| abstract |
The present invention relates to a curable silicone composition, which comprises (A) a diorganopolysiloxane having at least two alkenyl groups in one molecule, (B) at least two resinous organopolysiloxanes having different mass average molecular weights, (C) An organopolysiloxane having at least two silicon-bonded hydrogen atoms in the molecule, and (D) a hydrosilylation reaction catalyst. The present curable silicone composition can suppress the remarkable increase in the viscosity of the resulting composition even when the organopolysiloxane resin is blended to form a cured product having appropriate hardness and strength and is superior in fluidity and packaging characteristics and can be used as a sealing material Has excellent gas barrier properties when used, and makes it possible to manufacture an optical semiconductor device having excellent initial light output efficiency. |