Barium titanate ceramic capacitor medium and preparing method thereof

Abstract

This invention discloses a condenser medium of barium titanate ceramics and its preparation method, which takes BaTiO3 as the main composition, its weight is 1 added by the following weight percentages: Nb2O5: 1.00~1.50%, CoCO3 0.1~0.5%, CeO2: 0.1~0.5% and a fusing agent: 0.25~0.50%. They are mixed to an adjuvant to be ball-ground, prilled and dry-pressed to a round green compact sheet to be burnt in oven under 1240deg.C to be insulated for 4-8 hours and cooled for 10 hours in the oven to be manufactured to a ceramic condenser medium. Since the dielectric constant of the medium is high the medium loss is small and its volume temperature absolute value is less than 13%, thermal stability is good, it can be used in producing large volume condensers or other electronic devices.

Description

technical field [0001] The invention relates to a dielectric ceramic composition and a preparation method, in particular to a barium titanate-based ceramic medium and a preparation method thereof. Background technique [0002] With the development of surface mount technology in electronic circuits, the volume of multilayer ceramic capacitors (MLCs) is required to be more miniaturized, which requires dielectric materials with higher capacitance and better thermal stability. The dielectric materials used to manufacture low-frequency, high-dielectric and thermally stable MLCs are currently mainly X7R ceramic materials. X7R represents a temperature-capacity characteristic, that is, in the range of -55 to +125°C, its capacity-temperature change rate |ΔC / C 25℃ |≤15%. This type of capacitor is widely used in the coupling circuit of high-end electronic equipment such as mobile phones. During the transmission process of the front and rear stages, the distortion of the signal shoul...

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Problems solved by technology

Chinese patent 98124799.7 discloses the composition and preparation method of a temperature-stable high-dielectric multilayer ceramic capacitor material. The material is based on barium titanate and the additive is Co 2 o 3 , Nb 2 o 5 , rare earth oxides and MnO 2 , the dielectric constant at room temperature can reach 4400, the capacity temperature change rate is ≤±15%, and the resistivity is 10 12～13 Ω cm, although the performance of this ceramic material can meet the requirements of X7R capacitors, its dielectric constant is not large enough, and the dielectric loss is not mentioned. In addition, its preparation method still adopts a two-step process of raw material synthesis and then sintering. Therefore, the production cost is higher