US Patent 7330492 Optical coupler and electronic equipment using same

On one surface of a lead frame 4 having an aperture 7 passing through in thickness direction thereof, a submount having transparency for closing the aperture 7 of the lead frame 4 is disposed. On a surface of the submount opposite to a surface of the submount 8 facing the aperture 7 of the lead frame 4, a semiconductor optical device 3 is disposed in such a way that an optical portion thereof faces toward the aperture. The semiconductor optical device 3 is electrically connected to the lead frame 4 via wire 5. At least one surface of the lead frame 4, the semiconductor optical device 3 and the submount 8 are encapsulated with a molding portion 10 made of a non-transparent molding resin in a state that the aperture 7 on the other surface side of the lead frame 4 is exposed.