The STPS10L25G-TR is a 25 V, 10 A Schottky rectifier from STMicroelectronics in a D2PAK (TO-263) surface-mount package. It is a standard-recovery Schottky — fast enough for low-frequency switching and OR-ing, not a hyperfast diode for MHz power supplies. The 460 mV forward drop at 10 A sets the conduction loss; at full load that is 4.6 W, which the D2PAK tab must sink to a copper island on the board.
Conduction loss and thermal budget
At 10 A forward current the Vf is 460 mV max — that is the number to use for worst-case dissipation, not the typical curve. The junction temperature ceiling is 150 °C. The D2PAK tab is the cathode, so the PCB copper pour under the tab carries the output current and acts as the heatsink. Board layout that starves the tab of copper will push the junction above 150 °C at 10 A continuous. Reverse leakage at 25 V is 800 µA — negligible at room temperature but it rises with junction temperature. In a high-ambient enclosure (85 °C+), the leakage contribution to self-heating needs a quick check against the thermal resistance of the board footprint.
D2PAK is a large-tab surface-mount package. The tab is the cathode — the board copper pour under it is at the output voltage. Rework is doable with a hot-air station if you preheat the board from the bottom; the tab soaks heat fast, so a standard soldering iron on the leads alone will not wet the tab joint. The tab has no pin 1 marker — orientation is by the bevel on the plastic body, same as a TO-220 but laid flat.