Epoxy resin composition for semiconductor encapsulation and semiconductor device using the same

1. An epoxy resin composition for semiconductor encapsulation, comprising the following ingredients A to E:

A: an epoxy resin;

B: a silicone mixture containing the following ingredients b1 and b2, with a weight ratio of the ingredients b1 and b2 being from 5/95 to 25/75 in terms of b1/b2:

b1: a silicone compound having an amino group in both ends thereof and having a weight average molecular weight of from 600 to 900, and

b2: a silicone compound having an amino group in both ends thereof and having a weight average molecular weight of from 10,000 to 20,000;

C: a phenol resin;

D: a curing accelerator; and

E: an inorganic filler containing the following ingredients e1 and e2:

e1: a crystalline silica, and

e2: a fused silica.

2. The epoxy resin composition for semiconductor encapsulation according to claim 1 , wherein the ingredient E is contained in an amount of from 70 to 93% by weight relative to the whole of the epoxy resin composition.

3. The epoxy resin composition for semiconductor encapsulation according to claim 1 , wherein a weight ratio of the ingredients e1 and e2 is from 45/55 to 75/25 in terms of e1/e2.

4. The epoxy resin composition for semiconductor encapsulation according to claim 1 , further comprising the following ingredient F:

F: a wax mixture containing the following ingredients f1 and f2:

f1: an amide wax, and

f2: an ester wax.

5. A semiconductor device comprising a semiconductor element encapsulated with the epoxy resin composition for semiconductor encapsulation according to claim 1 .

6. An epoxy resin composition for semiconductor encapsulation, comprising a silicone-modified epoxy resin obtained by reacting the following ingredient A with the following ingredient B; and the following ingredients C to E:

A: an epoxy resin;

B: a silicone mixture containing the following ingredients b1 and b2, with a weight ratio of the ingredients b1 and b2 being from 5/95 to 25/75 in terms of b1/b2:

b1: a silicone compound having an amino group in both ends thereof and having a weight average molecular weight of from 600 to 900, and

b2: a silicone compound having an amino group in both ends thereof and having a weight average molecular weight of from 10,000 to 20,000;

C: a phenol resin;

D: a curing accelerator; and

E: an inorganic filler containing the following ingredients e1 and e2:

e1: a crystalline silica, and

e2: a fused silica.

7. The epoxy resin composition for semiconductor encapsulation according to claim 6 , wherein the ingredient E is contained in an amount of from 70 to 93% by weight relative to the whole of the epoxy resin composition.

8. The epoxy resin composition for semiconductor encapsulation according to claim 6 , wherein a weight ratio of the ingredients e1 and e2 is from 45/55 to 75/25 in terms of e1/e2.

9. The epoxy resin composition for semiconductor encapsulation according to claim 6 , further comprising the following ingredient F:

F: a wax mixture containing the following ingredients f1 and f2:

f1: an amide wax, and

f2: an ester wax.

10. A semiconductor device comprising a semiconductor element encapsulated with the epoxy resin composition for semiconductor encapsulation according to claim 6 .