Hey JGK...
Quote:
silicone baking sheets made of thicker silicone would something like that work?
The main purpose of the Silpad (or the mica/thermal compound) is for a more efficient heat transfer between the MOSFET and the chassis, which is our heatsink in this case. Too thick a silicone material will insulate the MOSFET from the chassis and essentially do nothing thermally. I've read that we also need to isolate the MOSFET electrically from the chassis which the Silpad or mica will do as well.
To isolate the MOSFET
completely may require the addition of small shoulder washers to assure that the mounting screw is
also isolated from the MOSFET's heatsink, since the screw is hard mounted to the chassis via a lock washer and nut. (I've never confirmed that the MOSFET really needs to be electrically isolated). There appears to be enough clearance of the MOSFET heatsink to prevent this, but if you're concerned about things shifting this would be some extra insurance.
A piece of Kapton or electrical tape just under the eyelets and wiring of the VRM wouldn't hurt either.
Joe G