A tape-casting process for electronic ceramics

Abstract

The invention relates to the field of electronic ceramic materials, in particular to an electronic ceramic tape casting molding process, wherein water is used as a ball milling medium to perform a primary ball milling on electronic ceramic powder, epoxy-modified polyvinyl alcohol, polyamine compounds and a plasticizer are added to a first slurry obtained by the primary ball milling, and then a secondary ball milling is performed, and a second slurry obtained by the secondary ball milling is defoamed and tape casting is performed, and the obtained tape casting sheet is dried to obtain a ceramic blank, and finally the ceramic blank is debinded and sintered. The electronic ceramic prepared by the process of the invention has good mechanical properties.

Description

Technical Field

[0001] The invention relates to the field of electronic ceramic materials, in particular to an electronic ceramic tape casting process. Background Art

[0002] Tape casting is the process of blowing the prepared ceramic slurry into the scraper of the tape casting machine through nitrogen, leveling the slurry on the rotating steel belt by its own weight, and then drying and peeling. It is an important process for preparing single-layer or multi-layer electronic ceramic materials and is widely used in the production of electronic ceramic components or substrates. According to the solvent used in the current tape casting process, it can be divided into two categories: non-aqueous series and aqueous series. From the research situation at home and abroad in recent years, the research on the tape casting process of the non-aqueous system has been relatively mature. The prepared electronic ceramic green sheets have uniform structure, high strength, good flexibility, and are easy to cut and process. They have been widely used in industrial production. However, due to the use of a large amount of flammable and toxic organic solvents in the non-aqueous series of tape casting processes, it will cause certain harm to the human body and the environment. Therefore, the study of tape casting technology using water as a solvent instead of organic solvents has become an irreversible trend. However, the ceramic green sheets after tape casting with water as a solvent are prone to shrinkage and cracking during sintering, resulting in a decrease in sintering density. The mechanical strength of the prepared electronic ceramic materials is generally not high, which limits its wide application. Summary of the invention

[0003] Purpose of the invention: In view of the above technical problems, the present invention proposes an electronic ceramic tape casting process based on a water-based adhesive.

[0004] The technical solutions adopted are as follows:

[0005] An electronic ceramic tape casting process, as follows:

[0006] S1: Using water as the ball milling medium, the electronic ceramic powder is ball milled once;

[0007] S2: adding epoxy-modified polyvinyl alcohol, polyamine compounds and plasticizer to the first slurry obtained by the first ball milling, and then performing a second ball milling;

[0008] S3: degassing the second slurry obtained by the secondary ball milling, and then tape casting, and drying the obtained tape casting sheet to obtain a ceramic green body;

[0009] S4: Finally, the ceramic green body is debonded and sintered.

[0010] Furthermore, the mass ratio of the electronic ceramic powder, epoxy-modified polyvinyl alcohol, polyamine compound and plasticizer is 100:5-10:0.01-0.1:1-5.

[0011] Furthermore, the preparation method of the epoxy-modified polyvinyl alcohol is as follows:

[0012] Polyvinyl alcohol and ammonium cerium nitrate are dissolved in water to obtain solution A and solution B respectively, the pH of solution A is adjusted to 4-6, solution B is added dropwise to solution A, and then glycidyl methacrylate is added, the obtained mixed solution is reacted for 5-10 hours, and then concentrated under reduced pressure and the solid is filtered out.

[0013] Furthermore, the mass ratio of the polyvinyl alcohol to glycidyl methacrylate is 1:0.01-0.1.

[0014] Furthermore, the reaction temperature is 40-70°C.

[0015] Furthermore, the structure of the polyamine compound is shown in Formula 1:

[0016] ;

[0017] R 1 , R 2 , R 3 Each independently is hydrogen, amino or the structural formula shown in Formula 2:

[0018] ;

[0019] And R 1 , R 2 , R 3 At least one of them is a structural formula shown in Formula 2, R 1 , R 2 , R 3 At most one of them is hydrogen.

[0020] Furthermore, the polyamine compound is any one of the following compounds:

[0021] .

[0022] Furthermore, the plasticizer is dibutyl phthalate and / or dioctyl phthalate.

[0023] Furthermore, the debinding temperature is 650-750°C, and the debinding time is 5-10h.

[0024] Furthermore, the sintering temperature is 1350-1600° C., and the sintering time is 1-3 hours.

[0025] Beneficial effects of the present invention:

[0026] The invention provides an electronic ceramic tape-casting forming process based on a water-based adhesive. Polyvinyl alcohol is epoxy-modified to introduce epoxy groups with high cross-linking activity, and then a three-dimensional cross-linking structure polymer is formed by the reaction of a polyamine compound with the epoxy group to wrap ceramic particles. During the tape-casting forming and drying process, a three-dimensional network shape is formed. At the same time, amide bonds in the polyamine compound react with each other to generate hydrogen bonding forces, so that ceramic particles are tightly bonded to each other, thereby obtaining a ceramic green blank with a dense structure, which is not easy to shrink and crack during sintering, so that the sintered electronic ceramic has high density and good mechanical properties. DETAILED DESCRIPTION

[0027] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially. The techniques not mentioned in the present invention are all referenced to the prior art. Unless otherwise specified, the following examples and comparative examples are parallel experiments, using the same processing steps and parameters.

[0028] Embodiment 1:

[0029] An electronic ceramic tape casting process based on water-based adhesive:

[0030] Alumina powder (D 50 The alumina powder is 3.4 μm, Alteo Company) is used as electronic ceramic powder, the alumina powder is put into the ball mill of a planetary ball mill, the same mass of water is used as the ball milling medium, and the first slurry is obtained by ball milling at a speed of 600 r / min for 5 h, and epoxy-modified polyvinyl alcohol, polyamine compounds and plasticizer DOP are added to the first slurry, the mass ratio of alumina powder, epoxy-modified polyvinyl alcohol, polyamine compounds and plasticizer DOP is 100:8:0.08:3, and then at 60 The second slurry is degassed on a vacuum degassing machine and then tape-cast on a tape-casting machine. The cast sheet is dried at 50°C for 48 hours and then demolded to obtain a ceramic green sheet. The ceramic green sheet is placed in a muffle furnace, first heated to 650°C at a rate of 1°C / min and kept for 5 hours to debind, then heated to 1600°C at a rate of 5°C / min and sintered for 2 hours. After cooling to room temperature in the furnace, an alumina ceramic substrate is obtained.

[0031] Wherein, the preparation method of epoxy-modified polyvinyl alcohol is as follows:

[0032] Dissolve 100 g of polyvinyl alcohol and 0.5 g of ammonium cerium nitrate in appropriate amounts of water to obtain solution A and solution B, respectively. Adjust the pH of solution A to 5, add solution B dropwise into solution A, and then add 5 g of glycidyl methacrylate. Finally, react the obtained mixture at 50 ° C for 8 h, concentrate under reduced pressure to remove most of the water, cool to 0-5 ° C, filter, collect the solid and dry it.

[0033] Polyamine compounds are the following compounds:

[0034] .

[0035] Embodiment 2:

[0036] An electronic ceramic tape casting process based on water-based adhesive:

[0037] Alumina powder (D 50 The alumina powder is 3.4 μm, Alteo Company) is used as electronic ceramic powder, the alumina powder is put into the ball mill of a planetary ball mill, the same mass of water is used as the ball milling medium, and the first slurry is obtained by ball milling at a speed of 600 r / min for 5 h, and epoxy-modified polyvinyl alcohol, polyamine compounds and plasticizer DOP are added to the first slurry, the mass ratio of alumina powder, epoxy-modified polyvinyl alcohol, polyamine compounds and plasticizer DOP is 100:8:0.08:3, and then at 60 The second slurry is degassed on a vacuum degassing machine and then tape-cast on a tape-casting machine. The cast sheet is dried at 50°C for 48 hours and then demolded to obtain a ceramic green sheet. The ceramic green sheet is placed in a muffle furnace, first heated to 650°C at a rate of 1°C / min and kept for 5 hours to debind, then heated to 1600°C at a rate of 5°C / min and sintered for 2 hours. After cooling to room temperature in the furnace, an alumina ceramic substrate is obtained.

[0038] Wherein, the preparation method of epoxy-modified polyvinyl alcohol is as follows:

[0039] Dissolve 100 g of polyvinyl alcohol and 0.5 g of ammonium cerium nitrate in appropriate amounts of water to obtain solution A and solution B, respectively. Adjust the pH of solution A to 5, add solution B dropwise into solution A, and then add 5 g of glycidyl methacrylate. Finally, react the obtained mixture at 50 ° C for 8 h, concentrate under reduced pressure to remove most of the water, cool to 0-5 ° C, filter, collect the solid and dry it.

[0040] Polyamine compounds are the following compounds:

[0041] .

[0042] Embodiment 3:

[0043] An electronic ceramic tape casting process based on water-based adhesive:

[0044] Alumina powder (D 50 The alumina powder is 3.4 μm, Alteo Company) is used as electronic ceramic powder, the alumina powder is put into the ball mill of a planetary ball mill, the same mass of water is used as the ball milling medium, and the first slurry is obtained by ball milling at a speed of 600 r / min for 5 h, and epoxy-modified polyvinyl alcohol, polyamine compounds and plasticizer DOP are added to the first slurry, the mass ratio of alumina powder, epoxy-modified polyvinyl alcohol, polyamine compounds and plasticizer DOP is 100:8:0.08:3, and then at 60 The second slurry is degassed on a vacuum degassing machine and then tape-cast on a tape-casting machine. The cast sheet is dried at 50°C for 48 hours and then demolded to obtain a ceramic green sheet. The ceramic green sheet is placed in a muffle furnace, first heated to 650°C at a rate of 1°C / min and kept for 5 hours to debind, then heated to 1600°C at a rate of 5°C / min and sintered for 2 hours. After cooling to room temperature in the furnace, an alumina ceramic substrate is obtained.

[0045] Wherein, the preparation method of epoxy-modified polyvinyl alcohol is as follows:

[0046] Dissolve 100 g of polyvinyl alcohol and 0.5 g of ammonium cerium nitrate in appropriate amounts of water to obtain solution A and solution B, respectively. Adjust the pH of solution A to 5, add solution B dropwise into solution A, and then add 5 g of glycidyl methacrylate. Finally, react the obtained mixture at 50 ° C for 8 h, concentrate under reduced pressure to remove most of the water, cool to 0-5 ° C, filter, collect the solid and dry it.

[0047] The polyamine compound is any one of the following compounds:

[0048] .

[0049] Embodiment 4:

[0050] An electronic ceramic tape casting process based on water-based adhesive:

[0051] Alumina powder (D 50The alumina powder was put into the ball mill of a planetary ball mill, and the same mass of water was used as the ball milling medium. The alumina powder was ball milled at a speed of 600r / min for 5h to obtain a first slurry. Epoxy-modified polyvinyl alcohol, polyamine compounds and plasticizer DOP were added to the first slurry. The mass ratio of alumina powder, epoxy-modified polyvinyl alcohol, polyamine compounds and plasticizer DOP was 100:5:0.05:3. Then the alumina powder was mixed with water at a speed of 600r / min for 5h. The mass ratio of alumina powder, epoxy-modified polyvinyl alcohol, polyamine compounds and plasticizer DOP was 100:5:0.05:3. The second slurry is degassed on a vacuum degassing machine and then tape-cast on a tape-casting machine. The cast sheet is dried at 50°C for 48 hours and then demolded to obtain a ceramic green sheet. The ceramic green sheet is placed in a muffle furnace, first heated to 650°C at a rate of 1°C / min and kept for 5 hours to debind, then heated to 1600°C at a rate of 5°C / min and sintered for 2 hours. After cooling to room temperature in the furnace, an alumina ceramic substrate is obtained.

[0052] Wherein, the preparation method of epoxy-modified polyvinyl alcohol is as follows:

[0053] Dissolve 100 g of polyvinyl alcohol and 0.5 g of ammonium cerium nitrate in appropriate amounts of water to obtain solution A and solution B, respectively. Adjust the pH of solution A to 5, add solution B dropwise into solution A, and then add 5 g of glycidyl methacrylate. Finally, react the obtained mixture at 50 ° C for 8 h, concentrate under reduced pressure to remove most of the water, cool to 0-5 ° C, filter, collect the solid and dry it.

[0054] Polyamine compounds are the following compounds:

[0055] .

[0056] Embodiment 5:

[0057] An electronic ceramic tape casting process based on water-based adhesive:

[0058] Alumina powder (D 50The alumina powder is 3.4 μm, Alteo Company) is used as electronic ceramic powder, the alumina powder is put into the ball mill of a planetary ball mill, the same mass of water is used as the ball milling medium, and the first slurry is obtained by ball milling at a speed of 600 r / min for 5 h, and epoxy-modified polyvinyl alcohol, polyamine compounds and plasticizer DOP are added to the first slurry, the mass ratio of alumina powder, epoxy-modified polyvinyl alcohol, polyamine compounds and plasticizer DOP is 100:10:0.1:3, and then at 60 The second slurry is degassed on a vacuum degassing machine and then tape-cast on a tape-casting machine. The cast sheet is dried at 50°C for 48 hours and then demolded to obtain a ceramic green sheet. The ceramic green sheet is placed in a muffle furnace, first heated to 650°C at a rate of 1°C / min and kept for 5 hours to debind, then heated to 1600°C at a rate of 5°C / min and sintered for 2 hours. After cooling to room temperature in the furnace, an alumina ceramic substrate is obtained.

[0059] Wherein, the preparation method of epoxy-modified polyvinyl alcohol is as follows:

[0060] Dissolve 100 g of polyvinyl alcohol and 0.5 g of ammonium cerium nitrate in appropriate amounts of water to obtain solution A and solution B, respectively. Adjust the pH of solution A to 5, add solution B dropwise into solution A, and then add 5 g of glycidyl methacrylate. Finally, react the obtained mixture at 50 ° C for 8 h, concentrate under reduced pressure to remove most of the water, cool to 0-5 ° C, filter, collect the solid and dry it.

[0061] Polyamine compounds are the following compounds:

[0062] .

[0063] Comparative Example 1:

[0064] The method is basically the same as Example 1, except that no polyamine compound is added.

[0065] Comparative Example 2:

[0066] The method is basically the same as Example 1, except that the epoxy-modified polyvinyl alcohol is replaced by polyvinyl alcohol of the same mass, and no polyamine compound is added.

[0067] Performance testing:

[0068] The alumina ceramic substrates prepared in Examples 1-5 of the present invention and Comparative Examples 1-2 were used as samples for performance testing.

[0069] The relative density of the sample was tested by the drainage method;

[0070] The three-point bending method was used to determine the bending strength of the sample. The testing equipment was a WDW-10 multifunctional material testing machine. The sample size was 25 mm × 5 mm × 5 mm, and the loading rate was 0.05 mm / s.

[0071] The fracture toughness of the specimens was determined by the single-edge notched beam method, and the specimen size was 25 mm × 5 mm × 5 mm;

[0072] The test results are shown in Table 1 below:

[0073] Table 1:

[0074] Relative density / % Bending strength / MPa Fracture toughness / Mpa·m1 / 2 Example 1 99.9 468.5 4.64 Example 2 99.8 457.4 4.56 Example 3 99.6 442.1 4.47 Example 4 99.3 429.6 4.28 Example 5 99.4 432.4 4.31 Comparative Example 1 98.8 380.4 4.05 Comparative Example 2 98.2 367.2 3.83

[0075] As shown in Table 1 above, the alumina ceramic substrate prepared using epoxy-modified polyvinyl alcohol and polyamine compounds as adhesives has good mechanical properties;

[0076] By comparing the data of Example 1 with those of Examples 2 and 3, it can be seen that the increase in the number of amide bonds plays a positive role in improving the mechanical properties of the alumina ceramic substrate;

[0077] By comparing the data of Example 1 with those of Examples 4 and 5, it can be seen that the mechanical properties of the alumina ceramic substrate are optimal when the mass ratio of alumina powder, epoxy-modified polyvinyl alcohol, polyamine compound and plasticizer DOP is 100:8:0.08:3.

[0078] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electronic ceramic tape casting process, characterized in that: The details are as follows: S1: Using water as the ball milling medium, the electronic ceramic powder is ball milled once; S2: adding epoxy-modified polyvinyl alcohol, polyamine compounds and plasticizer to the first slurry obtained by the first ball milling, and then performing a second ball milling; The structure of the polyamine compound is shown in Formula 1: ； R1, R2, and R3 are each independently hydrogen, amino, or a structure shown in Formula 2: ； At least one of R1, R2, and R3 is a structural formula shown in Formula 2, and at most one of R1, R2, and R3 is hydrogen; S3: degassing the second slurry obtained by the secondary ball milling, and then tape casting, and drying the obtained tape casting sheet to obtain a ceramic green body; S4: Finally, the ceramic green body is debonded and sintered.

2. The electronic ceramic tape casting process according to claim 1, characterized in that: The mass ratio of the electronic ceramic powder, epoxy-modified polyvinyl alcohol, polyamine compound and plasticizer is 100:5-10:0.01-0.1:1-5.

3. The electronic ceramic tape casting process according to claim 1, characterized in that: The preparation method of the epoxy-modified polyvinyl alcohol is as follows: Polyvinyl alcohol and ammonium cerium nitrate are dissolved in water to obtain solution A and solution B respectively, the pH of solution A is adjusted to 4-6, solution B is added dropwise to solution A, and then glycidyl methacrylate is added, the obtained mixed solution is reacted for 5-10 hours, and then concentrated under reduced pressure and the solid is filtered out.

4. The electronic ceramic tape casting process according to claim 3, characterized in that: The mass ratio of the polyvinyl alcohol to glycidyl methacrylate is 1:0.01-0.

1.

5. The electronic ceramic tape casting process according to claim 3, characterized in that: The reaction temperature is 40-70°C.

6. The electronic ceramic tape casting process according to claim 1, characterized in that: The polyamine compound is any one of the following compounds: 。 7. The electronic ceramic tape casting process according to claim 1, characterized in that: The plasticizer is dibutyl phthalate and / or dioctyl phthalate.

8. The electronic ceramic tape casting process according to claim 1, characterized in that: The debinding temperature is 650-750℃ and the debinding time is 5-10h.

9. The electronic ceramic tape casting process according to claim 1, characterized in that: The sintering temperature is 1350-1600°C and the sintering time is 1-3h.

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