Hybrid solder and filled paste in microelectronic packaging

Abstract

Hybrid solder for solder balls and filled paste are described. A solder ball may be formed of a droplet of higher temperature solder and a coating of lower temperature solder. This may be used with a solder paste that has an adhesive and a filler of low temperature solder particles, the filler comprising less than 80 weight percent of the paste. The solder balls and paste may be used in soldering packages for microelectronic devices. A package may be formed by applying a solder paste to a bond pad of a substrate, attaching a hybrid solder ball to each pad using the paste, and attaching the package substrate to a microelectronic substrate by reflowing the hybrid solder balls to form a hybrid solder interconnect.

Dependencies are inferred from the claim text.