A method for molybdenum metallization of alumina ceramics

Abstract

The present invention relates to the technical field of ceramic metallization processing, specifically a molybdenum metallization method for alumina ceramics. A molybdenum metallization method for alumina ceramics, comprising the following steps: surface treatment of an alumina ceramic substrate; plating a Ti-Al-Nd-Cr2O3 alloy layer by magnetron sputtering; preparation of a metallization paste; coating and sintering of a metallization paste for a ceramic sheet coated with an alloy layer. The present invention prepares Ti-Al-Nd-Cr2O3 alloy powder and plates it on the surface of a clean ceramic sheet by magnetron sputtering. In the subsequent coating and sintering process of the metallization paste, a more stable oxidation product is formed between the titanium element, the neodymium element and the oxygen atoms of the aluminum oxide, so that the metallization paste is tightly bonded to the ceramic. The dielectric film formed by Cr2O3 and the Cr-Al spinel generated by the reaction with the Al element are then combined to greatly reduce the internal stress of the sintering process, and promote the mutual diffusion migration of the glass phase in the ceramic and the metallization layer, further improving the bonding ability of the metallization paste with the alumina ceramic and making the metallization layer denser.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic metallization processing, in particular to a molybdenum metallization method for alumina ceramics. Background Art

[0002] With the development of semiconductor devices and the electronics manufacturing industry, people have higher requirements for the performance and reliability of semiconductor devices and electronic components, and the packaging of semiconductor devices and electronic components has received more and more attention. Ceramics are widely used in the packaging of semiconductor devices and electronic components, such as alumina ceramics, silicon nitride ceramics, etc. Among them, alumina ceramics were developed the earliest, have the most mature technology, and the lowest cost, and have great advantages in the packaging field.

[0003] In the process of ceramic packaging of semiconductor devices and electronic components, due to the inherent poor sealing ability of ceramics, in most cases the ceramic surface needs to be metallized so that the ceramic can be welded more tightly to the metal parts during the packaging process to ensure the airtightness of the device. Molybdenum-manganese metallization is one of the most commonly used ceramic metallization methods.

[0004] Existing molybdenum-manganese metallization usually involves first preparing a metallizing slurry, then directly applying the metallizing slurry to the ceramic surface, and finally subjecting it to high-temperature treatment to obtain a molybdenum-manganese metallized ceramic. Although various components are added to the metallizing slurry to match the thermal expansion coefficient of the ceramic, during the sintering process, the metallizing slurry cannot bond well with the ceramic due to the high smoothness of the ceramic surface and the fact that only a small portion of the various components added to the metallizing slurry come into contact with the ceramic.

[0005] To solve the above-mentioned process difficulties, the present invention provides a molybdenum metallization method for alumina ceramics, which can make the molybdenum metallization layer denser during the sintering process and the molybdenum metallization layer more tightly bonded to the ceramic, thereby improving the airtightness of the ceramic. Summary of the Invention

[0006] In order to solve the above technical defects, the present invention provides a molybdenum metallization method for alumina ceramics, which can make the molybdenum metallization layer denser during the sintering process and the molybdenum metallization layer more tightly bonded to the ceramic, thereby improving the airtightness of the ceramic.

[0007] A method for molybdenum metallization of alumina ceramics, comprising the following steps:

[0008] S1: Surface treatment of alumina ceramic substrate;

[0009] S2: Ti-Al-Nd-Cr2O3 alloy layer deposited by magnetron sputtering;

[0010] S3: Preparation of a metallization paste, wherein the metallization paste comprises SiO2, MnO, ZnO, Li2O, BaO, Mo, terpineol, and an adhesive;

[0011] S4: Metallization paste coating and sintering of alloy-plated ceramic sheets.

[0012] Furthermore, step S1 of surface treatment of the alumina ceramic substrate specifically includes the following steps:

[0013] S1.1: Add 5-6 parts of sulfuric acid to a container, then place the container in a drying oven at 30-32°C. Heat the sulfuric acid in the container for 12-15 minutes. Remove the container and quickly immerse the alumina ceramic substrate in the sulfuric acid using tweezers. Gently shake the alumina ceramic substrate in the sulfuric acid using the tweezers for 2-3 minutes. Remove the substrate to obtain the acid-treated ceramic.

[0014] S1.2: Place the acid-treated ceramic in a container, add acetone solvent until the acid-treated ceramic is immersed, then place it in an ultrasonic cleaning machine, adjust the frequency to 30-40KHz, and perform ultrasonic cleaning for 10-15 minutes. Then rinse with deionized water 2-3 times to obtain a surface-cleaned ceramic piece.

[0015] Furthermore, step S2 is to deposit a Ti-Al-Nd-Cr2O3 alloy layer by magnetron sputtering, which specifically includes the following steps:

[0016] S2.1: 2-3 parts of titanium blocks, 2-3 parts of aluminum blocks, and 0.05-0.06 parts of neodymium blocks are crushed in a crusher. The resulting titanium-aluminum fragments are placed in a vacuum medium-frequency induction melting furnace and melted at a temperature of 1600-1700°C. The resulting melt is air-cooled to 800-850°C and then placed in a four-column hydraulic press. The pressure is adjusted to 2-3 GPa and the high-pressure treatment is continued for 15-20 minutes. The melt is then removed and naturally cooled to room temperature to obtain a titanium-aluminum-neodymium alloy.

[0017] S2.2: Crush the titanium-aluminum-neodymium alloy into 2-3 mm alloy fragments using a crusher. Place the alloy fragments and 4-5 parts of anhydrous ethanol in a planetary ball mill at a speed of 450-500 rpm. After ball milling for 3-4 hours, add 0.4-0.5 parts of Cr2O3 powder to the planetary ball mill and continue ball milling at 450-500 rpm for 2-3 hours to obtain Ti-Al-Nd-Cr2O3 alloy powder.

[0018] S2.3: Place the surface-cleaned ceramic sheet in the vacuum chamber of a magnetron sputtering coating machine, use Ti-Al-Nd-Cr2O3 alloy powder as the target material, adjust the parameters of the magnetron sputtering coating machine to coat the clean ceramic, and the coating thickness is 4-5μm to obtain an alloy-coated ceramic sheet.

[0019] Furthermore, step S3 of preparing the metallization paste specifically includes the following steps:

[0020] S3.1: Add 4-6 parts of SiO2, 2-3 parts of MnO, 1-2 parts of ZnO, 0.3-0.4 parts of Li2O, and 0.2-0.3 parts of BaO powder into a container and mix thoroughly. Then, add 6-8 parts of anhydrous ethanol and mill in a planetary ball mill at 300-320 rpm for 8-10 hours. Then, dry in a drying oven at 80-85°C for 2-3 hours and cool naturally to obtain glass powder.

[0021] S3.2: Place 8-10 parts of terpineol in a container and heat in a water bath to 85-90°C. Slowly add 0.6-0.8 parts of adhesive over 55-60 minutes while stirring on a magnetic stirrer at 85-90°C. After the adhesive is fully added, cool for 20-24 hours to obtain the adhesive.

[0022] S3.3: Mix 16-20 parts of molybdenum powder and glass powder, add them to a ball mill, and ball mill at a speed of 180-200 rpm for 2-3 hours. Then place them in a drying oven at a temperature of 75-80°C for 55-60 minutes to obtain a mixed powder. After mixing the mixed powder with the rubber material, place it in an ultrasonic oscillator and oscillate it at a frequency of 30-40KHz for 20-25 minutes to obtain a metallized paste.

[0023] Furthermore, step S4 of applying and sintering the metallization paste of the alloy-plated ceramic sheet specifically includes the following steps:

[0024] S4.1: Apply the metallization paste evenly on the surface of the alloy-plated ceramic sheet by roller coating, so that the slurry amount on the surface of the alloy-plated ceramic sheet is 180-200g / m 2 , and then placed in a drying oven at a temperature of 70-75 ° C for 4-5 hours to obtain a film-coated ceramic sheet;

[0025] S4.2: Place the coated ceramic sheet in an atmosphere furnace, then introduce high-purity nitrogen to make the content of high-purity nitrogen in the atmosphere furnace be 90-95%, adjust the temperature to 1400-1450℃ and sinter for 1-1.5 hours, then cool the temperature in the atmosphere furnace to 750-800℃ at a cooling rate of 8-10℃ / min, keep it warm for 1-2 hours, then cool it to 400-450℃ at a cooling rate of 2-3℃ / min, and then naturally cool it to room temperature to obtain molybdenum metallized ceramics.

[0026] Furthermore, the concentration of sulfuric acid in step S1.1 is 18-25%.

[0027] Furthermore, the purity of the titanium block, aluminum block and neodymium block in step S2.1 is all above 99.9%.

[0028] Furthermore, the parameters of the magnetron sputtering coating machine in step S2.3 are sputtering power of 4-6 W / cm 2 The distance between the sputtering system and the clean ceramic is 4-5 cm, and the vacuum degree of the vacuum chamber is 5×10 -5 -2×10 -4 Pa, 99.9% argon gas was introduced into the sputtering system.

[0029] Furthermore, the adhesive in step S3.2 is acrylamide-vinyl acetate copolymer.

[0030] Furthermore, in step S3.3, the particle size of the molybdenum powder is 1-1.5 μm, and the purity is above 99.9%.

[0031] The beneficial effects are: 1. The present invention prepares Ti-Al-Nd-Cr2O3 alloy powder and plates it on the surface of a clean ceramic sheet by magnetron sputtering to form an alloy layer with a special alternating layered microstructure. In the subsequent coating and sintering process of the metallization paste, stable oxidation products are formed between the titanium element, neodymium element and the oxygen atoms of alumina, so that the metallization paste is tightly bonded to the ceramic. Combined with the dielectric film formed by Cr2O3 itself and the Cr-Al spinel generated by the reaction with the Al element, the Cr-Al spinel has a good thermal expansion coefficient match with both ceramics and metals, greatly reducing the internal stress during the sintering process, preventing gaps and cracks between the ceramic and metal layers, and promoting the mutual diffusion and migration of the glass phase in the ceramic and metallization layers, further improving the bonding ability between the metallization paste and the alumina ceramic and making the metallization layer denser, thereby ensuring the airtightness of the alumina ceramic in the packaging field.

[0032] 2. The present invention prepares glass powder by mixing and ball-milling SiO2, MnO, ZnO, Li2O and BaO, and then mixes and ball-mills the obtained glass powder with the prepared sizing material and molybdenum powder, and performs ultrasonic oscillation to obtain a metallized paste. During the sintering process of the obtained metallized paste, SiO2, MnO, ZnO and Li2O interact with each other to form a glass phase, which can wet molybdenum well. Moreover, due to the lower melting point and viscosity and the further reduction of the viscosity of the glass phase by BaO, the glass phase will migrate into the voids of the molybdenum and the ceramic body. This migration can also reduce the melting point and viscosity of a small amount of glass phase in the ceramic, so that the ceramic and the metallized layer form a tight and effective bond, thereby increasing the bonding strength.

[0033] 3. The present invention performs a cooling heat treatment on the coated ceramic sheet after sintering at a certain cooling rate in sections. During this process, the glass phase in the metallized layer on the surface of the molybdenum metallized ceramic and the glass phase in the ceramic slowly cool down, allowing the particles to further penetrate each other, further improving the bonding strength between the metallized layer and the ceramic. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a flow chart of a molybdenum metallization method for alumina ceramics used in an embodiment of the present invention.

[0035] Figure 2 This is a table comparing the peeling strength of the metallized layer of the molybdenum metallized ceramic prepared in Example 1 of the present invention and the high-quality aluminum oxide molybdenum manganese metallized ceramic ring.

[0036] Figure 3 This is a table comparing the volumes of the metallized layer of 10 g of the molybdenum metallized ceramic prepared in Example 1 and 10 g of the molybdenum metallized ceramic prepared in Example 1 by removing step 2 in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] Example 1

[0039] A method for molybdenum metallization of alumina ceramics, such as Figure 1 As shown, the specific steps include:

[0040] S1: Surface treatment of alumina ceramic substrate

[0041] S1.1: Add 5 parts of 18% sulfuric acid into a container, then place the container in a drying oven at 30°C. Heat the sulfuric acid in the container for 12 minutes. Remove the container and quickly immerse the alumina ceramic substrate in the sulfuric acid using tweezers. Gently shake the alumina ceramic substrate in the sulfuric acid using the tweezers for 2 minutes. Remove the substrate to obtain the acid-treated ceramic.

[0042] S1.2: Place the acid-treated ceramic in a container, add acetone solvent until the acid-treated ceramic is immersed, then place it in an ultrasonic cleaning machine, adjust the frequency to 30KHz, and perform ultrasonic cleaning for 10 minutes. Then rinse it with deionized water twice to obtain a surface-cleaned ceramic piece.

[0043] S2: Ti-Al-Nd-Cr2O3 alloy layer deposited by magnetron sputtering

[0044] S2.1: Two parts of titanium blocks, two parts of aluminum blocks, and 0.05 parts of neodymium blocks, all with a purity of 99.9% or greater, are crushed in a crusher. The resulting titanium-aluminum fragments are placed in a vacuum medium-frequency induction melting furnace and melted at 1600°C. The resulting melt is air-cooled to 800°C and then placed in a four-column hydraulic press. The pressure is adjusted to 2 GPa and the high-pressure treatment is continued for 15 minutes. The melt is then removed and naturally cooled to room temperature to obtain a titanium-aluminum-neodymium alloy.

[0045] S2.2: Crush the titanium-aluminum-neodymium alloy into 2 mm alloy fragments using a crusher. Place the alloy fragments and 4 parts of anhydrous ethanol in a planetary ball mill at 450 rpm. After ball milling for 3 hours, add 0.4 parts of Cr2O3 powder to the planetary ball mill and continue ball milling at 450 rpm for 2 hours to obtain Ti-Al-Nd-Cr2O3 alloy powder.

[0046] S2.3: Place the surface-cleaned ceramic sheet in the vacuum chamber of a magnetron sputtering coating machine, use Ti-Al-Nd-Cr2O3 alloy powder as the target material, and adjust the sputtering power of the magnetron sputtering coating machine to 4W / cm 2 The distance between the sputtering system and the clean ceramic is 4 cm, and the vacuum degree of the vacuum chamber is 5×10 -5 Pa, 99.9% argon gas is introduced into the sputtering system to coat the clean ceramic with a coating thickness of 4μm, forming an alloy layer with a special alternating layered microstructure to obtain an alloy-coated ceramic sheet. During the subsequent coating and sintering of the metallization paste, more stable oxidation products are formed between the titanium element, neodymium element and the oxygen atoms of aluminum oxide, so that the metallization paste and the ceramic are tightly bonded. Combined with the dielectric film formed by Cr2O3 and the Cr-Al spinel generated by the reaction with Al element, the internal stress of the sintering process is greatly reduced, and the mutual diffusion migration of the glass phase in the ceramic and metallization layer is promoted, further improving the bonding ability of the metallization paste with the aluminum oxide ceramic and making the metallization layer denser.

[0047] S3: Preparation of metallization paste

[0048] S3.1: Add 5 parts of SiO2, 2 parts of MnO, 1 part of ZnO, 0.3 parts of Li2O, and 0.2 parts of BaO powder into a container and mix thoroughly. Then, add 6 parts of anhydrous ethanol and place in a planetary ball mill at 300 rpm for 8 hours. Then, place in a drying oven at 80°C for 2 hours and cool naturally to obtain glass powder.

[0049] S3.2: Place 8 parts of terpineol in a container and heat in a water bath to 85°C. Slowly add 0.6 parts of acrylamide-vinyl acetate copolymer over 55 minutes while stirring on a magnetic stirrer at 85°C. After the adhesive is fully added, cool for 20 hours to obtain the adhesive.

[0050] S3.3: 16 parts of molybdenum powder with a particle size of 1 μm and a purity of more than 99.9% and glass powder are mixed and added into a ball mill and ball-milled at a speed of 180 rpm for 2 hours, and then placed in a drying oven and dried at a temperature of 75°C for 55 minutes to obtain a mixed powder. The mixed powder is mixed and stirred with the glue and then placed in an ultrasonic oscillator and oscillated at a frequency of 30 kHz for 20 minutes to obtain a metallized paste. During the sintering process of the obtained metallized paste, SiO2, MnO, ZnO, and Li2O interact to form a glass phase, which can wet molybdenum well. Due to the lower melting point and viscosity and BaO further reducing the viscosity of the glass phase, the glass phase will migrate into the voids of the molybdenum and the ceramic body. This migration can also reduce the melting point and viscosity of a small amount of glass phase in the ceramic, so that the ceramic and the metallized layer form a tight and effective bond, thereby increasing the bonding strength.

[0051] S4: Metallization paste coating and sintering of alloy-coated ceramic sheets

[0052] S4.1: Apply the metallization paste evenly on the surface of the alloy-plated ceramic sheet by roller coating, so that the slurry amount on the surface of the alloy-plated ceramic sheet is 180g / m 2 , and then placed in a drying oven at a temperature of 70°C for 4 hours to obtain a film-coated ceramic sheet;

[0053] S4.2: Place the coated ceramic sheet into an atmosphere furnace, then introduce high-purity nitrogen to make the content of high-purity nitrogen in the atmosphere furnace 90%, adjust the temperature to 1400℃ and sinter for 1 hour, then cool the temperature in the atmosphere furnace to 750℃ at a cooling rate of 8℃ / min, keep it warm for 1 hour, and then cool it to 400℃ at a cooling rate of 2℃ / min. During this process, the glass phase in the metallized layer on the surface of the molybdenum metallized ceramic and the glass phase in the ceramic slowly cool down, so that the particles further penetrate each other, further improving the bonding strength between the metallized layer and the ceramic, and then naturally cool to room temperature to obtain the molybdenum metallized ceramic.

[0054] Example 2

[0055] A method for molybdenum metallization of alumina ceramics, such as Figure 1 As shown, the specific steps include:

[0056] S1: Surface treatment of alumina ceramic substrate

[0057] S1.1: Add 6 parts of 25% sulfuric acid into a container, then place the container in a drying oven at 30°C. Heat the sulfuric acid in the container for 12 minutes. Remove the container and quickly immerse the alumina ceramic substrate in the sulfuric acid using tweezers. Gently shake the alumina ceramic substrate in the sulfuric acid using the tweezers for 2 minutes. Remove the substrate to obtain the acid-treated ceramic.

[0058] S1.2: Place the acid-treated ceramic in a container, add acetone solvent until the acid-treated ceramic is immersed, then place it in an ultrasonic cleaning machine, adjust the frequency to 30KHz, and perform ultrasonic cleaning for 10 minutes. Then rinse it with deionized water twice to obtain a surface-cleaned ceramic piece.

[0059] S2: Ti-Al-Nd-Cr2O3 alloy layer deposited by magnetron sputtering

[0060] S2.1: 3 parts of titanium blocks, 3 parts of aluminum blocks, and 0.06 parts of neodymium blocks, all with a purity of 99.9% or greater, are crushed in a crusher. The resulting titanium-aluminum fragments are placed in a vacuum medium-frequency induction melting furnace and melted at 1600°C. The resulting melt is air-cooled to 800°C and then placed in a four-column hydraulic press at a pressure of 2 GPa for 15 minutes. The press is then removed and naturally cooled to room temperature to obtain a titanium-aluminum-neodymium alloy.

[0061] S2.2: Crush the titanium-aluminum-neodymium alloy into 2 mm alloy fragments using a crusher. Place the alloy fragments and 5 parts of anhydrous ethanol in a planetary ball mill at 450 rpm. After ball milling for 3 hours, add 0.5 parts of Cr2O3 powder to the planetary ball mill and continue ball milling at 450 rpm for 2 hours to obtain Ti-Al-Nd-Cr2O3 alloy powder.

[0062] S2.3: Place the surface-cleaned ceramic sheet in the vacuum chamber of a magnetron sputtering coating machine, use Ti-Al-Nd-Cr2O3 alloy powder as the target material, and adjust the sputtering power of the magnetron sputtering coating machine to 4W / cm 2 The distance between the sputtering system and the clean ceramic is 4 cm, and the vacuum degree of the vacuum chamber is 5×10 -5Pa, 99.9% argon gas is introduced into the sputtering system to coat the clean ceramic with a coating thickness of 4μm, forming an alloy layer with a special alternating layered microstructure to obtain an alloy-coated ceramic sheet. During the subsequent coating and sintering of the metallization paste, more stable oxidation products are formed between the titanium element, neodymium element and the oxygen atoms of aluminum oxide, so that the metallization paste and the ceramic are tightly bonded. Combined with the dielectric film formed by Cr2O3 and the Cr-Al spinel generated by the reaction with Al element, the internal stress of the sintering process is greatly reduced, and the mutual diffusion migration of the glass phase in the ceramic and metallization layer is promoted, further improving the bonding ability of the metallization paste with the aluminum oxide ceramic and making the metallization layer denser.

[0063] S3: Preparation of metallization paste

[0064] S3.1: 6 parts SiO2, 3 parts MnO, 2 parts ZnO, 0.4 parts Li2O, and 0.3 parts BaO powders were added to a container and mixed uniformly. The mixture was then ball-milled with 8 parts anhydrous ethanol in a planetary ball mill at 300 rpm for 8 hours. The mixture was then dried in a drying oven at 80°C for 2 hours and allowed to cool naturally to obtain glass powder.

[0065] S3.2: Place 10 parts of terpineol in a container and heat in a water bath to 85°C. Slowly add 0.8 parts of acrylamide-vinyl acetate copolymer over 55 minutes while stirring on a magnetic stirrer at 85°C. After the adhesive is fully added, cool for 20 hours to obtain the adhesive.

[0066] S3.3: Mix 20 parts of molybdenum powder with a particle size of 1 μm and a purity of more than 99.9% and glass powder, add them to a ball mill and ball mill at a speed of 180 rpm for 2 hours, then place them in a drying oven and dry them at a temperature of 75°C for 55 minutes to obtain a mixed powder, mix the mixed powder with the glue, and put it into an ultrasonic oscillator to oscillate at a frequency of 30 kHz for 20 minutes to obtain a metallized paste. During the sintering process of the obtained metallized paste, SiO2, MnO, ZnO, and Li2O interact to form a glass phase, which can wet molybdenum well, and due to the lower melting point and viscosity and BaO further reducing the viscosity of the glass phase, the glass phase will migrate into the voids of the molybdenum and the ceramic body. This migration can also reduce the melting point and viscosity of a small amount of glass phase in the ceramic, so that the ceramic and the metallized layer form a tight and effective bond, thereby increasing the bonding strength.

[0067] S4: Metallization paste coating and sintering of alloy-coated ceramic sheets

[0068] S4.1: Apply the metallization paste evenly on the surface of the alloy-plated ceramic sheet by roller coating, so that the amount of slurry on the surface of the alloy-plated ceramic sheet is 200g / m 2, and then placed in a drying oven at a temperature of 70°C for 4 hours to obtain a film-coated ceramic sheet;

[0069] S4.2: Place the coated ceramic sheet into an atmosphere furnace, then introduce high-purity nitrogen to make the content of high-purity nitrogen in the atmosphere furnace 90%, adjust the temperature to 1400℃ and sinter for 1 hour, then cool the temperature in the atmosphere furnace to 750℃ at a cooling rate of 8℃ / min, keep it warm for 1 hour, and then cool it to 400℃ at a cooling rate of 2℃ / min. During this process, the glass phase in the metallized layer on the surface of the molybdenum metallized ceramic and the glass phase in the ceramic slowly cool down, so that the particles further penetrate each other, further improving the bonding strength between the metallized layer and the ceramic, and then naturally cool to room temperature to obtain the molybdenum metallized ceramic.

[0070] Example 3

[0071] A method for molybdenum metallization of alumina ceramics, such as Figure 1 As shown, the specific steps include:

[0072] S1: Surface treatment of alumina ceramic substrate

[0073] S1.1: Add 5 parts of 18% sulfuric acid into a container, then place the container in a drying oven at 32°C. Heat the sulfuric acid in the container for 15 minutes. Remove the container and quickly immerse the alumina ceramic substrate in the sulfuric acid using tweezers. Gently shake the alumina ceramic substrate in the sulfuric acid using the tweezers for 3 minutes. Remove the substrate to obtain the acid-treated ceramic.

[0074] S1.2: Place the acid-treated ceramic in a container, add acetone solvent until the acid-treated ceramic is immersed, then place it in an ultrasonic cleaner, adjust the frequency to 40KHz, and perform ultrasonic cleaning for 15 minutes. Then rinse with deionized water three times to obtain a surface-cleaned ceramic piece.

[0075] S2: Ti-Al-Nd-Cr2O3 alloy layer deposited by magnetron sputtering

[0076] S2.1: Two parts of titanium blocks, two parts of aluminum blocks, and 0.05 parts of neodymium blocks, all with a purity of 99.9% or greater, are crushed in a crusher. The resulting titanium-aluminum fragments are placed in a vacuum medium-frequency induction melting furnace and melted at 1700°C. The resulting melt is air-cooled to 850°C and then placed in a four-column hydraulic press at a pressure of 3 GPa for 20 minutes. The press is then removed and naturally cooled to room temperature to obtain a titanium-aluminum-neodymium alloy.

[0077] S2.2: Crush the titanium-aluminum-neodymium alloy into 3 mm alloy fragments using a crusher. Place the alloy fragments and 4 parts of anhydrous ethanol in a planetary ball mill at 500 rpm. After ball milling for 4 hours, add 0.4 parts of Cr2O3 powder to the planetary ball mill and continue ball milling at 500 rpm for 3 hours to obtain Ti-Al-Nd-Cr2O3 alloy powder.

[0078] S2.3: Place the surface-cleaned ceramic sheet in the vacuum chamber of a magnetron sputtering coating machine, use Ti-Al-Nd-Cr2O3 alloy powder as the target material, and adjust the sputtering power of the magnetron sputtering coating machine to 6W / cm 2 The distance between the sputtering system and the clean ceramic is 5m, and the vacuum degree of the vacuum chamber is 2×10 -4 Pa, 99.9% argon gas is introduced into the sputtering system to coat the clean ceramic with a coating thickness of 5μm, forming an alloy layer with a special alternating layered microstructure to obtain an alloy-coated ceramic sheet. During the subsequent coating and sintering of the metallization paste, more stable oxidation products are formed between the titanium element, neodymium element and the oxygen atoms of aluminum oxide, so that the metallization paste and the ceramic are tightly bonded. Combined with the dielectric film formed by Cr2O3 and the Cr-Al spinel generated by the reaction with Al element, the internal stress of the sintering process is greatly reduced, and the mutual diffusion migration of the glass phase in the ceramic and metallization layer is promoted, further improving the bonding ability of the metallization paste with the aluminum oxide ceramic and making the metallization layer denser.

[0079] S3: Preparation of metallization paste

[0080] S3.1: Add 5 parts of SiO2, 2 parts of MnO, 1 part of ZnO, 0.3 parts of Li2O, and 0.2 parts of BaO powder into a container and mix thoroughly. Then, add 6 parts of anhydrous ethanol and mill the mixture in a planetary ball mill at 320 rpm for 10 hours. Then, dry the mixture in a drying oven at 85°C for 3 hours and cool naturally to obtain glass powder.

[0081] S3.2: Place 10 parts of terpineol in a container and heat in a water bath to 90°C. Slowly add 0.8 parts of acrylamide-vinyl acetate copolymer over 60 minutes while stirring on a magnetic stirrer at 90°C. After the adhesive is fully added, cool for 24 hours to obtain the adhesive.

[0082] S3.3: 16 parts of molybdenum powder with a particle size of 1.5 μm and a purity of more than 99.9% and glass powder are mixed and added to a ball mill and ball-milled at a speed of 200 rpm for 3 hours, and then placed in a drying oven and dried at a temperature of 80°C for 60 minutes to obtain a mixed powder. The mixed powder is mixed and stirred with the glue, and then placed in an ultrasonic oscillator and oscillated at a frequency of 40 kHz for 25 minutes to obtain a metallized paste. During the sintering process of the obtained metallized paste, SiO2, MnO, ZnO, and Li2O interact to form a glass phase, which can wet molybdenum well. Due to the lower melting point and viscosity and BaO further reducing the viscosity of the glass phase, the glass phase will migrate into the voids of the molybdenum and the ceramic body. This migration can also reduce the melting point and viscosity of a small amount of glass phase in the ceramic, so that the ceramic and the metallized layer form a tight and effective bond, thereby increasing the bonding strength.

[0083] S4: Metallization paste coating and sintering of alloy-coated ceramic sheets

[0084] S4.1: Apply the metallization paste evenly on the surface of the alloy-plated ceramic sheet by roller coating, so that the slurry amount on the surface of the alloy-plated ceramic sheet is 180g / m 2 , and then placed in a drying oven at a temperature of 75°C for 5 hours to obtain a film-coated ceramic sheet;

[0085] S4.2: Place the coated ceramic sheet into an atmosphere furnace, then introduce high-purity nitrogen to make the content of high-purity nitrogen in the atmosphere furnace 95%, adjust the temperature to 1450℃ and sinter for 1.5 hours, then cool the temperature in the atmosphere furnace to 800℃ at a cooling rate of 10℃ / min, keep it warm for 2 hours, and then cool it to 450℃ at a cooling rate of 3℃ / min. During this process, the glass phase in the metallized layer on the surface of the molybdenum metallized ceramic and the glass phase in the ceramic slowly cool down, so that the particles further penetrate each other, further improving the bonding strength between the metallized layer and the ceramic, and then naturally cool to room temperature to obtain the molybdenum metallized ceramic.

[0086] Comparative Example 1

[0087] Compared with Example 1, the difference of Comparative Example 1 is that Comparative Example 1 is a high-quality aluminum oxide molybdenum manganese metallized ceramic ring, specifically a high-quality aluminum oxide molybdenum manganese metallized ceramic ring purchased from Shenzhen Huaxin Precision Ceramics Technology Co., Ltd.

[0088] The molybdenum metallized ceramics prepared in Example 1, Example 2, and Example 3, as well as Comparative Example 1, were respectively measured for peel strength of their metallized layers using a Shimadzu tensile testing machine. The test was conducted three times, and the data were recorded and tabulated. Figure 2 It can be seen that the peel strength of the molybdenum metallized ceramics prepared in Example 1, Example 2, and Example 3 is better than the peel strength of Comparative Example 1, which proves that the examples prepare a molybdenum metallized ceramic with a tighter combination of the metallization layer and the ceramic.

[0089] Comparative Example 2

[0090] Compared with Example 1, the difference of Comparative Example 2 is that Comparative Example 2 is Example 1 without step S2, and the remaining steps are the same as Example 1.

[0091] Take the metallized layer peeled off from the molybdenum metallized ceramic prepared in Example 1 and the metallized layer peeled off from the molybdenum metallized ceramic prepared in Comparative Example 2, weigh 10g of each, and measure its volume using the water level method. When the proportion of the metallized layer components is the same, the larger the volume, the lower the density and the worse the compactness. Repeat the weighing and volume measurement three times, record the data and make a table, as shown in FIG. Figure 3 It can be seen that the density of the metallized layers of the molybdenum metallized ceramics prepared in Examples 1, 2, and 3 is better than that of the metallized layer of Comparative Example 2. This proves that the examples use a magnetron sputtering method to plate Ti-Al-Nd-Cr2O3 alloy powder on the surface of a clean ceramic sheet to prepare a molybdenum metallized ceramic with a denser metallized layer.

[0092] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for molybdenum metallization of alumina ceramics, characterized in that: Here are the steps: S1: Surface treatment of alumina ceramic substrate; S2: Ti-Al-Nd-Cr2O3 alloy layer deposited by magnetron sputtering; S3: Preparation of a metallization paste, wherein the metallization paste comprises SiO2, MnO, ZnO, Li2O, BaO, Mo, terpineol, and an adhesive; S4: coating and sintering of the metallization paste of the alloy-plated ceramic sheet; Step S4 specifically includes the following steps: S4.1: Apply the metallization paste evenly on the surface of the alloy-plated ceramic sheet by roller coating, so that the slurry amount on the surface of the alloy-plated ceramic sheet is 180-200g / m 2 , and then placed in a drying oven at a temperature of 70-75 ° C for 4-5 hours to obtain a film-coated ceramic sheet; S4.2: Place the coated ceramic sheet in an atmosphere furnace, then introduce high-purity nitrogen to make the content of high-purity nitrogen in the atmosphere furnace be 90-95%, adjust the temperature to 1400-1450℃ and sinter for 1-1.5 hours, then cool the temperature in the atmosphere furnace to 750-800℃ at a cooling rate of 8-10℃ / min, keep it warm for 1-2 hours, then cool it to 400-450℃ at a cooling rate of 2-3℃ / min, and then naturally cool it to room temperature to obtain molybdenum metallized ceramics.

2. The molybdenum metallization method of alumina ceramics according to claim 1, characterized in that: step S1 Surface treatment of alumina ceramic substrate, specifically including the following steps: S1.1: Add 5-6 parts of sulfuric acid to a container, then place the container in a drying oven at 30-32°C. Heat the sulfuric acid in the container for 12-15 minutes. Remove the container and quickly immerse the alumina ceramic substrate in the sulfuric acid using tweezers. Gently shake the alumina ceramic substrate in the sulfuric acid using the tweezers for 2-3 minutes. Remove the substrate to obtain the acid-treated ceramic. S1.2: Place the acid-treated ceramic in a container, add acetone solvent until the acid-treated ceramic is immersed, then place it in an ultrasonic cleaning machine, adjust the frequency to 30-40KHz, and perform ultrasonic cleaning for 10-15 minutes. Then rinse with deionized water 2-3 times to obtain a surface-cleaned ceramic piece.

3. The molybdenum metallization method of alumina ceramics according to claim 2, characterized in that: step The S2 magnetron sputtering method is used to deposit a Ti-Al-Nd-Cr2O3 alloy layer, which specifically includes the following steps: S2.1: 2-3 parts of titanium blocks, 2-3 parts of aluminum blocks, and 0.05-0.06 parts of neodymium blocks are crushed in a crusher. The resulting titanium-aluminum fragments are placed in a vacuum medium-frequency induction melting furnace and melted at a temperature of 1600-1700°C. The resulting melt is air-cooled to 800-850°C and then placed in a four-column hydraulic press. The pressure is adjusted to 2-3 GPa and the high-pressure treatment is continued for 15-20 minutes. The melt is then removed and naturally cooled to room temperature to obtain a titanium-aluminum-neodymium alloy. S2.2: Crush the titanium-aluminum-neodymium alloy into 2-3 mm alloy fragments using a crusher. Place the alloy fragments and 4-5 parts of anhydrous ethanol in a planetary ball mill at a speed of 450-500 rpm. After ball milling for 3-4 hours, add 0.4-0.5 parts of Cr2O3 powder to the planetary ball mill and continue ball milling at 450-500 rpm for 2-3 hours to obtain Ti-Al-Nd-Cr2O3 alloy powder. S2.3: Place the surface-cleaned ceramic sheet in the vacuum chamber of a magnetron sputtering coating machine, use Ti-Al-Nd-Cr2O3 alloy powder as the target material, adjust the parameters of the magnetron sputtering coating machine to coat the clean ceramic, and the coating thickness is 4-5μm to obtain an alloy-coated ceramic sheet.

4. The molybdenum metallization method of alumina ceramics according to claim 3, characterized in that: step The preparation of S3 metallization paste specifically includes the following steps: S3.1: Add 4-6 parts of SiO2, 2-3 parts of MnO, 1-2 parts of ZnO, 0.3-0.4 parts of Li2O, and 0.2-0.3 parts of BaO powder into a container and mix thoroughly. Then, add 6-8 parts of anhydrous ethanol and mill in a planetary ball mill at 300-320 rpm for 8-10 hours. Then, dry in a drying oven at 80-85°C for 2-3 hours and cool naturally to obtain glass powder. S3.2: Place 8-10 parts of terpineol in a container and heat in a water bath to 85-90°C. Slowly add 0.6-0.8 parts of adhesive over 55-60 minutes while stirring on a magnetic stirrer at 85-90°C. After the adhesive is fully added, cool for 20-24 hours to obtain the adhesive. S3.3: Mix 16-20 parts of molybdenum powder and glass powder, add them to a ball mill, and ball mill at a speed of 180-200 rpm for 2-3 hours. Then place them in a drying oven at a temperature of 75-80°C for 55-60 minutes to obtain a mixed powder. After mixing the mixed powder with the rubber material, place it in an ultrasonic oscillator and oscillate it at a frequency of 30-40KHz for 20-25 minutes to obtain a metallized paste.

5. The molybdenum metallization method of alumina ceramics according to claim 2, characterized in that: The concentration of sulfuric acid in step S1.1 is 18-25%.

6. The molybdenum metallization method of alumina ceramics according to claim 3, characterized in that: The purity of the titanium block, aluminum block and neodymium block in step S2.1 is all above 99.9%.

7. The molybdenum metallization method of alumina ceramics according to claim 3, characterized in that: The parameters of the magnetron sputtering coating machine in step S2.3 are as follows: the distance between the sputtering system and the clean ceramic is 4-5 cm, the vacuum degree is 5×10 -5 -2×10 - 4 Pa, then introduce 99.9% argon, and the sputtering power is 4-6W / cm 2 .

8. The molybdenum metallization method of alumina ceramics according to claim 4, characterized in that: The adhesive in step S3.2 is acrylamide-vinyl acetate copolymer.

9. The molybdenum metallization method of alumina ceramics according to claim 4, characterized in that: The particle size of the molybdenum powder in step S3.3 is 1-1.5 μm, and the purity is above 99.9%.

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