Epoxy resin composition for encapsulating semiconductor and semiconductor device

An epoxy resin composition for encapsulating a semiconductor comprising an epoxy resin (A),

• wherein the epoxy resin (A) includes:
• a crystalline epoxy resin (a1) having a melting point of 50° C. to 150° C.,
• an epoxy resin (a2) represented by formula (1), and
• at least one epoxy resin (a3) selected from an epoxy resin represented by formula (2) and an epoxy resin represented by a formula (3),
• wherein the epoxy resin (a1) is different from the epoxy resin (a2) and the epoxy resin (a3);
• wherein the composition has a spiral flow of 80 cm or more measured according to EMMI-1-66 method;
• the composition in the cured state has a glass transition temperature of 150° C. or higher;
• and
• the composition in the cured state has a linear expansion coefficient of 5 ppm/° C. to 10 ppm/° C., at a temperature not higher than the glass transition temperature of the composition:
• wherein, in formula (1), R1's which may be the same or different, represent a hydrocarbon group having 1 to 4 carbon atoms;
• R2's, which may be same or different, represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms;
• and n is an integer of 0 to 6;
• wherein, in formula (2), R1's which may be same or different, represent a hydrocarbon group having 1 to 4 carbon atoms;
• R2's, which may be the same or different, represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms;
• m is an integer of 0 to 5;
• and n is an integer of 0 to 6;
• wherein, in formula (3), R1's which may be the same or different, represent a hydrocarbon group having 1 to 4 carbon atoms;
• R2's, which may be the same or different, represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms;
• and m is an integer of 0 to 5,
• wherein the epoxy resin (a1) is in an amount of 60 wt % to 95 wt % based on the total amount of the epoxy resin (a1), the epoxy resin (a2), and the epoxy resin (a3), and
• wherein the epoxy resin (a2) is in an amount of 2.5 wt % to 20 wt %, and the epoxy resin (a3) is in an amount of 2.5 wt % to 20 wt %, based on the total amount of the epoxy resin (a1), the epoxy resin (a2), and the epoxy resin (a3).