Patent ID: 8883883

Claim:
A resin composition for encapsulating a semiconductor comprising a phenol resin (A) having one or more components containing a component (A1) composed of a polymer having a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2); an epoxy resin (B); and an inorganic filler (C), wherein, in the above general formula (1), R1 is each independently a hydrocarbon group having 1 to 6 carbon atoms; a is an integer of 0 to 3; and R2, R3, R4 and R5 are each independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, wherein, in the above general formula (2), R1 is each independently a hydrocarbon group having 1 to 6 carbon atoms; a is an integer of 0 to 3; R6 is each independently a hydrocarbon group having 1 to 6 carbon atoms; b is an integer of 1 to 4; and R7, R8, R9 and R10 are each independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, wherein the ICI viscosity at 150 degrees centigrade of said phenol resin (A) is equal to or less than 1.5 dPa·s; wherein a mixing amount of the phenol resin (A) is equal to or more than 0.5% by mass and equal to or less than 10% by mass based on the total mass of the resin composition; wherein a mixing amount of the epoxy resin (B) is equal to or more than 2% by mass and equal to or less than 15% by mass based on the total mass of the resin composition; and wherein the content of said inorganic filler (C) is equal to or more than 80% by mass and equal to or less than 93% by mass.