Aluminum nitride ceramic substrate and preparation method thereof

Abstract

The invention relates to an aluminum nitride ceramic substrate and a preparation method thereof, and belongs to the technical field of aluminum nitride ceramic substrate preparation, and the aluminum nitride ceramic substrate is prepared by the following steps: mixing modified aluminum nitride powder with zirconium oxide powder and yttrium oxide powder, carrying out ball milling to prepare slurry, adding an organic medium, and sintering to obtain the aluminum nitride ceramic substrate. The preparation method comprises the following steps: firstly preparing raw materials, then preparing a biscuit through tape casting and glue discharging treatment, then sintering the biscuit at high temperature to prepare a semi-finished product, and finally carrying out post-treatment on the semi-finished product to prepare the high-temperature-resistant high-strength wear-resistant ceramic tile, which comprises the following steps: step 1, preparing and modifying the raw materials; step 2, ball-milling and pulping; step 3, tape casting; 4, glue discharging and high-temperature sintering; in the preparation process, the content of organic matters in the aluminum nitride ceramic substrate can be reduced by changing the temperature and time during glue discharging, so that the thermal conductivity, the bending strength and the fracture toughness of the aluminum nitride ceramic substrate are improved.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum nitride ceramic substrate preparation, and in particular to an aluminum nitride ceramic substrate and a preparation method thereof. Background Art

[0002] Aluminum nitride ceramic substrate is a new type of high-performance integrated circuit substrate material. The thermal conductivity of aluminum nitride ceramic substrate ranges from 170 to 320W / m·K, which is 5-10 times higher than that of traditional alumina substrate. This high thermal conductivity enables it to quickly dissipate heat in high-performance electronic systems, effectively improving the efficiency and life of electronic equipment. Aluminum nitride ceramics have a thermal conductivity of more than 10 at room temperature. 13 The high resistivity of Ohm cm gives it excellent electrical insulation performance, which can effectively prevent circuit short circuits and improve the overall safety of electronic equipment. Aluminum nitride ceramics can maintain their strength and stability at temperatures as high as 1000°C. This refractory property enables it to operate reliably under extreme temperature conditions without deformation or deterioration. Aluminum nitride ceramics are highly tolerant to a variety of chemicals and can remain stable in strong acid and alkali environments. This chemical resistance enables it to still work stably in corrosive environments. Aluminum nitride ceramic substrates are light in weight and compact in structure, which helps to reduce the total weight of electronic equipment. Therefore, aluminum nitride ceramic substrates have become indispensable materials in the fields of electronics, optoelectronics, and aerospace. However, the existing aluminum nitride ceramic substrates have different preparation methods and preparation conditions for high-temperature sintering during preparation, which will affect the parameters of the aluminum nitride ceramic substrates. In view of this, the present invention is specially proposed. Summary of the invention

[0003] In order to overcome the technical defects of the prior art, the present invention provides an aluminum nitride ceramic substrate and a preparation method thereof, which has good thermal conductivity, flexural strength and fracture toughness. By changing the temperature and time during debinding, the content of organic matter in the aluminum nitride ceramic substrate can be reduced, thereby improving the thermal conductivity, flexural strength and fracture toughness of the aluminum nitride ceramic substrate.

[0004] The technical solution adopted by the present invention is: an aluminum nitride ceramic substrate, which is prepared by mixing modified aluminum nitride powder with zirconium oxide powder and yttrium oxide powder, ball-milling the slurry, adding an organic medium, then forming a blank through tape casting and debinding treatment, then sintering the blank at high temperature to form a semi-finished product, and finally post-processing the semi-finished product.

[0005] A method for preparing an aluminum nitride ceramic substrate comprises the following steps: Step 1: Raw material preparation and modification: Aluminum compounds are reacted with carbon and nitrogen at high temperature to form aluminum nitride powder, thereby completing the modification, and then the modified aluminum nitride powder is mixed with zirconium oxide powder and yttrium oxide powder in a certain proportion for secondary modification; Step 2, ball milling: putting the raw materials into a ball mill, adding carbon black, aluminum oxide, lanthanum chloride and ethanol for high-speed ball milling and mixing, thereby completing the preparation of a mixed slurry, then adding random polypropylene and polymethacrylate to the mixed slurry, and then mixing and stirring to obtain a casting slurry; Step 3, tape casting: the prepared tape casting slurry is made into a green body through a tape casting process, and then cut into ceramic green bodies of required size; Step 4: debinding and high-temperature sintering: removing organic matter from the ceramic green body to complete the debinding process, and then subjecting the debinded ceramic green body to high-temperature hot pressing sintering to complete the production of the aluminum nitride ceramic substrate; Step 5: Post-processing and evaluation: Post-process the finished aluminum nitride ceramic substrate to meet application requirements, and sample the processed aluminum nitride ceramic substrate for performance evaluation to ensure that it meets the application standards of electronic devices.

[0006] Furthermore: In order to complete the modification of the raw materials and improve the densification during the sintering process, the aluminum compound in the step one is aluminum oxide, and aluminum oxide, carbon and nitrogen are reacted at a ratio of 1:3:1 at a temperature of 1600°C-1800°C for 5-6 hours to prepare aluminum nitride powder, and the prepared aluminum nitride powder is mixed with zirconium oxide powder and yttrium oxide powder in a weight ratio of 92:5:3 to complete the secondary modification.

[0007] Further: In order to change the flow properties of the casting slurry and facilitate subsequent casting molding, the aluminum nitride mixed powder prepared in the step one is added to a ball mill with carbon black, aluminum oxide, and lanthanum oxide in a ratio of 1:0.4:0.05, and then an appropriate amount of ethanol is added to the ball mill, followed by initial ball milling for 8-12 hours to complete the preparation of the mixed slurry, and then random polypropylene and polymethacrylate are added to the mixed slurry, the ratio of the mixed slurry, random polypropylene and polymethacrylate is 100:3:2, and then ball milling is performed for 6-10 hours to complete the preparation of the casting slurry.

[0008] Furthermore: In order to fix the casting slurry and facilitate subsequent debinding and sintering, the casting slurry prepared in the step 2 is placed in a vacuum degassing machine with a stirring speed of 30-80r / min and a degassing time of 8-30 minutes for degassing treatment, and then the degassing casting slurry is evenly coated on a carrier, and then the carrier transports the casting slurry to a drying area, where the casting slurry is dried, thereby completing the preparation of the ceramic green body, and then the ceramic green body is removed from the carrier.

[0009] Further: In order to remove organic matter in the ceramic green body and thus improve the performance of the aluminum nitride ceramic substrate, the ceramic green body prepared in the step three is placed in a nitrogen atmosphere, then gradually heated to 290°C-320°C and kept warm for 1-2 hours, then the temperature is increased to 530°C-550°C, and kept warm for 3-5 hours, then the temperature is reduced to 190°C-210°C and kept warm for 1-2 hours, then the temperature is adjusted to 480°C-500°C, then the nitrogen is converted to air, and kept warm for 1-2 hours, and finally the product is taken out for natural cooling.

[0010] Further: in order to complete the sintering of the aluminum nitride ceramic substrate, the green blank after the binder removal in the step 4 is placed in a hot pressing sintering device for hot pressing sintering. The hot pressing sintering temperature is 1600°C-2000°C. After the sintering is completed, it is cooled to complete the preparation of the aluminum nitride ceramic substrate.

[0011] Further: In order to ensure the quality of the aluminum nitride ceramic substrate, the aluminum nitride ceramic substrate prepared in step 4 is post-processed by grinding, cutting and surface polishing, and then the post-processed aluminum nitride ceramic substrate is sampled and evaluated to determine parameters such as thermal conductivity, bending strength and fracture toughness to ensure compliance with application standards for electronic devices.

[0012] The beneficial effects of the present invention are: by changing the temperature and time during debinding, the content of organic matter in the aluminum nitride ceramic substrate can be reduced, thereby improving the thermal conductivity, bending strength and fracture toughness of the aluminum nitride ceramic substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a preparation flow chart of the present invention; Figure 2 This is a comparative table of embodiments of the present invention. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with the accompanying drawings: like Figure 1-Figure 2 As shown, this embodiment provides an aluminum nitride ceramic substrate and a preparation method thereof. The aluminum nitride ceramic substrate is prepared by mixing modified aluminum nitride powder with zirconium oxide powder and yttrium oxide powder, ball-milling the mixture into a slurry, adding an organic medium, and then forming a green blank through tape casting and debinding treatment. The green blank is then sintered at a high temperature to form a semi-finished product, and finally the semi-finished product is post-processed and prepared.

[0015] A method for preparing an aluminum nitride ceramic substrate comprises the following steps: Step 1: Raw material preparation and modification: Aluminum compounds are reacted with carbon and nitrogen at high temperature to form aluminum nitride powder, thereby completing the modification, and then the modified aluminum nitride powder is mixed with zirconium oxide powder and yttrium oxide powder in a certain proportion for secondary modification; Step 2, ball milling: putting the raw materials into a ball mill, adding carbon black, aluminum oxide, lanthanum chloride and ethanol for high-speed ball milling and mixing, thereby completing the preparation of a mixed slurry, then adding random polypropylene and polymethacrylate to the mixed slurry, and then mixing and stirring to obtain a casting slurry; Step 3, tape casting: the prepared tape casting slurry is made into a green body through a tape casting process, and then cut into ceramic green bodies of required size; Step 4: debinding and high-temperature sintering: removing organic matter from the ceramic green body to complete the debinding process, and then subjecting the debinded ceramic green body to high-temperature hot pressing sintering to complete the production of the aluminum nitride ceramic substrate; Step 5: Post-processing and evaluation: Post-process the finished aluminum nitride ceramic substrate to meet application requirements, and sample the processed aluminum nitride ceramic substrate for performance evaluation to ensure that it meets the application standards of electronic devices.

[0016] Embodiment 1 The aluminum compound in step one is aluminum oxide. Aluminum oxide, carbon and nitrogen are reacted at a ratio of 1:3:1 at a temperature of 1600°C-1800°C for 5-6 hours to produce aluminum nitride powder. The produced aluminum nitride powder is mixed with zirconium oxide powder and yttrium oxide powder in a weight ratio of 92:5:3 to complete secondary modification.

[0017] The aluminum nitride mixed powder prepared in step one is added to a ball mill with carbon black, aluminum oxide, and lanthanum oxide in a ratio of 1:0.4:0.05, and then an appropriate amount of ethanol is added to the ball mill, followed by initial ball milling for 8-12 hours to complete the preparation of a mixed slurry, and then random polypropylene and polymethacrylate are added to the mixed slurry, the ratio of the mixed slurry, random polypropylene and polymethacrylate is 100:3:2, and then ball milling is performed for 6-10 hours to complete the preparation of the casting slurry.

[0018] The casting slurry prepared in step 2 is placed in a vacuum degassing machine with a stirring speed of 30-80r / min and a degassing time of 8-30 minutes for degassing treatment. Subsequently, the degassing casting slurry is evenly coated on a carrier tape, and then the carrier tape transports the casting slurry to a drying area, where the casting slurry is dried to complete the preparation of the ceramic green body, and then the ceramic green body is removed from the carrier tape.

[0019] Place the ceramic green body prepared in step 3 in a nitrogen atmosphere, then gradually heat it to 290°C and keep it for 1 hour, then raise the temperature to 530°C and keep it for 3 hours, then reduce the temperature to 190°C and keep it for 1 hour, then adjust the temperature to 480°C, then convert the nitrogen to air and keep it for 1 hour, finally take out the product for natural cooling.

[0020] The green blank after debinding in step 4 is placed in a hot pressing and sintering device for hot pressing and sintering at a temperature of 1600° C.-2000° C. After sintering, it is cooled to complete the preparation of the aluminum nitride ceramic substrate.

[0021] The aluminum nitride ceramic substrate prepared in step 4 is post-processed by grinding, cutting and surface polishing, and then the post-processed aluminum nitride ceramic substrate is sampled and evaluated to determine parameters such as thermal conductivity, flexural strength and fracture toughness to ensure that it meets the application standards of electronic devices. At this time, the thermal conductivity of the aluminum nitride ceramic substrate is 170 W / m·K, the flexural strength is 300 MPa, and the fracture toughness is 2.0MPa·m 1 / 2 .

[0022] Embodiment 2 The aluminum compound in step one is aluminum oxide. Aluminum oxide, carbon and nitrogen are reacted at a ratio of 1:3:1 at a temperature of 1600°C-1800°C for 5-6 hours to produce aluminum nitride powder. The produced aluminum nitride powder is mixed with zirconium oxide powder and yttrium oxide powder in a weight ratio of 92:5:3 to complete secondary modification.

[0023] The aluminum nitride mixed powder prepared in step one is added to a ball mill with carbon black, aluminum oxide, and lanthanum oxide in a ratio of 1:0.4:0.05, and then an appropriate amount of ethanol is added to the ball mill, followed by initial ball milling for 8-12 hours to complete the preparation of a mixed slurry, and then random polypropylene and polymethacrylate are added to the mixed slurry, the ratio of the mixed slurry, random polypropylene and polymethacrylate is 100:3:2, and then ball milling is performed for 6-10 hours to complete the preparation of the casting slurry.

[0024] The casting slurry prepared in step 2 is placed in a vacuum degassing machine with a stirring speed of 30-80r / min and a degassing time of 8-30 minutes for degassing treatment. Subsequently, the degassing casting slurry is evenly coated on a carrier tape, and then the carrier tape transports the casting slurry to a drying area, where the casting slurry is dried to complete the preparation of the ceramic green body, and then the ceramic green body is removed from the carrier tape.

[0025] Place the ceramic green body prepared in step three in a nitrogen atmosphere, then gradually heat it to 295°C and keep it for 1.2 hours, then raise the temperature to 535°C and keep it for 3.5 hours, then reduce the temperature to 195°C and keep it for 1.2 hours, then adjust the temperature to 485°C, then convert the nitrogen to air and keep it for 1.2 hours, and finally take out the product for natural cooling.

[0026] The green blank after debinding in step 4 is placed in a hot pressing and sintering device for hot pressing and sintering at a temperature of 1600° C.-2000° C. After sintering, it is cooled to complete the preparation of the aluminum nitride ceramic substrate.

[0027] The aluminum nitride ceramic substrate prepared in step 4 is post-processed by grinding, cutting and surface polishing, and then the post-processed aluminum nitride ceramic substrate is sampled and evaluated to determine parameters such as thermal conductivity, flexural strength and fracture toughness to ensure that it meets the application standards of electronic devices. At this time, the thermal conductivity of the aluminum nitride ceramic substrate is 180W / m·K, the flexural strength is 340 MPa, and the fracture toughness is 2.2MPa·m 1 / 2 .

[0028] Embodiment 3 The aluminum compound in step one is aluminum oxide. Aluminum oxide, carbon and nitrogen are reacted at a ratio of 1:3:1 at a temperature of 1600°C-1800°C for 5-6 hours to produce aluminum nitride powder. The produced aluminum nitride powder is mixed with zirconium oxide powder and yttrium oxide powder in a weight ratio of 92:5:3 to complete secondary modification.

[0029] The aluminum nitride mixed powder prepared in step one is added to a ball mill with carbon black, aluminum oxide, and lanthanum oxide in a ratio of 1:0.4:0.05, and then an appropriate amount of ethanol is added to the ball mill, followed by initial ball milling for 8-12 hours to complete the preparation of a mixed slurry, and then random polypropylene and polymethacrylate are added to the mixed slurry, the ratio of the mixed slurry, random polypropylene and polymethacrylate is 100:3:2, and then ball milling is performed for 6-10 hours to complete the preparation of the casting slurry.

[0030] The casting slurry prepared in step 2 is placed in a vacuum degassing machine with a stirring speed of 30-80r / min and a degassing time of 8-30 minutes for degassing treatment. Subsequently, the degassing casting slurry is evenly coated on a carrier tape, and then the carrier tape transports the casting slurry to a drying area, where the casting slurry is dried to complete the preparation of the ceramic green body, and then the ceramic green body is removed from the carrier tape.

[0031] The ceramic green body prepared in step three is placed in a nitrogen atmosphere, and then gradually heated to 300°C and kept warm for 1.4 hours, then raised to 540°C and kept warm for 3.8 hours, then lowered to 200°C and kept warm for 1.4 hours, then adjusted to 490°C, then converted nitrogen to air and kept warm for 1.4 hours, and finally the product is taken out for natural cooling.

[0032] The green blank after debinding in step 4 is placed in a hot pressing and sintering device for hot pressing and sintering at a temperature of 1600° C.-2000° C. After sintering, it is cooled to complete the preparation of the aluminum nitride ceramic substrate.

[0033] The aluminum nitride ceramic substrate prepared in step 4 is post-processed by grinding, cutting and surface polishing, and then the post-processed aluminum nitride ceramic substrate is sampled and evaluated to determine parameters such as thermal conductivity, flexural strength and fracture toughness to ensure that it meets the application standards of electronic devices. At this time, the thermal conductivity of the aluminum nitride ceramic substrate is 190 W / m·K, the flexural strength is 370 MPa, and the fracture toughness is 2.4 MPa·m 1 / 2 .

[0034] Embodiment 4 The aluminum compound in step one is aluminum oxide. Aluminum oxide, carbon and nitrogen are reacted at a ratio of 1:3:1 at a temperature of 1600°C-1800°C for 5-6 hours to produce aluminum nitride powder. The produced aluminum nitride powder is mixed with zirconium oxide powder and yttrium oxide powder in a weight ratio of 92:5:3 to complete secondary modification.

[0035] The aluminum nitride mixed powder prepared in step one is added to a ball mill with carbon black, aluminum oxide, and lanthanum oxide in a ratio of 1:0.4:0.05, and then an appropriate amount of ethanol is added to the ball mill, followed by initial ball milling for 8-12 hours to complete the preparation of a mixed slurry, and then random polypropylene and polymethacrylate are added to the mixed slurry, the ratio of the mixed slurry, random polypropylene and polymethacrylate is 100:3:2, and then ball milling is performed for 6-10 hours to complete the preparation of the casting slurry.

[0036] The casting slurry prepared in step 2 is placed in a vacuum degassing machine with a stirring speed of 30-80r / min and a degassing time of 8-30 minutes for degassing treatment. Subsequently, the degassing casting slurry is evenly coated on a carrier tape, and then the carrier tape transports the casting slurry to a drying area, where the casting slurry is dried to complete the preparation of the ceramic green body, and then the ceramic green body is removed from the carrier tape.

[0037] The ceramic green body prepared in step three is placed in a nitrogen atmosphere, and then gradually heated to 305°C and kept warm for 1.6 hours, then raised to 543°C and kept warm for 4 hours, then lowered to 203°C and kept warm for 1.6 hours, then adjusted to 193°C, then converted nitrogen to air and kept warm for 1.6 hours, and finally the product was taken out for natural cooling.

[0038] The green blank after debinding in step 4 is placed in a hot pressing and sintering device for hot pressing and sintering at a temperature of 1600° C.-2000° C. After sintering, it is cooled to complete the preparation of the aluminum nitride ceramic substrate.

[0039] The aluminum nitride ceramic substrate prepared in step 4 is post-processed by grinding, cutting and surface polishing, and then the post-processed aluminum nitride ceramic substrate is sampled and evaluated to determine parameters such as thermal conductivity, flexural strength and fracture toughness to ensure that it meets the application standards of electronic devices. At this time, the thermal conductivity of the aluminum nitride ceramic substrate is 185 W / m·K, the flexural strength is 400 MPa, and the fracture toughness is 2.6MPa·m 1 / 2 .

[0040] Embodiment 5 The aluminum compound in step one is aluminum oxide. Aluminum oxide, carbon and nitrogen are reacted at a ratio of 1:3:1 at a temperature of 1600°C-1800°C for 5-6 hours to produce aluminum nitride powder. The produced aluminum nitride powder is mixed with zirconium oxide powder and yttrium oxide powder in a weight ratio of 92:5:3 to complete secondary modification.

[0041] The aluminum nitride mixed powder prepared in step one is added to a ball mill with carbon black, aluminum oxide, and lanthanum oxide in a ratio of 1:0.4:0.05, and then an appropriate amount of ethanol is added to the ball mill, followed by initial ball milling for 8-12 hours to complete the preparation of a mixed slurry, and then random polypropylene and polymethacrylate are added to the mixed slurry, the ratio of the mixed slurry, random polypropylene and polymethacrylate is 100:3:2, and then ball milling is performed for 6-10 hours to complete the preparation of the casting slurry.

[0042] The casting slurry prepared in step 2 is placed in a vacuum degassing machine with a stirring speed of 30-80r / min and a degassing time of 8-30 minutes for degassing treatment. Subsequently, the degassing casting slurry is evenly coated on a carrier tape, and then the carrier tape transports the casting slurry to a drying area, where the casting slurry is dried to complete the preparation of the ceramic green body, and then the ceramic green body is removed from the carrier tape.

[0043] The ceramic green body prepared in step three is placed in a nitrogen atmosphere, and then gradually heated to 310°C and kept warm for 1.8 hours, then raised to 545°C and kept warm for 4.3 hours, then lowered to 207°C and kept warm for 1.8 hours, then adjusted to 497°C, then converted nitrogen to air and kept warm for 1.8 hours, and finally the product was taken out for natural cooling.

[0044] The green blank after debinding in step 4 is placed in a hot pressing and sintering device for hot pressing and sintering at a temperature of 1600° C.-2000° C. After sintering, it is cooled to complete the preparation of the aluminum nitride ceramic substrate.

[0045] The aluminum nitride ceramic substrate prepared in step 4 is post-processed by grinding, cutting and surface polishing, and then the post-processed aluminum nitride ceramic substrate is sampled and evaluated to determine parameters such as thermal conductivity, flexural strength and fracture toughness to ensure that it meets the application standards of electronic devices. At this time, the thermal conductivity of the aluminum nitride ceramic substrate is 220 W / m·K, the flexural strength is 450 MPa, and the fracture toughness is 2.8MPa·m 1 / 2 .

[0046] Embodiment 6 The aluminum compound in step one is aluminum oxide. Aluminum oxide, carbon and nitrogen are reacted at a ratio of 1:3:1 at a temperature of 1600°C-1800°C for 5-6 hours to produce aluminum nitride powder. The produced aluminum nitride powder is mixed with zirconium oxide powder and yttrium oxide powder in a weight ratio of 92:5:3 to complete secondary modification.

[0047] The aluminum nitride mixed powder prepared in step one is added to a ball mill with carbon black, aluminum oxide, and lanthanum oxide in a ratio of 1:0.4:0.05, and then an appropriate amount of ethanol is added to the ball mill, followed by initial ball milling for 8-12 hours to complete the preparation of a mixed slurry, and then random polypropylene and polymethacrylate are added to the mixed slurry, the ratio of the mixed slurry, random polypropylene and polymethacrylate is 100:3:2, and then ball milling is performed for 6-10 hours to complete the preparation of the casting slurry.

[0048] The casting slurry prepared in step 2 is placed in a vacuum degassing machine with a stirring speed of 30-80r / min and a degassing time of 8-30 minutes for degassing treatment. Subsequently, the degassing casting slurry is evenly coated on a carrier tape, and then the carrier tape transports the casting slurry to a drying area, where the casting slurry is dried to complete the preparation of the ceramic green body, and then the ceramic green body is removed from the carrier tape.

[0049] Place the ceramic green body prepared in step three in a nitrogen atmosphere, then gradually increase the temperature to 300°C and keep it for 2 hours, then increase the temperature to 550°C and keep it for 5 hours, then reduce the temperature to 210°C and keep it for 2 hours, then adjust the temperature to 500°C, then convert the nitrogen to air and keep it for 2 hours, finally take out the product for natural cooling.

[0050] The green blank after debinding in step 4 is placed in a hot pressing and sintering device for hot pressing and sintering at a temperature of 1600° C.-2000° C. After sintering, it is cooled to complete the preparation of the aluminum nitride ceramic substrate.

[0051] The aluminum nitride ceramic substrate prepared in step 4 is post-processed by grinding, cutting and surface polishing, and then the post-processed aluminum nitride ceramic substrate is sampled and evaluated to determine parameters such as thermal conductivity, flexural strength and fracture toughness to ensure that it meets the application standards of electronic devices. At this time, the thermal conductivity of the aluminum nitride ceramic substrate is 230 W / m·K, the flexural strength is 500 MPa, and the fracture toughness is 3.0MPa·m 1 / 2 .

[0052] In summary, with the increase of debinding temperature and time, the thermal conductivity, flexural strength and fracture toughness of aluminum nitride ceramic substrates also gradually increase. The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An aluminum nitride ceramic substrate, characterized in that: The aluminum nitride ceramic substrate is prepared by mixing modified aluminum nitride powder with zirconium oxide powder and yttrium oxide powder, ball-milling the mixture into slurry, adding an organic medium, and then tape-casting and debinding treatment to form a green blank, then high-temperature sintering the green blank to form a semi-finished product, and finally post-processing the semi-finished product.

2. A method for preparing an aluminum nitride ceramic substrate, according to the method for preparing an aluminum nitride ceramic substrate according to claim 1, characterized in that: The following steps are involved: Step 1: Raw material preparation and modification: Aluminum compounds are reacted with carbon and nitrogen at high temperature to form aluminum nitride powder, thereby completing the modification, and then the modified aluminum nitride powder is mixed with zirconium oxide powder and yttrium oxide powder in a certain proportion for secondary modification; Step 2, ball milling: putting the raw materials into a ball mill, adding carbon black, aluminum oxide, lanthanum chloride and ethanol for high-speed ball milling and mixing, thereby completing the preparation of a mixed slurry, then adding random polypropylene and polymethacrylate to the mixed slurry, and then mixing and stirring to obtain a casting slurry; Step 3, tape casting: the prepared tape casting slurry is made into a green body through a tape casting process, and then cut into ceramic green bodies of required size; Step 4: debinding and high-temperature sintering: removing organic matter from the ceramic green body to complete the debinding process, and then subjecting the debinded ceramic green body to high-temperature hot pressing sintering to complete the production of the aluminum nitride ceramic substrate; Step 5: Post-processing and evaluation: Post-process the finished aluminum nitride ceramic substrate to meet application requirements, and sample the processed aluminum nitride ceramic substrate for performance evaluation to ensure that it meets the application standards of electronic devices.

3. The method for preparing an aluminum nitride ceramic substrate according to claim 2, characterized in that: The aluminum compound in the step 1 is aluminum oxide. Aluminum oxide, carbon and nitrogen are reacted at a ratio of 1:3:1 at a temperature of 1600°C-1800°C for 5-6 hours to prepare aluminum nitride powder. The prepared aluminum nitride powder is mixed with zirconium oxide powder and yttrium oxide powder in a weight ratio of 92:5:3 to complete secondary modification.

4. The method for preparing an aluminum nitride ceramic substrate according to claim 2, characterized in that: The aluminum nitride mixed powder prepared in the step 1 is added to a ball mill in a ratio of 1:0.4:0.05 with carbon black, aluminum oxide, and lanthanum oxide, and then an appropriate amount of ethanol is added to the ball mill, followed by initial ball milling for 8-12 hours to complete the preparation of a mixed slurry, and then random polypropylene and polymethacrylate are added to the mixed slurry, the ratio of the mixed slurry, random polypropylene, and polymethacrylate is 100:3:2, and then ball milling is performed for 6-10 hours to complete the preparation of a casting slurry.

5. The method for preparing an aluminum nitride ceramic substrate according to claim 2, characterized in that: The casting slurry prepared in the step 2 is placed in a vacuum degassing machine with a stirring speed of 30-80r / min and a degassing time of 8-30 minutes for degassing treatment, and then the degassing casting slurry is evenly coated on a carrier tape, and then the carrier tape transports the casting slurry to a drying area, where the casting slurry is dried to complete the preparation of the ceramic green body, and then the ceramic green body is removed from the carrier tape.

6. The method for preparing an aluminum nitride ceramic substrate according to claim 2, characterized in that: The ceramic green body prepared in the step three is placed in a nitrogen atmosphere, and then gradually heated to 290°C-320°C and kept warm for 1-2 hours, then raised to 530°C-550°C and kept warm for 3-5 hours, then lowered to 190°C-210°C and kept warm for 1-2 hours, then adjusted to 480°C-500°C, then converted nitrogen to air, and kept warm for 1-2 hours, and finally the product is taken out for natural cooling.

7. The method for preparing an aluminum nitride ceramic substrate according to claim 2, characterized in that: The green blank after the binder removal in step 4 is placed in a hot pressing and sintering device for hot pressing and sintering at a temperature of 1600° C.-2000° C. After sintering, it is cooled to complete the preparation of the aluminum nitride ceramic substrate.

8. The method for preparing an aluminum nitride ceramic substrate according to claim 2, characterized in that: The aluminum nitride ceramic substrate prepared in step 4 is post-processed by grinding, cutting and surface polishing, and then the post-processed aluminum nitride ceramic substrate is sampled and evaluated to determine parameters such as thermal conductivity, bending strength and fracture toughness to ensure that it meets the application standards of electronic devices.

Images