, but these are completely eliminated when the green film 4 is sintered, so this does not pose any problem.

Note that the above description and drawings are intended to facilitate understanding of the present invention, and do not specify the present invention. The point is that a plurality of green sheets, in which electrodes and green films are formed on both sides of a plastic film, can be stacked and fired. Therefore, it goes without saying that various changes in design or processing may be made without departing from the spirit of the present invention. Particularly in the above embodiments, each laminate 6 was cut out before firing, but it may be cut out after firing.

As described above, the present invention uses a green sheet in which electrodes and green films are formed on both sides of a plastic film, thereby completely eliminating the drawbacks of sheet stretching and tearing during electrode application (printing). This can significantly improve manufacturing efficiency and yield. In addition, since electrodes are not applied directly to the green sheet, it is easy to print fine patterns, and the electrodes do not diffuse into the green sheet, improving insulation resistance and reliability. . Furthermore, since the green sheet can be easily handled during the processing process, productivity is improved, and in particular, positioning can be ensured, and a multilayer capacitor with stable characteristics and excellent dimensional accuracy can be obtained.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing a general multilayer capacitor, Fig. 2 is a sectional view of the same side, Fig. 3 is a plan view of a green sheet used in the present invention, Fig. 4 is a sectional view of the same side, and Fig. 5 3 is a side sectional view showing a state in which a plurality of green sheets are stacked, FIG. 6 is a side sectional view of an independent laminate, and FIG. 7 is a side sectional view of a multilayer capacitor obtained by the method of the present invention. be. 1... Green sheet, 2... Plastic film, 3... Electrode, 4... Green film,
6...Laminated body, 7...External electrode.

Claims (1)

[Claims] 1. A plurality of green sheets each having an electrode provided on one side of a plastic film and a dielectric green film formed on the other side are stacked and crimped so that the electrodes are alternately led out to opposite ends,
A method for manufacturing a multilayer capacitor, characterized in that after firing, external electrodes are provided and connected to each of the derived electrodes.