COMPOSITIONAL DESIGN AND PROPERTIES OF A LOW-KAPPA SILICA DIELECTRIC FOR MULTILAYER CERAMIC SUBSTRATE

Compositional design and properties of a lo N-dielectric-constant sili ca composite containing borosilicate glass, high-silica glass and gall ium oxide are described. A cristobalite-free silica dielectric with a high sintered density, >95%, is obtained at temperatures less than 100 0 degrees C. An analytical approach assuming the mixing rule is used t o design compositions with desirable properties, and validated by expe rimental results. Compositions with a thermal expansion coefficient co mpatible with Si and GaAs, and dielectric constants in the ranges of 4 -5 and 5-6, respectively, at 1 MHz, are developed.