Sony might be useing 3D stacked chips to be more power effecient, have better cooling.

[Bofferbrauer2]

Reading through the patent, it made itself look quite old. As in, nothing about stacked hardware, but instead the description in the OP is mostly one of FCPGA, or Flipped Chip Pin Grid Array. Those were originally developed because non-flipped ones started needing some active cooling at the time, and they still needed to figure out how to do that effectively. The only new stuff are some holes for coolant, basically integrated heatpipes, which allow for the heat to also exit from the sides of the die, not just above, hence no need for a cooler on the upper side. But that doesn't mean no cooler at all.