The BTA08-600SWRG comes in a TO-220-3 through-hole package (supplier device package TO-220) — the three-lead power tab footprint that has been a standard for triacs and thyristors for decades. The tab is the main conduction path, so the PCB copper area under it sets the thermal resistance; a generous pad or a heatsink keeps the junction below the 125 °C ceiling during an 8 A RMS load.
What the sensitive gate means on the bench
Logic-level sensitive gate means the gate trigger current (Igt) is 10 mA max, with a gate trigger voltage (Vgt) of 1.3 V max — low enough to be driven directly by a 5 V logic output or a microcontroller GPIO through a series resistor, without a separate driver transistor. The hold current (Ih) is 15 mA max, so the triac stays latched once triggered as long as the load current stays above that threshold; if the load is a low-wattage incandescent lamp or a relay coil that drops below 15 mA near the zero crossing, it may drop out prematurely.
Surge current and inrush handling
Non-repetitive surge current is rated 80 A at 50 Hz and 84 A at 60 Hz — this covers the cold-filament inrush of an incandescent load or the start-up surge of a small motor, as long as the surge duration is within one mains half-cycle. The 8 A RMS continuous rating is the steady-state ceiling; for loads with repetitive inrush (like a capacitive power supply), the surge rating sets the margin for the first few cycles.