Method for manufacturing plastic package for electronic device having a fully insulated dissipator

摘要

A method for forming a package (30) of plastic material for a semiconductor electronic device having heat sink fully embedded within the package plastic case, is of the type which provides for forming the plastic case (31) within a mold (10) on whose interior a heat sink (21) has been placed which has a first major surface (22) to be insulated by means of a plastic material layer with a first thickness, whereon a metal leadframe (3) and at least one semiconductor material die (11) having an electronic circuit formed thereon have been fixed, and a second major surface (25) opposite from the first and to be insulated by means of a plastic material layer with a second thickness, thinner than said first thickness; and at least one supporting element (23) adapted to be positioned inside the mold cavity facilitating properly spacing the second surface (25) of the heat sink out from a facing wall (15) of the mold cavity during the process of introducing the plastic material for molding. The heat sink (21) is supported only from the side of the second surface (25) by said at least one supporting element (23) being attached to said wall of the cavity (15) and held within the mold cavity during the injection of plastic material and until the latter becomes fully solidified; each of the supporting elements (23) is provided with a tip (24) having a sharp top of negligible cross-sectional area compared to the tip base; during the molding process, each of the tips (24) is inserted into a portion of a corresponding trench (26) formed in the second surface (25) of the heat sink such that is left unencumbered in said trench (26) portion a peripheral region around said tip (24) to let a flow of plastic material run past during the molding process.