Heat pipes have a vacuum so phase change happens at lower temperatures than normal
Earth atmosphere. This essentially is how you do what you’ve proposed without having the CPU makers change their designs to run hotter. If you boil water at low pressure and 30C you have the same net effect as boiling itself uses huge amounts of heat energy compared to raising the temperature of water one degree. This is the same energy at any temperature level.
On flexibility I think it’s just that vacuum and the wicking structure that limits the materials. I’m not a material science expert by any means but I have to imagine someone has worked on this.
We don’t bond heat plates to the top of CPUs due to the coefficient of thrermal expansion right? Isn’t that why we need paste?
Because of CoTE was a non issue I would think we could dig heat dissipation channels into the top of chips, maybe Serpinski gasket style. A little proper lapping and you’d get an airtight seal with the heat sink.
CoTE between nickel plater copper integrated heat spreaders and copper heat pipes can be a non-issue, especially over such a small area.
Increasing the effective surface area is an interesting idea, though minimizing the seam thickness also works to reduce the thermal resistance of the joint, and seems to be more common.
On flexibility I think it’s just that vacuum and the wicking structure that limits the materials. I’m not a material science expert by any means but I have to imagine someone has worked on this.