An encapsulant composition. The encapsulant composition includes a resin material consisting of epoxy or cyanate ester resins, from about 1.0% by weight to about 5% by weight of the composition of a flexibilizing agent including a flexibilizer containing functional groups capable of reaction with the epoxy or cyanate ester resin during thermally induced curing, a filler material including substantially spherical or spheroidal particles such that each particle has a diameter less than about 41 microns, and a thermoplastic other than the flexibilizer. The thermoplastic is separated from the cured epoxy or cyanate ester resin. The thermoplastic includes a poly(arylene)ether. The flexibilizer includes bis(2,3-epoxy-2-methylpropyl)ether.