Thermalright CB-6L Heatsink Review
Thermalright
broke all the cooling barriers with the introduction of their full-copper SK-6
heatsink and many people expected the CB-6L to follow in the same
footsteps. The difference this time around is that the CB-6L is only partially
copper, and more importantly, doesn't employ highly efficient thin-fin construction.
Rather we
are faced with a typical aluminum legacy extrusion which has seen some
upgrades in an attempt to improve its's overall performance characteristics.
The additions include plating the entire heatsink so that a 2mm thick copper
base plate can be affixed to the base via solder. Other manufacturers have
attempted similar upgrades to existing extrusions by mechanically attachments or thermal adhesives
- usually with less than ideal results.
Will the CB-6L be the one technology to shine on?
The answer is possibly, but since we are now in the times of high performance
fans and full copper thermal solutions it will have stiff competition to face up
against.
More on the CB-6L:
There seems
to be an active movement by some manufacturers to tag copper heatspreaders onto the
base of existing aluminum extrusion design heatsinks. As if to extend the lifespan
of their expensive extrusion dies, all manner of attachment methods have been attempted to
get the copper to stick to the aluminum.
Under normal circumstances you can't solder copper to aluminum, so some
companies have resorted to bolting on plates, gluing them with thermal epoxy, or
in the case of Thermalright, soldering. Of the three methods we mentioned solder
is apt to be the best form of thermal joint. The problem is that aluminum isn't
that receptive to soldering attempts, so a another coating of a more workable
metal is needed.

In this case the aluminum extrusion has been plated with a metal that enables
the manufacturers to solder the 2mm thick copper plate to the base of the CB-6L,
hopefully improving the overall performance of an otherwise standard aluminum
extrusion.