Nickel Electrode Y5u Anti Restore The Development Of The Ceramic Material

The anti-reduction property of the acceptor or rare earth doped barium titanate sintered in reducing atmosphere has been studied in this thesis. The basic composition of this kind of dielectric can be expressed as the following formular: [(Ba1-xCax)O]m [(Ti1-yZry)]O2, wherein 1.00≤m≤1.02, 0.05≤x≤0.10, 0.10≤y≤0.20. The solubility and segregation of different acceptor ions or rare earth ions such as Mn2+,Mg2+,Co3+,Y3+,Ce4+ and their regular effect on the properties of ceramic dielectric are discussed. Different kinds of synthesis processes of ceramics are displayed and compared in this thesis. The dielectric behavior of this anti-reduction ceramic which can be co-fired with nickel electrode at optimal sintering condition reached the level as follows: ε>8000, tgδ<3%, ρ>1011Ω·cm, Eb>5000V/mm and ΔC/C(-30～+85℃) ≤(+22～-56)%.The nickel internal electrode MLC using this ceramic has been prepared. The influence of various process factors on the properties of MLC has been studied, especially the doctor blading process, the screenprinting property of nickel electrode, the compatibility of nickel electrode with dielectric and the feasibility of MLC sintering with nickel external at the same time. The properties of MLC samples have been obtained: C>300nF, Ri≈20～100MΩ(DC10V), tgδ<5%, and the temperature dependence of the capacitance satisfies the specification of Y5U. All the work has established the foundation of the practical manufacturing process of nickel internal electrode MLC.