Resin composition and hardened film

Abstract

The object of the present invention is to provide a resin composition capable of forming a hardened film with high puncture strength. A resin composition comprises an epoxy resin, alumina particles, and a flux, wherein the value Z of the resin composition, calculated according to formula (1), is 220 (g0.5×m / mol) or less. Z = S0.5×E ···(1) [In formula (1), S represents the BET specific surface area (m2 / g) of the alumina particles determined by nitrogen adsorption, and E represents the acid equivalent (g / mol) of the flux]