ArcticSilver: Really isolating ?

If I mount an Emitter to a bare aluminium heatsink and use ArcticSilver-ThermalAdhesive to connect it, does it really isolate?
Even if the heatsink is polished nearly perfect ?
This would result in a really thin ArcticSilver Layer.

Thanks !

I don't know if you want nothing but arctic silver between the emitter and the heatsink. Actual contact is the best heat transfer method. AS is just there to fill in the air gaps. So a small lining of AS should do the job. Obviously, you don't want it running or spread so liberally that it can cake and form an insulation between the emitter and the heatsink.

I'd apply the same concept to a CPU heatsink and the CPU as I do here: evenly spread out, the thinner the uniformed layer, the better, and don' t overdo the application.

Isolation: Thermal or Electrical?

As you have described your method of bonding the LED to sink, I wouldn't count on electrical isolation. I believe you will have a great thermal path. You will also likely have an electrical path between sink slug of LED and heat sink. If the heat sink is grounded, this may present a real problem in some cases. IE. Red or Orange Luxeons or in the case of your driver requiring the LED to be isolated from ground (Dat2zip's Wizard driver comes to mind).

- Don