TW202100453A - Method of directly producing spherical aluminum nitride from aluminum metal - Google Patents

Abstract

A method of directly producing spherical aluminum nitride from aluminum metal includes a preparation step, a pelletizing step, a sieving step, a mixing step, and a sintering step. The preparation step is to prepare aluminum metal with a purity over 80% and pelletize through a spray pelletizer to obtain spherical aluminum powder after the aluminum metal is hot melted in the pelletizing step. The sieving step is to sieve the spherical aluminum powder to have a required particle size. The mixing step is to mix the spherical aluminum powder and a promoter under a certain ratio to obtain a mixture. Finally, the sintering step is to place the mixture into a high pressure atmosphere sintering furnace and execute the shift reaction of the spherical aluminum powder with a temperature higher than 400°C and a pressure smaller than 50 kg/cm2 to form spherical aluminum nitride, thereby producing the aluminum nitride quickly, and attaining energy-saving, low cost, and mass production of the aluminum nitride.

Description

Method for directly producing spherical aluminum nitride from aluminum metal

The invention relates to a manufacturing method, in particular to a method for directly manufacturing spherical aluminum nitride from aluminum metal.

Aluminum nitride has high conductivity, low dielectric length loss, good electrical insulation and other characteristics, so aluminum nitride is a very popular raw material in electronic application materials, and its applicable range is very wide. It can be widely used in semiconductor and microelectronic packaging substrates, high-brightness LED chip carrier substrates, automotive electronics and lighting components, and high-power electronic components heat dissipation materials. It is one of the potential materials in the future.

Check, there are many conventional methods for the synthesis of aluminum nitride powder, for example, the conventional production method is used, and the following steps are taken in order: (1) Use r-alumina and carbon powder to mix, put in a high-temperature atmosphere sintering furnace for sintering, and the sintering temperature is about 1400 degrees Celsius to prepare aluminum nitride powder. (2) Using an explosion-proof granulator, granulate again to the required size, and at the same time, the surface obtained by the granulation still adheres to carbon powder. (3) Put it into a high-temperature atmosphere sintering furnace again for sintering, and the sintering temperature is about 1850 degrees Celsius to obtain aluminum nitride powder. (4) Put it into a low-temperature atmospheric furnace to remove carbon. Because of the uneven carbon layer on the surface, the aluminum nitride that is easily sintered becomes a block. (5) Use a pulverizer to crush the massive aluminum nitride, and then screen the required particle size according to the sieving machine. After crushing the aluminum nitride powder, the aluminum nitride powder obtained is different (Figure 1). (6) Put the sixth different aluminum nitride powder into a plasma machine with a temperature of 2300 degrees Celsius to modify the surface of the aluminum nitride powder to 90% true circle.

However, the above-mentioned manufacturing method of the aluminum nitride cannot be mass-produced. The main reason is that the aluminum nitride does not show the required spherical particle state after being formed, and the manufacturing process of the aluminum nitride is easy. Because of the mutual connection, crushing and grinding must be carried out. In addition, the particles of aluminum nitride are small. Therefore, the processing speed and the safety of the equipment must be paid attention to during the grinding operation. Otherwise, the risk of gas explosion may occur. Therefore, conventional production can only produce about 5 kilograms in one hour. Therefore, the production cost is high and energy and time consuming, and it needs to be improved.

Therefore, the purpose of the present invention is to provide a method of directly manufacturing spherical aluminum nitride from aluminum metal, which can achieve rapid, energy-saving, low-cost and mass-produced manufacturing of spherical aluminum nitride.

Therefore, the aluminum metal of the present invention directly produces spherical aluminum nitride, which includes a material preparation step, a granulation step, a screening step, a mixing step, and a sintering step; wherein, the aluminum metal with a purity of 80% or more is used in the material preparation step; The granulation step is to melt the aluminum metal into a spray granulator and then granulate to form a spherical aluminum powder; in the screening step, a sieving machine is used to screen out spherical aluminum with a particle size of less than 200um As for the mixing step, an accelerator is prepared to uniformly stir and mix the aforementioned spherical aluminum powder and the accelerator at an appropriate ratio; finally, the sintering step puts the mixture into a high-pressure atmosphere sintering furnace, And the temperature is 400 degrees Celsius or more, and the pressure is controlled below 50 kg, so that the spherical aluminum powder undergoes a conversion reaction to form a spherical aluminum nitride; therefore, through the above process, the spherical nitrogen can be greatly simplified The process of manufacturing aluminum, and the required spherical aluminum nitride shape is produced, and unnecessary grinding operations are avoided during this process, which effectively increases the production speed and reduces the production cost. At the same time, the production process can also be reduced Energy consumption is required to achieve rapid, energy-saving, low-cost and mass-produced purposes.

The foregoing and other technical content, features, and effects of the present invention will be clearly understood in the following detailed description of the preferred embodiment with reference to the drawings.

Referring to FIG. 2, the first preferred embodiment of the method for directly manufacturing spherical aluminum nitride from aluminum metal of the present invention includes a preparation step, a granulation step, a screening step, a mixing step, and a sintering step; wherein, the preparation step Prepare aluminum metal with a purity of more than 80% by weight. The aluminum metal can be aluminum ingots, aluminum scraps, etc.; in addition, the pelletizing step is to input the aluminum metal into a pelletizer to pelletize to form a ball Type aluminum powder, and the hot-melting temperature is at least 500 degrees Celsius, so that the aluminum metal can be hot-melted into a liquid state, and then input to the granulator for granulation, and the granulator is in this embodiment Take a spray granulator as an example to illustrate, and the inlet air pressure of the spray granulator is adjusted to an appropriate kilogram pressure range, and the appropriate pressure and melt flow are adjusted to obtain various ranges of aluminum powder particle size.

Continuing the foregoing, the screening step is equipped with a screening machine to input the spherical aluminum powder into the screening machine to screen out the spherical aluminum powder with a particle size of less than 200um; in addition, the mixing step is equipped with a Accelerator. In this embodiment, sodium azide is used as an example for the accelerator. The spherical aluminum powder and the accelerator are uniformly mixed in a ratio of 70% to 98% by weight: 2% to 30% by weight. Mixture; Finally, the sintering step is to put the mixture into a high-pressure atmosphere sintering furnace (not shown in the figure), and the temperature of the furnace body of the high-pressure atmosphere sintering furnace is at least 400 degrees Celsius, and the preferred range is 500 degrees ~ 1400 degrees, and the furnace body pressure can be set within 50 kg, preferably in the range of 2-40 kg, so that the spherical powder is sintered, except when the furnace body of the high-pressure atmosphere sintering furnace reaches the set required temperature After holding the temperature for 1 to 3 hours, the power can be turned off, so that the previously placed mixture undergoes a conversion reaction to form a spherical aluminum nitride, which is in the state shown in Figure 3. Therefore, through the above manufacturing method, it can be The manufacturing steps of the spherical aluminum nitride are simplified, so that the production speed can be quickly increased, and the effect of mass production can be achieved, while the production cost and the required energy consumption can be relatively reduced, thereby making the spherical aluminum nitride The process has the advantages of fast, energy-saving, low-cost and mass production.

Referring to FIG. 4, the second preferred embodiment of the method for directly manufacturing spherical aluminum nitride from aluminum metal of the present invention still includes the steps of material preparation, granulation, screening, mixing, and sintering, and the requirements disclosed in the foregoing steps and The effects to be achieved are the same as those of the first embodiment and will not be described in detail. In particular, in this embodiment, in order to reduce the oxygen content characteristics of the spherical aluminum nitride, a coating step can be continued after the sintering step. , High-temperature sintering step and refining step; wherein, the coating step is to coat the spherical aluminum nitride surface with carbon powder using a coating machine, and the carbon powder can be carbon powder below 200 nanometers; The high-temperature sintering step is to put the carbon powder-coated spherical aluminum nitride into a high-temperature atmosphere sintering furnace, and heat the furnace to a temperature of at least 1400 degrees Celsius, and then lower the temperature; finally, the refining step is Put the spherical aluminum nitride after the foregoing steps into a high-temperature gas furnace and control the temperature within the range of 400 to 700 degrees to remove carbon from the spherical aluminum nitride to obtain a low oxygen content characteristic The spherical aluminum nitride.

To summarize the foregoing, the method for directly producing spherical aluminum nitride from aluminum metal of the present invention uses the steps of material preparation, granulation, screening, mixing, and sintering to directly use aluminum metal with a purity of more than 80%, and the aluminum metal is hot melted , After being granulated by a spray granulator to form a spherical aluminum powder, the spherical aluminum powder smaller than a certain particle size is screened out, and the spherical aluminum powder and the accelerator are mixed into a mixture in a certain ratio, and then Put the mixture into a high-pressure atmosphere sintering furnace, and set the temperature above 400 degrees Celsius and control the pressure below 50 kg to make the spherical powder undergo a conversion reaction to form a spherical aluminum nitride, which will be fast, energy-saving, Low-cost and mass-produced spherical aluminum nitride; In addition, if the spherical aluminum nitride is followed by a coating step, a high-temperature sintering step, and a refining step, a spherical nitrogen with low oxygen content can be obtained. Aluminum.

However, the above is only to illustrate the preferred embodiments of the present invention, and should not be used to limit the scope of implementation of the present invention, that is, simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the content of the description of the invention , Should still fall within the scope of the invention patent.

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Fig. 1 is a state diagram of the conventionally manufactured aluminum nitride. Fig. 2 is a block diagram of the first preferred embodiment of the present invention. Fig. 3 is a state diagram of aluminum nitride produced by the present invention. Fig. 4 is a block diagram of the second preferred embodiment of the present invention.

Claims (3)

A method for directly manufacturing spherical aluminum nitride from aluminum metal, which includes: A material preparation step, which prepares aluminum metal with a purity of more than 80%; A granulation step, which, after the aluminum metal is hot-melted, is fed into a spray granulator to be granulated to form a spherical aluminum powder; In a screening step, the spherical aluminum powder is screened out with a particle size of less than 200um by using a screening machine; In a mixing step, an accelerator is prepared, which uniformly mixes the spherical aluminum powder and the accelerator at a ratio of 70% to 98% by weight: 2 to 30% by weight to form a mixture; and In a sintering step, the mixture is placed in a high-pressure atmosphere sintering furnace, and the spherical powder undergoes a conversion reaction at a temperature of 400 degrees Celsius or more and a pressure of 50 kg or less to form a spherical aluminum nitride. According to the first item in the scope of patent application, the method of directly manufacturing spherical aluminum nitride from aluminum metal. Another is to reduce the oxygen content of the spherical aluminum nitride. The sintering step can be followed by: A coating step, which uses a coating machine to coat the spherical aluminum nitride with a layer of carbon powder; A high-temperature sintering step, in which carbon powder-coated spherical aluminum nitride is placed in a high-temperature atmosphere sintering furnace for sintering, and the furnace temperature of the high-temperature atmosphere sintering furnace is at least heated in the range of 1200 degrees Celsius to 1900 degrees Celsius, and then cooled ;and In a refining step, the spherical aluminum nitride after the aforementioned steps is placed in a high-temperature gas furnace, and the temperature is controlled within the range of 400 to 700 degrees to obtain a spherical aluminum nitride with low oxygen content. According to the method for directly producing spherical aluminum nitride from aluminum metal according to item 1 of the scope of patent application, the granulator is a spray granulator.

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