An easy approach to adjust microstructure and physical properties in alumina

In the ceramic industry, alumina is widely used as a ceramic filler for thermal interface materials (TIM) and a heat dissipation substrate for power semiconductor devices. In this study, using additives, the grain size was grown to obtain high thermal conductivity, and it was minimized to achieve the high flexural strength. For the ceramic filler of TIM, the grain size of alumina could be larger through liquid phase sintering to obtain the high thermal conductivity. On the contrary, for the ceramic substrate, the flexural strength could be improved by minimizing not only the grain sizes of alumina but also the difference in the grain sizes of an additive and alumina. Consequently, the high thermal conductivity of 36 W m −1 K −1 was obtained in the alumina which has large grains. In addition, the high flexural strength of 745 MPa were obtained in the alumina for the ceramic substrate.