Do they actually process the wafers thru the fab when they are thin? That would lead to many issues for conformity across the wafer during critical process steps. I think what they are saying, is that they thin the wafer (back grind) after processing. They are just making the wafer thinner than most semiconductor suppliers. I guess this gives them better heat conduction. I don't see how this gives them a cost advantage.
Do wafers actually become "floppy" when thinned to this degree? I see the image but it still seems that the lattice structure would prevent that degree of deflection. Manufacturing on floppy wafers would actually be very good because it could significantly ease wafer handling requirements.