▎ 摘　　要

NOVELTY - A high-performance alumina ceramic substrate comprises a substrate main unit composed of 96-99 %mass aluminum oxide, 0.01-0.02 %mass zirconium dioxide, 0.015-0.02 %mass yttrium trioxide, 0.01-0.015 %mass magnesium oxide, and remaining graphene. The surface of the substrate main unit is provided with a coating. The substrate main unit includes a substrate provided with heat dissipation holes, which penetrate the upper and lower surfaces of the substrate, and are distributed in an array, and a support assembly arranged at the bottom of the substrate. The support assembly includes horizontal plates and vertical plates, which are crisscrossed to form a grid structure. The upper end of the horizontal plate is fixedly connected with the lower surface of the substrate. The upper end of the vertical plate is fixedly connected with the lower surface of the substrate. The heat dissipation holes are located between two adjacent horizontal plates and two adjacent vertical plates. USE - The high-performance alumina ceramic substrate is useful for automobile hybrid circuit substrate, communication hybrid circuit universal substrate, printer and substrate for semiconductor device, and new energy automobile field substrate. ADVANTAGE - The high-performance alumina ceramic substrate uses substrate main unit, which has improved thermal conductivity by adding graphene, high flexural strength, and electrical breakdown strength, and prolonged service life, and is inexpensive. The weldability of the surface of the alumina ceramic substrate is changed, which facilitates the installation of components and reduces the surface roughness of the alumina ceramic substrate by arranging the coating on the surface of the substrate main unit. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the high-performance alumina ceramic substrate.