Isolation pads

[Devil_H@ck]

I have some isolation pads here for TO-3 and TO-220 cases.
These are those "new" synthetic (so not mica) pads. Do I need to apply thermal compound or not? I have some Arctic Silver 3 lying around.

I think these are the isolation pads I've got: http://www.aavidthermalloy.com/products/options/pads.shtml#insil
In case you don't know what the Arctic Silver 3 is: http://www.arcticsilver.com/as3.htm (this is supposed to be one of the best thermal compounds available for CPUs) (Thermal resistance: <0.005°C-in²/Watt )

Oh, btw, do I have to use the isolation pads on BD139 & BD140? I suppose I have to, since there's iron on the back of it, right?

 

[Jan Dupont]

These are silicone pads mentioned to use without compound, however some compound never will do no damage

And YES!!! All transistors with some metal in the housing MUST be fitted with insulation pads....

 

[JOE DIRT®]

I beleive you are referring to "sil-pad"......and I would still use compound

 

[Devil_H@ck]

Ok, thanks!
I guess I'll have to loosen the screws and apply a bit of compound to both sides of the isolation pads.

Work for tomorrow, time to go to bed now.

 

[trigon]

Where I can get silicon vashers for TO-220. ?

Thank you in advance

Trigon.

 

[azira]

Are you talking about the little rubber looking pads? I saw some of those when I was getting some Mica wafers for my transistors at the surplus store. I also saw some thicker opaque white ones for my transistors that were stuck to a plastic backing. You were supposed to peel them off, what are those?

 

[trigon]

These are the ones that I have been asking for. They are used with mounting screws.

Trigon

 

[Peter Daniel]

Digi-Key certainly carry those as well the Chinese store Downtown

PS: I don't think it's recommended to use thermal grease on sil-pads

 

[JOE DIRT®]

Peter they don`t reccomend thermal grease on Sil-Pad but through extensive testing we found it to be better.....the problem is that people tend to use exorberate amounts which degrades thermal transfer

 

[Devil_H@ck]

Ah, well, I certainly wouldn't apply lots of it. I put a plastic bag around my finger and rub it on top of the area where it needs to go. Very thin layers guaranteed!