The invention provides low-temperature sintered lead-free
microwave dielectric ceramic and a preparation method thereof. By adopting the method, continuous adjustable
dielectric constant is realized by regulating the Mg / Ca ratio of [Cax, Mg(1-x)]TiO3
powder which serves as a base material; low-temperature
sintering of the
ceramic material at 800-900 DEG C is realized by adding CaO-Al2O3-B2O3-SiO2
microcrystalline glass. The method comprises the following steps: firstly, synthesizing [Cax, Mg(1-x)]TiO3
ceramic powder, and synthesizing CaO-Al2O3-B2O3-SiO2
microcrystalline glass; then, performing ball-milling, dosing, tape-
casting, molding and batching out,
sintering and annealing to obtain a low-consumption multi-layer ceramic
dielectric material with excellent performance. According to the method, the
microcrystalline glass / ceramic green-compact is molded by adopting thick film tape-
casting, and multiple
layers of the green compact are laminated and subjected to low-temperature
sintering to prepare a
ceramic substrate, so that the
dielectric loss can be reduced, the dielectric constant is adjustable in a range of 9-35,
tan delta is less than 0.0002 under 10MHz, and
tan delta is less than 0.0015 under 1-10GHz; low-temperature sintering is realized, and industrial production can be realized by combining with an Ag-Pd
electrode.