Patent attributes
An optical semiconductor device 1a includes a lead frame 4 having a through hole 7, a semiconductor optical element 3 which is placed on one surface of the lead frame 4 for an optical portion 6 to face and overlap with the through hole 7, a first molding portion 9 of a non-transparent molding resin which covers the semiconductor optical element 3 and is placed on one surface of the lead frame 4, and a second molding portion 10 of a transparent molding resin which covers the through hole 7 and is placed on the other surface of the lead frame 4. An area of a confronting surface of the second molding portion 10 confronting the first molding portion 9 is smaller than an area of a confronting surface of the first molding portion 9 confronting the second molding portion 10.
