A solder ball being levitated and heated by a strong electric AC field generated by two coils. As soon as it gets too hot the induced force won't be sufficient to keep the ball levitating. By falling down "stuff" can be soldered...
The "red halves" of the ball show that it oscillated during the exposure time.
Well, since it is actually desired that the solder balls drop when they reached a certain temperature, superconducting balls wouldn't be really usefull..