| abstract |
[PROBLEMS] To provide a cured product having both high heat resistance and high humidity resistance, which is suitable for many applications including power semiconductor applications, and at the same time, storage stability and fast curing that contribute to improvement of work efficiency. Providing an epoxy resin composition having both properties. An epoxy resin containing at least a naphthalene-type tetrafunctional epoxy resin represented by the following formula (1), a curing agent, and a phosphorus-based curing accelerator containing one or more tetraarylphosphonium tetraphenylborate adducts. Composition. [Selection figure] None |