The technology to do this is pretty old, and it's basically just a very precise pick-and-place machine (disclaimer - this is for 3D stacking, not necessarily AM

The technology to do this is pretty old, and it's basically just a very precise pick-and-place machine (disclaimer - this is for 3D stacking, not necessarily AMD's thing). The rub is that it doesn't need to be that precise: surface tension from the soldering process will actually correct a small mis-placement as long as you aren't off by too much, so the tolerances are bigger than you think.