Patent ID: 8519067

Claim:
An epoxy resin composition for encapsulating a semiconductor chip comprising, (A) a crystalline epoxy resin represented by general formula (4): wherein X is group selected from single bond, —O—, —S— and —C(R2) 2 —; R1 is alkyl having 1 to 6 carbon atoms; two or more R1s are the same or different; m is an integer of 0 to 4; R2 is hydrogen or alkyl having 1 to 4 carbon atoms; and two or more R2s are the same or different, (B) a phenol resin represented by general formula (5): wherein R1 and R2 are independently hydrogen or alkyl having 1 to 4 carbon atoms; two or more R1s or two or more R2s are the same or different; a is an integer of 0 to 3; b is an integer of 0 to 4; n is an average and is a positive number of 1 to 5, (C-2) from 0.05 wt % to 0.5 wt % of a carboxyl-terminated butadiene-acrylonitrile copolymer both inclusive in the total epoxy resin composition represented by general formula (3) HOOC (Bu) x (CAN) y ) z COOH (3) Wherein Bu represents a butadiene-derived structural unit, ACN represents an acrylonitrile-derived structural unit, x is a positive number of less than 1; y is a positive number of less than 1; x+y=1; and z is an integer of from 50 to 62, (D) an inorganic filler in the amount of 80 wt % to 95 wt % both inclusive in the total epoxy resin composition, and (F) an epoxy resin represented by general formula (6): wherein R1 and R2 are independently hydrogen or alkyl having 1 to 4 carbon atoms; two or more R1s or two or more R2s are the same or different; a is an integer of 0 to 3, b is an integer of 0 to 4; and n is an average and is a positive number of 1 to 5.