Definition

Specify high-Tg laminate (Tg ≥170°C) when: your board uses lead-free assembly (required - standard FR-4 fails at 260°C reflow), the board will see more than 3 reflow cycles (rework, double-sided assembly), operating temperature exceeds 105°C, or you need IPC Class 3 reliability. High-Tg materials like IS410, 370HR, and FR408 cost 10-20% more than standard FR-4 but prevent via barrel cracking and delamination under thermal stress. For most lead-free commercial products, high-Tg is now standard practice.