Compositional Design and Properties of a Low-k Silica Dielectric for Multilayer Ceramic Substrate

Abstract

Compositional design and properties of a low-dielectric-constant silica composite containing borosilicate glass, high-silica glass and gallium oxide are described. A cristobalite-free silica dielectric with a high sintered density, >95%, is obtained at temperatures less than 1000° C. An analytical approach assuming the mixing rule is used to design compositions with desirable properties, and validated by experimental results. Compositions with a thermal expansion coefficient compatible with Si and GaAs, and dielectric constants in the ranges of 4-5 and 5-6, respectively, at 1 MHz, are developed.