Patent ID: 7560501

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