What are the properties of halogen-free PCB?

Insulation: Since the halogen is replaced by P or N, the polarity of the epoxy molecular bonds is reduced, which improves the insulation resistance and breakdown voltage.

Water absorption: Due to the relatively low electrons of N and P in the nitrogen-phosphorus-oxygen reduction resin, the probability of forming hydrogen bonds with hydrogen atoms in water is lower than that of halogens. The water absorption rate of halogen-free PCB is lower than that of conventional boards, which affects reliability to a certain extent.

Thermal stability: The nitrogen and phosphorus content in halogen-free PCB is higher than that of ordinary board, so monomer molecular weight and Tg value increase.