Its 25 ns reverse recovery time places it in the fast-recovery class (≤500 ns, >200 mA) needed for high-frequency switched-mode power supplies, power-factor-correction stages, and output rectification in flyback or half-bridge converters. The 1.1 V forward drop at 5 A is typical for a 200 V ultrafast part and sets the conduction loss budget for the thermal design.
STMicroelectronics lists the STTH1002CG as obsolete. That means no further factory orders or last-time-buy windows are available from the authorized channel.
Package and thermal — D2PAK tab is the thermal path
The STTH1002CG comes in the TO-263-3 (D2PAK) surface-mount package. The exposed tab on the D2PAK is the cathode connection for both diodes and the primary heat path — the PCB copper area and via stitch under the tab determine junction temperature, not just the ambient. The tube shipping medium is the factory packaging, not a selection parameter.