METHOD OF PRODUCING ALUMINIUM NITRIDE-BASED HEAT-CONDUCTING CERAMIC Russian patent published in 2011 - IPC C04B35/581 

FIELD: chemistry.

SUBSTANCE: invention relates to production of aluminium nitride-based heat-conducting ceramic which can be used in electronics and electrical engineering, particularly as substrate material for powerful microwave and power semiconductor devices, as well as other devices where there is need for good dielectric properties, strength and heat conductivity of the material. Powder of aluminium nitride with particle size less than 1 mcm, containing not less than 10% cubic phase of aluminium nitride with particle size less than 100 nm, and a technical additive selected from Y₂O₃, CaO, MgO in amount of not more than 6 wt % is used to prepare a mixture, with addition of not more than 65 vol. % organic component containing a solvent (mixture of methylethyl ketone with ethanol in ratio of 1:2), a dispersant (phosphate ether), binder (polyvinyl butyral) and a plasticiser (mixture of polyethylene glycol with dibutyl phthalate), followed by stirring with simultaneous deaeration for not less than 30 minutes rarefaction of air of not less than 0.15 atm. A belt is formed from the obtained slip, dried and cooled to room temperature. A plate is formed from the belt. The organic component is removed at temperature 150-500°C. The obtained half-finished product is sintered at pressure 0.1-1.0 MPa in the atmosphere of a nitrogen-containing gas at temperature 1650-1820°C for 1-3 hours and then cooled under given conditions.

EFFECT: increase in heat-conductivity to 230 W/m·K, strength and output of the ceramic material.

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