Ramsink covering more than one mofset? Or chop them up?

[brafman]

I am installing a new 8rda+ in my machine and want to attach some ramsinks to the mofsets. But the ramsinks are bigger than 1 mofset. My question is: is it OK to have the ramsink cover more than one mofset, acting unintentionally like a heatspreader? Or must I chop the ramsinks up so it covers only one at a time?

[tex4]

No problem covering more than one with one heat sink.

[Veky]

I have a question too, I have little heatsinks and 2 of them cover all the mosfets but they are very very short. I was thinking of putting one and 2 more on top of it, connected with paste. Doable?

[jcool]

not a very good solution I'd say because you won't be able to make good contact between the 2 HS.
Better replace them with longer ones if you think that better cooling is required.

[Veky]

Hmm, well it's pretty short but it shouldnt mather much, as the shorter it is the faster will the heat spread th the top and into the air.

[timbob2469]

I also covered 6 of mine with 2 heatsinks, I wouldn't stack them because you might be defeating the purpose of the "Passive" cooling effect. Also if you use a cpu cooler like a Zalman or an SLK 800-900 you get the added benefit of some "overflow" cooling , especially if you get a 92mm fan.
PS. Don't forget the 2 smaller chips that are nearby. This link will get you to some thermal images that show the heat.
http://homepage.ntlworld.com/bubo/Mosfets/mosfets.html
Bob

[Veky]

Thanks Bob, I'll put something on today.