Patent ID: 7384682

Claim:
An electronic package comprising: a substrate having an upper surface; a semiconductor chip mounted on a portion of said upper surface of said substrate and electrically coupled to said substrate, said semiconductor chip having a bottom surface and at least one edge surface being substantially perpendicular to said bottom surface; and a material positioned on at least said portion of said upper surface of said substrate and against at least a portion of said at least one edge surface of said semiconductor chip, said material being an encapsulant composition comprising: (A) a resin material selected from the group consisting of epoxy resins and cyanate ester resins, (B) 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, the thermoplastic being separated from the cured epoxy resin or cyanate ester resin, wherein the flexibilizer comprises a poly(arylene)ether and the thermoplastic comprises bis(2,3-epoxy-2-methylpropyl)ether, and (C) a filler comprising substantially spherical or spheriodal particles, each particle having a diameter exceeding 31 microns and less than 41 microns, wherein the composition has a higher fracture toughness, lower viscosity or increased thermal shock resistance at a temperature excursion below −40° C., or combinations thereof, than the composition would have if the flexibilizing agent were not present in the composition.