Study On The High Performance X8R Dielectric Material Used By EMI

In this paper, the low frequency high dielectric constant X8R series dielectricmaterial for EMI and the powder for making were studied.Metal M were doped into BaTiO3 based material through the method ofmetal-dielectric composite. The inside interaction mechanics of the system werediscussed. The interaction of liquation metal M and dielectric can described bypercolation theory.In the experiment, through the discussion of composite technology,the choose offlux and the condition of sintering, gain a new type high performance intermediatetemperature range sintering X8R series dielectric material. the composite material canmeet the requirement of EMI filter capacitor. The results listed as follow (sintered at1150℃):ε≥5200ΔC/C≤±8% (-55℃～+150℃)tgδ≤1.5%ρv≥2×10¹¹Ω·cmIn the experiment, on the base of experiments been done before, the way ofB-site substitution using precursor in BaTiO3-NiNb2O6-MnNb2O6 system was alsostudied. Doping glass flux into this system can lower down it's sintering temperatureto intermediate temperature range so it can use cheaper alloy such as 70%Ag-30%Pdas inner electrodes. The mechanics of precursor replacement of B-site ion was alsodiscussed. The results listed as follow (sintered at 1150℃):ε≥4200ΔC/C≤±15% (-55℃～+150℃)tgδ≤1.2%ρv≥1012Ω·cm...