Controlling Warpage During Reflow
Thermal warpage grows with uneven copper balance and thin, large panels. Above the paste liquidus, parts simply float away from the pad.
Symmetry first
Balanced copper on both layers and a symmetric stack-up minimize the bow.
Profile tuning
A gentle ramp and a soak window reduce differential expansion across the board.
Support and hold-down
Carrier trays and edge clamping keep large thin boards from lifting.
Key Takeaways
Key Takeaways
- Balance copper and stack-up symmetry.
- Soften the ramp to limit differential expansion.
- Use carriers for large, thin panels.
