On Thu, 19 Apr 2018 17:09:23 -0700 (PDT), wrote:

...I also agree with Jeff Leiberman's caveat

Argh. It's Jeff Liebermann. Spell my name correctly or I shall call
upon the gods for divine retaliation. Heed this first and last
warning lest the wrath of the gods fall upon thy house, when darkness
shall envelope thy LCD monitor, and a plague of bugs infest the
software by which you have taken my name in vain.

I've been hearing of laptops with mo fan, and of course smartphones
don't have them.

Most of my Chromebooks do not have a fan. Heat is conducted from the
CPU to either a metal case or the metal shield on the bottom of the
keyboard.

Will it eventually get to the point where they don't
need heatsinks ?

Methinks not. For every decrease in CPU power consumption, there is
an equal and opposite increase in clock speeds. The result is that
the maximum power remains about the same or slightly lower. However,
when the CPU is at idle and not active, the power consumption is much
lower.

Get an efficient enough switch and it could happen. I have already
seen power switching transistors with no heat sink except the tab
itself.
At 0 Vcesat, 0 Vceo, 0 Vbe, 0 tOFF and 0 tON there is no heat to sink.

There's also no signal. Might be an IGBT FET. Very low Vce(sat) at
high currents. However, it's not zero, so there's still some heat
that needs to removed.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558