| abstract |
Disclosed is a dielectric material that can detect a dielectric breakdown sign before or during use, and therefore can predict dielectric breakdown in advance. A dielectric material according to the present invention is a dielectric material made of a composite sintered body in which conductive particles are dispersed in an insulating material, and the conductive particles have a cumulative volume percentage in the volume particle size distribution. The particle diameter D10 of 10 volume% is 0.2 μm or less, the cumulative volume percentage is 90 volume%, the particle diameter D90 is 2 μm or less, the cumulative volume percentage is 90 volume% and the cumulative volume percentage of the particle diameter D90 is 10 volume%. The ratio (D90 / D10) with respect to the particle diameter D10 is 3.0 or more, and the ratio (D90 / D50) with respect to the particle diameter D50 where the cumulative volume percentage is 90 volume% and the cumulative volume percentage is 50 volume%. 1.4 or more. [Selection figure] None |