Patent attributes
A package for high frequency usages 10 has a notched area 16 on each longitudinal end of a substantially rectangular heat sink plate 11 for fastening the package to a base 20 with a screw. The package includes a joined member 17 formed by joining a surface of a ring-like frame member 12 made of a ceramic material to the longitudinal center of a surface of heat sink plate 11 and joining another surface to an external connection terminal 15. The other surface of heat sink plate 11 presents a curved protruding shape 18 bowing from its longitudinal ends toward its longitudinal center, so that curved protruding shape 18 causes at least an area of the other surface heat sink plate 11 that corresponds to an area dedicated for mounting a semiconductor device 19 within ring-like frame member 12 to make a close contact with base 20 when the package is fastened to base 20 by the screw at notched areas 16.
