JPH01221202A - Manufacture of ceramic green sheet - Google Patents

Abstract

PURPOSE:To contrive to reduce the occurrence of inferiority or swell due to the defect such as bores or pin holes by a method in which the ceramic green sheets of two layers or more are laminated, whereby one ceramic green sheets is integrally formed. CONSTITUTION:A carrier film 16 is coated with the ceramic slurry 20 from inside a vessel 22 into a prescribed thickness by a doctor blade 24. The ceramic slurry 20 is dried in a drier 28 with the transportation of the carrier film 16, and then a ceramic green sheet 28 is obtained and is successively wound up on a take-up roll 14. The take-up roll 14 having wound up the ceramic green sheet 28 is set at the side of sending out, and an empty sending out roller 12 is set at the side of take up. Then similarly to the first process, the ceramic green sheet 28' of a second layer is formed on the green sheet 28 having been formed. Further, in order to obtain the necessary number of laminating the second process may be repeated. Consequently, the ceramic green sheet, in which the green sheets of at least two layers are integrally laminated in a desired thickness, is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a green ceramic sheet, and in particular, to a method for manufacturing a ceramic raw sheet, which is used for multilayer ceramic electronic components such as a multilayer ceramic capacitor, a multilayer ceramic substrate, etc.
The present invention relates to a method for producing a raw ceramic sheet.

[Prior art]

As a conventional method for manufacturing laminated ceramic electronic components, there is a method in which an internal electrode paste is printed on a raw ceramic sheet, dried, and a predetermined number of the thus formed raw ceramic sheets are laminated and then press-bonded.

In addition, another method has been devised in which the internal electrode paste is printed on a green ceramic sheet with a carrier film attached, is dried, is laminated by thermocompression bonding, and the process of peeling off the carrier film is repeated. ing.

[Problem that the invention seeks to solve]

In either method, the ceramic raw sheet is a one-layer or single-layer sheet produced by a doctor blade method or the like. Therefore, if the raw ceramic sheet is made thinner to increase the capacity, defects such as bores and pinholes will become apparent in the raw ceramic sheet, and the conductive paste used as the internal electrode material will penetrate through the defective parts and transfer to the lower layer. This has led to problems such as a drop in withstand voltage and even a short circuit.

In order to solve these problems, there has been a method of inserting a ceramic raw sheet (white sheet) on which no internal electrode is formed between the ceramic raw sheets to be laminated and the internal electrodes.

However, although this method can prevent the breakdown voltage drop and short circuit accidents due to conduction of the internal electrodes as described above, it is difficult to increase the capacitance because the dielectric layer (ceramic layer) between the internal electrodes cannot be made thin. To do this, the raw ceramic sheet itself must be made thin, and if it is too thin, it becomes difficult to handle.Furthermore, when making the white sheet mentioned above, an expensive carrier film must be used. This will result in high costs.

Therefore, the main object of the present invention is to provide a method for manufacturing a green ceramic sheet that can produce a green ceramic sheet without defects at a lower cost.

[Means for solving problems]

This invention is a ceramic green sheet in which the process of applying ceramic slurry and then drying is repeated two or more times to form one ceramic green sheet in which two or more layers are integrally laminated on a carrier film. This is a manufacturing method.

[Effect]

A ceramic slurry is applied onto the carrier film and then dried, and further ceramic slurry is continuously applied onto the dried ceramic green sheet and then dried. Application and drying of the ceramic slurry are repeated as necessary to obtain a ceramic raw sheet in which two or more layers are laminated on a carrier film.

〔Effect of the invention〕

According to this invention, two or more layers of ceramic raw sheets are laminated to form one ceramic raw sheet.
Even if there is a defect such as a bore or pinhole in one layer, it is covered by another layer, so that the occurrence of defects caused by such defects can be reduced as much as possible.

In addition, since there is no need to make the thickness of each green ceramic sheet extremely thin, it is easier to handle, and the swelling (leaching of conductive paste and resulting deformation of the green ceramic sheet) that was a problem when the sheet was thin is alleviated. be done.

Furthermore, compared to the case where a white sheet is used, the amount of carrier film consumed can be reduced, so high costs can be avoided.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

〔Example〕

FIG. 1A and FIG. 1B are illustrative views showing one embodiment of the present invention. In the manufacturing apparatus 1° of this embodiment, a carrier film 16 is passed between the feed roller 12 and the take-up roller 14. As the carrier film 16, one that has been subjected to a mold release treatment on one side, such as a polyethylene film coated with a silicone resin, can be used.

The carrier film 16 fed out from the feeding roller 12 is flattened by two tension rollers 18 and guided to the take-up roller 14.

A container 22 for storing the ceramic slurry 2o therein is provided on the passage in the flat portion of the carrier film 16 so as to be movable up and down.

A doctor blade 24 is provided on the downstream side of the container 22 in the transport direction of the carrier film 16 .

On the transport path of the carrier film 16, a dryer 26 is arranged further downstream of the container 22, and this dryer 26
The ceramic slurry 2o applied by the doctor blade 24 is dried to form a green ceramic sheet 28.

First, the ceramic slurry 20 in the container 22 is applied onto the carrier film 16 to a predetermined thickness using the doctor blade 24 . The thickness of the applied ceramic slurry 20 is the same as that of the top surface of the carrier film 16 and the thickness of the doctor blade 24.
It depends on the size of the gap with the bottom edge of the Therefore, the doctor blade 24 is configured such that the gap can be adjusted as desired so that the ceramic slurry can be applied to a required thickness.

The ceramic slurry 20 applied on the carrier film 16 is brought to the above-mentioned dryer 28 as the carrier film 16 is transported, and is dried there to become a green ceramic sheet 28. The single-layer ceramic raw sheet 2 days thus formed is sequentially wound up by the winding roller 14 together with the carrier film 16, and the first step is completed.

Then move on to the second process. As shown in Figure 1B, 1
The take-up roller 14 that took up the raw ceramic sheet 28 (and the carrier film 16) in the second step is set on the delivery side, and the empty delivery roller 12 is set on the take-up side.

Thereafter, in the same manner as the first time, the ceramic slurry 20 is again applied to the previously formed ceramic raw sheet 28 to a predetermined thickness using the doctor blade 24, and dried.
A layered ceramic green sheet 28' is formed. At this time, it is necessary to adjust the gap between the tip of the doctor blade 24 and the ceramic raw sheet 28 after raising the container 22 in consideration of the thickness of the raw ceramic sheet 28 formed in the first process. .

If you want to further increase the number of layers, you can repeat the second process.

By repeating the application and drying of the ceramic slurry a predetermined number of times in this manner, a single ceramic green sheet having a desired thickness and having two or more layers of ceramic green sheets integrally laminated is obtained.

In this embodiment, the ceramic slurry 20 was applied by a doctor blade method, but the application method may also be a gravure transfer method as shown in FIG.

In the case of gravure transfer shown in FIG. 2, the ceramic slurry 20 in the container 30 is lifted by the gravure roller 32, the amount of the ceramic slurry IJ20 is adjusted by the blade 34, and the ceramic slurry 20 is applied to the lower surface of the carrier film 16 passing through. do.

In addition, in the above-mentioned embodiment, the carrier film 16 is
Although winding and resetting were performed after each step, this may be done by making the carrier film 16 endless so that it can be repeated continuously without removing and resetting the rollers.

[Brief explanation of the drawing]

Figures 1A and 1B are illustrative diagrams showing one embodiment of the invention, with Figure 1A showing the manufacturing process of the first layer of green ceramic sheet, and Figure 1B showing the manufacturing process of the second layer of green ceramic sheet. The manufacturing process is shown. FIG. 2 shows a modification of the ceramic slurry application method. In the figure, 16 indicates the carrier film, 20 indicates the ceramic slurry, and 28.28" indicates the ceramic green sheet. Patent applicant Murata Manufacturing Co., Ltd. Representative Patent attorney Yama 1) Yoshito-21B figure Tomi figure 2

Claims (1)

[Claims] A method for producing a ceramic green sheet, in which a step of applying a ceramic slurry and then drying is repeated two or more times to form a single ceramic green sheet in which two or more layers are integrally laminated on a carrier film.