Nanocomposite sol-gel route to low K ceramic substrates

Aluminosilicate gels of different alumina and silica ratios and cordierite, Mg₂Al₄Si₅O₁₈ gels were made by the nanocomposite sol-gel route and sintered to obtain highly dense materials. Measurements of the dielectric constant, K, and dissipation (loss) as a function of temperature and frequency showed that low dielectric constants of 5.6 and 5.4 at 1 and 4 MHz, respectively, for cordierite and of 6.9 and 6.7 at 1 and 4 MHz, respectively for mullite at 25°C were achieved. Aluminosilicate materials prepared with 10 wt% Al₂O₃ and 90 wt% SiO₂ showed the lowest dielectric constants of 4.27 and 4.20 at 1 and 4 MHz, respectively.