Enhanced dielectric properties of alumina ceramic substrate for microwave application

Alumina ceramic with enhanced dielectric property was reported in this paper, which indicates its microwave application. Commercial A1203 powder and sintering aids including MgO were utilized to fabricate alumina ceramic substrate. Liquid deposit was introduced to wrap the surface of A1203 powder with MgO additives uniformly. The prepared composite powder was shaped by tape casting and sintered by two-step sintering to ensure density and suitable microstructure. It is shown that MgO addition restrains gain growing and decreases porosity in scanning electron micrograph. MgA1204 spinel, formed by MgO was detected by XRD. The dielectric loss of the alumina ceramic substrate is 6.84 × 10^-4.