Composite interconnect structure using injection molded solder technique

Abstract

Composite interconnect structure forming methods using injection molded solder are disclosed. The methods provide a mold having at least one opening formed therein with each opening including a member of a material dissimilar to a solder to be used to fill the opening, and then fill the remainder of each opening with solder to form the composite interconnect structure. The resulting composite interconnect structure can be leveraged to achieve a much larger variety of composite structures than exhibited by the prior art. For example, the material may be chosen to be more electrically conductive than the solder portion, more electromigration-resistant than the solder portion and/or more fatigue-resistant than the solder portion. In one embodiment, the composite interconnect structure can include an optical structure, or plastic or ceramic material. The optical structure provides radiation propagation and/or amplification between waveguides in the substrate and device, and the plastic material provides fatigue-resistance.