whats the differnece between a copper heatsink and aluminum heatsink

[mmmkdrugsarebad]

whats the difference between a coppper heatsink and aluminum heatsink?(besides the fact that one copper and ones aluminum)... liike what they do differently? and is one better than the other? thanks

 

[norbyx]

There has been a long discussion on this in the forum. You should search it out. Copper trasnfers heat faster than aluminum, but aluminum has the capacity to "retain" more heat than copper.

If you look at computer heatsinks the best one normally have a combination of copper and aluminum. There is still no one that has done such a thing here, but that would be the best solution having a heatsink that against the diode is copper and further away it's aluminum.

Also copper is heavy and many like the "feel" of a heavy host in their hands.

 

[EpicHam]

Well that depends .
Aluminium has a higher specific heat capacity but a lower transmittance .
If your host is sucky and is made of flat surface aluminium anyway.
It then really becomes a SINK of heat.
Good for short duration ,but a longer cooling cycle.

If you have a good host with radiator flaps or the heat sink would stick out of the host and contact the air , go for copper.
But bear in mind tho , it may speed up the corrosion of surrounding material since it practically uses other metals for sacrificial protection , so that'll take a little bit more maintenance in a span of 5 years ish.

In the end , the host design is mainly what matters the most

 

[grainde]

There has been a long discussion on this in the forum. You should search it out. Copper trasnfers heat faster than aluminum, but aluminum has the capacity to "retain" more heat than copper.

Actually copper has a higher specific heat capacity than aluminium and so it stores more heat and heats up less quickly than Alu. Copper does transfer heat more effectively though.

If you look at computer heatsinks the best one normally have a combination of copper and aluminum. There is still no one that has done such a thing here, but that would be the best solution having a heatsink that against the diode is copper and further away it's aluminum.

Haha have you ever heard of a copper module in an Aluminium heat sink...


Anyway there have been many threads dealing with the issue of Cu vs Al but this one might be of interest: http://laserpointerforums.com/f54/copper-vs-aluminum-vs-ect-76259.html :beer:

 

[EpicHam]

Actually copper has a higher specific heat capacity than aluminium and so it stores more heat and heats up less quickly than Alu. Copper does transfer heat more effectively though.



Haha have you ever heard of a copper module in an Aluminium heat sink...


Anyway there have been many threads dealing with the issue of Cu vs Al but this one might be of interest: http://laserpointerforums.com/f54/copper-vs-aluminum-vs-ect-76259.html :beer:

Aluminum 0.91 (kJ/kg K)
Copper 0.39 (kJ/kg K)

you are absolutely sure about copper having higher specific heat than aluminium?

 

[grainde]

Ok I was trying to simplify things.

What I was trying to say is that eg in our lasers a copper heat sink will take longer to heat up than an aluminium one. This is due to the density of copper ie for the same sized volume heat sink you have more material.

If you take a 100 g piece of copper with density 8.96 gcm-3 = 11.16 cm3
so 11.16 cm3 * 2.7 gcm-3 = 30 g equivalent Al heat sink.

100 g x specific heat Cu (0.385 Jg-1°C-1) = 38.5 J°C-1
30 * x SH Al (0.902 Jg-1°C-1) = 27.2 J°C-1

So the actual heat capacity of our heat sink made of copper is higher. :beer:


Edit: Just read through the thread I linked. We did lots of calculations, even including the radiative efficiencies of different host surfaces and worked out how well the hosts we use work.

 

[EpicHam]

Ok I was trying to simplify things.

What I was trying to say is that eg in our lasers a copper heat sink will take longer to heat up than an aluminium one. This is due to the density of copper ie for the same sized volume heat sink you have more material.

If you take a 100 g piece of copper with density 8.96 gcm-3 = 11.16 cm3
so 11.16 cm3 * 2.7 gcm-3 = 30 g equivalent Al heat sink.

100 g x specific heat Cu (0.385 Jg-1°C-1) = 38.5 J°C-1
30 * x SH Al (0.902 Jg-1°C-1) = 27.2 J°C-1

So the actual heat capacity of our heat sink made of copper is higher. :beer:


Edit: Just read through the thread I linked. We did lots of calculations, even including the radiative efficiencies of different host surfaces and worked out how well the hosts we use work.

DOH!
:worthy:
Drinks are on me , mate lol
:beer: