Need an electrically conductive thermal paste

D

draksia

Supreme [H]ardness
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Nov 16, 2000
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Alright I am building a power distribution system that uses mosfet based switches. These need to have heatsinks attached. The problem is that the area used to attach the heatsink also is conductor for the current load. I would like to be able to use some type of thermal paste on them but it needs to be electrically conductive. These devices pull about 10 amps each so good conductivity is important both thermally and electrically.

If any one knows a thermal paste that is conductive let me know.

Thanks.
 
i dont think its a real good idea to do that, thermal paste isnt meant to carry any kind of current, your best bet is probably just bolting a copper plate on
 
In reality the actual bolt should carry most of the currrent but it would be nice for the paste to handle some too.
 
Hmm... you could try RadioShack, they may have something. As well, try Mouser Electronics, Partsexpress, and Digikey.
 
You're in luck, if my memory serves me right, plain ol' arctic silver 5 is electrically conductive.
 
It is conductive, but not at low voltages. I've tried pushing 2kv throgh one centimeter of AS, and got zero current.
 
draksia said:
Alright I am building a power distribution system that uses mosfet based switches. These need to have heatsinks attached. The problem is that the area used to attach the heatsink also is conductor for the current load. I would like to be able to use some type of thermal paste on them but it needs to be electrically conductive. These devices pull about 10 amps each so good conductivity is important both thermally and electrically.

If any one knows a thermal paste that is conductive let me know.

Thanks.
Click to expand...

Would it be possible for you to solder the heatsink to the FET? I would think that would conduct the heat pretty well (and I know it's conductive).
 
I was thinking about soldering the mosfets right to the heatsink but that makes replacement a lot harder especially for in field replacement. Plus a lot more risk with burning them out during the soldering.


I think I will just try using the orginal or artic silver II.

The newer ones are not conductive but are slightly capacitive.

I think using a copper bolt to attach them and some artic silver will be more then adaquate.
 
None of the earlier versions of Arctic Silver are not electrically conductive.

You may want to look into CircuitWorks 7100. Since it is formulated for electrical conductivity, it's thermal performance will not match AS5.

Colin Thompson
Arctic Silver, Inc.
 
Mr. Thompson said:
None of the earlier versions of Arctic Silver are not electrically conductive.

You may want to look into CircuitWorks 7100. Since it is formulated for electrical conductivity, it's thermal performance will not match AS5.

Colin Thompson
Arctic Silver, Inc.
Click to expand...


Thanks thats exactly what I was looking for.
 
the screw you use to bolt the heatsink to the mosfet will be sufficient to carry the current actually
 
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