JPH0610112B2 - Ceramic plate manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a ceramic plate used as a substrate material or the like, and relates to a method for producing a ceramic plate having an arbitrary length.

“Prior Art” Conventionally, plate-shaped ceramics used as a substrate in the field of electronics and the like are mainly manufactured by a doctor blade method.

In this method, a solvent or water is added to ceramic powder such as Al ₂ O ₃ or ZrO _2, and necessary peptizing agents such as a disintegrating peptizer, a binder and a plasticizer are appropriately added and mixed to obtain a homogeneous slurry. Is manufactured, and the slurry is applied to a predetermined thickness on a carrier tape with a doctor blade, and then hot air drying or infrared drying is performed to volatilize the solvent or water to solidify the unsintered ceramic sheet (green sheet). To make. Then, the obtained green sheet is cut into a predetermined size and heated and fired in a firing furnace to produce a ceramic plate.

[Problems to be Solved by the Invention] However, since the green sheet formed by the doctor blade method has a slight variation in the component distribution in the thickness direction, when a thin green sheet is fired alone, it is shown in FIG. As in the case of the fired ceramics plate A, a warp occurs in a state where the edge is raised.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing a flat plate-shaped ceramic plate without warpage or undulation.

"Means for Solving the Problem" As a means for solving the above problems, the present invention is to provide another ceramic raw sheet on a plate-shaped ceramic raw sheet produced by the doctor blade method, and to provide an upper surface of both ceramic raw sheets. They are placed so that their lower surfaces overlap each other, and further, both green sheets are bonded to each other by using an adhesive containing a solvent of a system different from the binder contained in the ceramic green sheet to form a green sheet, and then the green sheet is formed. The green sheet was fired to obtain a fired sheet, and then the fired sheet was divided from the bonded portion to produce two ceramic plates.

Hereinafter, an example of the method of the present invention will be described in detail with reference to the drawings.

The ceramics used in the method of the present invention include:
A material having high toughness and plasticity is preferably used,
Particularly suitable ceramics include ZrO ₂ , Y ₂ O ₃ , MgO, CaO, and C.
It is a ceramic material such as partially stabilized zirconia (PSZ) in which a stabilizer such as eO ₂ is dissolved, silicon nitride, and sialon.

In order to produce a ceramic plate using such a ceramic material, first, a solvent and a chemical agent necessary for producing a raw sheet such as a plasticizer, a binder, and a dispersant are added to the above-mentioned ceramic powder and mixed, Slip 1 is prepared as a homogeneous slurry and a raw sheet is prepared by the doctor blade method.

FIG. 1 is a diagram showing an example of a doctor blade device suitably used for producing a green sheet. This doctor blade device has a supply port 2 for supplying a slip 1 in the form of slurry containing a ceramic material, a belt 3 for conveying the slip 1 formed in a thin plate, and a thin plate on the belt 3 from the supply port 2. It comprises a doctor blade 4 for pulling out the slip 1 in a uniform shape, and a dryer 5 for heating and drying the thin plate-shaped slip 1 on the belt 3.

In order to produce a green sheet using this doctor blade device, the slip 1 is put into the supply port 2 and the two rollers 6a and 6b for driving the belt 3 are rotated to move the belt 3. The slip 1 is from the supply port 2 to the doctor blade 4
Is drawn out onto the belt 3 in a thin plate shape, conveyed by the belt 3 and enters the dryer 5, and is heated and dried in the dryer 5 to form a rubber-like green sheet 7a. The dried green sheet 7a is separated from the belt 3 and wound up by the winding roller.

The size of the green sheet produced in this way is limited in the width direction to the sheet forming width of the doctor blade device,
The length can be set to an arbitrary length to some extent. The thickness of the green sheet is appropriately set in consideration of the mechanical strength after firing, etc., but it is usually desirable to set it to about 10 to 1000 μm (10 to 200 μm in the case of coiling).

Then, as shown in FIG. 2, another raw sheet 7b is placed on the long raw sheet 7a produced as described above such that the upper surfaces or the lower surfaces of both sheets are overlapped with each other. The green sheet 8 is formed by applying an adhesive between the green sheets 7a and 7b and bonding them together. At the time of this bonding, as shown in FIG. 3, two raw sheets 7a and 7b are used.
It is preferable to apply an adhesive between them, and then put them between a pair of pressure-bonding rollers 9 and pressure-bond them to bond them together.

The adhesive used to bond the two green sheets 7a, 7b is an adhesive containing a solvent of a different system from the binder contained in the green sheets 7a, 7b, and is included in the green sheets 7a, 7b. When the binder used is an organic binder such as polyvinyl alcohol, a water-soluble adhesive such as an alcohol adhesive or a starch adhesive is used. When the binder contained in the raw sheets 7a and 7b is water-based, an organic solvent-based adhesive such as polyvinyl alcohol-based adhesive or chloroprene-based adhesive is used.

Next, as shown in FIG. 4, the green sheet 8 obtained by the above-mentioned bonding is provided on one surface thereof with the release material 1
0 is additionally provided and wound around the cylindrical core body 11 in a coil shape. The mold release material 10 is made of a material that does not exhibit adhesiveness or reactivity to the ceramic material used during firing. When zirconia is used as the ceramic material, it contains alumina powder and boron powder as main components. A sheet (or it may be sprayed with powder and sprinkled on it) may be preferably used.

Next, after placing the green sheet 8 wound around the core 11 on the setter 12, the core 11 is gently removed. Then, this is placed in a firing furnace and fired under the usual firing conditions for the ceramic material used. The firing conditions are appropriately set depending on the type of ceramic material used. For example, when zirconia is used as the ceramic material, the firing conditions are preferably a firing temperature of 1300 to 1600 ° C. and a firing time of 30 minutes to several hours.

By this firing, the long coil-shaped fired sheet 13 shown in FIG. 5 is produced.

The fired sheet 13 is in a state in which the two thin coil-shaped ceramic plates 14a, 14b can be easily separated from the bonded portion resulting from the bonded portion of the two green sheets 7a, 7b.

Then, insert an ultra-thin metal piece or a blade into the bonded portion of the fired sheet 13 to divide it into two ceramic plates 14a and 14b, and gently separate the two, as shown in FIG. Coil-shaped ceramic plates 14a, 14b
Is obtained.

For the ceramic plates 14a and 14b, by increasing the diameter of the core body 11, it is possible to obtain partially flat ceramics by utilizing the toughness of the ceramic material. Also, circuits, electrodes and other parts can be mounted by using this portion.

In the method of manufacturing a ceramic plate according to this example, two green sheets 7a and 7b manufactured by the doctor blade method are used.
Are bonded together using an adhesive containing a solvent of a system different from the binder to form a green sheet 8, and then the green sheet 8 is baked to bond the baked sheet 13 to the two ceramic plates from the bonded portion. It can be divided into 14a and 14b.

Here, the relationship between the adhesive used for forming the green sheet 8 and the state of the bonded portion will be described with reference to FIG. 7 and FIG. 8 when the two raw sheets 7a and 7b are bonded together. Adhesive containing solvent similar to binder in sheet 15
When a is used, as shown in FIG. 7, the binder in the raw sheets 7a and 7b, which has bonded the raw material particles 16 to each other, is melted on the surface by the solvent in the adhesive agent 15a, and the raw material particles 16 are bonded to each other. It diffuses into the layer of 15a. Due to the diffusion of the raw material particles 16, the raw material particles in the adhesive 15a layer are dense enough to be sintered, and when the green sheet is fired, a thick ceramic plate in which two green sheets are integrated is obtained.

On the other hand, if the adhesive 15b containing a solvent of a system different from the binder is used to bond the green sheets 7a and 7b, as shown in FIG. The diffusion of the raw material particles 16 is suppressed. Therefore, even if this green sheet is fired, the two sheets will not be sintered together, and the two sheets will be sintered as separate bodies, and can be easily peeled off from the bonded portion after firing. It is possible to obtain two thin ceramic plates.

In the method for manufacturing a ceramic plate according to the above-mentioned example, the two green sheets are attached to each other so that the upper surfaces or the lower surfaces of the green sheets 7a and 7b are overlapped with each other.
By manufacturing the green sheet 8 and firing the green sheet 8, the forces (nonuniformity in the thickness direction) that cause the warpage of the sheets during firing are offset to produce a flat ceramic plate without warpage or undulation. You can Further, since this warp occurs at an early stage of sintering, even if it is temporarily fixed with an adhesive containing a solvent of a system different from the binder, the adhesive strength is sufficiently strong and the sheets are not peeled off.

In addition, a thin green sheet is difficult to handle, but if the two green sheets 7a and 7b are pasted together, the handling becomes easy. For example, when a long coil-shaped ceramic plate is produced, the green sheet 8 is erected on the setter 12 and fired. Even in such a case, one raw sheet will be destroyed, but two raw sheets 7a, 7b The green sheet 8 bonded with can stand up in a coiled form and can be fired without warping or waviness. Therefore, the manufacture of a thin latex plate having a thickness of 50 μm or less can be facilitated.

Furthermore, in the manufacturing method according to this example, a mold release material 10 is additionally provided on one surface of the green sheet 8, the core material 11 is wound around the core material 11 to form a coil shape, and then firing is performed. A long ceramics plate having an arbitrary length can be produced by using it.

In the previous example, an example in which the method of the present invention was applied to the production of a coil-shaped ceramic plate was shown.
It goes without saying that the present invention can also be applied to a method for manufacturing a ceramic plate in which a plate-shaped green sheet is fired without being wound into a coil.

"Example" A ceramic plate was manufactured based on the present invention.

Raw powder ... 3 mol% of Y ₂ O containing ₃ ZrO ₂ solvent ... MEK (methyl ethyl Kent) plasticizer ... D-butyl phthalate binder ... polyvinyl alcohol dispersing agent ... triolein each of these raw materials, several tens of hours in a ball mill It was pulverized and mixed to obtain a uniform slurry. Then, this slurry was formed into a sheet by the doctor blade method, further dried with hot air to volatilize and remove the solvent to solidify, and then cut to have a width of 1 cm and a length of 1 cm.
A green sheet with a thickness of 50 μm was prepared.

On the obtained green sheet, another green sheet is placed so that the upper surfaces of both sheets overlap each other. At this time, an acrylic adhesive is applied between both surfaces to bond the two green sheets to each other to form a green sheet. It was made. Next, on one side of the green sheet, a sheet-shaped release material (width 1 cm, length 1 meter, thickness 150 μm) containing alumina powder as a main component was added, and the release material was placed inside and a circle with a diameter of 10 cm was attached. It was wound around a columnar core material.
Then, this was placed on a setter, the core material was gently extracted, and subsequently placed in a firing furnace, and subjected to a firing treatment at 1500 ° C. for 1 hour.

After this firing, a thin metal plate is inserted into the bonded portion of the obtained fired sheet to divide it into two ceramic plates, and the two ceramic plates are gently separated to form two long coil-shaped ceramics. I got a plate.

The resulting ceramic plate is very thin (40-50 μm thick).
m), uniform and free from warpage, showing good elasticity.

"Effects of the Invention" As described above, the method for manufacturing a ceramic plate according to the present invention has the following effects.

In the present invention, two green sheets are bonded to each other so that the upper surfaces or the lower surfaces of the green sheets overlap each other to form a green sheet, and the green sheet is fired, so that it is possible to suppress the occurrence of warpage or waviness during firing. Therefore, it is possible to manufacture a ceramic plate without warpage or undulation.

Also, two green sheets are bonded together with an adhesive containing a solvent of a system different from the binder to produce a green sheet, and the obtained fired sheet is divided into two ceramic plates to obtain an extremely thin ceramics. The manufacture of the plate can be facilitated.

[Brief description of drawings]

1 to 6 are views for explaining an example of a method for manufacturing a ceramic plate according to the present invention in the order of steps, and FIG. 1 shows a doctor blade device suitably used for carrying out the method of the present invention. 1 is a configuration diagram showing an example, FIG. 2 is a perspective view showing a pasted state of green sheets, FIG. 3 is a side view of the same, and FIG. 4 is a perspective view showing a state in which a green sheet is wound in a coil shape, and FIG. Is a perspective view of the fired sheet, FIG. 6 is a perspective view of the ceramic plate, and FIGS. 7 and 8 are side views for explaining the relationship between the adhesive used for forming the green sheet and the state of the bonded portion, FIG. 9 is a perspective view showing an example of a warped state of a ceramic plate manufactured by a conventional method. 7a, 7b …… Raw sheet, 8 …… Green sheet, 13 ……
Firing sheet, 14a, 14b ... Ceramic plate, 15
b ... adhesive.

Claims (1)

[Claims] Claim: What is claimed is: 1. On a plate-shaped ceramic green sheet produced by the doctor blade method, another ceramic green sheet is placed so that the upper surfaces or the lower surfaces of both ceramic green sheets are overlapped with each other, and the ceramics are further stacked. A green sheet is formed by sticking both raw sheets together using an adhesive containing a solvent of a system different from the binder contained in the green sheet, and then the green sheet is fired to form a fired sheet, and then the fired sheet. A method for manufacturing a ceramics plate, characterized in that the two ceramics plates are manufactured by dividing from the bonded portion.