Preparation method of alumina ceramic slurry based on organic tape casting system

Abstract

The invention discloses a preparation method of alumina ceramic slurry based on an organic tape casting system, and belongs to the technical field of preparation of electrostatic chuck ceramic slurry, the preparation method comprises the following steps: S1, weighing powder, a solvent and a dispersing agent of corresponding mass, ball-milling and mixing by a horizontal ball mill, and sieving to obtain first prefabricated slurry; s2, weighing a binder and a plasticizer with corresponding mass, carrying out secondary ball milling and mixing on the obtained first prefabricated slurry, binder and plasticizer through a horizontal ball mill, and sieving to obtain second prefabricated slurry; s3, the obtained prefabricated slurry is subjected to defoaming treatment through a vacuum defoaming machine, and then the organic tape casting system aluminum oxide ceramic slurry is obtained.According to the preparation method, magnesium oxide, lanthanum oxide and samarium oxide are introduced into nanometer aluminum oxide powder, so that the volume density and mechanical strength of a ceramic product are improved; through the dispersing agent, the solvent, the binder and the plasticizer in the formula system, the prepared blank sheet has no problems of warping, cracking, poor flexibility and the like.

Description

Technical Field

[0001] The invention relates to the technical field of electrostatic chuck ceramic slurry preparation, and in particular to a method for preparing alumina ceramic slurry based on an organic tape casting system. Background Art

[0002] The tape casting process is widely used in ceramic forming processes in the fields of electronic substrates, multilayer capacitors, multilayer packaging and electrostatic chucks because the ceramic sheets produced by the tape casting process have good uniformity and high permeability. Before the tape casting of ceramic green bodies, the preparation process of the slurry is crucial. The selection and addition amount of additives such as solvents, dispersants, binders and plasticizers are the main factors affecting the preparation of the slurry, and are also the key to restricting the quality of ceramic green bodies.

[0003] The existing traditional casting technology still has different types of green sheet quality problems in the actual production process, such as green sheet warping, cracking, and poor flexibility. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing alumina ceramic slurry based on an organic tape casting system to solve the problems raised in the background technology.

[0005] In order to solve the above technical problems, the technical solution of the present invention is:

[0006] A method for preparing alumina ceramic slurry based on an organic tape casting system, the preparation method comprising:

[0007] S1: weighing the corresponding masses of powder, solvent, and dispersant, mixing them by ball milling in a horizontal ball mill, and then sieving to obtain a first prefabricated slurry, wherein the powder comprises 92-95wt.% of nano-alumina, 3-5wt.% of magnesium oxide, 0.5-1wt.% of lanthanum oxide, and 0.5-1wt.% of samarium oxide. The raw material composition and dosage of the solvent are 2-3wt.% of methyl ethyl ketone, 2-2.5wt.% of trichloroethylene, 2-2.5wt.% of xylene, and 2-3wt.% of ethanol, respectively, and the raw material composition and dosage of the dispersant are 0.8-1wt.% of glyceride, 0.8-1wt.% of fatty acid ammonium, and 0.4-0.6wt.% of phosphate ester, respectively.

[0008] S2: Weigh the corresponding masses of binder and plasticizer, and subject the obtained first prefabricated slurry, binder and plasticizer to secondary ball milling in a horizontal ball mill, and then sieve to obtain a second prefabricated slurry, wherein the raw material composition and amount of the binder are 3-6wt.% of polyvinyl butyral and 3-6wt.% of polymethyl methacrylate, respectively, and the raw material composition and amount of the plasticizer are 3-5wt.% of diethyl phthalate and 2-6wt.% of butyl phthalate, respectively.

[0009] S3: The obtained prefabricated slurry is subjected to a degassing treatment by a vacuum degassing machine to obtain an organic tape-casting system alumina ceramic slurry.

[0010] Preferably, in step S1, the ball milling time is 25 to 30 hours, and the product is sieved through a 200-mesh standard sieve.

[0011] Preferably, in step S2, the ball milling time is 15 to 20 hours, and the product is sieved through a 250-mesh standard sieve.

[0012] Preferably, in step S3, the vacuum degree of the degassing treatment in the vacuum degassing machine is -0.1 to -0.08 MPa, the degassing time is 0.5 to 2 hours, and the viscosity is 5000 to 7000 mPa·s.

[0013] The above technical solution has the following beneficial effects:

[0014] 1. The present invention introduces magnesium oxide, lanthanum oxide and samarium oxide into nano-alumina powder. On the one hand, they can form a low eutectic compound at high temperature, thereby playing the role of Mg-La-Sm multi-component system composite fluxing to greatly reduce the firing temperature, promote the sintering densification process of the alumina ceramic body and improve its surface microstructure; on the other hand, MgO can form a solid solution with Al2O3, which helps to maintain the liquid phase in the sintering system, effectively inhibit the excessive growth of grains while stabilizing the fine grain microstructure of alumina crystals, thereby improving the volume density and mechanical strength of ceramic products;

[0015] 2. The operation process of the present invention is relatively simple and easy to control. By organically combining and scientifically proportioning the dispersant, solvent, binder and plasticizer in the formula system, the viscosity, fluidity, uniformity and dispersibility of the powder particles of the alumina ceramic slurry are greatly improved. The green sheets prepared in this way do not have problems such as warping, cracking, poor flexibility, etc., and the short drying time is conducive to improving work efficiency. It can fully meet the needs of market development and has broad application prospects. DETAILED DESCRIPTION

[0016] The specific embodiments of the present invention are further described below. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0017] Example 1

[0018] A method for preparing alumina ceramic slurry based on an organic tape casting system specifically comprises the following steps:

[0019] S1: weighing the corresponding masses of powder, solvent and dispersant, mixing by ball milling in a horizontal ball mill and then sieving to obtain the first prefabricated slurry, the ball milling time is 25-30 hours, and the slurry is sieved through a 200-mesh standard sieve, wherein the powder comprises 92-95wt.% of nano-alumina, 3-5wt.% of magnesium oxide, 0.5-1wt.% of lanthanum oxide, 0.5-1wt.% of samarium oxide, and the raw material composition and amount of the solvent are 2-3wt.% of methyl ethyl ketone, 2-2.5wt.% of trichloroethylene, 2-2.5wt.% of xylene, and 2-3wt.% of ethanol, respectively, and the raw material composition and amount of the dispersant are 0.8-1wt.% of glyceride, 0.8-1wt.% of fatty acid ammonium, and 0.4-0.6wt.% of phosphate ester of the powder;

[0020] S2: Weigh the corresponding masses of binder and plasticizer, and subject the obtained first prefabricated slurry, binder and plasticizer to secondary ball milling in a horizontal ball mill, and then sieve to obtain a second prefabricated slurry, the ball milling time is 15 to 20 hours, and the slurry is sieved through a 250-mesh standard sieve, the raw material composition and amount of the binder are 3 to 6 wt.% of polyvinyl butyral and 3 to 6 wt.% of polymethyl methacrylate, respectively, and the raw material composition and amount of the plasticizer are 3 to 5 wt.% of diethyl phthalate and 2 to 6 wt.% of butyl phthalate, respectively, of the powder;

[0021] S3: The obtained prefabricated slurry is subjected to a degassing treatment by a vacuum degassing machine to obtain an organic tape casting system alumina ceramic slurry. The technical requirements of the vacuum degassing machine are as follows: vacuum degree -0.1 to -0.08 MPa, degassing time 0.5 to 2 hours, and viscosity 5000 to 7000 mPa·s;

[0022] The present invention introduces magnesium oxide, lanthanum oxide and samarium oxide into nano-alumina powder. On the one hand, they can form a low eutectic compound at high temperature, thereby playing the role of Mg-La-Sm multi-component system composite fluxing to greatly reduce the firing temperature, promote the sintering densification process of the alumina ceramic body and improve its surface microstructure; on the other hand, MgO can form a solid solution with Al2O3, which is helpful to maintain the liquid phase amount in the sintering system, effectively inhibit the excessive growth of grains while stabilizing the fine grain microstructure of the alumina crystal, thereby improving the volume density and mechanical strength of the ceramic product;

[0023] The operation process of the present invention is relatively simple and easy to control. By organically combining and scientifically proportioning the dispersant, solvent, binder and plasticizer in the formula system, the viscosity, fluidity, uniformity and dispersibility of the powder particles of the alumina ceramic slurry are greatly improved. The green sheets prepared in this way do not have problems such as warping, cracking and poor flexibility. The short drying time is conducive to improving work efficiency. It can fully meet the needs of market development and has broad application prospects.

[0024] Example 2

[0025] A method for preparing alumina ceramic slurry based on an organic tape casting system specifically comprises the following steps:

[0026] S1: weigh the corresponding masses of powder, solvent and dispersant, mix them by ball milling in a horizontal ball mill and then sieve them to obtain the first prefabricated slurry, the ball milling time is 25 hours, and the slurry is sieved through a 200-mesh standard sieve after ball milling, wherein the powder comprises 92wt.% of nano-alumina, 3wt.% of magnesium oxide, 0.5wt.% of lanthanum oxide and 0.5wt.% of samarium oxide, and the raw material composition and dosage of the solvent are 2wt.% of methyl ethyl ketone, 2wt.% of trichloroethylene, 2wt.% of xylene and 2wt.% of ethanol of the powder, respectively, and the raw material composition and dosage of the dispersant are 0.8wt.% of glyceride, 0.8wt.% of fatty acid ammonium and 0.4wt.% of phosphate of the powder, respectively;

[0027] S2: Weigh the corresponding masses of binder and plasticizer, and mix the obtained first prefabricated slurry, binder and plasticizer by secondary ball milling in a horizontal ball mill and then sieve to obtain a second prefabricated slurry, the ball milling time is 15 hours, and the slurry is sieved through a 250-mesh standard sieve, the raw material composition and amount of the binder are 3wt.% of polyvinyl butyral and 3wt.% of polymethyl methacrylate of the powder, and the raw material composition and amount of the plasticizer are 3wt.% of diethyl phthalate and 2wt.% of butyl phthalate of the powder;

[0028] S3: The obtained prefabricated slurry is subjected to degassing treatment by a vacuum degassing machine to obtain an organic tape-casting system alumina ceramic slurry. The technical requirements of the vacuum degassing machine are vacuum degree -0.1MPa, degassing time 0.5h, and viscosity 5000mPa·s.

[0029] Example 3

[0030] A method for preparing alumina ceramic slurry based on an organic tape casting system specifically comprises the following steps:

[0031] S1: weigh the corresponding masses of powder, solvent, and dispersant, and sieve to obtain the first prefabricated slurry after ball milling in a horizontal ball mill for 30 hours. After ball milling, the slurry is sieved through a 200-mesh standard sieve, wherein the powder comprises 95wt.% of nano-alumina, 5wt.% of magnesium oxide, 1wt.% of lanthanum oxide, and 1wt.% of samarium oxide. The raw material composition and amount of the solvent are 3wt.% of methyl ethyl ketone, 2.5wt.% of trichloroethylene, 2.5wt.% of xylene, and 3wt.% of ethanol, respectively. The raw material composition and amount of the dispersant are 1wt.% of glyceride, 1wt.% of fatty acid ammonium, and 0.6wt.% of phosphate ester, respectively.

[0032] S2: Weigh the corresponding masses of binder and plasticizer, and mix the obtained first prefabricated slurry, binder and plasticizer by secondary ball milling in a horizontal ball mill and then sieve to obtain a second prefabricated slurry, the ball milling time is 20 hours, and the mixture is sieved through a 250-mesh standard sieve, the raw material composition and amount of the binder are 6wt.% of polyvinyl butyral and 6wt.% of polymethyl methacrylate of the powder, and the raw material composition and amount of the plasticizer are 5wt.% of diethyl phthalate and 6wt.% of butyl phthalate of the powder;

[0033] S3: The obtained prefabricated slurry is subjected to degassing treatment by a vacuum degassing machine to obtain an organic tape-casting system alumina ceramic slurry. The technical requirements of the vacuum degassing machine are as follows: vacuum degree -0.08MPa, degassing time 2h, and viscosity 7000mPa·s.

[0034] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the protection scope of the present invention.

Claims

1. A method for preparing alumina ceramic slurry based on an organic tape casting system, characterized in that: The preparation method comprises: S1: weighing the corresponding masses of powder, solvent, and dispersant, mixing them by ball milling in a horizontal ball mill, and then sieving to obtain a first prefabricated slurry, wherein the powder comprises 92-95wt.% of nano-alumina, 3-5wt.% of magnesium oxide, 0.5-1wt.% of lanthanum oxide, and 0.5-1wt.% of samarium oxide. The raw material composition and dosage of the solvent are 2-3wt.% of methyl ethyl ketone, 2-2.5wt.% of trichloroethylene, 2-2.5wt.% of xylene, and 2-3wt.% of ethanol, respectively, and the raw material composition and dosage of the dispersant are 0.8-1wt.% of glyceride, 0.8-1wt.% of fatty acid ammonium, and 0.4-0.6wt.% of phosphate ester, respectively. S2: Weigh the corresponding masses of binder and plasticizer, and subject the obtained first prefabricated slurry, binder and plasticizer to secondary ball milling in a horizontal ball mill, and then sieve to obtain a second prefabricated slurry, wherein the raw material composition and amount of the binder are 3-6wt.% of polyvinyl butyral and 3-6wt.% of polymethyl methacrylate, respectively, and the raw material composition and amount of the plasticizer are 3-5wt.% of diethyl phthalate and 2-6wt.% of butyl phthalate, respectively. S3: The obtained prefabricated slurry is subjected to a degassing treatment by a vacuum degassing machine to obtain an organic tape-casting system alumina ceramic slurry.

2. The method for preparing alumina ceramic slurry based on an organic tape casting system according to claim 1, characterized in that: In the step S1, the ball milling time is 25 to 30 hours, and the product is sieved through a 200-mesh standard sieve.

3. The method for preparing alumina ceramic slurry based on an organic tape casting system according to claim 1, characterized in that: In the step S2, the ball milling time is 15 to 20 hours, and the product is sieved through a 250-mesh standard sieve.

4. The method for preparing alumina ceramic slurry based on an organic tape casting system according to claim 1, characterized in that: In step S3, the vacuum degree of the degassing treatment in the vacuum degassing machine is -0.1 to -0.08 MPa, the degassing time is 0.5 to 2 hours, and the viscosity is 5000 to 7000 mPa·s.