JPH0418689B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for manufacturing laminated ceramic parts, and in particular, to an improvement in the cutting form when cutting a laminated body stuck to a resin sheet when manufacturing a laminated ceramic capacitor. It is related to.

[Prior art]

Generally, this type of multilayer ceramic capacitor is manufactured, for example, as follows. That is, first, a green sheet having a predetermined thickness is formed from slurry containing ceramic powder, a binder, and a solvent using a doctor blade method, and after drying, it is punched into a predetermined size. Next, internal electrodes are screen printed in a predetermined pattern onto this green sheet. Then, a plurality of green sheets are laminated so that the internal electrodes of each sheet are staggered, and protective sheets made of green sheets are also laminated on the upper and lower surfaces of these green sheets, and they are integrated by hot pressing to form a laminated layer. form the body. Next, as shown in FIG. 8, this laminate A is adhered to a resin sheet B having an adhesive layer on one side. Then, this resin sheet B is placed on a heated stage C,
Vacuum adsorption. In this state, the laminate A is cut into a predetermined size using a cutter D. Next, the capacitor chip is peeled off from the resin sheet B and sintered. Thereafter, a multilayer ceramic capacitor is manufactured by forming external electrodes on the end faces of the capacitor chips.

[Problem that the invention seeks to solve]

By the way, in this manufacturing method, the laminate A is attached to the resin sheet B as described above, and then cut by vacuum adsorption on a heated stage. If air is partially interposed between the laminate A and the resin sheet B when bonding to the resin sheet B, the air expands due to the heating from the stage C.
Partial peeling may occur as shown by the dotted line in the figure.

When the laminate A is cut in this state, as shown in FIG. 9, a sloped portion F is formed on the end face of the capacitor E, causing the external electrode G and the internal electrode to undesirably approach each other. or come into contact with it. For example, if the external electrode G and the internal electrode are brought undesirably close to each other, application of a slight overvoltage will easily result in a breakdown voltage failure, and if they come into contact, they will no longer function as a capacitor.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a method for manufacturing a laminated ceramic component which has a simple structure and can eliminate partial peeling from the sheet even if the laminated body is heated prior to cutting.

[Means for solving problems]

Therefore, in order to achieve the above-mentioned object of the present invention, the steps include: forming a laminate by laminating a plurality of green sheets so that ears are formed on the outer periphery and integrating them under pressure; A process of attaching the laminate to a sheet that is breathable and has an adhesive layer on one side, and then placing the sheet on a stage and cutting the laminate into predetermined dimensions while being vacuum-adsorbed. It is manufactured through a process.

[Effect]

According to this invention, since the sheet to which the laminate is attached has air permeability, even if the sheet is interposed between the laminate and the sheet during attachment, it can be placed on a stage and vacuum-adsorbed. This allows the intervening air layer to be easily and reliably removed. Therefore, even when placed on a heated stage, there is no peeling of the stack due to intervening air, and diagonal cutting of the stack can be effectively prevented.

〔Example〕

Next, an example of application of the present invention to a multilayer ceramic capacitor will be described with reference to FIGS. 1 to 7.

First, as shown in FIGS. 1 and 2, a ceramic green sheet 1 having a predetermined thickness is formed from a slurry made of ceramic powder, a binder, a plasticizer, a dispersant, and a solvent by a doctor blade method. After drying, punch out to the specified dimensions. Internal electrodes 2 are screen printed in a predetermined pattern on the punched green sheet 1 and dried. Then, a plurality of green sheets 1 are connected to the internal electrode 2.
are laminated in an alternating manner, and protective sheets 3 and 4 made of green sheets thicker than the green sheet 1 are also laminated on the upper and lower surfaces thereof.
Then, the protective sheet, green sheet, and internal electrode are integrated by hot pressing to form a laminate 5. Note that a cutting guide line 6 for cutting the laminate 5 to a predetermined size is printed on the top surface of the protective sheet 4, and the outermost part of the cutting guide line 6 has a cutting guide line 6 printed on it, which serves as the original capacitor. A closed ear portion 7 is formed. Next, Figures 3 to 4
As shown in the figure, the laminate 5 is attached to the adhesive layer 8a of a resin sheet (sheet) 8 so that the portion surrounded by the ears 7 is located in the mesh-shaped ventilation hole portion 9. Note that the ventilation hole portion 9 of the resin sheet 8 can be formed throughout the resin sheet 8, and the ventilation hole portion 9 can also be formed in the shape of a mesh or a hole. Next, as shown in FIGS. 5 and 6, the resin sheet 8
is placed on the heated stage 10, and the laminate 5 is vacuum suctioned through the vacuum suction hole 10a and the ventilation hole portion 9. In this state, the laminate 5 is cut into a predetermined size along the cutting guide line 6 by vertical movement of the cutter 11 to form a capacitor chip 12. Next, as shown in FIG. 7, after sintering the capacitor chip 12, external electrodes 13 are formed on the exposed end surfaces of the internal electrodes 2, thereby obtaining a multilayer ceramic capacitor.

In the present invention, the laminated ceramic component can be applied not only to a laminated ceramic capacitor but also to a laminated varistor, a chip resistor, and the like. In addition to resin materials, paper materials can also be used for the sheet, and in addition to actively forming holes in the sheet, it is also possible to use the air permeability of Japanese paper.

〔Effect of the invention〕

As described above, according to the present invention, the sheet to which the laminate is attached has air permeability, so even if an air layer is interposed between the laminate and the sheet, the heated stage The intervening air layer can be almost completely removed through the ventilation holes by vacuum adsorption. For this reason, peeling of the laminate from the sheet due to heating can be prevented, diagonal cutting can also be prevented, and problems with properties can be reduced.

In particular, if the sheet is configured in a mesh shape, it is possible to reduce the adhesion of adhesive to the back surface of the capacitor chip when it is peeled off from the sheet. Therefore, in the burnout process, it is possible to suppress the temperature of the capacitor chip itself from becoming undesirably high, and it is possible to prevent a drop in breakdown voltage due to peeling between the internal electrodes and the ceramic layer.

[Brief explanation of drawings]

1 to 7 are explanatory diagrams of the method of the present invention, in which FIG. 1 is a side sectional view of a laminate, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a laminate formed into a sheet. A side sectional view showing the adhesion state, Figure 4 is a bottom view of Figure 3, and Figure 5 is a bottom view of Figure 3.
The figure is a side cross-sectional view showing the laminated body being cut on the stage, Figure 6 is a plan view of Figure 5, Figure 7 is a side cross-sectional view of the completed state, and Figure 8 explains the conventional cutting method. FIG. 9 is a side sectional view showing the completed state of the conventional product. In the figure, 1 is a clean sheet, 5 is a laminate, 8 is a sheet, 8a is an adhesive layer, 9 is a vent portion, 10 is a stage, 10a is a vacuum suction hole, and 12 is a laminated ceramic component (capacitor chip).

Claims (1)

[Claims] 1. A process of forming a laminate by mainly laminating a plurality of green sheets so that ears are formed on the outer periphery and integrating them under pressure; A step of adhering the laminate to a sheet having an adhesive layer on the surface thereof, and a step of placing the sheet on a stage and cutting the laminate into predetermined dimensions while vacuum adsorbing the sheet. A method for manufacturing laminated ceramic parts. 2. A method for manufacturing a laminated ceramic component according to claim 1, characterized in that the laminate is heated during cutting.