The optical semiconductor sealing composition, its preparation and the optical semiconductor sealing material

PROBLEM TO BE SOLVED: To provide an optical semiconductor-encapsulating composition giving an optical semiconductor-encapsulating agent which is used for potting, colorless, transparent, durable and not liable to crack for solder reflow and heat cycle. SOLUTION: The optical semiconductor-encapsulating composition contains (A) a polyorganosiloxane having an epoxy group with an epoxy equivalent of 150-600 g/mole, a glass transition temperature of -80°C-150°C and a polystyrene-converted weight average molecular weight of 500-1,000,000 and (B) a polyorganosiloxane having an epoxy group with an epoxy equivalent of over 600 g/mole and not more than 1,600 g/mole, a glass transition temperature of not higher than -50°C and a polystyrene-converted weight average molecular weight of 500-1,000,000. COPYRIGHT: (C)2007,JPO&INPIT