Patent ID: 8120151

Claim:
An optical semiconductor device comprising: an optical semiconductor chip; a wire extending from the optical semiconductor chip; a holder part having a frame shape and an inside space configured to accommodate the optical semiconductor chip; a sealing part configured to cover the optical semiconductor chip within the inside space of the holder part, the sealing part being made of a soft resin; a first lead having a mount part configured for the optical semiconductor chip to be mounted on, the first lead extending out of two sides of the holder part including a first side and a second side opposite from the first side; a second lead having a junction with the wire extending from the optical semiconductor chip, the second lead having one end extending out of the first side of the holder part at a location different from where the first lead extends out, and the other end extending in the inside space of the holder part so as to be covered with the sealing part; and a third lead having one end extending out of the second side of the holder part at a location different from where the first lead extends out and the other end extending in the inside space of the holder part so as to be covered with the sealing part, wherein the third lead is entirely separated from and not in electrically conductive contact with the first lead and the second lead, wherein the other end of the third lead is arranged to be opposed to the other end of the second lead positioned within the inside space of the holder part, at least one of the other end of the second lead and the other end of the third lead, lying within the inside space of the holder part, has a bent shape, the bent shape is composed of two bends and an end parallel to a direction of extension of the first lead, and the two bends include a bend directed approximately in an optical axis direction and a parallel bend to the direction of extension of the first lead.