Flip chip interconnects with electroplated, extended eutectic solder

A study was performed on electroplating of an extended eutectic solder structure. The use of electroplating technology enabled firm control over the size and shape of grains in the deposit. Grain size and shape in turn affected the diffusion of lead and tin through bulk phases as well as along grain boundaries. The control over diffusion affected the reflow properties of the final solder structure. The reflow properties affected the strength of the flip-chip bond, as well as the self-alignment properties of the solder. The structures were then tested for their electrical resistance.