[derefr]

In theory, laptop manufacturers that use aluminum in their chassis could just put the CPU die right up against the chassis, Remove the bottom feet, and then tell you to only ever use it sitting on top of a table designed to function as a top-down heat pipe (i.e. the kind they use to make “scraped” frozen yoghurt.) The table would become the CPU’s direct-contact heatsink.

Not practical at all, of course, but this is well within the laws of physics. (And people do lesser things all the time, using e.g. those laptop “cooling stands” with clearance and fans built in.)

[BenjiWiebe]

It would be practical to at least have some form of heat transfer to the case for passive cooling advantage, but this can have the downside of the end user getting burned/uncomfortable and saying, Why does my computer get so hot?

The recent metal-cased RTL-SDR's from rtl-sdr-blog have this "problem". The metal case actually helps the chip run cooler, but it gets hotter to the touch then the early insulating plastic models.