Industry secrets about halogen-free substrates

1. At present, most halogen-free materials are mainly phosphorus and phosphorus nitrogen systems. When the phosphorus containing resin is burned, it will decompose to generate metapolyphosphoric acid, which is highly dehydrated, making the surface of the polymer resin form a carbonized film, isolating the burning surface of the resin from the touch of the air, calming the fire and achieving the flame retardant effect. The high molecular resin containing phosphorus and nitrogen compounds can produce non combustible gas when burning, helping the resin system to be flame retardant.

Halogen free glass fiber

2. Characteristics of halogen-free plate

2.1 insulation of materials

Because P or n is selected to replace halogen atom, the polarity of molecular bond segment of epoxy resin is reduced to a certain extent, and then the insulation resistance and resistance to penetration are improved.

2.2 water absorption of materials

The halogen-free sheet material has less electrons of N and P in nitrogen phosphorus oxygen reducing resin than halogen, and the probability of forming hydrogen bond with hydrogen atom in water is lower than that of halogen material, so the water absorption of the material is lower than that of conventional halogen flame retardant material. As for the plate, the low water absorption has a certain impact on the reliability and stability of the improved material.

2.3 thermal stability of materials

The content of nitrogen and phosphorus in Halogen-free plate is higher than that of halogen in general halogen-based materials, so the monomer molecular weight and TG value are increased. When heated, the movement of its molecules will be lower than that of conventional epoxy resins, so the thermal expansion coefficient of halogen-free materials is relatively small.