Method for preparing submicron aluminum nitride powder from aluminum oxide powder, carbon black and yttrium oxide auxiliaries

Abstract

The invention discloses a method for preparing submicron aluminum nitride powder from aluminum oxide powder, carbon black and yttrium oxide auxiliaries. The preparation method specifically comprises the following steps: mixing alumina powder, carbon black and yttrium oxide in absolute ethyl alcohol according to a certain proportion, putting the mixed liquid and a certain mass of ball-milling beads into an alumina ball-milling tank, and carrying out ball-milling for a certain time in a planetary ball mill at a certain rotating speed; transferring the obtained mixture into a glass dish, and drying in a drying oven for a period of time to obtain a precursor mixture; and grinding the dried precursor mixture, placing the ground precursor mixture in an alumina crucible, nitriding in a nitrogen atmosphere, and decarburizing in an air atmosphere to obtain the aluminum nitride powder.

Description

Technical Field

[0001] The invention relates to a method for preparing submicron aluminum nitride powder by utilizing aluminum oxide powder, carbon black and yttrium oxide auxiliary agent. Background Art

[0002] In recent years, the rapid development of electronic technology has put forward higher requirements for the thermal conductivity of substrates and packaging materials. Due to the good thermal conductivity of aluminum nitride ceramics, good mechanical properties, linear expansion coefficient similar to silicon, high volume resistivity, low dielectric constant and dielectric loss, high temperature and corrosion resistance, it is an ideal material for a new generation of semiconductor substrates and electronic device packaging. Aluminum nitride powder is widely used in the field of electronic communications due to its high thermal conductivity, low thermal expansion coefficient, low dielectric constant and dielectric loss characteristics. The traditional carbon thermal reduction method directly uses aluminum oxide powder and carbon black as raw materials, and mixes the two raw materials evenly by mechanical ball milling. However, due to the low activity of the raw materials, the reaction temperature is high and the reaction time is long. In order to reduce the calcination temperature and shorten the heat preservation time, reduce energy consumption, the method mentioned in the present invention is to produce a liquid phase reaction during the calcination process by using yttrium oxide as an auxiliary agent, promote the nitridation reaction, reduce the synthesis temperature and heat preservation time, and synthesize high-purity submicron aluminum nitride powder. Summary of the invention

[0003] The technical problem to be solved by the present invention is to improve the defects of the existing preparation method such as high synthesis temperature and long synthesis time, and to provide a preparation method of aluminum nitride submicron powder which is simple to operate, pollution-free, low in energy consumption and has high purity of sample product.

[0004] The specific scheme of the present invention is: A method for preparing submicron aluminum nitride powder using aluminum oxide powder, carbon black and yttrium oxide additive, comprising the following steps: (1) mixing alumina powder, carbon black and yttrium oxide in anhydrous ethanol in a certain proportion; (2) placing the mixed liquid and a certain mass of ball milling beads in an alumina ball milling jar, and ball milling them at a certain speed for a period of time in a planetary ball mill; (3) The obtained mixture is transferred into a glass dish and dried in an oven to obtain a precursor mixture. (4) After nitriding in a nitrogen atmosphere, decarburization is performed in an air atmosphere to obtain aluminum nitride powder.

[0005] Furthermore, the particle size of the alumina powder described in (1) is 250-500 nm, and the particle size of the carbon black is 20 nm.

[0006] Furthermore, in (1), the molar ratio of aluminum oxide to carbon black is 1:8-10, the mass ratio of aluminum oxide to yttrium oxide is 100:1-3, and the mass ratio of the solid mixture of aluminum oxide, carbon black and yttrium oxide to anhydrous ethanol is 1:3-4.

[0007] Furthermore, in (2), the mass ratio of the solid mixture to the ball milling beads is 1:2-3.

[0008] Furthermore, in (2), the rotation speed of the planetary ball mill is 180-200 revolutions per minute, and the ball milling time is 6-8 hours.

[0009] Furthermore, in (3), the drying temperature is 70°C to 90°C.

[0010] Furthermore, in (4), the temperature for nitridation by carbon thermal reduction is obtained by a programmed temperature rising method, and the temperature rising program is: heating from room temperature to an intermediate temperature at a first heating rate, heating from the intermediate temperature to a temperature for nitridation by carbon thermal reduction at a second heating rate, and then keeping warm; the first heating rate is 4°C / min to 6°C / min, the intermediate temperature is 900°C to 1100°C, the second heating rate is 2°C / min to 4°C / min, the temperature for nitridation by carbon thermal reduction is 1500°C to 1550°C, and the holding time is 6h to 8h.

[0011] Furthermore, in (4), the decarburization temperature is programmed by heating to 600°C to 700°C at a rate of 6°C / min to 8°C / min and then kept at that temperature for 2h to 4h.

[0012] Furthermore, in (4), the average particle size of the aluminum nitride powder is 420nm~440nm.

[0013] The technical problem to be solved by the present invention is to improve the defects of the existing preparation method such as high synthesis temperature and long synthesis time, and to provide a preparation method of aluminum nitride submicron powder which is simple to operate, pollution-free, low in energy consumption and has high purity of sample product.

[0014] The present invention provides submicron aluminum nitride powder prepared by the above preparation method.

[0015] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0016] The reagents and raw materials used in the present invention are commercially available.

[0017] The positive and progressive effects of the present invention are: (1) Simple operation, no pollution, and low energy consumption; (2) The product has high purity. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the SEM image of Example 1.

[0019] Figure 2 This is the XRD pattern of Example 1.

[0020] Figure 3 This is the SEM image of Example 2.

[0021] Figure 4 This is the XRD pattern of Example 2. DETAILED DESCRIPTION

[0022] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principle of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention. The experimental methods in the following examples that do not specify specific conditions are selected according to conventional methods and conditions, or according to the product instructions.

[0023] Example 1 (1) mixing alumina powder with a particle size of 500 nm, carbon black with a particle size of 20 nm, and yttrium oxide in a ratio of 1:8 in molar ratio of alumina to carbon black and 100:1 in mass ratio of alumina to yttrium oxide, and then mixing the solid mixture of alumina, carbon black, and yttrium oxide with anhydrous ethanol in a mass ratio of 1:3; (2) the mixed liquid and ball milling beads were mixed in a mass ratio of 1:2 and placed in an alumina ball milling jar, and ball milled at a speed of 180 rpm for 8 h in a planetary ball mill; (3) The obtained mixture is transferred into a glass dish and dried in an oven at 70° C. to obtain a precursor mixture; (4) After nitriding in a nitrogen atmosphere, decarburization is performed in an air atmosphere to obtain submicron aluminum nitride powder. The procedure for nitriding by carbothermal reduction in a nitrogen atmosphere is: heating from room temperature to 1100°C at a rate of 4°C / min, and from 1100°C to 1400°C at a rate of 2.5°C / min, and keeping the temperature for 8 hours; the procedure for decarburization in an air atmosphere is: heating from room temperature to 600°C at a rate of 6°C / min and keeping the temperature for 2 hours; (5) Figure 1 This is a SEM image of submicron aluminum nitride powder prepared in Example 1 of the present invention. Figure 1 It can be seen that the average particle size of the aluminum nitride powder prepared in Example 1 is 420 nm. Figure 2 The XRD pattern of the submicron aluminum nitride powder prepared in Example 1 of the present invention is as follows: Figure 2It can be seen that the aluminum nitride powder prepared in this embodiment is pure phase aluminum nitride. Example 2

[0024] (1) mixing alumina powder with a particle size of 250 nm, carbon black with a particle size of 20 nm, and yttrium oxide in a ratio of 1:10 in molar ratio of alumina to carbon black and 100:3 in mass ratio of alumina to yttrium oxide, and then mixing the solid mixture of alumina, carbon black, and yttrium oxide with anhydrous ethanol in a mass ratio of 1:4; (2) the mixed liquid and ball milling beads were mixed in a mass ratio of 1:3 and placed in an alumina ball milling jar, and ball milled at a speed of 200 rpm for 6 h in a planetary ball mill; (3) The obtained mixture is transferred into a glass dish and dried in an oven at 90° C. to obtain a precursor mixture; (4) After nitriding in a nitrogen atmosphere, decarburization is performed in an air atmosphere to obtain submicron aluminum nitride powder. The procedure for nitriding by carbothermal reduction in a nitrogen atmosphere is: heating from room temperature to 1100°C at a rate of 6°C / min, and from 1100°C to 1400°C at a rate of 3.5°C / min, and keeping the temperature for 6 hours; the procedure for decarburization in an air atmosphere is: heating from room temperature to 580°C at a rate of 6°C / min and keeping the temperature for 3 hours; (5) Figure 3 This is a SEM image of submicron aluminum nitride powder prepared in Example 2 of the present invention. Figure 3 It can be seen that the average particle size of the aluminum nitride powder prepared in Example 2 is 440 nm. Figure 4 The XRD pattern of the submicron aluminum nitride powder prepared in Example 2 of the present invention is as follows: Figure 4 It can be seen that the aluminum nitride powder prepared in this embodiment is pure phase aluminum nitride.

Claims

1. A method for preparing submicron aluminum nitride powder using aluminum oxide powder, carbon black and yttrium oxide additive, characterized in that: The following steps are involved: (1) mixing alumina powder, carbon black and yttrium oxide in anhydrous ethanol in a certain proportion; (2) placing the mixed liquid and a certain mass of ball milling beads in an alumina ball milling jar, and ball milling them at a certain speed for a period of time in a planetary ball mill; (3) The obtained mixture is transferred into a glass dish and dried in an oven to obtain a precursor mixture; (4) After nitriding in a nitrogen atmosphere, decarburization is performed in an air atmosphere to obtain aluminum nitride powder.

2. The method for preparing submicron aluminum nitride powder using aluminum oxide powder, carbon black and yttrium oxide additive according to claim 1, characterized in that: The particle size of the alumina powder is 250-500 nm, and the particle size of the carbon black is 20 nm.

3. The method for preparing submicron aluminum nitride powder using aluminum oxide powder, carbon black and yttrium oxide additive according to claim 1, characterized in that: The molar ratio of aluminum oxide to carbon black is 1:8-10, the mass ratio of aluminum oxide to yttrium oxide is 100:1-3, and the mass ratio of the solid mixture of aluminum oxide, carbon black and yttrium oxide to anhydrous ethanol is 1:3-4.

4. The method for preparing submicron aluminum nitride powder using aluminum oxide powder, carbon black and yttrium oxide additive according to claim 1, characterized in that: The mass ratio of the solid mixture to the ball milling beads is 1:2-3.

5. The method for preparing submicron aluminum nitride powder using aluminum oxide powder, carbon black and yttrium oxide additive according to claim 1, characterized in that: The rotation speed of the planetary ball mill is 180-200 revolutions per minute, and the ball milling time is 6-8 hours.

6. The method for preparing submicron aluminum nitride powder using aluminum oxide powder, carbon black and yttrium oxide additive according to claim 1, characterized in that: The drying temperature is 70°C to 90°C.

7. The method for preparing submicron aluminum nitride powder using aluminum oxide powder, carbon black and yttrium oxide additive according to claim 1, characterized in that: The temperature for nitriding by carbon thermal reduction is obtained by a programmed temperature rising method, and the temperature rising program is: heating from room temperature to an intermediate temperature at a first heating rate, heating from the intermediate temperature to a temperature for nitriding by carbon thermal reduction at a second heating rate, and then keeping warm; the first heating rate is 4°C / min to 6°C / min, the intermediate temperature is 900°C to 1100°C, the second heating rate is 2°C / min to 4°C / min, the temperature for nitriding by carbon thermal reduction is 1500°C to 1550°C, and the holding time is 6h to 8h.

8. The method for preparing submicron aluminum nitride powder using aluminum oxide powder, carbon black and yttrium oxide additive according to claim 1, characterized in that: The decarburization temperature is programmed by heating to 600°C to 700°C at a rate of 6°C / min to 8°C / min and then kept at that temperature for 2h to 4h.

9. The method for preparing submicron aluminum nitride powder using aluminum oxide powder, carbon black and yttrium oxide additive according to claim 1, characterized in that: The average particle size of the aluminum nitride powder is 400nm~450nm.

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