KR20220071460A - Manufacturing method of ceramic greet sheet - Google Patents

Abstract

The present invention relates to a method for manufacturing a ceramic green sheet. The method comprises the following steps: a step of an aging treatment after a surface treatment of ceramic powder with a silane solution in which a silane coupling agent is dissolved in a first solvent to form a silane-based compound coating film on a surface of the ceramic powder; a step of preparing a ceramic slurry by adding an epoxy binder, a dispersant, a plasticizer, and a second solvent to the aged ceramic powder; and a step of forming a green sheet by tape casting the ceramic slurry. Accordingly, dispersibility and viscoelasticity of the ceramic powder are further increased, thereby increasing packing density between the powders and improving roughness of the green sheet formed. In addition, when a bulk chip is manufactured by sintering the green sheet, sintering density and dielectric properties thereof are improved. Therefore, a mechanism according to the present invention is very advantageous in manufacturing an MLCC or the like which is ultra-thin and has electrical properties of high dielectric permittivity while having flexibility.

Description

Manufacturing method of ceramic green sheet {MANUFACTURING METHOD OF CERAMIC GREET SHEET}

The present invention relates to a method of manufacturing a ceramic green sheet.

In accordance with the recent trend of slimming portable devices such as smartphones, so-called stacked devices are mainly used as stacked chip components that can be miniaturized and highly integrated. A typical example of such a multilayer device is a Multi Layer Ceramic Condenser (MLCC), and since it can be miniaturized, it is possible to minimize battery consumption as well as slimming portable devices.

In general, multilayer devices are mostly composed of various stacked bulks, such as in which ceramic dielectric layers and metal electrodes are alternately stacked, or metal electrodes are attached to a stack in which one or more ceramic dielectric layers are stacked. manufactured as a component.

At this time, the dielectric layer is formed into a thick film of a small thickness by adding and mixing a binder, a dispersant, a solvent, and, if necessary, a plasticizer, etc. to the ceramic composition powder to form a viscous slurry in which the ceramic powder is uniformly dispersed in the solvent. , it is manufactured into a thick green sheet by tape casting like a doctor blade. Then, a plurality of the green sheets are laminated or alternately laminated with metal electrodes according to the structure of the final laminated device designed, and the green sheets are press-compressed to be integrated into a single bulk, and then calcined to form a laminated device as a bulk.

1 is a schematic structural diagram of a general tape casting apparatus for manufacturing a ceramic green sheet.

1, the general tape casting process is roughly described. First, a ceramic slurry (1) in which a ceramic composition powder, a binder, a dispersant and/or a plasticizer, etc. are mixed is introduced, which is a blade that can be adjusted in height to achieve the intended thickness ( 3) is cast through thick film tape. And, for support, the thick film tape is usually cast on a carrier film 8 such as PET. Thereafter, the cast thick film tape is removed by vaporizing at least a portion of its solvent while passing through the heating and drying zone 5, and then naturally cooled at room temperature while further on the conveyor to form a gelled green sheet 7, which is formed as a winding part It is wound in (9).

However, since the bulk itself formed by laminating a plurality of these green sheets 7 in the structure and manufacturing process of the laminated device directly forms the laminated device, the physical properties of the green sheet 7 directly influence the electrical characteristics of the final laminated device. do. In particular, the physical properties of the green sheet 7 greatly depend on the viscosity of the ceramic slurry 1, the dispersion degree of ceramic powders, and the viscoelasticity, and the control thereof is difficult. Furthermore, the dispersion degree of the ceramic powder is maintained above a certain level because the viscosity of the ceramic slurry solution 1 has to be lowered due to the thinning of the green sheet 7 according to the recent trend of high lamination of multilayer devices. It has become more difficult to do, especially in the case of using a ceramic powder having a nano-sized particle size in order to meet the demands such as high dielectric constant and low dielectric loss in recent multilayer devices. The low dispersion of the ceramic powder in the green sheet 7 greatly deteriorates the dielectric properties of the bulk or device finally formed by lamination and firing heat treatment of the green sheet 7 .

1. Unexamined Patent Publication No. 87-2621 (published on April 6, 1987) 2. Unexamined Patent Publication No. 1995-0013711 (published on June 15, 1995)

Accordingly, an object of the present invention is to provide a method for manufacturing a green sheet that can have excellent sintering density and dielectric properties during sintering by improving the packing density and roughness of ceramic powder.

A method of manufacturing a ceramic green sheet according to the present invention for solving the above problems includes the following steps:

- surface-treating the ceramic powder with a silane solution in which a silane coupling agent is dissolved in a first solvent to form a silane-based compound coating film on the surface of the ceramic powder, followed by aging;

- preparing a ceramic slurry by adding an epoxy binder, a dispersant, and a second solvent to the aged ceramic powder; and

- Forming a green sheet by tape-casting the ceramic slurry.

Also, optionally, preparing the ceramic slurry may further include adding a plasticizer to the ceramic powder.

In addition, optionally, the aging treatment may be performed at room temperature. Alternatively, the aging treatment may be performed at a temperature in the range of -3 to 72 ℃.

Also, optionally, the aging treatment may be performed for a time in the range of 1 to 72.

In addition, optionally, the first solvent is water (H ₂ O), ethanol (C ₂ H ₅ OH), methanol (CH ₃ OH), methyl ethyl ketone (CH ₃ COC ₂ H ₅ ) and benzene (C ₆ H) ₆ ) may be selected from the group including one or more.

In addition, optionally, the amount of the silane coupling agent may be adjusted in the range of 0.05 to 5 wt% based on the total amount of the ceramic powder.

Also optionally, the silane coupling agent is 3-glycide oxypropyl trimethoxysilane, 3-glycide oxypropyl triethoxysilane, vinyl trimethoxysilane, vinyl triethoxysilane, 3-aminopropyl trime Toxysilane, trimethoxy[(3-(phenylamino)propyl]silane, 3-aminopropyl triethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-methacryl oxypropyl triethoxysilane, 3 -Mercaptopropyl trimethoxysilane, vinylethoxysilane, vinyl-tolyl (2-methoxy-ethoxy)silane, γ-methacryloxypropyl trimethoxysilane, γ-aminopropyl trimethoxysilane, γ- Aminopropyl triethoxysilane, N-phenyl-γ-aminopropyl trimethoxysilane, N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane, N-β-(aminoethyl)-γ-amino Propyl triethoxysilane, N-phenyl-γ-aminopropyl trimethoxysilane, β-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, γ-glycidoxypropyl trimethoxysilane, and γ-mer At least one may be selected from the group consisting of captopropyl trimethoxysilane.

Also, optionally, the ceramic powder may include a powder having a particle diameter in the range of 100 to 300 nm.

Also, optionally, the second solvent may be ethanol.

In addition, optionally, the thickness of the silane-based compound coating film formed may be in the range of 0.5 to 5 nm.

In addition, optionally, the amount of the epoxy binder added may be less than or equal to 60 wt% based on the weight of the ceramic powder. In addition, optionally, the amount of the dispersant added may be 3 wt% or less based on the weight of the ceramic powder. Also, optionally, the amount of the plasticizer added may be adjusted to 5 wt% or less based on the weight of the ceramic powder.

Also, optionally, forming a silane-based compound coating film on the surface of the ceramic powder may be performed by immersing the ceramic powder in the silane solution.

According to the present invention, the ceramic powder of the ceramic slurry prepared for tape casting is surface-treated with a silane coupling agent so that the surface thereof is coated with a silane-based compound and then subjected to aging treatment to uniformly disperse the ceramic powder. And the silane-based compound coating film induces a more uniform and stronger bonding with the epoxy binder added for later moldability. This uniform and stronger bonding with the epoxy binder further increases the dispersibility and viscoelasticity between the powders, thereby increasing the packing density between the powders, improving the roughness of the green sheet, and sintering the green sheet to produce bulk chips. It improves density and dielectric properties. Therefore, the mechanism according to the present invention is very advantageous for manufacturing MLCCs having high dielectric constant electrical characteristics while being ultra-thin and flexible.

1 is a schematic structural diagram of a general tape casting apparatus for manufacturing a ceramic green sheet.
2a is a schematic diagram explaining the mechanism of forming a silane-based compound coating film through hydrolysis and dehydration condensation reaction of a silane coupling agent on the surface of a ceramic powder according to the present invention as above, sequentially through steps (i) to (iii) , FIG. 2b is a schematic diagram showing the structure of the silane-based compound coating film 20 formed on the ceramic powder surface 10, and FIG. 2c is a schematic diagram showing the state of the ceramic powders on which the aging-treated silane-based compound coating film 20 is formed.
3A is a photograph of the surface of a green sheet prepared with a slurry of ceramic mixed powder having a silane-based compound coating film formed on the surface according to the embodiment of the present invention. The photo wound in (9), the right photo (B) is a photo of only the formed green sheet itself, and FIG. 3b is a comparative example of the surface of a green sheet prepared from a slurry of ceramic mixed powder not coated with a silane-based compound. As the photos, the left photo (A) is a photo in which the formed green sheet is wound around the winding unit 9 of FIG. 1, and the right photo (B) is a photo of only the formed green sheet itself.
4 is a silane solution content of chips fired at each firing temperature after stacking and pressing a plurality of green sheets of FIG. 3A prepared as a slurry of ceramic mixed powder having a silane compound coating film formed on the surface according to an embodiment of the present invention; Shows a change in the dielectric constant (“Dielectric constants (ε _r )”) characteristics, and as a comparative example, a plurality of green sheets made of a slurry of ceramic mixed powder whose surface is not coated with a silane-based compound are laminated and pressed, followed by each firing temperature shows the change in the dielectric constant characteristic of the fired chip.
5 is a sintering according to the silane solution content of chips fired at each firing temperature after stacking and pressing a plurality of green sheets of FIG. 3a prepared as a slurry of ceramic powder having a silane-based compound coating film formed on the surface according to an embodiment of the present invention; Shows the change in density ("Density (g/cc)") It shows the change of the sintering density of the fired chip.

As described above, in general, a laminated device is generally composed of a simple structure of a ceramic bulk and a metal electrode, and the ceramic bulk is composed of a plurality of laminated ceramic green sheets. It absolutely determines the dielectric properties and reliability. In particular, when the ceramic green sheet has a composition in which the main component powder is mixed with various additive powders to control various properties, a lot of empty spaces are formed between these powders due to the various particle size distributions, which leads to a decrease in the filling rate, which is the dielectric constant in the final laminated device. It causes a decrease in dielectric characteristics and a decrease in electrical characteristics. Therefore, it is very important to increase the dispersibility of the ceramic powder dispersed in the ceramic green sheet.

Moreover, when the ceramic composition powder used is a nano-sized powder (hereinafter, “nano-powder”), the specific surface area of these nano-powders is very high, so that the friction force between the powders filled in the green sheet is greatly increased. Therefore, when the ceramic slurry in which these ceramic powders are dispersed is tape-casted as shown in FIG. 1 to manufacture a green sheet, and a plurality of layers are laminated and pressed, no matter how high a pressure is applied due to the high friction between the powders, a certain level ( For example, it is difficult to obtain a relative density of 70% or more). This phenomenon is difficult to improve with the current binding system even if a very large amount (eg, about 5 to 6 times or more) of the binder is added compared to the existing one. As a result, this poor relative density deteriorates the dielectric properties of the ceramic bulk.

In order to solve this problem, in particular, according to the present invention, the ceramic powder of the ceramic slurry prepared for tape casting is surface-treated with a silane coupling agent, so that the surface thereof is coated with a silane-based compound. The ceramic powder usable in the present invention includes all ceramic powders as well as ceramic nanopowders.

In the present invention, the silane solution in which the silane coupling agent is dissolved in a solvent is hydrolyzed to generate a silanol group (Si-OH) with excellent reactivity, which is hydrogen-bonded with a hydroxyl group (-OH) on the surface of the ceramic powder to form a silane-based compound to form a coating film. And, in particular, since this silane-based compound coating film is formed to a non-uniform thickness through the rapid reaction as above, the silane-based compound coating film is then at room temperature, preferably in the range of about -3 to 75° C. for a long time, preferably about 1 Aging treatment for ~72 hours proceeds the dehydration condensation reaction and forms covalent bonds with the surface of the ceramic powder mediated through oxygen.

2a is a schematic diagram illustrating the mechanism of forming a silane-based compound coating film through hydrolysis and dehydration condensation reaction of a silane coupling agent on the surface of a ceramic powder according to the present invention as above, sequentially through steps (i) to (iii). , FIG. 2b is a schematic diagram showing the structure of the silane-based compound coating film 20 formed on the ceramic powder surface 10, and FIG. 2c is a schematic diagram showing the state of the ceramic powders on which the aging-treated silane-based compound coating film 20 is formed.

Referring to FIGS. 2a to 2c, first, a silane coupling agent as a starting material is dissolved in a solvent so that the alkoxy group (Si-OR) of the silane coupling agent is hydrolyzed by water (H ₂ O) to form a siloxane bond (-Si-O -Si-) generated silane solution is applied to the surface of the ceramic powder particles (“(i)” in FIG. 2A). In one embodiment, the application may be performed by immersing the ceramic powder in the silane solution.

In addition, in one embodiment of the present invention, the silane coupling agent is 3-glycide oxypropyl trimethoxysilane, 3-glycide oxypropyl triethoxysilane, vinyl trimethoxysilane, vinyl triethoxysilane, 3 -Aminopropyl trimethoxysilane, trimethoxy[(3-(phenylamino)propyl]silane, 3-aminopropyl triethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-methacryl oxypropyl tri Ethoxysilane, 3-mercaptopropyl trimethoxysilane, vinylethoxysilane, vinyl-tolyl (2-methoxy-ethoxy) silane, γ-methacryloxypropyl trimethoxysilane, γ-aminopropyl trime Toxysilane, γ-aminopropyl triethoxysilane, N-phenyl-γ-aminopropyl trimethoxysilane, N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane, N-β-(aminoethyl) )-γ-aminopropyl triethoxysilane, N-phenyl-γ-aminopropyl trimethoxysilane, β-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, γ-glycidoxypropyl trimethoxysilane One or more may be selected from the group consisting of , and γ-mercaptopropyl trimethoxysilane In one embodiment, the silane coupling agent may be added in an amount ranging from about 0.1 to 1.0 wt% relative to the total amount of the ceramic powder. have.

In addition, in one embodiment of the present invention, as the solvent of the silane coupling agent, water (H ₂ O), ethanol (C ₂ H ₅ OH), methanol (CH ₃ OH), methyl ethyl ketone (CH ₃ COC ₂ H) ₅ ) and one or more solvents selected from the group including benzene (C ₆ H ₆ ) may be used, but the present invention is not limited thereto.

Then, the hydroxyl group (-OH) on the surface of the ceramic powder particles and the silanol group (Si-OH) of the siloxane compound are self-assembled to form a silane-based compound coating film in which hydrogen bonds are formed (“(ii)” in FIG. 2a) .

And, in order to surface-treat the silane-based compound coating film that is non-uniformly formed by rapid reaction, it is aged at room temperature, preferably in the range of about -3 to 75° C. for a long time, and dehydration condensation reaction proceeds to form a uniform surface layer. (“(iii)” in FIG. 1). In one embodiment, the thickness of the finally formed coating film of the silane-based compound is in the range of about 0.5 to 5 nm, preferably 5 nm.

In particular, in the present invention, the silane-based compound coating film 20 formed on the surface 10 of the ceramic powder particles shown in FIG. 2B has uniform and strong bonding properties with the epoxy-based binder added to the mixed powder for later molding.

In addition, this increased bonding property produces a greater effect when the ceramic powder is a nanopowder. That is, during molding, the epoxy binder is uniformly adsorbed to the nanopowder having a large specific surface area, thereby reducing friction between the powders, and at the same time increasing the dispersibility and viscoelasticity between the powders so that the nanopowder is absorbed into the empty space between the powders. Allows for more effective prying in and filling. Accordingly, the packing density of the ceramic powder is improved, which leads to improvement of the final dielectric properties. In an embodiment, the ceramic nanopowder may have a particle diameter in the range of approximately 100 to 300 nm, but the present invention is not limited thereto, and may be any ceramic powder having a particle diameter in nano units.

In addition, in one embodiment of the present invention, the ceramic powder on which the silane-based compound coating film 20 is formed as described above is mixed with a solvent to which an epoxy-based binder, a plasticizer, and/or a dispersant is added to improve formability during compression, thereby making the ceramic ceramic. After preparing a viscous slurry in which the powder is uniformly dispersed, it is tape-casted as shown in FIG. 1 to prepare a thick green sheet.

In the present invention, the solvent may be any known solvent including ethanol. In addition, in the present invention, the binder may be any known binder including an epoxy-based low-polymerization binder, and in one embodiment may be added in an amount of about 60 wt% or less based on the weight of the ceramic powder. Also, in the present invention, the dispersant may be any known dispersant including BYK 111 ^® (BYK-Chemie GmbH), and in one embodiment, may be added in an amount of about 3 wt% or less based on the weight of the ceramic powder. In addition, in the present invention, the plasticizer may be any known plasticizer including C ₁₆ H ₂₂ O ₂₄ and may be added in an amount of about 5 wt% or less based on the weight of the ceramic powder in one embodiment. In addition, in one embodiment of the present invention, the green sheets manufactured as above are laminated in plurality and compressed to form a single bulk, which may be sintered and manufactured as a laminated device.

Preferred embodiments of the present invention as described above will be described in detail below. However, the following examples of the present invention are provided to help the overall understanding of the present invention, and the present invention is not limited only to the following examples.

Example

First, BaTiO ₃ nanopowder having a particle size of approximately 150 nm, Dy ₂ O ₃ in an amount of 0.1 to 2 mol% relative to the total weight of the mixed powder as an additive, MgO in a content of 0.1 to 1.5 mol%, and 0.1 to 1.5 mol% of the content Ceramic mixed powder of each nanopowder of SiO ₂ was prepared. In addition, the ceramic mixed powder is surface treated with a trimethoxy[(3-(phenylamino)propyl]silane solution (Tokyo Chemical Industry Co., Ltd.) in the range of about 0.1 to 1.0 wt% based on the total weight of the mixed powder. After aging at room temperature (about 25° C.) for 24 hours, a silane-based compound coating film was coated on the surface of the ceramic mixed powder.

Then, 60wt% or less of the epoxy-based low-polymerization binder, 3wt% or less of BYK 111 ^® dispersant, and 5wt% or less of C ₁₆ H ₂₂ O ₂₄ plasticizer were added thereto, respectively, and 40-60 wt% of ethanol was added to the Apex mill (Apex mill). ), high-speed milling was performed at 2000-4500 rpm for 1 to 3 hours to prepare a ceramic slurry for MLCC.

Then, the ceramic slurry is tape-casted at a feed rate of 0.5 m/min and coated on a carrier film, which is then applied to a plurality of drying zones (the first drying zone is 25°C, the second drying zone is 35°C, and the third drying zone is The zone was passed through 35 ° C., and the last fourth drying zone was maintained at 60 ° C.) in turn, and was formed into a green sheet with a thickness in the range of about 20 to 40 μm. In addition, the formed green sheet was measured for gloss (GU) of the green sheet based on incident light of 20°, 60°, and 85° using a glossmeter. At this time, the gloss (GU) decreases as the green sheet becomes more transparent and approaches a maximum of 0, and increases as the green sheet becomes opaque and approaches a maximum of 100.

Then, the green sheet is cut according to the standard, and a plurality of 10 to 20 sheets are laminated to form a bulk, and then hot pressed for 10 to 30 seconds at a molding pressure of 3 to 5 ton/cm ² in a temperature range of about 100 to 150 ° C. After pressing) into bulk with a thickness of 0.7 to 1.5 mm, sintered at 1000 to 1300 ° C for 1 to 3 hours at a temperature increase rate of 1 ° C/min, followed by slow cooling to room temperature to final chips with a thickness in the range of 0.6 to 0.9 mm was prepared, at this time, the bulk shrinkage was in the range of about 7-15%. Then, the dielectric constant and the firing density of the chip were measured.

3A is a photograph of the surface of a green sheet prepared with a slurry of ceramic mixed powder having a silane-based compound coating film formed on the surface according to the embodiment of the present invention. The photo wound in (9), the right photo (B) is a photo of the formed green sheet itself, and FIG. 3b is a comparative example of the surface of a green sheet prepared from a slurry of ceramic mixed powder not coated with a silane-based compound. As the photos, the left photo (A) is a photo in which the formed green sheet is wound around the winding unit 9 of FIG. 1, and the right photo (B) is a photo of only the formed green sheet itself.

3A to 3B, it is observed that a significant amount of cracks and cracks occurred in the case of the green sheet of the comparative example (FIG. 3B), but according to the present invention, a green sheet prepared from a slurry of ceramic mixed powder having a silane-based compound coating film formed on the surface In the case of (Fig. 3a), it is observed that the surface is smooth and no cracks occur at all.

In addition, Table 1 below shows a green sheet prepared from a slurry of ceramic mixed powder having a silane-based compound coating film formed on the surface according to the embodiment of the present invention of FIG. 3A and a comparative example of FIG. 3B. The surface is not coated with a silane-based compound Each of the measured glossiness (GU) values of green sheets prepared with a slurry of untreated ceramic powder are summarized.

Glossiness (GU) green sheet
Thickness (㎛) 20˚ angle of incidence 60˚ angle of incidence 85˚ angle of incidence comparative example 1.88 24.66 85.5 34 Example 1
(Added 0.1wt% of silane solution) 1.7 17.3 85.02 36.6 Example 2
(Added 0.5wt% of silane solution) 1.7 18.12 85.7 36.8 Example 3
(1.0wt% of silane solution added) 1.72 19.12 87.08 35.4

Referring to Table 1 above, as compared to Comparative Example, in Examples 1 to 3, which are green sheets prepared with a slurry of ceramic mixed powder having a silane-based compound coating film on the surface, the gloss (GU) value was low and the transparency of the sheet was large. In particular, it can be seen that the transparency was improved by about 25% compared to the comparative example at an incident angle of 60°, which is a standard gloss measurement angle. Such improvement in glossiness and transparency means that the illuminance of the manufactured green sheet is improved, and this improvement in illuminance means improvement of the firing density and dielectric constant of a laminated device manufactured by subsequently stacking and firing a plurality of green sheets. .

4 is a silane solution content of chips fired at each firing temperature after stacking and pressing a plurality of green sheets of FIG. 3A prepared as a slurry of ceramic mixed powder having a silane compound coating film formed on the surface according to an embodiment of the present invention; Shows a change in the dielectric constant (“Dielectric constants (ε _r )”) characteristics, and as a comparative example, a plurality of green sheets made of a slurry of ceramic mixed powder whose surface is not coated with a silane-based compound are laminated and pressed, followed by each firing temperature shows the change in the dielectric constant characteristic of the fired chip. In addition, Table 2 below summarizes each dielectric constant value of FIG. 4 numerically.

firing temperature 1150℃ 1170℃ 1200℃ 1300℃ Comparative Example (Ref.) 2016 2050 1586 1436 Example 1
(Added 0.1wt% of silane solution) 2001 2011 1555 1425 Example 2
(Added 0.5wt% of silane solution) 2020 2372 1689 1502 Example 3
(1.0wt% of silane solution added) 1999 2043 1571 1420

4 and Table 2, when comparing the dielectric constant of the chip obtained by sintering the green sheet-stacked bulk at a firing temperature of about 1170° C. with the comparative example, the dielectric constant value of up to about 15.7% is improved in Example 2 of the present invention it is confirmed that

5 is a silane solution content of chips fired at each firing temperature after stacking and pressing a plurality of green sheets of FIG. 3A prepared as a slurry of ceramic powder having a silane-based compound coating film formed on the surface according to an embodiment of the present invention It represents the change in sintering density ("Density (g/cc)") by star, and as a comparative example, a plurality of green sheets prepared from a slurry of ceramic powder whose surface is not coated with a silane-based compound are laminated and pressed, and then each firing It shows the change in the sintering density of the chip fired at the temperature. In addition, Table 3 below summarizes each sintered density value of FIG. 5 numerically.

firing temperature 1150℃ 1170℃ 1200℃ 1300℃ Comparative Example (Ref.) 5.28 5.44 5.55 5.55 Example 1
(Added 0.1wt% of silane solution) 5.62 5.48 5.61 5.6 Example 2
(Added 0.5wt% of silane solution) 5.46 5.44 5.71 5.55 Example 3
(1.0wt% of silane solution added) 5.39 5.33 5.54 5.4

5 and Table 3, it can be seen that the sintering density is improved in the present invention prepared as a slurry of ceramic powder coated with a silane-based compound coating film on the surface as compared to Comparative Example.

As described above, according to the present invention, the ceramic powder of the ceramic slurry prepared for tape casting is surface-treated with a silane coupling agent so that the surface thereof is coated with a silane-based compound and then subjected to aging treatment to induce uniform dispersion of the ceramic powder. In addition, the silane-based compound coating film induces a more uniform and stronger bond with an epoxy binder added for later moldability. This uniform and stronger bonding with the epoxy binder further increases the dispersibility and viscoelasticity between the powders to increase the packing density between the powders, and improves the roughness of the green sheet to produce bulk chips by sintering the sintering density and dielectric strength. improve properties. Therefore, the mechanism according to the present invention is very advantageous for manufacturing MLCCs having high dielectric constant electrical characteristics while being ultra-thin and flexible.

Above, in the above-described embodiments and examples of the present invention, the powder properties such as the average particle size, distribution and specific surface area of the composition powder, the purity of the raw material, the amount of impurities added and the sintering conditions slightly fluctuate within the normal error range. It is very natural for those of ordinary skill in the relevant field that this may exist.

In addition, preferred embodiments and embodiments of the present invention are disclosed for the purpose of illustration, and any person skilled in the art may make various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications , changes, additions, etc. shall be regarded as belonging to the scope of the claims.

1: ceramic slurry
3: Blade
5: Heat drying zone
7: Green seat
8: carrier film
9: Winding part

Claims (15)

In the method for manufacturing a ceramic green sheet,
Aging;
preparing a ceramic slurry by adding an epoxy binder, a dispersant, and a second solvent to the aged ceramic powder;
and tape-casting the ceramic slurry to form a green sheet. According to claim 1,
The preparing of the ceramic slurry further comprises adding a plasticizer to the ceramic powder. 3. The method of claim 1 or 2,
The aging treatment is a method of manufacturing a ceramic green sheet, characterized in that performed at room temperature. 3. The method of claim 1 or 2,
The aging treatment is a method of manufacturing a ceramic green sheet, characterized in that it is performed at a temperature in the range of -3 ~ 72 ℃. 3. The method of claim 1 or 2,
The method of manufacturing a ceramic green sheet, characterized in that the aging treatment is performed for a time in the range of 1 to 72. 3. The method of claim 1 or 2,
The first solvent is water (H ₂ O), ethanol (C ₂ H ₅ OH), methanol (CH ₃ OH), methyl ethyl ketone (CH ₃ COC ₂ H ₅ ) and benzene (C ₆ H ₆ ) A method of manufacturing a ceramic green sheet, characterized in that at least one is selected from 3. The method of claim 1 or 2,
The method of manufacturing a ceramic green sheet, characterized in that the amount of the silane coupling agent is adjusted in the range of 0.05 to 5 wt% based on the total amount of the ceramic powder. 3. The method of claim 1 or 2,
The silane coupling agent is 3-glycide oxypropyl trimethoxysilane, 3-glycide oxypropyl triethoxysilane, vinyl trimethoxysilane, vinyl triethoxysilane, 3-aminopropyl trimethoxysilane, trime Toxy[(3-(phenylamino)propyl]silane, 3-aminopropyl triethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-methacryl oxypropyl triethoxysilane, 3-mercaptopropyl tri Methoxysilane, vinylethoxysilane, vinyl-tolyl (2-methoxy-ethoxy)silane, γ-methacryloxypropyl trimethoxysilane, γ-aminopropyl trimethoxysilane, γ-aminopropyl triethoxy Silane, N-phenyl-γ-aminopropyl trimethoxysilane, N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane, N-β-(aminoethyl)-γ-aminopropyl triethoxysilane , N-phenyl-γ-aminopropyl trimethoxysilane, β-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, γ-glycidoxypropyl trimethoxysilane, and γ-mercaptopropyl trimethoxy A method of manufacturing a ceramic green sheet, characterized in that at least one selected from the group consisting of silanes. 3. The method of claim 1 or 2,
The ceramic powder is a method of manufacturing a ceramic green sheet, characterized in that it comprises a powder having a particle diameter in the range of 100 ~ 300㎚. 3. The method of claim 1 or 2,
The method of manufacturing a ceramic green sheet, characterized in that the second solvent is ethanol. 3. The method of claim 1 or 2,
A method of manufacturing a ceramic green sheet, characterized in that the thickness of the formed silane-based compound coating film is in the range of 0.5 to 5 nm. 3. The method of claim 1 or 2,
The method of manufacturing a ceramic green sheet, characterized in that the added amount of the epoxy binder is 60 wt% or less based on the weight of the ceramic powder. 3. The method of claim 1 or 2,
The method of manufacturing a ceramic green sheet, characterized in that the amount of the dispersant added is 3 wt% or less based on the weight of the ceramic powder. 3. The method of claim 2,
The method of manufacturing a ceramic green sheet, characterized in that the added amount of the plasticizer is 5 wt% or less based on the weight of the ceramic powder. 3. The method of claim 1 or 2,
The method for manufacturing a ceramic green sheet, characterized in that forming the silane-based compound coating film on the surface of the ceramic powder is performed by immersing the ceramic powder in the silane solution.

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