Low-loss high-voltage ceramic capacitor dielectric

Abstract

The invention relates to a low-loss high-voltage ceramic capacitor dielectric which is characterized by comprising the following raw materials in percentage by weight: 58-91% of BaTiO3, 1-3% of SrTiO3, 4-20% of BaZrO3, 3-12% of CaZrO3, 0.03-1.0% of CeO2, 0.1-1.5% of ZnO and 0.5-4.5% of Bi2TiO5. The low-loss high-voltage ceramic capacitor dielectric provided by the invention has the advantages of high voltage resistance, low dielectric loss and no environment pollution in the preparation and use process, can lower the cost of the ceramic capacitor, and is suitable for preparing single-chip ceramic capacitors and multilayer chip ceramic capacitors.

Description

technical field [0001] The present invention relates to capacitor dielectrics, in particular to a low-loss high-voltage ceramic capacitor dielectric. Background technique [0002] Ceramic capacitors with high performance (such as high breakdown voltage, good temperature stability, high reliability, miniaturization, and large capacity) are urgently needed in the fields of color TV, computer, communication, aerospace, missile, and navigation. In order to obtain high-performance ceramic capacitors, the dielectric of ceramic capacitors is required to have the characteristics of low loss and high withstand voltage; at the same time, as people pay more and more attention to health and environmental protection, the dielectric of ceramic capacitors is required to be in the process of preparation, use and disposal. It will not cause harm to the human body and the environment, so the dielectric of ceramic capacitors is required to contain no metal elements such as lead and cadmium. ...

AI Technical Summary

Problems solved by technology

As another example, the Chinese journal "Journal of Nanjing University of Chemical Technology" in 1999 No. 4 in "SrTiO 3 Composition and performance of high-voltage ceramic capacitor materials based on "a low-loss high-voltage capacitor ceramic medium is disclosed in the article, but the medium contains about 18 mol% lead titanate, which will be harmful to the environment and human body during preparation and use. Pollution

Another example is the Chinese Invention Patent Application Publication Note CN1212443A (the name of the invention is "high dielectric high performance medium temperature sintered chip type multilayer ceramic capacitor ceramic material", the patent application number is 97117286.2), although the disclosed ceramic capacitor ceramic material has a dielectric constant High (dielectric constant ≥ 16000), but poor withstand voltage (withstand voltage 700V / mm), and its components contain a certain amount of lead

Also have, Chinese invention patent application public specification CN1212444A (invention name is " high-performance mid-temperature sintered chip type multilayer ceramic dielectric capacitor ceramic material ", and the patent application number is 97117287.0), the disclosed capacitor ceramic material dielectric constant is too small (dielectric The electrical constant is 3000), the dielectric loss is high, and the withstand voltage is low (the withstand voltage is 860V / mm), and its components contain a certain amount of lead

[0004] Although the dielectric of some ceramic capacitors does not contain lead, it is less harmful to the human body and the environment during the production, use and disposal of ceramic capacitors, but its dielectric constant is too small and / or the withstand voltage is low

For example, the Chinese journal "Electronic Components and Materials" in the fifth issue of 1989 in "High Dielectric High Voltage 2B 4 Dielectric ceramics" discloses a high-voltage ceramic capacitor dielectric material. This dielectric material does not contain lead, but the dielectric constant is too small (dielectric constant ε=2500-2600), tgδ=0.5-1.4%, and the voltage resistance Poor (DC withstand voltage strength is 7KV / mm), and the dielectric loss is high

As another example, Chinese invention patent application publication CN1619726A (invention name is "a medium-low temperature sintered high-voltage ceramic capacitor dielectric", patent application number is 200410041863.x), the weight percentage content of each component of the disclosed ceramic capacitor dielectric is: BaTiO 3 60-90%, SrTiO 3 1-20%, CaZrO 3 0.1-10%, Nb 2 o 5 0.01-1%, MgO 0.01-1%, CeO 2 0.01-0.8%, ZnO 0.01-0.6%, Co 2 o 3 0.03-1%, bismuth-lithium solid solution 0.05-10%, the dielectric constant is 2000-3000, the withstand voltage is above 6kV / mm, the dielectric constant and withstand voltage are still not ideal, and the dielectric loss is high

[0005] In summary, the existing dielectrics for ceramic capacitors cannot meet the requirements of low loss, high withstand voltage and environmental protection at the same time.

Images