| abstract |
An optical semiconductor device encapsulated with a silicone resin that suffers no discoloration of the lead and exhibits excellent thermal shock resistance. The optical semiconductor device includes an optical semiconductor element and a cured product of a silicone resin composition that encapsulates the optical semiconductor element, wherein the amount of (Φ SiO3/2) units (wherein O represents a phenyl group) within the cured product, determined by solid Si-DD/MAS analysis, is within a range from 0.13 mol/100 g to 0.37 mol/100 g. |