Anti-static black aluminum oxide ceramic substrate and preparation process thereof

Abstract

The invention relates to an anti-static black aluminum oxide ceramic substrate and a preparation process thereof. The ceramic substrate comprises ceramic powder, an organic solvent, a dispersing agent, a binder and a plasticizer. The black aluminum oxide ceramic substrate is prepared through the processes of tape casting, warm pressing and sintering. The ceramic powder comprises the following materials in parts by weight: 40-55 parts of aluminum oxide, 2.5-5 parts of nano semiconductor whiskers, 5-20 parts of special anti-static black pigment, 20-30 parts of an organic solvent, 1-3 parts of a dispersing agent, 5-8 parts of an adhesive and 3-7 parts of a plasticizer. The special anti-static black pigment can form a continuous conductive phase, and static accumulation is reduced. The added nano semiconductor whiskers have certain conductivity, and the whiskers form a conductive and heat-conducting network channel in the substrate through a warm-pressing process, so that generated electrostatic charges can be discharged in time, and meanwhile, the heat dissipation performance of the substrate is further enhanced. The light-shielding and light-absorbing material has good light-shielding and light-absorbing performance, and is suitable for photosensitive integrated circuits, semiconductor components, nixie tube packaging shells and the like. The problem that electronic components are damaged due to static electricity accumulation generated in the manufacturing and using processes of the electronic devices is effectively solved.

Description

Technical Field

[0001] The invention belongs to the field of ceramic materials and relates to a preparation process of a black alumina ceramic substrate with anti-static function. The substrate has good light-shielding and light-absorbing properties and is suitable for photosensitive integrated circuits, semiconductor devices, and digital tube packaging shells. Background Art

[0002] In recent years, with the rapid development of electric vehicles, electric locomotives, semiconductor lighting, aerospace, satellite communications, etc. with high-power integrated circuit characteristics, higher requirements have been put forward for chip carriers to meet the stability of device and circuit operation, and the challenges faced in electronic packaging are even greater. Many photosensitive integrated circuits are limited by traditional electronic packaging technology, while black alumina ceramic substrates are widely used in photosensitive integrated circuit packaging shells, digital tube linings, crystal oscillator bases and other fields due to their unique light-shielding properties, high mechanical strength and insulation. The commonly used white alumina substrate must reach a certain thickness to avoid the influence of light on photosensitive devices. The black alumina substrate with light-shielding and light-absorbing properties can avoid the problem of light transmission and reflection even if it is processed to a very thin thickness. The crystal oscillator packaged with black alumina ceramic can reduce the volume by 30-100 times, which is in line with the trend of chip thinning. At the same time, the problem of generating and accumulating static electricity during the manufacture and use of electronic components is difficult to avoid. Static electricity can cause irreversible damage to electronic components and even cause equipment failure. Static electricity is a ubiquitous physical phenomenon. With the rapid development of integrated circuits and polymer materials, the losses caused by static electricity hazards are becoming more and more serious. Antistatic black alumina ceramic substrates can effectively eliminate or reduce static electricity accumulation and protect electronic components from static electricity damage. Therefore, the preparation of an electronic packaging material with antistatic function and suitable for photosensitive integrated circuits has broad market prospects. Summary of the invention

[0003] In view of the poor light shielding and light absorption performance of conventional white alumina ceramic substrates on the market, and the static electricity problem when used as electronic packaging materials, the present invention proposes a preparation process for a black alumina ceramic substrate with anti-static function. The specific technical scheme is as follows: An antistatic black alumina ceramic substrate and a preparation process thereof are characterized in that the substrate comprises the following components in parts by weight: 40-55 parts of alumina, 2.5-5 parts of nano-semiconductor whiskers, 5-20 parts of special antistatic black pigments, 20-30 parts of organic solvents, 1-3 parts of dispersants, 5-8 parts of adhesives, and 3-7 parts of plasticizers.

[0004] The specially prepared antistatic black pigment of the present invention can form a continuous conductive phase and reduce static electricity accumulation. The pigment is pre-sintered at 1200-1300°C to form a stable spinel structure, which avoids the volatilization of the pigment due to the increase in temperature during subsequent processing and ensures the blackness of the substrate. At the same time, nano-semiconductor whiskers are introduced, which have certain conductive properties. Through the warm pressing process, a conductive and heat-conducting network channel is formed inside the substrate, which can discharge the generated static electricity in time, and also further enhance the heat dissipation performance of the substrate.

[0005] Preferably, the special antistatic black colorant is composed of the following raw materials: 30-48 parts of zinc oxide, 3-6 parts of titanium dioxide, 16-19 parts of manganese oxide, 10-13 parts of iron oxide, 13-16 parts of nickel oxide, 4-7 parts of molybdenum oxide and 6-9 parts of cobalt oxide.

[0006] Preferably, the particle size of the aluminum oxide is 0.5 μm, and the particle size of the antistatic black colorant is 100 nm-300 nm.

[0007] Preferably, the chromaticity value L* value of the special antistatic black colorant is in the range of 18 to 30, the a* value is in the range of -2 to 2, and the b* value is in the range of -1 to 1.

[0008] Preferably, the nano-semiconductor whiskers are nano-silicon carbide whiskers.

[0009] Preferably, the diameter of the nano-semiconductor whisker is 100-500 nm, and the aspect ratio is greater than 10.

[0010] Preferably, the organic solvent is a binary azeotropic mixed solution of ethanol and butanone, the dispersant is one or more of tributyl phosphate, oleic acid, and herring oil, and the plasticizer is polyethylene glycol.

[0011] An antistatic black alumina ceramic substrate and a preparation process thereof, comprising the following steps: (a) weighing a transition metal oxide in proportion, placing it in a normal pressure sintering furnace and calcining it at 1200-1300° C. for 2-2.5 hours to ensure that the free transition metal oxide forms a stable spinel structure during sintering, and the sintering atmosphere is one of air, vacuum or nitrogen; (b) The calcined black pigment is sand-milled to a particle size range of 100 nm to 300 nm to obtain an antistatic black pigment.

[0012] An antistatic black alumina ceramic substrate and a preparation process thereof, comprising the following steps: (1) Preparation of tape casting slurry: Add antistatic black colorant, alumina powder, nano semiconductor whiskers, organic solvent and dispersant into a ball mill in proportion, and perform ball milling dispersion at 60-80 r / min for 12-24 hours. Add binder and plasticizer to the evenly dispersed slurry and perform secondary ball milling dispersion at 50-70 r / min for 24-48 hours. After discharge, the material is degassed by a vacuum degassing machine to obtain a tape casting slurry with a viscosity of 2500-3500 mPa·s.

[0013] (2) Casting: The prepared slurry is sieved and placed in a casting machine for casting and drying to obtain a ceramic green tape.

[0014] (3) Warm pressing: The cut green ceramic strips are stacked to the required height and placed on a warm pressing machine for warm pressing. The pressure of the warm pressing machine is set to 90-100 MPa and the temperature is 30-50°C. After holding the pressure for 3-4 minutes, the green ceramic substrate is obtained.

[0015] (4) Debinding and sintering: Place the green tape after warm pressing in a normal pressure sintering furnace, heat it to 100-120℃ at 1℃ / min and keep it at that temperature for 0.5h to facilitate the complete volatilization of the organic solvent, and then heat it to 500-600℃ at 2℃ / min for debinding, and the debinding time is 1-2h. Then continue to heat it to 1320-1400℃ at 5℃ / min for sintering, keep it at that temperature for 2-3h, and finally cool it to room temperature at 5℃ / min to complete the sintering. The debinding and sintering atmosphere is one of nitrogen or vacuum atmosphere.

[0016] The present invention has at least the following advantages and beneficial effects: (1) The present invention uses zinc oxide, iron oxide, titanium dioxide, nickel oxide and molybdenum oxide as raw materials to prepare antistatic black pigment, which can form a continuous conductive phase and reduce static electricity accumulation. At the same time, nano silicon carbide whiskers are introduced, which have certain conductive properties. Through the temperature pressing process, a conductive and thermal conductive network channel is formed inside the substrate, which can timely discharge the generated static electricity charge, so that the ceramic substrate has an antistatic function, avoiding the accumulation of static electricity during the production and use of electronic components and damaging the electronic components, and further enhancing the heat dissipation performance of the substrate.

[0017] (2) The special antistatic pigment with nano-particle size prepared by the present invention can achieve the greatest degree of compact distribution in the warm pressing process, and is fully filled between the large micron alumina particles, so that the final color of the substrate is more uniform. The antistatic black pigment forms a stable spinel structure through pre-sintering, avoiding the problem of pigment volatilization due to temperature increase in subsequent processing, and ensuring the blackness of the substrate. The light absorption and light-shielding properties of the substrate are much higher than those of ordinary black alumina substrates, making it more suitable for photosensitive integrated circuits, electronic components and digital tube packaging shells. At the same time, the black substrate can cover the circuits and tungsten electrodes embedded in it, making the components more beautiful as a whole.

[0018] (3) The sintering temperature of the present invention is below 1400°C, which is much lower than the sintering temperature of conventional alumina ceramic substrates of about 1600°C, and is more energy-saving and environmentally friendly. The preparation process is simple and easy to control, and has ideal heat dissipation performance, dielectric properties and mechanical strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the appearance of the special anti-static black pigment; Figure 2 This is the appearance of the anti-static black alumina ceramic substrate; Figure 3 This is a high-magnification scanning electron microscope image of an anti-static black substrate. The strips are silicon carbide whiskers, which are neatly stacked inside the substrate to form a network channel for eliminating static electricity. Implementation

[0020] The present invention will be further described below in conjunction with specific implementation modes. Example

[0021] (1) An antistatic black alumina ceramic substrate comprises the following raw materials in parts by weight: 55 parts of alumina, 5 parts of nano silicon carbide whiskers, 9 parts of special antistatic black pigment, 20 parts of a binary azeotropic mixture of anhydrous ethanol and butanone, 3 parts of oleic acid, 5 parts of polyvinyl butyral, and 3 parts of polyethylene glycol. The special antistatic black pigment comprises: 30 parts of zinc oxide, 6 parts of titanium dioxide, 19 parts of manganese oxide, 13 parts of iron oxide, 16 parts of nickel oxide, 7 parts of molybdenum oxide, and 9 parts of cobalt oxide.

[0022] (2) Weighed zinc oxide, titanium dioxide, manganese oxide, iron oxide, nickel oxide, molybdenum oxide and cobalt oxide are mixed and calcined at 1200°C for 2 hours to prepare an antistatic black pigment.

[0023] (3) Add antistatic black pigment, alumina powder, silicon carbide whisker, organic solvent and dispersant into a ball mill according to the above proportions, and perform ball milling dispersion at 60 r / min for 24 h. Add binder and plasticizer to the evenly dispersed slurry and perform secondary ball milling dispersion at 70 r / min for 48 h. After discharge, the material is degassed by a vacuum degassing machine to obtain a casting slurry with a viscosity of 3000 mPa·s.

[0024] (4) The prepared slurry is sieved and placed in a tape casting machine to obtain a ceramic green tape after tape casting. The green tape is cut into a certain shape and size.

[0025] (5) The cut green ceramic tapes are stacked to the required height and placed on a warm press for warm pressing. The pressure of the warm press is set to 90 MPa and the temperature is set to 35°C. After holding the pressure for 3 minutes, the green ceramic substrate is obtained.

[0026] (6) Place the green tape after warm pressing in a normal pressure sintering furnace, heat it to 120°C at a rate of 1°C / min and keep it at that temperature for 0.5 h, then heat it to 500°C at a rate of 2°C / min for debinding. The debinding atmosphere is nitrogen atmosphere and the debinding time is 2 h.

[0027] (7) The temperature is continued to be raised to 1350°C at a rate of 5°C / min for sintering, and kept at this temperature for 3 h. Finally, the temperature is cooled to room temperature at a rate of 5°C / min to complete the sintering. Example

[0028] (1) An antistatic black alumina ceramic substrate comprises the following raw materials in parts by weight: 50 parts of alumina, 5 parts of nano silicon carbide whiskers, 12 parts of a special antistatic black pigment, 23 parts of a binary azeotropic mixture of anhydrous ethanol and butanone, 2.5 parts of tributyl phosphate, 4.5 parts of polyvinyl butyral, and 3 parts of polyethylene glycol. The special antistatic black pigment comprises: 34 parts of zinc oxide, 4 parts of titanium dioxide, 17 parts of manganese oxide, 10 parts of iron oxide, 13 parts of nickel oxide, 4 parts of molybdenum oxide, and 8 parts of cobalt oxide.

[0029] (2) Weighed zinc oxide, titanium dioxide, manganese oxide, iron oxide, nickel oxide, molybdenum oxide and cobalt oxide are mixed and calcined at 1250° C. for 2.5 h, and then sand-milled to obtain an antistatic black pigment.

[0030] (3) Add antistatic black pigment, alumina powder, nano silicon carbide whisker, organic solvent and dispersant into a ball mill according to the above ratio, and perform ball milling dispersion at 70 r / min for 24 h. Add binder and plasticizer to the evenly dispersed slurry and perform secondary ball milling dispersion at 70 r / min for 24 h. After the material is discharged, it is degassed by a vacuum degassing machine to obtain a casting slurry with a viscosity of 2500 mPa·s.

[0031] (4) The prepared slurry is sieved and placed in a tape casting machine to obtain a ceramic green tape after tape casting. The green tape is cut into a certain shape and size.

[0032] (5) The cut green ceramic tapes are stacked to the required height and placed on a warm press for warm pressing. The pressure of the warm press is set to 95 MPa and the temperature is set to 45°C. After maintaining the pressure for 3.5 minutes, the green ceramic substrate is obtained.

[0033] (6) The green tape after warm pressing is placed in a normal pressure sintering furnace, and the temperature is raised to 120°C at a rate of 1°C / min and kept at that temperature for 0.5 h. The temperature is then raised to 600°C at a rate of 2°C / min for debinding. The debinding atmosphere is nitrogen and the debinding time is 2 h.

[0034] (7) The temperature is continued to be raised to 1400°C at a rate of 5°C / min for sintering, and the temperature is kept at this level for 3 h. Finally, the temperature is cooled to room temperature at a rate of 5°C / min to complete the sintering. Example

[0035] (1) An antistatic black alumina ceramic substrate comprises the following raw materials in parts by weight: 48 parts of alumina, 3 parts of nano silicon carbide whiskers, 15 parts of a special antistatic black pigment, 23 parts of a binary azeotropic mixture of anhydrous ethanol and butanone, 2.5 parts of herring oil, 5.5 parts of polyvinyl butyral, and 3 parts of polyethylene glycol. The special antistatic black pigment comprises: 38 parts of zinc oxide, 4.5 parts of titanium dioxide, 18 parts of manganese oxide, 12.5 parts of iron oxide, 14 parts of nickel oxide, 6 parts of molybdenum oxide, and 7 parts of cobalt oxide.

[0036] (2) Weighed zinc oxide, titanium dioxide, manganese oxide, iron oxide, nickel oxide, molybdenum oxide and cobalt oxide are mixed and calcined at 1250° C. for 2.5 h, and then sand-milled to obtain an antistatic black pigment.

[0037] (3) Add antistatic black pigment, alumina powder, nano silicon carbide whisker, organic solvent and dispersant into a ball mill according to the above ratio, and perform ball milling dispersion at 60 r / min for 24 h. Add binder and plasticizer to the evenly dispersed slurry and perform secondary ball milling dispersion at 60 r / min for 48 h. After the material is discharged, it is degassed by a vacuum degassing machine to obtain a casting slurry with a viscosity of 2500 mPa·s.

[0038] (4) The prepared slurry is sieved and placed in a tape casting machine to obtain a ceramic green tape after tape casting. The green tape is cut into a certain shape and size.

[0039] (5) The cut green ceramic tapes are stacked to the required height and placed on a warm press for warm pressing. The pressure of the warm press is set to 100 MPa and the temperature is set to 40°C. After holding the pressure for 4 minutes, the green ceramic substrate is obtained.

[0040] (6) Place the green tape after warm pressing in a normal pressure sintering furnace, heat it to 120°C at a rate of 1°C / min and keep it at that temperature for 0.5 h, then heat it to 550°C at a rate of 2°C / min for debinding. The debinding atmosphere is nitrogen atmosphere and the debinding time is 1 h.

[0041] (7) The temperature is continued to be raised to 1380°C at a rate of 5°C / min for sintering, and the temperature is kept for 3 h. Finally, the temperature is cooled to room temperature at a rate of 5°C / min to complete the sintering. Example

[0042] (1) An antistatic black alumina ceramic substrate comprises the following raw materials in parts by weight: 43 parts of alumina, 3 parts of nano silicon carbide whiskers, 17 parts of special antistatic black pigment, 26 parts of a binary azeotropic mixture of anhydrous ethanol and butanone, 2.5 parts of tributyl phosphate, 5.5 parts of polyvinyl butyral, and 3 parts of polyethylene glycol. The special antistatic black pigment comprises: 36 parts of zinc oxide, 5 parts of titanium dioxide, 17 parts of manganese oxide, 13 parts of iron oxide, 15.5 parts of nickel oxide, 6.5 parts of molybdenum oxide, and 7 parts of cobalt oxide.

[0043] (2) Weighed zinc oxide, titanium dioxide, manganese oxide, iron oxide, nickel oxide, molybdenum oxide and cobalt oxide are mixed and calcined at 1280° C. for 2.5 h, and then sand-milled to obtain an antistatic black pigment.

[0044] (3) Add antistatic black pigment, alumina powder, nano silicon carbide whiskers, organic solvent and dispersant into a ball mill according to the above ratio, and perform ball milling dispersion at 60 r / min for 24 h. Add binder and plasticizer to the evenly dispersed slurry and perform secondary ball milling dispersion at 70 r / min for 24 h. After the material is discharged, it is degassed by a vacuum degassing machine to obtain a casting slurry with a viscosity of 2800 mPa·s.

[0045] (4) The prepared slurry is sieved and placed in a tape casting machine to obtain a ceramic green tape after tape casting. The green tape is cut into a certain shape and size.

[0046] (5) The cut green ceramic tapes are stacked to the required height and placed on a warm press for warm pressing. The pressure of the warm press is set to 94 MPa and the temperature is set to 48°C. After holding the pressure for 3 minutes, the green ceramic substrate is obtained.

[0047] (6) Place the green tape after warm pressing in a normal pressure sintering furnace, heat it to 110°C at a rate of 1°C / min and keep it at that temperature for 0.5 h, then heat it to 500°C at a rate of 2°C / min for debinding. The debinding atmosphere is a vacuum atmosphere and the debinding time is 2 h.

[0048] (7) The temperature is continued to be raised to 1350°C at a rate of 5°C / min for sintering, and kept at this temperature for 3 h. Finally, the temperature is cooled to room temperature at a rate of 5°C / min to complete the sintering. Example

[0049] (1) An antistatic black alumina ceramic substrate comprises the following raw materials in parts by weight: 41 parts of alumina, 2.5 parts of nano silicon carbide whiskers, 18.5 parts of a special antistatic black pigment, 25 parts of a binary azeotropic mixture of anhydrous ethanol and butanone, 1.5 parts of tributyl phosphate, 6.5 parts of polyvinyl butyral, and 5 parts of polyethylene glycol. The special antistatic black pigment comprises: 40 parts of zinc oxide, 4 parts of titanium dioxide, 17.5 parts of manganese oxide, 11.5 parts of iron oxide, 14 parts of nickel oxide, 5 parts of molybdenum oxide, and 8 parts of cobalt oxide.

[0050] (2) Weighed zinc oxide, titanium dioxide, manganese oxide, iron oxide, nickel oxide, molybdenum oxide and cobalt oxide are mixed and calcined at 1300° C. for 2 h. The mixture is sand-milled to obtain an antistatic black pigment.

[0051] (3) Add antistatic black pigment, alumina powder, nano silicon carbide whisker, organic solvent and dispersant into a ball mill according to the above ratio, and perform ball milling dispersion at 65 r / min for 24 h. Add binder and plasticizer to the evenly dispersed slurry and perform secondary ball milling dispersion at 75 r / min for 24 h. After discharging, the material is degassed by a vacuum degassing machine to obtain a casting slurry with a viscosity of 2800 mPa·s.

[0052] (4) The prepared slurry is sieved and placed in a tape casting machine to obtain a ceramic green tape after tape casting. The green tape is cut into a certain shape and size.

[0053] (5) The cut green ceramic tapes are stacked to the required height and placed on a warm press for warm pressing. The pressure of the warm press is set to 96 MPa and the temperature is set to 50°C. After holding the pressure for 3 minutes, the green ceramic substrate is obtained.

[0054] (6) The green tape after warm pressing was placed in a normal pressure sintering furnace, and the temperature was raised to 120°C at a rate of 1°C / min and kept at that temperature for 0.5 h. The temperature was then raised to 550°C at a rate of 2°C / min for debinding. The debinding atmosphere was nitrogen and the debinding time was 1.5 h.

[0055] (7) The temperature is continued to be raised to 1400°C at a rate of 5°C / min for sintering, and the temperature is kept at this level for 2 h. Finally, the temperature is cooled to room temperature at a rate of 5°C / min to complete the sintering. Example

[0056] (1) An antistatic black alumina ceramic substrate comprises the following raw materials in parts by weight: 40 parts of alumina, 5 parts of nano silicon carbide whiskers, 20 parts of a special antistatic black pigment, 24 parts of a binary azeotropic mixture of anhydrous ethanol and butanone, 3 parts of oleic acid, 5 parts of polyvinyl butyral, and 3 parts of polyethylene glycol. The special antistatic black pigment comprises: 48 parts of zinc oxide, 3 parts of titanium dioxide, 16 parts of manganese oxide, 10 parts of iron oxide, 13 parts of nickel oxide, 4 parts of molybdenum oxide, and 6 parts of cobalt oxide.

[0057] (2) Weighed zinc oxide, titanium dioxide, manganese oxide, iron oxide, nickel oxide, molybdenum oxide and cobalt oxide are mixed and calcined at 1260° C. for 2 h, and then sand-milled to obtain an antistatic black pigment.

[0058] (3) Add antistatic black pigment, alumina powder, nano silicon carbide whisker, organic solvent and dispersant into a ball mill according to the above ratio, and perform ball milling dispersion at 60 r / min for 24 h. Add binder and plasticizer to the evenly dispersed slurry and perform secondary ball milling dispersion at 70 r / min for 48 h. After discharge, the material is degassed by a vacuum degassing machine to obtain a casting slurry with a viscosity of 2500 mPa·s.

[0059] (4) The prepared slurry is sieved and placed in a tape casting machine to obtain a ceramic green tape after tape casting. The green tape is cut into a certain shape and size.

[0060] (5) The cut green ceramic tapes are stacked to the required height and placed on a warm press for warm pressing. The pressure of the warm press is set to 91 MPa and the temperature is set to 46°C. After holding the pressure for 3 minutes, the green ceramic substrate is obtained.

[0061] (6) The green tape after warm pressing is placed in a normal pressure sintering furnace, and the temperature is raised to 120°C at a rate of 1°C / min and kept at that temperature for 0.5 h. The temperature is then raised to 600°C at a rate of 2°C / min for debinding. The debinding atmosphere is nitrogen and the debinding time is 2 h.

[0062] (7) The temperature is continued to be raised to 1380°C at a rate of 5°C / min for sintering, and the temperature is kept for 3 h. Finally, the temperature is cooled to room temperature at a rate of 5°C / min to complete the sintering.

[0063] According to the national standard GB12014 anti-static regulation, the point-to-point resistance is 10 5 -10 11 Ω, of which Class A anti-static requires 10 5 -10 7 Ω, Class B anti-static requirement 10 7 -10 11 Ω.

[0064] The above embodiments are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An antistatic black alumina ceramic substrate and its preparation process, characterized in that: The invention comprises the following proportions by weight: 40-55 parts of aluminum oxide, 2.5-5 parts of nanometer semiconductor whiskers, 5-20 parts of special antistatic black pigment, 20-30 parts of organic solvent, 1-3 parts of dispersant, 5-8 parts of adhesive and 3-7 parts of plasticizer.

2. The antistatic black alumina ceramic substrate and its preparation process according to claim 1, characterized in that: The special antistatic black pigment is composed of the following raw materials: 30-48 parts of zinc oxide, 3-6 parts of titanium dioxide, 16-19 parts of manganese oxide, 10-13 parts of iron oxide, 13-16 parts of nickel oxide, 4-7 parts of molybdenum oxide and 6-9 parts of cobalt oxide.

3. The antistatic black alumina ceramic substrate and its preparation process according to claim 1, characterized in that: The chromaticity value L* value of the special anti-static black pigment ranges from 18 to 30, the a* value ranges from -2 to 2, and the b* value ranges from -1 to 1.

4. The antistatic black alumina ceramic substrate and its preparation process according to claim 1, characterized in that: The preferred particle size of aluminum oxide is 0.5 μm, and the preferred particle size of the antistatic black colorant is 100-300 nm.

5. The antistatic black alumina ceramic substrate and its preparation process according to claim 1, characterized in that: The nano semiconductor whisker is a nano silicon carbide whisker.

6. The antistatic black alumina ceramic substrate and its preparation process according to claim 1, characterized in that: The diameter of the nanometer semiconductor whisker is 100-500nm, and the aspect ratio is greater than 10.

7. The antistatic black alumina ceramic substrate and its preparation process according to claim 1, characterized in that: The organic solvent is a binary azeotropic mixed solution of ethanol and butanone, the dispersant is one or more of tributyl phosphate, oleic acid, and herring oil, the adhesive is polyvinyl butyral, and the plasticizer is polyethylene glycol.

8. The antistatic black alumina ceramic substrate and its preparation process according to claim 2, characterized in that: The steps include: (a) weighing metal oxides in proportion, placing them in a normal pressure sintering furnace and calcining them at 1200-1300° C. for 2-2.5 hours to ensure that the free transition metal oxides form a stable spinel structure during sintering, and the sintering atmosphere is one of air, vacuum or nitrogen; (b) The calcined black pigment is ground into a suitable particle size range by a sand mill to obtain an antistatic black pigment.

9. The antistatic black alumina ceramic substrate and its preparation process according to claim 1, characterized in that: The steps include: (1) Preparation of slurry: adding antistatic black colorant, alumina powder, nano semiconductor whiskers, organic solvent and dispersant to a ball mill in proportion, and performing ball milling dispersion at 60-80 r / min for 12-24 h, adding binder and plasticizer to the uniformly dispersed slurry and performing secondary ball milling dispersion at 50-70 r / min for 24-48 h, and degassing the obtained slurry by a vacuum degassing machine to obtain a casting slurry with a viscosity of 2500-3500 mPa•s; (2) Tape casting: the prepared slurry is sieved and placed in a tape casting machine for tape casting and drying to obtain a ceramic green tape; (3) Cutting: Cut the raw tape into certain shapes and sizes; (4) Warm pressing and lamination: The cut green ceramic tapes are stacked to a desired height and placed on a warm pressing machine for warm pressing. The pressure of the warm pressing machine is set to 90-100 MPa and the temperature is 30-50° C. The green ceramic substrate is obtained after holding the pressure for 1-6 minutes. (5) Debinding and sintering: The green tape after warm pressing is placed in a normal pressure sintering furnace, and the temperature is raised to 100-120°C at 1°C / min and kept at this temperature for 0.5h to facilitate the complete volatilization of the organic solvent. The temperature is then raised to 500-600°C at 2°C / min for debinding. The debinding time is 1-2h. The temperature is then raised to 1320-1400°C at 5°C / min for sintering. The temperature is kept at this temperature for 2-3h. Finally, the green tape is cooled to room temperature at 5°C / min to complete the sintering. The debinding and sintering atmosphere is either nitrogen or vacuum.

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