A first metal is plated onto a substrate comprising a second metal by immersing
the substrate into a bath comprising a compound of the first metal and an organic
diluent. The second metal is more electropositive than the first metal. The organic
diluent has a boiling point higher than a eutectic point in a phase diagram of
the first and second metals. The bath is operated above the eutectic point but
below the melting point of the second metal. For example, bismuth is immersion
plated onto lead-free tin-based solder balls, and subsequently redistributed by
fluxless reflow. Plated structures are also provided.