[NEED IDEA & ASK] Securing SOT-227 mosfet to heatsink base & Mosfet's FBSOA

[BravoV]

Any idea how to secure SOT-227 mosfet to the cpu heatpipes heat sink base ?

Cause drilling two holes for the standard SOT-227 mount is not possible I'm afraid, just look at the attached photos below as the base thickness to the heatpipes is quite thin.

I don't have any metal workshop here, so making a special custom metals thingy to secure this, is not easy for me. 

Also the securing mechanism must be easily detached in order to clean the heatsink once in a while, I bet most of you know how dusty and dirty a cpu heatsink with fan attached running for months can be, right ?


Also another question, the plan is to use this fet for DC dummy load, say assuming this heatsink can maintain the Fet's Tcase below 90 C, targeting at 300 watt max dissipation is not too ambitious right ? CMIIW or suggest even other numbers. Fyi, its IXYS IXTN46N50L linear mosfet and the FBSOA chart also attached below.

TIA