Abstract: An improved lead frame having an electrically isolated heat sink portion is provided for the manufacture of high heat dissipating semiconductor devices. A large heat sink metallic portion having an exposed surface has plastic encapsulating material partially disposed thereabout such that associated semiconductor device leads are correctly positioned with respect to the heat sink metallic portion but are electrically isolated from it. A semiconductor chip is mounted directly on the heat sink metallic portion such that high heat dissipation is obtained. The lead frame provides for a plurality of metallic heat sink portions joined to a corresponding plurality of semiconductor device lead portions. Joining means positioned in the frame between adjacent metallic heat sink portions and correspondingly between successive semiconductor device lead portions are attached to each other to hold the respective portions of the lead frame in proper relationship to each other during the assembly process.

Abstract: A high heat dissipating integrated circuit device having a large heat sink metalic portion surrounding the plastic encapsulation material of the semiconductor chip. The semiconductor chip is mounted in electrically insulated, close conjunction with the heat sink such that high heat dissipation is provided. The heat sink portion is conveniently formed surrounding most of the plastic encapsulation to provide for maximum heat dissipation from the device. The device provides for heat dissipation in the ten to higher watt range.