Integrated circuit package with integral leadrame heat dissipator and manufacturing method therefor

An electronic package (10) and packaging method in which integral convective fins are formed of portions of a leadframe (14) from which electrical leads (18) are also formed. The leadframe (14) comprises a base (16) and first and second sets of leads (18,28) extending from the base (16). The first set of leads (18) is separated from the base (16) and from the second set of leads (28), such that each lead of the first set has an interior end adjacent but separate from the base (16), and each lead of the second set has an interior portion that remains attached to the base (16). A circuit device (12) is mounted to the base (16) and electrically connected to the interior ends of the first set of leads (18). The device (12), base (16), and interior ends and portions of the leads are then encased within a housing (26). Exterior ends of the leads remain outside the housing (26) as package (10) terminals and thermal dissipaters.