Abstract:
A method utilizes easily obtained carbon as carbon source for sintering, followed by high energy ball milling process with planetary ball mill for high energy homogenous mixing of the carbon source, solvent and nano-level silicon dioxide powder, along with a high energy ball milling process repeatedly performed using different sized ball mill beads, so as to formulate a spray granulation slurry with the optimal viscosity, to complete the process of micronization of carbon source evenly encapsulated by silicon dioxide powders. The optimal ratio of C/SiO2 is 1-2.5 to produce a spherical silicon dioxide powder (40-50 μm) evenly encapsulated by the carbon source. The powder is then subjected to a high temperature (1450□) sintering process under nitrogen gas. Lastly, the sintered silicon nitride powder is subjected to homogenizing carbon removal process in a rotational high temperature furnace to complete the fabricating process.
Abstract:
A method for preparing aluminum nitride powder, comprising: (A) providing an aluminum metal powder and a carbon source, and mixing the aluminum metal powder and the carbon source to form a mixed powder; (B) performing a medium-low-temperature nitriding reaction on the mixed powder to form a partially nitrided aluminum nitride powder containing an intermediate aluminum carbide phase; (C) subjecting the partially nitrided aluminum nitride powder to a high-temperature nitriding reaction to remove the intermediate aluminum carbide phase and form a fully nitrided aluminum nitride powder; and (D) decarbonizing the fully nitrided aluminum nitride powder in the atmosphere to form a high-purity aluminum nitride powder. Compared with the direct nitriding method of aluminum powder, although additionally introduces the carbon mixing and decarbonizing steps, the subsequent grinding steps can also be omitted, thereby avoiding the introduction of redundant impurities and improving the purity of the output aluminum nitride powder.
Abstract:
A method of preparing a heterogeneous stacked co-fired ceramic for use in an aluminum nitride-based electrostatic chuck includes providing a first aluminum nitride blank layer; applying a metal ink to the first aluminum nitride blank layer to form thereon an electrostatic electrode layer by screen printing, wherein the metal ink mainly contains a metal of high melting point; stacking a second aluminum nitride blank layer on the electrostatic electrode layer; laminating the first aluminum nitride blank layer, the electrostatic electrode layer, and the second aluminum nitride blank layer (collectively known as a heterogeneous ceramic) together; and co-firing the laminated heterogeneous ceramic in accordance with a sintering temperature rising curve to prepare the heterogeneous stacked co-fired ceramic characterized by reduced differences in sintering shrinkage ratio between the electrostatic electrode and aluminum nitride blank and enhanced strength and adhesion of the interface between the electrostatic electrode and aluminum nitride blank.