Ultrahigh voltage ceramic capacitor medium and preparation method thereof

Abstract

The invention relates to the technical field of inorganic non-metallic materials, and especially relates to an ultrahigh voltage ceramic capacitor medium and a preparation method thereof. The formula of the medium comprises 55-90wt% of BaTiO3, 2-25wt% of SrTiO3, 2-15wt% of MgZr0.5Ti0.5O3, 0.05-10wt% of MgSnO3, 0.03-1.0wt% of CeO2, 0.1-1.5wt% of ZnO, and 0.03-1.0wt% of MnO2. A routine ceramic capacitor medium preparation method a capacitor ceramic common chemical raw material are adopted in the invention to prepare the lead-and-cadmium-free ultrahigh voltage ceramic capacitor medium and reduce the sintering temperature of the capacitor ceramic. The medium is suitable for preparing monolithic ceramic capacitors and multilayer tablet ceramic capacitors, substantially reduces the costs of the ceramic capacitors, improves the proof voltage to enlarge the application ranges of the capacitors and does not pollute the environment in the preparation and use processes.

Description

technical field [0001] The invention relates to the technical field of inorganic non-metallic materials, in particular to an ultra-high-voltage ceramic capacitor medium and a preparation method thereof; it adopts a conventional preparation method of a ceramic capacitor medium and utilizes common chemical raw materials of capacitor ceramics to prepare lead-free and cadmium-free ultra- The high-voltage ceramic capacitor medium can also reduce the sintering temperature of the capacitor ceramic. This medium is suitable for the preparation of monolithic ceramic capacitors and multilayer ceramic capacitors, which can greatly reduce the cost of ceramic capacitors and increase the withstand voltage to expand the application of ceramic capacitors. range, and does not pollute the environment during preparation and use. Background technique [0002] Color TVs, computers, communications, aerospace, missiles, navigation and other fields urgently need ceramic capacitors with high breakdow...

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Problems solved by technology

[0008] Another patent is "high dielectric high performance medium temperature sintered chip multilayer ceramic capacitor ceramic material" (patent application number: 97117286.2), which is synthesized by solid phase method and simultaneously replaced by equivalent and heterovalent ions (Sr 2+ ,Zr 4+ ,Sn 4+ ,Nb 5+ ) BaTiO 3 Solid solution, adding an appropriate amount of boron-lead-zinc-copper glass sintering agent, so that the ceramic material is sintered at medium temperature, its performance is: the dielectric constant is greater than or equal to 16000, and the withstand voltage is 700V / mm; although the patent has a high dielectric constant, the reported The withstand voltage of the material is too poor, only 700V / mm, and its components contain a certain amount of lead

[0009] There is another patent "Manufacturing Method of High Voltage Ceramic Capacitor Dielectric" (Patent No. 91101958.8), which uses an unconventional process to prepare the dielectric, that is, a tape-cast film, and then laminates the dielectric body. The multi-layer dielectric body is vacuum heated and uniformly pressed, punched The disadvantage of this patent is that the preparation process is complicated, which leads to an increase in product manufacturing costs. The dielectric constant of the high-voltage capacitor ceramics manufactured according to its dielectric formula is 1800-7200, and the dielectric constant High, the dielectric loss is large, and the withstand voltage is not as high as that of this patent

[0010] There is also the Chinese patent "High-performance Medium-temperature Sintered Chip Multilayer Ceramic Capacitor Porcelain Material" (patent application number: 97117287.0), which uses a unique formula (weight percentage) (BaTiO 3 93~96%+Nb 2 o 5 0.8~1.5%+Bi 2 o 3 1.0~2.2%+fluxing agent 1.8~3.5%+modifier 0.25~1.0%) to obtain capacitor ceramics sintered at medium temperature that meet the following properties: dielectric constant is 3000, dielectric loss is less than 1.5%, and withstand voltage is 860V / mm; The flux of this patent contains a certain amount of lead, the withstand voltage of this patent is too poor, and the dielectric constant is too low, far less than that of this patent

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