The primary purpose of this study is to develop the technology of fabricating silicon carbide thin substrate by means of tape casting in these experiments; silicon carbide ceramic by addition of Al 2 O 3 and Y 2 O 3 sintering aids can exhibit both high strength and toughness, simultaneously. The variables of these explorations include (1) silicon carbide raw powders: particle size and crystalline phase; (2) slurry formula: relative content of solvent and dispersant binder. To investigate the correlation /ships among the aforementioned variables are discussed by the green density, uniformity, Sintered density as well as microstructures. Based on prior experimental results, the best parameters of organic additives and tape casting processing for manufacturing silicon carbide thin tape are suggested. Furthermore, the green tapes with superior properties are densities by pressureless sintering to 97.5%.