Definition

Bismaleimide Triazine (BT) is a thermosetting resin system used in high-performance PCB laminates. BT-epoxy blends offer higher Tg (180-210°C) than standard FR-4, lower moisture absorption, better dimensional stability, and favorable electrical properties (Dk ~4.0, Df ~0.01 at 1 GHz). BT laminates are commonly used for IC package substrates, BGA substrates, and high-reliability applications where thermal performance exceeds what FR-4 can deliver. The material is more expensive than FR-4 but less costly than polyimide.