The STF18N60DM2 is a 600 V N-channel power MOSFET from ST's MDmesh DM2 series, built on a multi-drain mesh technology that cuts the on-resistance penalty typical of high-voltage planar devices. Input capacitance measures 800 pF at 100 V drain bias — moderate enough that the switching node ringing is manageable with a simple RC snubber, but not so low that the device becomes prone to dv/dt turn-on in half-bridge configurations.
Through-hole Full Pack — mounting and thermal reality
The TO-220FP body is a full-mold package with the drain tab fully encapsulated. No exposed metal on the mounting surface means you bolt it directly to the chassis or heatsink without a sil-pad or mica washer. The thermal resistance junction-to-case is higher than a standard TO-220 with an exposed tab — budget for a larger heatsink or forced airflow if running near the 25 W ceiling. The three through-hole leads are standard 0.6 mm square pins on 2.54 mm pitch; the middle pin is drain, which carries switching current, so keep the PCB trace from the drain pin to the transformer or inductor short and wide. The 10 V gate drive voltage listed for the rated Rds(on) is the target — the threshold voltage max is 5 V at 250 µA, so a 5 V logic gate drive won't fully enhance the channel. If your controller outputs 12 V or you have a 10–15 V auxiliary rail, you're fine. For 5 V-only systems, pair this with a gate driver that boosts to 10 V.
For BOM planning, there is no imminent obsolescence risk on this MPN.