Gregory K. Ruiz-Ade wrote:
On Oct 5, 2007, at 11:45 AM, James G. Sack (jim) wrote:
A sample k value for steel (AISI 1020) is 65, aluminum (alloy 1100) is
220 and copper is 380. Diamond (type IIa) is 1850. You can see this is
why heat sinks are made mostly of aluminum and copper until diamond
becomes more affordable.
<heh>
But that makes me wonder: is diamond actually used anywhere for its
thermal conductivity advantages?
Diamond will become affordable only when DeBeers decides it should be.
It's worse than the oil cartels.
DeBeers has nothing to do with industrial diamond manufacture. Their
market is gem quality diamonds for jewelry. What they are fighting
against is large synthetic diamonds, which would be nice but not
required to make a diamond heat sink. The current methods for making
large gem quality diamonds is either precipitation from iron (carbon
dissolves in molten iron) and organic vapor decomposition, both of which
take very precise control and lots of time. If you don't need gem
quality diamonds, you can use a precipitation technique, or one of the
graphite transformations. That's where most of the industrial diamonds
come from like the ones used on cutting blades and drill bits.
What DeBeers has done is convince people that a natural diamond is
somehow better than a synthetic stone and that people dying horrible
deaths in mines is well worth the extra price because it's, well, natural.
But that aside, diamond heat sinks are real. See
<http://www.freepatentsonline.com/4425195.html> and
<http://www.patentstorm.us/patents/6987318.html>. An actual product is
here: <http://www.sumitomoelectricusa.com/scripts/products/ts/hs_mat6.cfm>
Gus
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