thermal paste?

[marko]

ok, just bought some Akasa AK-460 thermal paste and don't like the look of it (grey stuff). have i just wasted my money on the wrong stuff? can't believe how difficult it is to get the stuff i want

 

[picowallspeaker]

Is it the same used for CPUs ? Don't use it !! It contains aluminium and it is conductive ,so there's a certain leakage between transistor's case and heatsink.

 

[marko]

Is it the same used for CPUs ? Don't use it !! It contains aluminium and it is conductive ,so there's a certain leakage between transistor's case and heatsink.

thanks, i knew i had bought the wrong stuff now the search begins for the proper stuff..

 

[jean-paul]

Fischer has a very good thermal glue if that is what you need. I use it instead of the pastes if I need a heatsink to be mounted thermally and mechanically to a semiconductor when there is no possibility to tighten it with clips/screws etc. The Farnell partnumber is 121-1723. It is expensive and it is toxic (please read the datasheet before you want to buy it !) when it is still fluid but it is a very good product. As you only need a very tiny drop of it for each heatsink a 5 gram container may last more than a year.

Recommended.

 

[marko]

i just want that white stuff that gets everywhere!!

 

[jean-paul]

You could go to computer shops and pay extreme prices for rebadged industrial stuff or you could just buy the same product in its industrial packaging for a much lower price:

ELECTROLUBE|HTC10S|HEAT SINK COMPOUND, 10ML, SYRINGE | Farnell Nederland

It is called "heatsink compound" or "heat transfer paste". It only fills up irregularities on the surface of the device that needs to be cooled and the surface of the heatsink. So do not make the standard mistake to apply too much of it as it will deteriorate the situation and perform much worse than it should....

Only a small dot in the center is enough.

BTW it would be better to ask a question and to give somewhat more details on where you need it for. You will get better answers when you do so.

 

[Perry Babin]

Dow corning 340.

 

[jean-paul]

Eminem.

 

[marko]

it's for a soundstream ref 10.0, just bought a new board for my sink and want to do the job right! the amp has a poyimide insulation film too..

 

[jean-paul]

If you mean the film to be polyimide you will need a thermal compound indeed. I would choose a non-conducting thermal compound to avoid issues.

Is it this one ?

http://www.soundbuggy.com/Eric/Car Audio/soundstream/class_a_10_0/class_a_10_0_board.jpg

 

[marko]

Don't know what a "poyimide insulation film" is but in most of the cases when a film is used there is no need for thermal compound. BTW i would choose a non-conducting thermal compound to avoid issues.

Is it this one ?

http://www.soundbuggy.com/Eric/Car Audio/soundstream/class_a_10_0/class_a_10_0_board.jpg

yes, you can see the yellow/amber film just above the board, SS use the film as well as paste, Jaime at janderlectronics advised i need the paste as well but he didn't have any in stock.. my old board had paste too so i'm not going to chance it without seen as though SS used it!

 

[jean-paul]

Hi,I edited my previous post as I found out "polyimide" needs thermal grease/compound. Just choose a thermal conductive compound from Farnell or any other supplier that does conduct heat but is electrically non-conductive (just in case).

Again, please make sure to clean the surfaces carefully and only use very tiny amounts of thermal compound. It only needs to fill up the small irregularities on both surfaces. I use a small clean plastic tool to apply it. Just think that a small particle between both surfaces will make the efficiency way worse.

 

[marko]

this is the stuff i got, says it's non conductive. it's quite hard and not soft like the stuff normally found in amps..

Akasa Pro-Grade Thermal Compound AK-460 on eBay (end time 12-Nov-10 20:25:13 GMT)

 

[jean-paul]

Although it is computer grade stuff (read: more expensive than it should be) it will certainly perform just fine in this application. If it is suitable for hothead CPUs it is suitable for your amp too.

 

[blakktalon]

there is one up for auction that may be cheaper if no one else bids. Or there is this one. DOW CORNING® 340 HEAT SINK COMPOUND 5oz tubes - eBay (item 130393070941 end time Nov-16-10 06:50:21 PST)

 

[midnightg35x]

If you have unlimited money, Arctic Cooling MX3. Expensive, but great thermal paste. For large scale applications, the dow corning 340 is good. We use it in the commercial RF market with no issue. Much cheaper in larger quantities compared to consumer products.