Hi, Kleinstein! Thank you for continuing to help me.
There is not absolute need to isolate the drain from the heat sink.
My case is metal and it is tied to Earth Ground. If I don't isolate the MOSFET and/or the aluminum Heat Sink, won't that short the Drain to Earth Ground?
It can work with a life heat sink, especially if active cooling is used and the heat sink deep inside the case.
I am sorry, but I do not understand the term "life heat sink." Do you mean live heat sink? Meaning that the heat sink is actively tied to Earth Ground?
So cooling is not that important and one cannot use the Ptot anyway. So a silpad is OK.
I am sorry, but I do not understand the term "Ptot." Please clarify. It is good to know that a Silpad is acceptable. I have that in stock.
Thank you, again!