Black aluminum oxide ceramic and manufacturing method thereof

Abstract

The invention relates to black aluminum oxide ceramic and a manufacturing method thereof, and the manufacturing method of the black aluminum oxide ceramic comprises the following steps: (1) weighing 800-1200 parts by weight of aluminum oxide, 13-17 parts by weight of cobalt oxide, 21-29 parts by weight of iron oxide and 14-22 parts by weight of manganese oxide, adding a solvent and a dispersant, and carrying out ball milling dispersion; (2) adding a binder and a plasticizer into the product obtained in the step (1), and then carrying out ball milling dispersion; (3) carrying out tape casting on the slurry obtained in the step (2) to obtain a green body; (4) the green body in the step (3) is subjected to punching and glue discharging; and (5) sintering to obtain the black alumina ceramic. The black aluminum oxide ceramic disclosed by the invention has excellent heat-conducting property, breaking strength and dielectric strength and low visible light reflectivity.

Description

Technical Field

[0001] The invention relates to the technical field of alumina ceramics, and in particular to a black alumina ceramic and a manufacturing method thereof. Background Art

[0002] In the electronic packaging industry, various materials are usually required to package semiconductors and display components with strong photosensitivity. Since white, ivory and other colored materials used as components around the light source or in the focal plane will cause reflected light and glare, and glare will cause visual discomfort, the packaging materials used for the digital tube lining are required to be black to ensure clear digital display, and the special materials used for the packaging tube shell need to have light shielding properties. The packaging materials of plastic products can be processed into black, but black plastic packaging materials are relatively poor in moisture resistance, air tightness, chemical stability and impact resistance, and it is difficult to meet the requirements of high-performance packaging; when ceramic materials are used, the firing temperature of aluminum nitride ceramics is too high and it is not easy to reduce it through the adjustment of formula and process, so it is difficult to produce black aluminum nitride ceramics; beryllium oxide is toxic and is restricted, and the prices of the two materials are relatively expensive. When black alumina ceramics are used as special ceramic packaging materials, they have high reliability, high air tightness and heat shock resistance, and the cost of black alumina ceramics is low. The patent with publication number CN107406328A discloses a black alumina ceramic body, but its thermal conductivity, flexural strength, electrical strength and visible light reflectivity are insufficient, and there is still an urgent need for a black alumina ceramic with better performance. Summary of the invention

[0003] In order to overcome the technical defects of the prior art, the present invention provides a black alumina ceramic and a manufacturing method thereof, wherein the black alumina ceramic has excellent thermal conductivity, flexural strength, electrical strength, and low visible light reflectivity.

[0004] The technical solution adopted by the present invention is: a method for manufacturing black alumina ceramics, comprising the following steps: (1) Weigh 800-1200 parts by weight of aluminum oxide, 13-17 parts by weight of cobalt oxide, 21-29 parts by weight of iron oxide, and 14-22 parts by weight of manganese oxide, add a solvent and a dispersant, and disperse by ball milling; (2) adding a binder and a plasticizer to the product obtained in step (1), and then ball-milling and dispersing the product; (3) using the slurry obtained in step (2) to perform tape casting to form a green body; (4) Punching and debinding the green body in step (3); (5) Sintering to obtain black alumina ceramics.

[0005] Preferably, the solvent comprises alcohol and butanone.

[0006] Preferably, the adhesive comprises PVB (polyvinyl butyral).

[0007] Preferably, the dispersant comprises OP.

[0008] Preferably, the plasticizer comprises DBP.

[0009] Preferably, the debinding temperature is 500-550° C., and the debinding time is 4-6 hours.

[0010] Preferably, the sintering temperature is 1550-1650°C.

[0011] Preferably, the blank is punched in step (4) to obtain a size of 150 mm*150 mm.

[0012] Preferably, the method further comprises step (6), grinding, grinding both sides of the black alumina ceramic.

[0013] The present invention also relates to a black oxide ceramic, which is manufactured by adopting the above-mentioned black aluminum oxide ceramic manufacturing method.

[0014] The beneficial effects of the present invention are as follows: the black alumina ceramics obtained by the method of the present invention have low manufacturing cost and excellent performance, do not contain harmful substances, have high thermal conductivity, and have a thermal conductivity greater than 18w / mK; have high flexural strength greater than 450Mpa; have high electrical strength greater than 15kV / mm, and have a visible light reflectivity of less than 5%, which can meet the light-shielding and anti-glare requirements of electronic products. DETAILED DESCRIPTION

[0015] The present invention will be further described below: This embodiment provides a method for manufacturing black alumina ceramics, which comprises the following steps: (1) Weigh 800-1200 parts by weight of aluminum oxide, 13-17 parts by weight of cobalt oxide, 21-29 parts by weight of iron oxide, and 14-22 parts by weight of manganese oxide, add a solvent and a dispersant, and disperse by ball milling; (2) adding a binder and a plasticizer to the product obtained in step (1), and then ball-milling and dispersing the product; (3) using the slurry obtained in step (2) to perform tape casting to form a green body; (4) Punching and debinding the green body in step (3); (5) Sintering to obtain black alumina ceramics; (6) Polishing: polishing both sides of the black alumina ceramic.

[0016] The invention adopts alcohol and butanone as solvents, PVB (polyvinyl butyral) as a binder, OP as a dispersant, DBP as a plasticizer, and aluminum oxide with a D50 of 0.8 um for preparation.

[0017] In step (3), a vacuum degassing process is used for tape casting, and the viscosity of the slurry is controlled at 10000-12000CP. The green body with a thickness of 0.75mm is tape cast, and then punched into green bodies with a size of 150*150mm. After powder coating, 10 pieces are stacked and debonded. After sintering, black alumina with a size of 127*127*0.56mm is obtained. After double-sided grinding, a black alumina substrate with a size of 127*127*0.38mm is obtained.

[0018] When testing the thermal conductivity of black alumina ceramics, it is measured according to standard ISO220072.

[0019] When the flexural strength test of black alumina ceramics is carried out, it is measured according to the standard GB / T 6569-1986. Example 1

[0020] This embodiment provides a black alumina ceramic and a manufacturing method thereof. The manufacturing method of the black alumina ceramic is as follows: (1) 800 parts by weight of aluminum oxide, 13 parts by weight of cobalt oxide, 21 parts by weight of iron oxide, 14 parts by weight of manganese oxide, 300 parts by weight of alcohol and 250 parts by weight of butanone as solvents, 7 parts by weight of OP as a dispersant, and ball milling for 10 hours; (2) adding 60 parts by weight of PVB (polyvinyl butyral) and 30 parts by weight of DBP to the product obtained in step (1), and then ball-milling and dispersing for 24 hours; (3) tape-casting the slurry obtained in step (2) using a vacuum degassing process to form a green body with a thickness of 0.75 mm; (4) Punching the green billet in step (3) to obtain a green billet of 150*150 mm, applying powder, and debinding 10 pieces in a stack at a debinding temperature of 500°C / 4h; (5) Sintering at 1580°C for 3 h in a high-temperature sintering furnace to obtain black alumina ceramics with a size of 127*127*0.56 mm; (6) Polishing: Polish both sides of the black alumina ceramic to obtain a black alumina ceramic substrate of 127*127*0.38 mm. Example 2

[0021] This embodiment provides a black alumina ceramic and a manufacturing method thereof. The manufacturing method of the black alumina ceramic is as follows: (1) Weigh 1000 parts by weight of aluminum oxide, 15 parts by weight of cobalt oxide, 25 parts by weight of iron oxide, and 18 parts by weight of manganese oxide, add 350 parts by weight of alcohol and 300 parts by weight of butanone as solvents, add 10 parts by weight of OP as a dispersant, and disperse by ball milling for 10 hours; (2) adding 90 parts by weight of PVB (polyvinyl butyral) and 50 parts by weight of DBP to the product obtained in step (1), and then ball-milling and dispersing for 24 hours; (3) tape-casting the slurry obtained in step (2) using a vacuum degassing process to form a green body with a thickness of 0.75 mm; (4) Punching the green billet in step (3) to obtain a green billet of 150*150 mm, applying powder, and debinding 10 pieces in a stack at a debinding temperature of 500°C / 4h; (5) Sintering at 1580°C for 3 h in a high-temperature sintering furnace to obtain black alumina ceramics with a size of 127*127*0.56 mm; (6) Polishing: Polish both sides of the black alumina ceramic to obtain a black alumina ceramic substrate of 127*127*0.38 mm. Example 3

[0022] (1) Weigh 1200 parts by weight of aluminum oxide, 17 parts by weight of cobalt oxide, 30 parts by weight of iron oxide, and 22 parts by weight of manganese oxide, add 400 parts by weight of alcohol and 350 parts by weight of butanone as solvents, add 13 parts by weight of OP as a dispersant, and disperse by ball milling for 10 hours; (2) adding 120 parts by weight of PVB (polyvinyl butyral) and 70 parts by weight of DBP to the product obtained in step (1), and then ball-milling and dispersing for 24 hours; (3) tape-casting the slurry obtained in step (2) using a vacuum degassing process to form a green body with a thickness of 0.75 mm; (4) Punching the green billet in step (3) to obtain a green billet of 150*150 mm, applying powder, and debinding 10 pieces in a stack at a debinding temperature of 500°C / 4h; (5) Sintering at 1580°C for 3 h in a high-temperature sintering furnace to obtain black alumina ceramics with a size of 127*127*0.56 mm; (6) Polishing: Polish both sides of the black alumina ceramic to obtain a black alumina ceramic substrate of 127*127*0.38 mm.

[0023] Test results, Table 1:

[0024] The black alumina ceramic in Patent Example 2 with Publication No. CN107406328A was used as a comparative example.

[0025] It can be seen from Table 1 above that the black alumina ceramics obtained in Examples 1-3 have better thermal conductivity, flexural strength and electrical strength, and have extremely low visible light reflectivity.

[0026] The above shows and describes the basic principles and main features of the black aluminum oxide 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 only illustrate 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 are all 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. A method for manufacturing black alumina ceramics, characterized in that: The following steps are included: (1) Weigh 800-1200 parts by weight of aluminum oxide, 13-17 parts by weight of cobalt oxide, 21-29 parts by weight of iron oxide, and 14-22 parts by weight of manganese oxide, add a solvent and a dispersant, and disperse by ball milling; (2) adding a binder and a plasticizer to the product obtained in step (1), and then ball-milling and dispersing the product; (3) using the slurry obtained in step (2) to perform tape casting to form a green body; (4) Punching and debinding the green body in step (3); (5) Sintering to obtain black alumina ceramics.

2. The method for producing black alumina ceramics according to claim 1, characterized in that: The solvent includes alcohol and butanone.

3. The method for manufacturing black alumina ceramics according to claim 1, characterized in that: The adhesive includes PVB.

4. The method for manufacturing black alumina ceramics according to claim 1, characterized in that: The dispersant includes OP.

5. The method for manufacturing black alumina ceramics according to claim 1, characterized in that: The plasticizer includes DBP.

6. The method for manufacturing black alumina ceramics according to claim 1, characterized in that: The debinding temperature is 500-550° C., and the debinding time is 4-6 hours.

7. The method for manufacturing black alumina ceramics according to claim 1, characterized in that: The sintering temperature is 1550-1650°C.

8. The method for manufacturing black alumina ceramics according to claim 1, characterized in that: In step (4), the green body is punched to obtain a size of 150 mm*150 mm.

9. The method for manufacturing black alumina ceramics according to claim 1, characterized in that: The method also includes step (6) of polishing, in which both sides of the black alumina ceramic are polished.

10. Black oxide ceramics, characterized in that: The black alumina ceramic is manufactured by the manufacturing method of any one of claims 1 to 9.

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