JPS60165240A - Method and device for manufacturing multilayer ceramic greensheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method and apparatus for manufacturing a multilayer ceramic green sheet, and more particularly to a technique for manufacturing a multilayer ceramic green sheet used, for example, in a multilayer capacitor.

(Description of Prior Art) Examples of products completed using ceramic green sheets include multilayer capacitors. Methods for producing ceramic green sheets used in manufacturing multilayer capacitors can be roughly divided into two methods: a doctor blade method and a screen printing method.

In the case of the doctor blade method, until now, a ceramic green sheet has been formed for each unit sheet and then stacked to create a multilayer ceramic green sheet. In this method, the ceramic green sheets had to be stacked one by one in order to make a multilayer body, which was complicated and not suitable for mass production.

Furthermore, the screen printing method involves repeating the steps of printing a dielectric ceramic paste or ceramic slurry using a silk screen to create a ceramic green sheet, and then printing a conductive paste that will become an internal electrode on top of the ceramic green sheet. However, since this method uses a screen, there is a problem in that the traces of the mesh of the screen remain on the dielectric ceramic green sheet in the form of an uneven pattern. In addition, in this screen printing method, the process of printing ceramic paste or ceramic slurry and then printing conductive paste that becomes internal electrodes is repeated, but the electrode surface and ceramic green sheet are separated by the thickness of the internal electrodes. A step occurs between the two, and this step causes delamination. In order to prevent the occurrence of such delamination, it is necessary to flatten the level of the ceramic green sheet in the screen printing method. for that,
An extra step was required to print ceramic paste or ceramic slurry to a thickness corresponding to the thickness of the internal electrodes. Moreover, if the printing position of the ceramic paste or ceramic slurry is shifted at this time, there is another problem such as a step difference. Furthermore, according to the screen printing method, the accuracy of the thickness of the ceramic green sheet was poor and it was difficult to obtain the required thickness. Another problem with the screen printing method is that if foreign matter gets stuck in the mesh of the screen, pinholes will form in the same places on the ceramic green sheets of each layer, causing problems with multilayer capacitors. When it was completed, the internal electrodes sometimes shorted together.

(Object of the Invention) Therefore, an object of the present invention is to provide a manufacturing method and an apparatus therefor that can efficiently manufacture a multilayer ceramic green sheet used, for example, in a multilayer capacitor.

(Summary of the Invention) Simply put, the present invention is a ceramic green sheet formed by defining a space using a formwork and a table fitted therein, applying ceramic paste or ceramic slurry to the space, and drying the ceramic paste or slurry in that space. Electrode paste is applied on top by screen printing method, the table is lowered further and ceramic paste or ceramic slurry is applied again.
This is a method for manufacturing a multilayer ceramic green sheet in which electrodes are formed and the process is repeated as necessary.

The manufacturing equipment includes a rod-shaped mold, a table fitted into the mold so as to be able to move up and down, an applicator for applying ceramic paste or ceramic slurry, a printing screen for forming electrodes, and a printing screen for applying electrode paste. applicator.

Embodiments of the present invention will be described in detail below with reference to the drawings.

(Description of an Embodiment) FIG. 1 is a diagram showing an apparatus used in an embodiment of the present invention to produce a multilayer ceramic green sheet. The formwork 1 and the platform 5 define the space in which the ceramic paste or ceramic slurry is to be applied, and the printing screen I3 is used for forming the electrodes. The formwork 1 is made of metal, for example, and its inner wall 3 forms a through hole.

The size of the inner wall surface 3 of this formwork 1, that is, the size of the through hole, is selected to be approximately the same as the size of the required ceramic green sheet. The stand 5 is fitted into the through hole defined by the inner wall 3. This stand 5 is also made of metal, for example. A blade 11 serving as a first applicator is used to apply ceramic paste or ceramic slurry to the space defined by the formwork l and the stand 5. Therefore, its width is selected to be slightly larger than the width of the through hole of the formwork 1.

The printing screen 13 has a predetermined pattern 15 for the necessary electrodes, through which the electrode paste is applied to the ceramic green sheet below the screen 13. Note that the squeegee 17 serving as the second applicator is used to apply the electrode paste, and its width is selected to be slightly larger than the width of the pattern 15 of the screen 13.

2 to 7 are diagrams sequentially showing a method for manufacturing a multilayer ceramic green sheet using the apparatus shown in FIG. 1. The manufacturing method will be explained below with reference to FIGS. 2 to 7.

First, as shown in FIG. 2, the stand 5 is inserted into the through hole of the formwork 1. At this time, the distance (g) between the surface of the platform 5 and the upper end of the inner wall of the formwork 1 is selected in relation to the required thickness of the ceramic green sheet (t: FIG. 7). In this state, a ceramic paste or ceramic slurry 19 is applied to a space defined by the inner wall of the formwork 1 and the upper surface of the stand 5 using the blade 11. This results in the state shown in FIG. 3, and when it is dried in this state, ceramic green sheets 19a are formed in the through holes of the formwork 1.

Next, as shown in FIG. 4, a printing screen 13 is placed above the formwork 1, and an electrode paste 21 is applied using a squeegee 17. At this time, if the upper surface of the ceramic green sheet 19a and the upper end surface of the mold l are not the same in the state shown in FIG. If so, it is desirable to raise the stand 5 a little before applying the electrode paste 21 so that the upper surface of the ceramic green sheet 19a and the upper end surface of the formwork 1 are flush with each other.

FIG. 5 shows a state in which a plurality of electrodes 21a, 21a, . . . are formed on the ceramic green sheet 19a in this manner. In this state, the electrode 21a is dried. In this way, one layer of ceramic green sheet 19a is formed.

In order to make the ceramic green sheet 19 even more multi-layered, as shown in FIG. The vertical position of the stand 5 is adjusted so that a predetermined step (g) is formed between the upper surface of the frame 1 and the upper end of the inner wall 3 of the formwork 1. Then, as in the previous figure 2, blade 1
1, a ceramic paste or ceramic slurry 19 is spread into a space defined by the surface of the ceramic green sheet 19a and the inner wall surface 3 of the formwork 1.

Then, the steps shown in FIGS. 3 to 5 are repeated.

In this way, as shown in FIG.
) Multilayer ceramic green sheets 19a, 1
9a, . . . are laminated with electrodes 21a formed on each surface. Then, by dividing the laminated state into required sizes, for example, a multilayer ceramic green sheet for a multilayer capacitor can be obtained.

In the above embodiment, the ceramic paste or ceramic slurry was applied directly onto the table 5, but the ceramic green sheet formed by drying and the ceramic slurry were applied directly onto the table 5.
When considering removability from the ceramic paste or ceramic slurry, it is necessary to remove the base film (not shown) such as a plastic film or glass plate before applying the ceramic paste or ceramic slurry.
It may be made to come into close contact with the upper surface of the table 5. in this case,
It is preferable to bring the base film into close contact with the upper surface of the table 5 and to keep the base film flush. In order to realize such a state, fine holes 7 may be formed on the upper surface of the table 5. These fine holes 7 are connected to a negative pressure source 9 such as a vacuum pump, for example.
As a result, the base film on the base 5 and the ceramic green sheets formed on the base film are sucked by negative pressure, and are attracted to the base 5 and held flush. .

Since the base film is interposed between the surface of the table 5 and the ceramic green sheet in this way, the ceramic green sheet can be easily peeled off from the table 5. It goes without saying that the material for the base film should be chosen to have good peelability from the base 5 or the ceramic green sheet.

However, if the ceramic slurry is applied directly onto the table 5 on which the fine holes 7 are formed, the fine holes 7 will be clogged by the ceramic paste or ceramic slurry, which is not a preferred embodiment.

Further, in order to apply the ceramic paste or ceramic slurry or the electrode paste, it is not necessary to use a blade or a squeegee, but a roller or other suitable device may be used.

Furthermore, in the above-described embodiment, the height adjustment of the table 5 and the operation of the squeegee are performed manually (in addition, the pneumatic circuit such as the air cylinder and other electrical control circuits etc. Of course, this may be done automatically using .

It goes without saying that the present invention can be used not only for producing multilayer ceramic green sheets for multilayer capacitors as described above, but also for producing multilayer substrates having internal electrodes and the like. .

(Effect of the invention) As described above, according to the present invention, using a simple device,
Moreover, multilayer ceramic green sheets having internal electrodes can be produced efficiently with simple operations.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a manufacturing apparatus used in the present invention. FIGS. 2 to 7 are sequential views showing the steps of manufacturing a multilayer ceramic green sheet using the apparatus shown in FIG. 1. In the figure, 1 is a formwork, 3 is an inner wall, 5 is a stand, 7 is a fine hole, 9 is a negative pressure source, 11 is a blade, 13 is a printing screen, 15 is an electrode pattern, 17 is a squeegee, and 19 is a ceramic paste or Ceramic slurry, 21 indicates electrode paste. 2151 Figure 3 Figure 5 Figure 6 Figure 7 Procedure Nefu official text (spontaneous) 1. Indication of the case 1980 Patent application No. 02.2321 2 Title of the invention Method for manufacturing multilayer ceramic green sheets and its apparatus 3 Person making the amendment Relationship to the case Patent applicant address 2-chome Tenjin, Nagaokakyo City, Kyoto Prefecture 26 No. 10 Name (623) Gyoda Seisakusho Co., Ltd. Representative Mura 1)
4th year of Showa, agent ・540'm Osaka (06) 764
-5443 (generation) Figure 1 Figure 4 Figure 6 Figure 7

Claims (1)

[Scope of Claims] 1 (a) preparing a formwork and a stand fitted thereto; (b) fitting the stand into the formwork and applying the necessary ceramic green from the upper edge of the formwork; (c) applying a ceramic paste or ceramic slurry to the space defined by the inner wall surface of the formwork and the surface of the platform; ) Drying the applied ceramic paste or ceramic slurry to form a ceramic green sheet, (e) Applying an electrode paste to the surface of the formed ceramic green sheet by screen printing, (f) drying the applied electrode paste; (g) further lowering the platform by an amount that correlates to the thickness of the ceramic green sheet; and (h) connecting the inner wall surface of the formwork with the surface of the ceramic green sheet. applying a ceramic paste or ceramic slurry to the defined space; (i) optionally performing steps (d), (e), (f);
), (g) and (h) are repeated to produce a multilayer ceramic green sheet. 2. The step (e) includes (e-i) raising the stand so that the upper surface of the formed ceramic green sheet and the upper end surface of the mold are flush with each other, (e-ii) the step of A multilayer ceramic green according to claim 1, comprising the steps of: placing a printing screen on a flush ceramic green sheet; and (g-1ii) applying an electrode paste on the printing screen. Method of manufacturing sheets. 3. a frame-shaped mold, a stand that is fitted into the mold to form a space between its surface and the inner wall surface of the mold, a ceramic paste in the space defined by the mold and the stand,
a first applicator for applying the applied ceramic paste or ceramic slurry, and a first applicator disposed on the surface of the ceramic green sheet for forming an electrode on the ceramic green sheet formed by drying the applied ceramic paste or ceramic slurry; a printing screen; and a second applicator for applying electrode paste to the surface of the ceramic green sheet using the printing screen; the stand is movable up and down while fitted in the mold; An apparatus for manufacturing a multilayer ceramic green sheet, in which the table can be further lowered to further apply ceramic paste or ceramic slurry onto the ceramic green sheet. 4. The platform has micropores communicating with its surface, and the micropores are connected to a negative pressure source, so that the ceramic green sheet formed on the platform via the base film passes through the micropores. The apparatus for producing a multilayer ceramic green sheet according to claim 3, wherein the multilayer ceramic green sheet is sucked by the negative pressure source and adsorbed onto the table.