Copper vs Aluminum vs Ect.

[Teslanium]

So, could one devise a two-part heat sink design with a high heat capacity material in contact with/around the diode, and a high thermal conductivity material around that... or would it be better the other way around - get the heat away from the diode as fast as possible, then move it into a larger mass that can absorb it?

T.

 

[TheDukeAnumber1]

It would be better to have high conductivity near the diode. I.E. - A silver module with a copper heat sink.

 

[Teslanium]

Here are two sources of experiments done with varying surface finishes. One source from an individual and one on behalf of a company.

http://www.dfrsolutions.com/uploads/white-papers/WP_Heatsinks.pdf

http://www.molalla.net/members/leeper/coatbar.htm

From our own calculations and these sources it looks like the surface finish does make a notable difference in temperature even at the handheld level of application.

+1!

Thanks very much for these, seeing actual test data is really what we need. I did take special note of this surprising tidbit (especially the last [my bolded] part) in the second link:


"For some, this doesn't make sense- the emissivity (the ability to radiate thermal heat) of a high solids white is within a percent as high solids black. However, if you run the test, or look up the data, one will find black or white paint has little difference, they both radiate very well in the thermal spectrum. One unique thing about white paint though, is that it reflects in the thermal spectrum, unlike black paint. However, polishing is a very, very bad thing for emissivity."

Might have to rethink those (high-power) polished hosts.

And thanks for your answering my question about inner/outer HS material!

:thanks:
T.