If you see a specification calling for on a drawing, it is almost certainly lead-free. For tin-lead, request the "warm" profile instead. Thermal Stress and Board Longevity The obvious concern with Xemu Complex 4627 hot is reliability. Does repeatedly exposing a board to 270°C damage it?
The profile increases the peak temperature to 265°C – 275°C at the component surface, with a longer "soak zone" (150°C to 200°C) lasting 90 to 120 seconds. This ensures that the thermal energy penetrates the inner layers before the top layer scorches. The Three Zones of "Hot" To execute a proper Xemu Complex 4627 hot cycle, your rework station must follow this specific thermal recipe: xemu complex 4627 hot
Use a nozzle 5mm larger than the component. For a 35mm BGA, use a 40mm nozzle. The Xemu Complex 4627 hot requires high airflow (40 liters per minute) to force heat into the interstitial spaces. If you see a specification calling for on
Set the Xemu bottom IR to 210°C . This is higher than usual. Because Complex 4627 is thick (2.4mm), the top surface will only see 180°C of that. The "hot" profile relies on bottom heat to pre-soak the board. Does repeatedly exposing a board to 270°C damage it