US Patent 7956455 RF power transistor package

An RF power transistor package with a rectangular ceramic base can house one or more dies affixed to an upper surface of the ceramic base. Source leads attached to the ceramic base extend from at least opposite sides of the rectangular base beneath a periphery of a non-conductive cover overlying the ceramic base. The cover includes recesses arranged to receive the one or more die, the ceramic base, gate and drain leads and a portion of the source leads. The cover further includes bolt holes arranged to clamp the ceramic base and source leads to a heat sink. Bosses at corners of the cover outward of the bolt holes exert a downward bowing force along the periphery of the cover between the bolt holes.