JPH01101104A - Production of ceramic sheet - Google Patents

Abstract

PURPOSE:To reduce time for drying and uniformly scatter binder on both sides of a ceramic sheet by a method wherein ceramic slurry is applied on a carrier film to form a ceramic layer, on which a permeable film is superimposed and dried. CONSTITUTION:Ceramic slurry 6 is applied with a doctor blade in a certain thickness on a releasing layer 2 of a carrier film 3 to form a ceramic layer 8. A permeable film 21 is fed on the upper face of the ceramic layer 8 transferred in front of a dry furnace 9. The ceramic layer 8 advances in the dry furnace 9 in the state of being pinched between the carrier film 3 and a film 21 from the upper and lower sides, film 21 is peeled off from the ceramic sheet 10 at the position just out of the dry furnace 9, and is wound up on a take-up roll 25. When both faces of the ceramic layer 8 are covered with the carrier film 3 and the permeable film 21, the segregation of a binder 11 can be controlled on both faces, which makes a uniform distribution of the binder 11 to produce a ceramic sheet 10.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method of manufacturing a ceramic sheet used for LA layer capacitors, multilayer substrates, etc.

<Prior Art and Problems> Conventionally, in order to manufacture a long ceramic sheet, as shown in FIGS. The carrier film 3 is moved from the feed roll 4 to the take-up roll 5 side, and while the film 3 is being moved, a ceramic slurry 6 is applied onto the release layer 2 using a doctor blade 7 or the like. A ceramic layer 8 is formed by applying the coating to a certain thickness, and this ceramic layer 8 is passed through a drying oven 9 by moving the carrier film 3, and is dried to form a ceramic sheet 10, which is wound on the winding roll 5 side. I was taking it.

Incidentally, the ceramic slurry 6 used for forming the ceramic sheet 10 is mixed with a binder and a solvent, and the solvent is scattered during the drying process to form the ceramic sheet 10. As shown in FIG. 5, the distribution of 11 is biased toward the carrier film 3 side, and decreases on the surface side.

This phenomenon occurs because the binder 11 is more easily released from the surface of the ceramic layer 8 that comes into contact with the air during drying, and even if the binder in the ceramic slurry 6 is diffused, the above-mentioned A phenomenon like this occurs.

By the way, a multilayer capacitor can be exemplified as an electronic component using ceramic sheets, and is manufactured by stacking several ceramic sheets of a predetermined size with internal electrodes coated on the - side, laminating them by pressure bonding, and then firing them. However, when the ceramic sheet 10 in which the binder 11 is segregated as described above is used in a multilayer capacitor, the following problems arise.

(11 The surface side of the ceramic sheet 10 has no distribution of the binder 11 that should provide adhesive force, so the adhesive force is weak and the
As shown in the figure, if the internal electrodes 12 are formed on this front side, peeling tends to occur, and for this reason, the internal electrodes 12 can only be applied to the back side as shown in FIG.
2 is applied from carrier film 3 to ceramic sheet 1.
The inconvenience is that it can only be performed by Shun who has peeled off 0. This is a factor that inhibits the formation of the i1 layer of the ceramic sheet.

[11 When the ceramic sheet 10 coated with the internal electrode 12 is multilayered, the internal electrode 12 and the ceramic sheet 10
and Ceramic Sea Mill 10 have weak adhesion to each other, so it is necessary to use very high pressing pressure after stacking, which may cause deformation of the internal electrodes or uneven elongation of the laminate blocks. Quality and capacity yields are reduced.

(ml) The adhesion of the ceramic sheet is weak, resulting in structural defects such as peeling of internal electrodes and delamination.

N Ceramic sheets have a rough surface when dried, and if internal electrodes are applied to this rough surface, the internal electrodes tend to penetrate inside the sheet and cause short circuits, so it is necessary to apply it to the flat surface. However, when the internal electrodes are dried, the contraction of the internal electrodes due to binder evaporation and the contraction of the segregated binder 11 of the ceramic sheet 10 are in the same direction, and the ceramic sheet 10 is dried as shown in FIG.
However, warpage occurs on the internal electrode 12 side, and in order to avoid this, temperature and humidity control after printing and drying the internal electrodes is required, which increases costs.

<Purpose of the Invention> This invention was made by focusing on the fact that the binder, which is supposed to provide adhesive strength, in a ceramic sheet is not sufficiently utilized. It is an object of the present invention to provide a method for manufacturing a ceramic sheet that can solve the above-mentioned conventional problems.

<Means for Solving the Problems> In order to solve the above problems, the present invention forms a ceramic layer by coating a moving carrier film with a ceramic slurry using a doctor blade or the like. The structure is such that an air-permeable film is layered on the ceramic layer to cover the surface, and a drying process is performed in this state to dry the ceramic layer to form a ceramic sheet.

Effect> Ceramic slurry is applied onto the moved carrier film using a doctor blade, etc. to form a ceramic layer, and a breathable film is placed on top of the ceramic layer before the drying process to make it adhere, and then left as is. A drying process is performed to dry the ceramic layer, and the air-permeable film is peeled off to form a ceramic sheet on the carrier film.The use of the air-permeable film shortens the drying time and at the same time removes the air-permeable film. The binder is evenly distributed on both sides of the ceramic sheet by suppressing the segregation of the binder mixed in the ceramic sheet.

<Embodiments> Hereinafter, embodiments of the present invention will be described based on FIGS. 1 and 2 of the accompanying drawings.

Note that the same parts as in FIGS. 3 to 8 will be described using the same reference numerals.

As shown in FIG. 1, the carrier film 3 is
A drying oven 9 is provided on the way from the carrier film 3 to the take-up roll 5, and a ceramic slurry 6 is placed between the feed roll 4 and the inlet of the drying oven 9 while the carrier film 3 is moving.
A doctor blade 7 is placed on the peeling layer 2 of the carrier film 3 to form a ceramic layer 8 by applying the coating to a constant thickness.

A breathable film 2 is placed on the upper surface of the ceramic layer 8 moving between the doctor blade 7 and the inlet of the drying oven 9.
Supply 1. Examples of the breathable film 21 include a porous resin sheet (Voretex, trade name), a fiber material mixed sheet, 4-fluoroethylene, and the like. Base plate 23 and presser roll 24
The ceramic layer 8 is sandwiched between the carrier film 3 and the air-permeable film 21 from above and below, enters the drying oven 9, and is dried to form a ceramic sheet ( Ceramic green sheet) 10 and the air permeable film 21 at the position where it comes out from the drying oven 9
It is peeled off from 0 and wound up on a winding roll 25.

As described above, when the air-permeable film 21 is brought into close contact with the ceramic layer 10 and the drying process is performed, the front surface of the ceramic sheet 10 is finished as flat as the back surface, and the segregation of the binder 11 on the front side is suppressed. do.

In this way, by sandwiching and covering both sides of the ceramic layer 8 with the carrier film 3 and the breathable film 21, segregation of the binder 11 during the drying process can be suppressed on both sides.
As shown in FIG. 2, a ceramic sheet 10 in which the binder 11 is distributed approximately evenly is obtained.

Note that the purpose of using the breathable film 21 is to improve the drying efficiency during the drying process.

Further, the release of the breathable film 21 is not limited to after the ceramic film 10 is completely dried as shown in the figure, and may be removed during the drying process. 1
It is necessary to make the peeling force smaller than the peeling force of the carrier film 3 with respect to 0.

Although the above embodiments have been described using a doctor blade as an example, the present invention is not limited to this and can be applied to a reverse roll coater, a comma coater, a clavier coater, and the like.

Effect> As described above, in this invention, ceramic slurry is applied,
After formation, it is covered with an air-permeable film and dried, resulting in the following effects.

(1) The binder is distributed almost evenly on both sides of the ceramic sheet, so when this ceramic sheet is used in multilayer capacitors and multilayer substrates, the adhesive strength between the sheets and between the sheet and internal electrodes increases. , layer peeling and electrode peeling are eliminated.

(If) Since the adhesion strength between sheets and between sheets and internal electrodes is improved, the pressing pressure when forming 1A layer capacitors and multilayer substrates can be lowered, and the reduction in pressing pressure will prevent deformation of internal electrodes and damage to laminated blocks. Non-uniform deformation is eliminated, making it possible to stabilize quality and improve yield.

(l The surface of the ceramic sheet is finished flat,
Moreover, since the binder is evenly distributed, it is possible to coat and form internal electrodes on the surface side while the ceramic sheet is attached to the carrier film, thereby simplifying workability and making the sheet thinner.

(To) Even if the ceramic sheet is peeled from the carrier film and the internal electrode is coated and dried, the ceramic sheet will not warp due to the even distribution of the binder.

M Since the ceramic sheet does not warp after coating and drying the internal electrodes, there is no need to control the temperature and humidity after drying the fired internal electrodes, and costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a manufacturing facility for carrying out the manufacturing method according to the present invention, FIG. 2 is an enlarged cross-sectional view of a ceramic sheet in the middle of manufacturing, FIG. 3 is an explanatory diagram showing a conventional manufacturing apparatus, and FIG. FIG. 5 is an enlarged sectional view of the same, and each of FIGS. 6 to 8 is an explanatory view of internal electrodes formed on a conventional ceramic sheet. 3...Carrier film 6...Ceramic slurry 7...Doctor blade 8...Ceramic layer 9
... Drying oven 10 ... Ceramic sheet 11 ... Binder 21 ... Breathable film Patent attorney Kazu 1) Showa W, 1 Figure 2 Figure 12 J

Claims (1)

[Claims] A ceramic slurry is applied onto a moving carrier film to form a ceramic layer, a breathable film is layered on top of the ceramic layer to cover the surface, and a drying process is performed in this state to dry the ceramic layer and form a ceramic layer. A method for manufacturing a ceramic sheet, characterized by forming it into a sheet.