CAS계 유리가 첨가된 CaCO3-Al2O3혼합물 및 화합물의 저온 소결 및 유전 특성

Abstract

Effects of ceramic filler types and dose on the low temperature sintering and dielectric properties of ceramic/<TEX>$CaO-Al_{2}O_{3}-SiO_2$</TEX> (CAS) glass composites were investigated. All of the specimens were sintered at <TEX>$850{\sim}900^{\circ}C$</TEX> for 2 h, which conditions are required by the low-temperature co-firing ceramic (LTCC) technology. Ceramic fillers of <TEX>$CaCO_3$</TEX>, <TEX>$Al_{2}O_{3}$</TEX>, <TEX>$CaCO_3-Al_{2}O_{3}$</TEX> mixture, and <TEX>$CaCO_3-Al_{2}O_{3}$</TEX> compound (<TEX>$CaAl_{2}O_{4}$</TEX>), respectively, were used. The addition of <TEX>$Al_{2}O_{3}$</TEX> yielded the crystalline phase of alumina, which was associated with the inhibition of sintering, while, <TEX>$CaCO_3$</TEX> resulted in no apparent crystalline phase but the swelling was significant. The additions of <TEX>$CaCO_3-Al_{2}O_{3}$</TEX> mixture and <TEX>$CaAl_{2}O_{4}$</TEX>, respectively, yielded the crystalline phases of alumina and anorthite, and the sintering properties of both composites increased with the increase of filler addition and the sintering temperature. In addition, the <TEX>$CaAl_{2}O_{4}$</TEX>/CAS glass composite, sintered at <TEX>$900^{\circ}C$</TEX>, demonstrated good microwave dielectric properties. In overall, all the investigated fillers of 10 wt% addition, except <TEX>$CaCO_3$</TEX>, yielded reasonable sintering (relative density, over 93 %) and low dielectric constant (less than 5.5), demonstrating the feasibility of the investigated composites for the application of the LTCC substrate materials.