Abstract: A heatsink assembly and method of fabrication and use for high power RF LDMOS transistors such as those used in mobile telephone basestation pre-antenna amplifiers wherein die attachment to the heatsink flange occurs prior to leadframe/spacer-to-flange bonding. Various bonding methods are disclosed which do not compromise the die-to-flange attachment bond. A unique leadframe/spacer/flange heatsink package is also disclosed which automatically properly orients attachment of the leadframe/spacer to the flange, and provides for a thickened spacer. A unique leadframe having contact projections also avoids later wire bonding. A unique leadframe/spacer/lid combination is disclosed which allows in one step the bonding of the leadframe to the flange, electrically contacting the die, and encapsulation.

Abstract: A process for low cost manufacturing light-weight, heat-dissipating structures such as heatsinks, heat spreaders, and covers or lids for microelectronic components such as flip-chip integrated circuits from difficult-to-machine metal matrix composites such as aluminum silicon carbide (generically referred to as “Al—SiC” or “AlSiC”). The process involves selecting a mass produced quantity of Al—SiC material, forming that material into a thin ribbon, then stamping/coining the ribbon into the structures. The ribbon can be formed by extruding a thin strip from a billet of the Al—SiC material, then plurally rolling it. In this way, commonly available AlSiC composites manufactured in high volume for use in other applications such as cast automotive parts may be used.