Patent ID: 7105614

Claim:
A curable epoxy resin composition comprising: (A) a crystalline epoxy resin, (B) a phenol resin, (C) a silicone resin, and, (D) an inorganic filler added in an amount of 400 to 1,200 parts by weight for each 100 parts by weight of the total weight of components (A) through (C), said silicone resin represented by the following average unit formula: (R 1 SiO 3/2 ) a (R 2 R 3 SiO 2/2 ) b (R 4 R 5 R 6 SiO 1/2 ) c (SiO 4/2 ) d, (XO 1/2 ) e wherein R 1 , R 2, R 3, R 4, R 5, and R 6 may be the same or different monovalent hydrocarbon groups or epoxy-containing organic groups, of which said epoxy-containing organic groups constitute 0.1 to 40 mole % of the total amount of R 1 through R 6 contained in the molecule, and 10 or more mole % are phenyl groups; X is a hydrogen atom or an alkyl group; a is a positive number; b is 0 or a positive number; c is 0 or a positive number; d is 0 or a positive number, e is 0 or a positive number; b/a is a number between 0 and 10; c/a is a number between 0 and 0.5; d/a+b+c+d is a number between 0 and 0.3; and e/(a+b+c+d) is a number between 0 and 0.4, component (C) being used in an amount of 0.1 to 500 parts by weight for each 100 parts by weight of the sum of components (A) and (B).