Hardening components

Abstract

The present invention aims to provide a curable composition with excellent flowability, which can form a curable material with excellent electrical properties (low relative permittivity, low dielectric tangent, etc.) and crack resistance, as well as mechanical properties and insulation, and is applicable to electronic components such as sealing materials, extension films, or underfill materials for semiconductor devices. The solution is as follows: a curable composition comprising epoxy resin, a curing agent, solid silica particles with an average particle size (D50) of 0.1µm or more and less than 4µm, and hollow silica particles with an average particle size (D50) of 0.1µm or more and less than 4µm; the absolute value of the difference in average particle size (D50) between the solid silica particles and the hollow silica particles is greater than 0.1µm, and the total content of the solid silica particles and the hollow silica particles is 25% by volume or more.