Low Temperature Sintering and Dielectric Properties of Alumina‐Filled Glass Composites for LTCC Applications

Glass + ceramic composites using lead‐free ultralow‐softening point glass matrices (brand names G 018‐249 and G 018‐250) with alumina fillers are investigated. The composites show good densification with near zero shrinkage at very low sintering temperature and do not show either the formation of secondary crystalline phases or dissolution of alumina. They further show no reactivity with the silver electrodes at a sintering temperature of 650°C and have permittivities of 9.5 and 8.8, loss tangents of 0.0068 and 0.0087 at 1 MHz for the samples containing G 018‐249 glass and G 018‐250 glass, respectively.