Definition

Isola 370HR is the industry's go-to high-Tg FR-4 for demanding applications. Specs: Tg 180°C, Td 340°C, Dk 4.04, Df 0.021, T260 60 min, T288 30 min, Z-CTE 45/230 ppm/°C (pre/post Tg). The material handles multiple lead-free reflow cycles and sequential lamination processes without degradation. 370HR is halogen-free, meeting environmental requirements without sacrificing reliability. Cost runs 1.1-1.3x standard FR-4. Specify 370HR for automotive, telecommunications, servers, and any design requiring IPC Class 3 reliability with lead-free assembly. It's the safe default when high-Tg FR-4 is required and material cost isn't the primary constraint.