Novel aluminium-silicon alloys for electronics packaging

A novel series of aluminium-silicon alloys has been developed using the Osprey method. These high silicon (50-70 wt%) content alloys have fine, isotropic microstructure. Unlike the conventional silicon-carbide-containing metal matrix composites (MMCs), the new alloys are readily machinable using conventional carbide tools and are easily platable with nickel, copper, silver and gold. The electroplated layers remain adherent and blister free up to 450/spl deg/C. The characterisation of the alloys in terms of their resistivity, thermal conductivity and thermal expansivity is described. The methodology for fabricating electronics packages is also described.