OPTICAL SEMICONDUCTOR DEVICE

摘要

An optical semiconductor device (M) comprises a stem (2) on which an electronic circuit component (1) is mounted, lead pins (3), a round cap (10), and a lens (5) provided inside said cap (10). The aforementioned cap (10) has a welding flange (12) at a welded edge on the side opposite from the aforementioned stem (2) to face outward in the radial direction. A welding line (b) can be aligned closer to perpendicular with respect to the flange (12) when the cap (10) is welded to a case (A), and weld strength can be improved. Because the flange does not constitute a wall of the cap, there is no risk of a wall breaking and airtightness being lost due to the welding. Furthermore, the flange faces outward in the radial direction of the cap edge and is positioned away from the lens (5), and there is little risk of lens damage due to the welding.