Low‐Temperature Sintering and Microwave Dielectric Properties of Li2MgSiO4 Ceramics

Development of a low‐temperature sintered dielectric material derived from Li 2 MgSiO 4 (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°C/4 h and 1250°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°C/2 h had ɛ r =5.1 and tan δ=5.2 × 10 −4 at 8 GHz. The sintering temperature of LMS is lowered from 1250°C/2 h to 850°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°C/2 h had ɛ r =5.5 and tan δ=7 × 10 −5 at 8 GHz. Two weight percent LMZBS mixed with LMS sintered at 875°C/2 h had ɛ r =5.9 and tan δ=6.7 × 10 −5 at 8 GHz.