Low-Temperature sintering and microwave dielectric properties of Li2MgSiO4 ceramics

Abstract

Development of a low-temperature sintered dielectric material derived from Li2MgSiO4 (LMS) for low-temperature cofired ceramic (LTCC) application is discussed in this paper. The LMS ceramics were prepared by the solid-state ceramic route. The calcination and sintering temperatures of LMS were optimized at 850 degrees C/4 h and 1250 degrees C/2 h, respectively, for the best density and dielectric properties. The crystal structure and microstructure of the ceramic were studied by the X-ray diffraction and scanning electron microscopic methods. The microwave dielectric properties of the ceramic were measured by the cavity perturbation method. The LMS sintered at 1250 degrees C/2 h had epsilon(r) = 5.1 and tan delta = 5.2 x 10(-4) at 8 GHz. The sintering temperature of LMS is lowered from 1250 degrees C/2 h to 850 degrees C/2 h by the addition of both lithium borosilicate (LBS) and lithium magnesium zinc borosilicate (LMZBS) glasses. LMS mixed with 1 wt% LBS sintered at 925 degrees C/2 h had epsilon(r) = 5.5 and tan delta = 7 x 10(-5) at 8 GHz. Two weight percent LMZBS mixed with LMS sintered at 875 degrees C/2 h had epsilon(r) = 5.9 and tan delta = 6.7 x 10(-5) at 8 GHz.