Quote Originally Posted by Tabbykatze View Post
Because the thermal mass is so small, it will hit equal temperature to source very rapidly then will actually impact heat transfer.

That's why copper heatpipes actually have a liquid within them as a heat transfer medium because the copper facilitates a better heat transfer strata but not over a distance.

Edit: And the copper cooling pins you're describing and showing are for the heat to be extracted from something actively travelling over it like air, water or in contact with the ground to increase the potential thermal mass.
I can't see how it would hit equal temperature to source when the pins would connected to a heat-spreader and that in turn has got a cooler on it. Also yes heat take time to transfer through a material but that's not why heatpipes are a thing, it's because they have a higher thermal conductivity.

And yes what I'm describing and showing is used with air blowing over it but it can also be reversed and used to take heat from whatever surrounds the pins to a cooler surface.