Method for preparing aluminum nitride ceramic powder based on urea/melamine nitrogen source

Abstract

The invention relates to a method for preparing aluminum nitride ceramic powder based on a urea / melamine nitrogen source. The method comprises the following steps: (1) preparing raw materials; (2) dissolving aluminum nitrate nonahydrate into water, adding a coupling agent and polyethylene glycol and uniformly stirring; (3) adding a precipitant, stirring to form a precursor gel, and filtering afteralcohol washing to obtain a gel; (4) putting the gel into absoluteethyl alcohol, adding phenolic resin under a stirring condition, stirring to form a paste body, baking, calcining and grinding to obtain a precursor powder; (5) grinding and mixing with a nitrogen source, placing into a heating furnace, increasing temperature to 950-1500 DEG C for performing nitridation synthesis when the air pressure in the heating furnace is higher than barometric pressure, performing furnace cooling, and grinding to obtain rough powder; and (6) and heating to 550-650 DEG C for removing carbon. According to the method provided by the invention, high-activity urea / melamine instead of nitrogen is taken as a nitrogen source, and a surface modification dispersion technology is adopted, so that atom- or molecule-level uniform mixing between an aluminum source and a carbon source is realized, and the temperature of carbon thermal reduction reaction is lowered.

Description

Technical field [0001] The invention belongs to the technical field of materials, and particularly relates to a method for preparing aluminum nitride ceramic powder based on a urea / melamine nitrogen source. Background technique [0002] Aluminum nitride is a ceramic material with excellent comprehensive properties. With the continuous deepening of research, the preparation process of aluminum nitride has become more mature and its application scope has been expanding; especially since the 21st century, with the rapid development of microelectronics technology With the development, electronic complete machines and electronic components are moving towards miniaturization, light weight, integration, and high reliability and high power output. More and more complex devices have improved the heat dissipation of substrates and packaging materials. High requirements; the thermal conductivity of traditional resin substrates and alumina ceramic substrates is below 30W / (m·K), which is far ...

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Problems solved by technology

[0002] Aluminum nitride is a ceramic material with excellent comprehensive performance. With the deepening of research, the preparation technology of aluminum nitride is becoming more and more mature, and its application range is also expanding; especially since the 21st century, with the rapid development of microelectronics technology With the development, electronic machines and electronic components are developing towards the direction of miniaturization, light weight, integration, high reliability and high power output. high requirements; the thermal conductivity of traditional resin substrates and alumina ceramic substrates is below 30W / (m K), which is far from meeting the development needs of large-scale integrated circuits and complex devices; the theoretical thermal conductivity of aluminum nitride ceramics The conductivity is 320W / (m K), and it has good electrical insulation, low dielectric constant and dielectric loss, a good thermal expansion coefficient with silicon, good chemical stability, environmental protection and non-toxicity, etc. Advantages, has become the most ideal substrate material and electronic device packaging material

[0003] At present, the methods for producing aluminum nitride ceramic powder mainly include direct nitriding of aluminum powder, carbothermal reduction and high-energy ball milling; in the direct nitriding of aluminum powder, since the nitriding reaction of aluminum powder is a strong exothermic reaction, the reaction The process is not easy to control, and the large amount of heat released can easily cause aluminum to form a fused block, which hinders the diffusion of nitrogen, resulting in incomplete reaction, and the reaction product often needs to be pulverized, so it is difficult to synthesize high-purity, fine-grained products; in the carbothermal reduction method, The mixed powder of alumina and carbon is in high temperature, flowing N 2 Reductive nitriding reaction occurs in the air to generate AlN powder; the nitrogen source used in this method is a flowing inert gas—nitrogen, which requires a higher temperature (1500-1800°C) for the carbothermal reduction reaction to occur, resulting in particle growth and sintering activity. Reduced; it is easy to introduce impurities in the high-energy ball milling method, resulting in lower purity of the powder, and this method has not been widely used so far

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