| abstract |
A B stage sheet comprises a semi-hardened material of an epoxy resin composition which contains an epoxy resin which has a biphenyl structure, a hardening agent which has a partial structure represented by the following Formula (IIa) or the like, an inorganic filler, and an elastomer. In the following Formula, m and n each represent a positive number, and Ar represents a group represented by the following Formula (IIIa) or (IIIb). R11 and R14 each represent a hydrogen atom or a hydroxy group. R12 and R13 each represent a hydrogen atom or an alkyl group. |