Porous alumina ceramic, preparation method thereof, semiconductor vacuum chuck and application

Abstract

The invention belongs to the technical field of aluminum oxide ceramic preparation, and particularly relates to porous aluminum oxide ceramic, a preparation method thereof, a semiconductor vacuum chuck and application. The porous alumina ceramic comprises a porous ceramic matrix, the porous ceramic matrix is prepared from the following raw materials in parts by weight: 100 parts of aluminum oxide, 10 to 20 parts of polyaniline, 10 to 20 parts of dopamine, 3 to 5 parts of borazane and 3 to 5 parts of aluminum oxide. The porous alumina ceramic provided by the invention has very high mechanical strength and thermal conductivity.

Description

[0001] This invention claims priority to the invention patent application filed with the State Intellectual Property Office on August 27, 2025, with application number 2025112044511, entitled "Porous alumina ceramics and their preparation methods, semiconductor vacuum chucks and their applications". Technical Field

[0002] This invention belongs to the field of alumina ceramic preparation technology, specifically relating to a porous alumina ceramic and its preparation method, a semiconductor vacuum chuck, and its applications. Background Technology

[0003] Porous alumina ceramics are high-performance structural materials with unique pore structures, widely used in filtration, catalysis, and biomedicine. The preparation processes for porous alumina ceramics generally include pore-forming agent methods, particle packing sintering methods, and sol-gel methods. These processes are extremely sensitive to parameters (such as temperature, pressure, and sintering aids); even slight deviations can lead to a decrease in porosity or mechanical properties. Therefore, the preparation process of porous alumina ceramics determines the performance of the finished ceramic. Products prepared using traditional porous alumina ceramic preparation processes exhibit significantly reduced mechanical and thermal conductivity properties, failing to meet requirements.

[0004] To improve the mechanical and thermal properties of porous alumina ceramics, processes such as introducing a second phase (e.g., ZrO2, TiO2) to enhance mechanical properties, surface modification of alumina, and structural optimization are commonly employed. However, these existing processes are difficult to control the pore size, distribution, and connectivity of alumina, and are prone to problems such as local density inhomogeneity or poor pore connectivity, affecting performance consistency and resulting in insufficient mechanical and thermal properties of the ceramics. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a porous alumina ceramic, its preparation method, a semiconductor vacuum chuck, and its applications. This addresses at least one aspect of solving the aforementioned technical problems.

[0006] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a porous alumina ceramic, comprising a porous ceramic matrix; The porous ceramic matrix comprises the following raw materials in parts by weight: 100 parts alumina, 10 to 20 parts polyaniline, 10 to 20 parts dopamine, 3 to 5 parts cycloborane, 3 to 5 parts zirconium oxide.

[0007] In some possible implementations, the average pore size of the porous ceramic matrix is ​​90 μm to 120 μm.

[0008] In some possible implementations, the porous alumina ceramic may further include a coating layer covering the surface of the ceramic matrix.

[0009] In some possible implementations, the coating material includes silicon oxide.

[0010] In some possible implementations, the thickness of the coating layer is 50 nm to 100 nm.

[0011] Secondly, the present invention provides a method for preparing the above-mentioned porous alumina ceramic, comprising the following steps: Prepare porous ceramic matrix.

[0012] In some possible implementations, the preparation of the porous ceramic matrix includes the following steps: The mixed raw materials are pressed and then sintered. The mixed raw materials include alumina, polyaniline, dopamine, hexacycloborane, and zirconium oxide.

[0013] In some possible implementations, the pressure of the compression is 8 MPa to 12 MPa.

[0014] In some possible implementations, the compression time is 12 to 15 minutes.

[0015] In some possible implementations, the sintering includes the following steps: Low-temperature sintering and high-temperature sintering are carried out under a nitrogen atmosphere.

[0016] In some possible implementations, the low-temperature sintering step includes: Heating to 300℃~500℃ at a heating rate of 20℃ / min~30℃ / min and then holding at that temperature.

[0017] In some possible implementations, the high-temperature sintering step includes: The temperature was increased from 200℃ to 400℃ to 1600℃ to 1800℃ at a heating rate of 20℃ / min to 30℃ / min, and then held at that temperature.

[0018] Thirdly, the present invention provides a semiconductor vacuum chuck, the material of which includes the aforementioned porous alumina ceramic.

[0019] Fourthly, the present invention provides an application of the above-mentioned porous alumina ceramic in the field of semiconductor manufacturing or electronic packaging.

[0020] The porous alumina ceramic and its preparation method, as well as the semiconductor vacuum chuck provided by this invention, have at least the following beneficial technical effects compared with the prior art: (1) The porous alumina ceramic provided by the present invention has high mechanical strength and thermal conductivity.

[0021] (2) In the preparation method of porous alumina ceramic provided by the present invention, low-temperature sintering and high-temperature sintering are adopted. Low-temperature sintering decomposes polyaniline, dopamine and cycloborane to create pores; high-temperature sintering completely decomposes the intermediates of residual polyaniline, dopamine and cycloborane, and carbonizes the residual carbon elements, thereby improving the mechanical strength of the ceramic. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this drawing or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this drawing. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0023] Figure 1 This is a three-dimensional structural diagram of a semiconductor vacuum chuck provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the microstructure of the porous alumina ceramic provided in Embodiment 1 of the present invention.

[0024] The purpose, features, and advantages of this accompanying drawing will be further explained in conjunction with the embodiments and with reference to the accompanying drawing. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described and illustrated below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments provided by this invention without inventive effort are within the scope of protection of this invention.

[0026] Obviously, the following description is merely some examples or embodiments of the present invention. Those skilled in the art can apply the present invention to other similar scenarios without any inventive effort. Furthermore, it is understood that although the effort involved in such development may be complex and lengthy, for those skilled in the art related to the content disclosed in this invention, modifications to design, manufacturing, or production based on the technical content disclosed in this invention are merely conventional technical means and should not be construed as insufficient disclosure of the present invention.

[0027] However, there may be instances where unnecessary detailed descriptions are omitted. For example, detailed descriptions of well-known matters or repetitive descriptions of essentially the same structures may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the following description is provided to enable those skilled in the art to fully understand the invention and is not intended to limit the subject matter of the claims.

[0028] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions, and all technical features and optional technical features of the present invention can be combined with each other to form new technical solutions.

[0029] The first aspect of this invention provides a porous alumina ceramic, comprising a porous ceramic matrix; The porous ceramic matrix comprises the following raw materials in parts by weight: 100 parts alumina, 10 to 20 parts polyaniline, 10 to 20 parts dopamine, 3 to 5 parts cycloborane, 3 to 5 parts zirconium oxide.

[0030] The porous alumina ceramic provided in this invention uses polyaniline, dopamine, and cycloborane as pore-forming agents in its raw materials. These agents decompose at high temperatures, creating micron-scale (polyaniline) and nano-scale (dopamine and cycloborane) pores in the alumina, thus forming a porous structure. Polyaniline and dopamine also act as nitrogen sources, decomposing at high temperatures to generate gases used for pore formation in the alumina ceramic. Nitrogen reacts with alumina to form aluminum nitride, improving the ceramic's mechanical properties and thermal conductivity. Cycloborane also acts as a boron and nitrogen source, decomposing at high temperatures to generate gases used for pore formation in the alumina ceramic. The generated boron nitride and aluminum nitride exhibit good corrosion resistance and mechanical properties, thereby improving the corrosion resistance and mechanical properties of the aluminum nitride ceramic. Zirconia enhances the ceramic's mechanical strength.

[0031] In some embodiments, the CAS number of alumina is 1344-28-1.

[0032] In some embodiments, the CAS number of polyaniline is 5612-44-2.

[0033] In some embodiments, the CAS number for dopamine is 51-61-6.

[0034] In some embodiments, the structural formula of cycloboronazine is as follows: .

[0035] In some embodiments, the CAS number of zirconium oxide is 1314-23-4.

[0036] In some embodiments, the average particle size of zirconium oxide is 50 nm to 70 nm.

[0037] In some embodiments, the average pore diameter in the porous ceramic matrix is ​​90 μm to 120 μm.

[0038] In some embodiments, porous alumina ceramics further include a coating layer covering the surface of the ceramic matrix.

[0039] In some embodiments, the coating material includes silicon oxide.

[0040] In some embodiments, the thickness of the coating layer is 50 nm to 100 nm.

[0041] In other embodiments, a porous alumina ceramic is provided, comprising a porous ceramic matrix; The porous ceramic matrix comprises the following raw materials in parts by weight: 100 parts alumina, 10-20 parts modified polyaniline, 10-20 parts dopamine, 3-5 parts cycloborane, 3-5 parts zirconium oxide.

[0042] In other embodiments, the raw materials for preparing modified polyaniline include sodium borohydride and polyaniline.

[0043] In other embodiments, the molar ratio of sodium borohydride to polyaniline repeating units is (1~4):1.

[0044] A second aspect of this invention provides a method for preparing the above-mentioned porous alumina ceramic, comprising the following steps: S10. Prepare a porous ceramic matrix.

[0045] In some embodiments, the preparation of the porous ceramic matrix in step S10 above includes the following steps: S101. Press the mixed raw materials and then sinter them; The mixed raw materials include alumina, polyaniline, dopamine, hexacycloborane, and zirconium oxide.

[0046] In some embodiments, the preparation of the mixed raw materials in step S101 above includes the following steps: S1011. Alumina, polyaniline, dopamine, hexacycloborane and zirconium oxide are mixed and ball-milled.

[0047] In the preparation of the above-mentioned mixed raw materials, ball milling the raw materials can refine the particle size of the raw materials and the uniformity of the mixed raw materials, thereby improving the density of the ceramics.

[0048] In some embodiments, in step S1011 above, the ball milling fluid includes at least one of acetone and tetrahydrofuran.

[0049] In some embodiments, in step S101 above, the pressing pressure is 8MPa~12MPa.

[0050] In some embodiments, the pressing time in step S101 is 12 min to 15 min.

[0051] In some embodiments, sintering in step S101 above includes the following steps: S1012. Low-temperature sintering and high-temperature sintering are carried out under a nitrogen atmosphere.

[0052] In the above sintering steps, low-temperature sintering is performed first, followed by high-temperature sintering. Low-temperature sintering decomposes the polyaniline, dopamine, and hexacyclohexane to create pores; high-temperature sintering completely decomposes the intermediates of the remaining polyaniline, dopamine, and hexacyclohexane, and carbonizes the remaining carbon elements, thereby improving the mechanical strength of the ceramic.

[0053] In some embodiments, the low-temperature sintering step in step S1012 above includes: S10121. Heat to 300℃~500℃ at a heating rate of 20℃ / min~30℃ / min and then hold at that temperature.

[0054] In some embodiments, in step S10121 above, the heat preservation time is 1h to 2h.

[0055] In some embodiments, the high-temperature sintering step in step S1012 above includes: S10122. Heating from 300℃~500℃ to 1600℃~1800℃ at a heating rate of 20℃ / min~30℃ / min and then holding at that temperature.

[0056] In some embodiments, in step S10122 above, the heat preservation time is 1h to 2h.

[0057] In other embodiments, in step S10 above, the preparation of the porous ceramic matrix includes the following steps: S102. Press the mixed raw materials and then sinter them; The mixed raw materials include alumina, modified polyaniline, dopamine, cycloborane, and zirconium oxide.

[0058] In other embodiments, the preparation of modified polyaniline in step S102 above includes the following steps: S1021. Under stirring and a nitrogen atmosphere, the NMP mixture of sodium borohydride is added dropwise to the NMP mixture of polyaniline to obtain a mixed reaction solution.

[0059] S1022. Modified polyaniline is obtained by reacting the mixed reaction solution under stirring at a constant temperature.

[0060] In the preparation of the modified polyaniline described above, a sodium borohydride NMP mixture is added dropwise to a polyaniline NMP mixture to avoid excessively high local concentrations that could lead to uneven or overly vigorous reduction. Ensuring a gentle and uniform reduction reaction is beneficial for obtaining a structurally homogeneous mixed reaction solution. The mixed reaction solution is then subjected to a constant temperature reaction to reduce the quinone structure in the polyaniline, thus achieving the modification of polyaniline by sodium borohydride.

[0061] NMP: N-methylpyrrolidone.

[0062] In other embodiments, the preparation of the sodium borohydride NMP mixture in step S1021 above includes the following steps: Sodium borohydride and NMP are mixed in a preset ratio; NMP is pre-degassed and dried NMP.

[0063] In other embodiments, in step S1021 above, the mass-to-volume ratio of sodium borohydride to NMP in the sodium borohydride-NMP mixture is 3 mg: (1 ml to 2 ml).

[0064] In other embodiments, the preparation of the NMP mixture of polyaniline in step S1021 above includes the following steps: Polyaniline and NMP were mixed and sonicated under an ice-water bath and a nitrogen protective atmosphere.

[0065] In other embodiments, the ultrasonication time for the polyaniline and NMP mixture is 30 min to 40 min.

[0066] In other embodiments, in step S1021 above, the mass-to-volume ratio of polyaniline to NMP in the polyaniline-NMP mixture is 2 mg: (1 ml to 2 ml).

[0067] In other embodiments, in step S1021 above, the NMP mixture of sodium borohydride is added to the NMP mixture of polyaniline over a time of 15 min to 20 min.

[0068] In other embodiments, in step S1022 above, the constant temperature in the isothermal holding reaction is 60°C to 70°C.

[0069] In other embodiments, in step S1022 above, the isothermal holding reaction time is 4h to 6h.

[0070] In other embodiments, obtaining modified polyaniline in step S1022 above includes the following steps: s10. Mix the reaction solution obtained after constant temperature reaction with methanol to obtain crude modified polyaniline.

[0071] s20. After washing the crude modified polyaniline with methanol, it was washed with water until neutral and then vacuum dried to constant weight to obtain pure modified polyaniline.

[0072] In the above process for obtaining modified polyaniline, the reaction solution and methanol are mixed to precipitate the crude modified polyaniline product. The precipitate is washed with methanol to remove NMP and organic byproducts, and then washed with water to remove impurities such as borates from the precipitate.

[0073] In some embodiments, in step s10 above, the volume ratio of the reaction solution to methanol is 1:(3.6~4).

[0074] In some embodiments, the methanol washing is performed 3 to 4 times in step s20 above.

[0075] In some embodiments, in step s20 above, the temperature of vacuum drying is 50°C to 60°C.

[0076] In some embodiments, the method for preparing porous alumina ceramics further includes the following steps: S20. Prepare the coating layer.

[0077] In some embodiments, in step S20 above, preparing the coating layer includes the following steps: S201. A silicon oxide coating layer is deposited on the surface of a porous ceramic substrate using plasma-enhanced chemical vapor deposition (PECVD).

[0078] In some embodiments, in step S201 above, the silicon source in plasma-enhanced chemical vapor deposition includes hexamethyldisiloxane ((CH3)3SiOSi(CH3)3, HMDSO).

[0079] In some embodiments, in step S201 above, the oxygen source in plasma-enhanced chemical vapor deposition includes oxygen plasma.

[0080] In some embodiments, in step S201 above, the volume ratio of HMDSO to O2 in plasma-enhanced chemical vapor deposition is 1:(10~18).

[0081] In some embodiments, in step S201 above, the carrier gas in plasma-enhanced chemical vapor deposition is helium or argon.

[0082] In some embodiments, in step S201 above, the volume percentage of the carrier gas in plasma-enhanced chemical vapor deposition is 50% to 80%.

[0083] In some embodiments, in step S201 above, the deposition temperature in plasma-enhanced chemical vapor deposition is 150°C to 200°C.

[0084] In some embodiments, in step S201 above, the deposition time in plasma-enhanced chemical vapor deposition is 5 min to 10 min.

[0085] In some embodiments, a method for preparing the above-mentioned porous alumina ceramic is provided, comprising the following steps: S11. Prepare a porous ceramic matrix.

[0086] S21. Prepare the coating layer.

[0087] A third aspect of the present invention provides a semiconductor vacuum chuck, such as... Figure 1 As shown, the material includes the aforementioned porous alumina ceramic.

[0088] The following description, in conjunction with specific embodiments, provides further details.

[0089] Example 1 Example 1 provides a porous alumina ceramic, which is composed of a porous ceramic matrix; The porous ceramic matrix is ​​composed of the following raw materials in parts by weight: 100 parts alumina, 15 parts polyaniline, 15 parts dopamine, 4 parts cycloborane and 3 parts zirconium oxide; The average particle size of zirconium oxide is 50 nm.

[0090] This embodiment also provides a method for preparing porous alumina ceramics, the steps of which are as follows: E10. Alumina, polyaniline, dopamine, hexacycloborane, and zirconium oxide are mixed and ball-milled to obtain a mixed raw material.

[0091] E20. Press the mixed raw materials to obtain a pressed body; The pressing pressure was 10 MPa and the pressing time was 10 min.

[0092] E30. Under a nitrogen atmosphere, the pressed body is subjected to low-temperature sintering and high-temperature sintering to produce a porous ceramic matrix, namely the porous alumina ceramic of this embodiment. The low-temperature sintering step is as follows: the temperature is raised to 400℃ at a heating rate of 25℃ / min and then held for 2 hours. The high-temperature sintering process is as follows: the temperature is increased from 400℃ to 1700℃ at a heating rate of 20℃ / min, and then held at that temperature for 1 hour.

[0093] Example 2 Example 2 provides a porous alumina ceramic, which is composed of a porous ceramic matrix; The porous ceramic matrix is ​​composed of the following raw materials in parts by weight: 100 parts alumina, 10 parts polyaniline, 20 parts dopamine, 3 parts cycloborane, and 5 parts zirconium oxide; The average particle size of zirconium oxide is 70 nm.

[0094] This embodiment also provides a method for preparing porous alumina ceramics, the steps of which are basically the same as those in Example 1, except that: In step E30, the low-temperature sintering step is as follows: the temperature is increased to 500℃ at a heating rate of 30℃ / min and then held for 1 hour. The high-temperature sintering process is as follows: the temperature is increased from 500℃ to 1800℃ at a heating rate of 25℃ / min, and then held at that temperature for 2 hours.

[0095] Example 3 Example 3 provides a porous alumina ceramic, which is composed of a porous ceramic matrix; The porous ceramic matrix is ​​composed of the following raw materials in parts by weight: 100 parts alumina, 20 parts polyaniline, 20 parts dopamine, 3 parts cycloborane and 4 parts zirconium oxide; The average particle size of zirconium oxide is 60 nm.

[0096] This embodiment also provides a method for preparing porous alumina ceramics, the steps of which are basically the same as those in Example 1, except that: In step E30, the low-temperature sintering step is as follows: the temperature is increased to 300℃ at a heating rate of 20℃ / min and then held for 2 hours. The high-temperature sintering process is as follows: the temperature is increased from 200℃ to 1600℃ at a heating rate of 30℃ / min, and then held at that temperature for 2 hours.

[0097] Example 4 Example 4 provides a porous alumina ceramic, which is composed of a porous ceramic matrix and a silica coating layer covering the surface of the ceramic matrix; The porous ceramic matrix is ​​composed of the following raw materials in parts by weight: 100 parts alumina, 15 parts polyaniline, 10 parts dopamine, 5 parts cycloborane, and 5 parts zirconium oxide; The average particle size of zirconium oxide is 50 nm.

[0098] This embodiment also provides a method for preparing porous alumina ceramics, the steps of which are as follows: E14. Alumina, polyaniline, dopamine, hexacyclohexane, and zirconium oxide are mixed and ball-milled to obtain a mixed raw material.

[0099] E24. Press the mixed raw materials to obtain a pressed body; The pressing pressure was 8 MPa and the pressing time was 15 min.

[0100] E34. Under a nitrogen atmosphere, the pressed body is subjected to low-temperature sintering and high-temperature sintering to produce a porous ceramic matrix; The low-temperature sintering step is as follows: the temperature is raised to 500℃ at a heating rate of 20℃ / min and then held for 1 hour. The high-temperature sintering process is as follows: the temperature is increased from 500℃ to 1800℃ at a heating rate of 30℃ / min, and then held at that temperature for 2 hours.

[0101] E44. A silicon oxide coating layer is deposited on the surface of a porous ceramic substrate using plasma-enhanced chemical vapor deposition. In the plasma-enhanced chemical vapor deposition method, the silicon source is hexamethyldisiloxane, the oxygen source is oxygen plasma, the deposition temperature is 180℃, the volume ratio of helium (carrier gas) is 60%, the volume ratio of HMDSO to O2 is 1:15, and the deposition time is 8 min.

[0102] Example 5 Example 5 provides a porous alumina ceramic, which is composed of a porous ceramic matrix and an alumina coating layer covering the surface of the ceramic matrix; The porous ceramic matrix is ​​composed of the following raw materials in parts by weight: 100 parts alumina, 10 parts polyaniline, 10 parts dopamine, 3 parts cycloborane and 3 parts zirconium oxide; The average particle size of zirconium oxide is 60 nm.

[0103] This embodiment also provides a method for preparing the porous alumina ceramic provided in this embodiment. The steps are basically the same as those in Example 4, except that: In step E44, in the plasma-enhanced chemical vapor deposition method, the silicon source is hexamethyldisiloxane, the oxygen source is oxygen plasma, the deposition temperature is 200℃, the volume ratio of helium (carrier gas) is 80%, the volume ratio of HMDSO to O2 is 1:10, and the deposition time is 8 min.

[0104] Example 6 Example 6 provides a porous alumina ceramic, which is composed of a porous ceramic matrix and an alumina coating layer covering the surface of the ceramic matrix; The porous ceramic matrix is ​​composed of the following raw materials in parts by weight: 100 parts alumina, 12 parts polyaniline, 15 parts dopamine, 4 parts cycloborane, and 4 parts zirconium oxide; The average particle size of zirconium oxide is 60 nm.

[0105] This embodiment also provides a method for preparing the porous alumina ceramic provided in this embodiment. The steps are basically the same as those in Example 4, except that: In step E44, in the plasma-enhanced chemical vapor deposition method, the silicon source is hexamethyldisiloxane, the oxygen source is oxygen plasma, the deposition temperature is 150℃, the volume ratio of helium (carrier gas) is 50%, the volume ratio of HMDSO to O2 is 1:18, and the deposition time is 5 min.

[0106] Example 7 Example 7 provides a porous alumina ceramic, which is composed of a porous ceramic matrix; The porous ceramic matrix is ​​composed of the following raw materials in parts by weight: 100 parts alumina, 15 parts modified polyaniline, 15 parts dopamine, 4 parts cycloborane and 3 parts zirconium oxide; The average particle size of zirconium oxide is 50 nm; The raw materials for preparing modified polyaniline are sodium borohydride and polyaniline, with a molar ratio of sodium borohydride to polyaniline repeating units of 3:1.

[0107] This embodiment also provides a method for preparing porous alumina ceramics, the steps of which are as follows: E17. Preparation of modified polyaniline: E171. Preparation of sodium borohydride-NMP mixture: Sodium borohydride and NMP were mixed at a mass-to-volume ratio of 3 mg: 1 ml to obtain sodium borohydride-NMP mixture; wherein, the NMP was pre-degassed and dried NMP.

[0108] E172. Preparation of NMP mixture of polyaniline: Under ice-water bath and nitrogen protection, polyaniline and NMP were mixed and sonicated for 30 min at a mass-to-volume ratio of 2 mg: 1 ml to obtain NMP mixture of polyaniline.

[0109] E173. Preparation of the mixed reaction solution: Under stirring and nitrogen atmosphere, the NMP mixture of sodium borohydride was added dropwise to the NMP mixture of polyaniline to obtain the mixed reaction solution. The addition time was 15 min.

[0110] E174. Constant temperature reaction: The mixed reaction solution is kept at 60°C for 4 hours with stirring.

[0111] E175. Obtaining modified polyaniline: (1) The reaction solution obtained after constant temperature reaction is mixed with methanol to obtain crude modified polyaniline, wherein the volume ratio of reaction solution to methanol is 1:3.7.

[0112] (2) After washing the crude modified polyaniline with methanol four times, it was washed with water until neutral and then vacuum dried at 50°C to constant weight to obtain pure modified polyaniline.

[0113] E27. Alumina, modified polyaniline, dopamine, hexacycloborane and zirconium oxide are mixed and then ball-milled to obtain a mixed raw material.

[0114] E37. Press the mixed raw materials to obtain a pressed body; The pressing pressure was 10 MPa and the pressing time was 10 min.

[0115] E47. Under a nitrogen atmosphere, the pressed body is subjected to low-temperature sintering and high-temperature sintering to produce a porous ceramic matrix, namely the porous alumina ceramic of this embodiment. The low-temperature sintering step is as follows: the temperature is raised to 400℃ at a heating rate of 25℃ / min and then held for 2 hours. The high-temperature sintering process is as follows: the temperature is increased from 400℃ to 1700℃ at a heating rate of 20℃ / min, and then held at that temperature for 1 hour.

[0116] Comparative Example 1 Comparative Example 1 provides an alumina ceramic, composed of the following raw materials in parts by weight: 100 parts alumina, 15 parts polyaniline, 15 parts dopamine, and 3 parts zirconium oxide; The average particle size of zirconium oxide is 50 nm.

[0117] This comparative example also provides a method for preparing alumina ceramics, the steps of which are as follows: D10. Alumina, polyaniline, dopamine and zirconium oxide are mixed and then pressed to obtain a pressed body; The pressing pressure was 10 MPa and the pressing time was 10 min.

[0118] D20. Under a nitrogen atmosphere, the pressed body was sintered at 1700℃ for 3 hours to obtain alumina ceramic.

[0119] Comparative Example 2 Comparative Example 2 provides an alumina ceramic, composed of the following raw materials in parts by weight: 100 parts alumina, 15 parts polyaniline, 4 parts cycloborane, and 3 parts zirconium oxide; The average particle size of zirconium oxide is 50 nm.

[0120] This comparative example also provides a method for preparing alumina ceramics, with the same steps as in Comparative Example 1.

[0121] Comparative Example 3 Comparative Example 3 provides an alumina ceramic, composed of the following raw materials in parts by weight: 100 parts alumina, 15 parts dopamine, 4 parts cycloborane, and 3 parts zirconium oxide; The average particle size of zirconium oxide is 50 nm.

[0122] This comparative example also provides a method for preparing alumina ceramics, with the same steps as in Comparative Example 1.

[0123] To verify the advancement of the porous alumina ceramic and its preparation method provided in this invention, the pore size distribution of the ceramics provided in the embodiments and comparative examples was detected using scanning electron microscopy. The results are shown in Table 1 below. The microstructure of the ceramic in Example 1 is as follows: Figure 2 As shown in Table 1, the flexural strength of the ceramics provided in the examples and comparative examples was tested according to standard GB / T 6569, and the results are shown in Table 1 below. The thermal conductivity of the ceramics provided in the examples and comparative examples was tested according to standard GB / T 5990, and the results are shown in Table 1 below.

[0124]

[0125] From the table above and the accompanying drawings in the instruction manual, at least the following conclusions can be drawn: (1) The method for preparing porous alumina ceramics provided in the embodiments of the present invention has an average pore size of 90μm~120μm. Within this pore size range, the porous alumina ceramics have excellent bending strength (mechanical strength) and thermal conductivity.

[0126] (2) In the preparation method of porous alumina ceramic provided in the embodiments of the present invention, low-temperature sintering and high-temperature sintering are adopted. Low-temperature sintering decomposes polyaniline, dopamine and cycloborane to create pores; high-temperature sintering completely decomposes the intermediates of residual polyaniline, dopamine and cycloborane, and carbonizes the residual carbon elements, thereby improving the mechanical strength of the ceramic.

[0127] It should be noted that the present invention is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments that have the same structure and perform the same effects as the technical concept within the scope of the present invention are included within the scope of the present invention. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of the present invention, are also included within the scope of the present invention.

Claims

1. A porous alumina ceramic, characterized by, The porous ceramic matrix comprises: The porous ceramic matrix comprises raw materials in the following proportions by weight: 100 parts of alumina, 10-20 parts of polyaniline, 10-20 parts of dopamine, 3-5 parts of cyclotriborazane, and 3-5 parts of zirconia.

2. The porous alumina ceramic of claim 1, wherein, The average pore size of the porous ceramic matrix is 90-120 μm.

3. The porous alumina ceramic according to claim 1 or 2, characterized in that, The porous alumina ceramic further comprises a coating layer coated on the surface of the ceramic matrix.

4. The porous alumina ceramic of claim 3, wherein, The coating layer satisfies at least one of the following conditions (1) and (2): (1) the material of the coating layer comprises silicon oxide; (2) the thickness of the coating layer is 50-100 nm.

5. A method for producing a porous alumina ceramic as claimed in any one of claims 1 to 4, characterized in that, The method comprises the following steps: Preparation of the porous ceramic matrix.

6. The method of claim 5, wherein the porous alumina ceramic is prepared by a method comprising: The preparation of the porous ceramic matrix comprises the following steps: pressing and sintering of the mixed raw materials; The mixed raw materials comprise alumina, polyaniline, dopamine, cyclotriborazane, and zirconia.

7. The method of claim 6, wherein the porous alumina ceramic is prepared by a method comprising: At least one of the following conditions (1)-(3) is satisfied: (1) the pressure of the pressing is 8-12 MPa; (2) the time of the pressing is 12-15 min; (3) the sintering comprises the following steps: low-temperature sintering and high-temperature sintering under a nitrogen atmosphere.

8. The method of claim 7, wherein the porous alumina ceramic is prepared by a method comprising: At least one of the following conditions (1)-(2) is satisfied: (1) the step of the low-temperature sintering comprises the following steps: heating to 300-500 °C at a heating rate of 20-30 °C / min and then holding; (2) the step of the high-temperature sintering comprises the following steps: heating from 300-500 °C to 1600-1800 °C at a heating rate of 20-30 °C / min and then holding.

9. A semiconductor vacuum chuck, characterized by The material comprises the porous alumina ceramic according to any one of claims 1-4.

10. Use of the porous alumina ceramic according to any one of claims 1-4 in the field of semiconductor manufacturing or electronic packaging.

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