Patent ID: 8669583

Claim:
A heat-curable silicone resin composition for sealing optical semiconductors comprising: Component (A): 100 parts by mass of a silicon compound expressed by Formula (1) below (R 1 SiO 3/2 ) a ((R 2 ) 2 SiO 2/2 ) b ((R 3 ) 3 SiO 1/2 ) c (SiO 4/2 ) d (XO 1/2 ) e . . . (1) wherein R 1 , R 2 , and R 3 are identical or differing monovalent organic groups, “X” is a hydrogen atom or a monovalent organic 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, and “e” is 0 or a positive number; however “a” to “e” satisfy the following conditions: b/a is a number from 0 to 10, c/a is a number from 0 to 0.5, d/(a+b+c+d) is a number from 0 to 0.3, and, when e is a positive number, e/(a+b+c+d) is a number from 0.01 to 1.5, wherein the component (A) is a silicon compound A1 having a melting point or softening point that is greater than 25° C. or the component (A) comprises both a silicon compound A1 having a melting point or softening point that is greater than 25° C. and a silicon compound A2 having a melting point or softening point that is not greater than 25° C., wherein the silicon compound A1 has a silsesquioxane skeleton; and Component (B): from 0.001 to 10 parts by mass of a condensation catalyst, wherein the component (B) includes both a transition metal compound and a base metal compound, and wherein the composition includes from 0.001 to 0.5 parts by mass of the transition metal compound per 100 parts by mass of the component (A) and 0.1 to 10 parts by mass of the base metal compound per 1 part by mass of the transition metal compound.