What is halogen-free PCB board? Halogen free plate refers to copper clad plate with chlorine (C1) and bromine (BR) content less than 0.09%
wt (weight ratio) respectively in accordance with jpca-es-01-2003
standard. Meanwhile, the total amount of CI + BR is = 0.15% [1500ppm].To
get more news about
Halogen Free PCB, you can visit pcbmake official website.
At present, most of the halogen-free plates are mainly composed of phosphorus and phosphorus nitrogen systems. When the phosphorus
containing resin is burned, it decomposes by heat to produce
metapolyphosphate, which is highly dehydrated, forming a carbonized film
on the surface of the polymer resin, separating the burning surface of
the resin from the air, and making the fire extinguished to achieve the
flame retardant effect. The polymer resin containing phosphorus and
nitrogen compounds can produce non combustible gas during combustion,
which helps the resin system to be flame retardant.
Characteristics of halogen free sheet
1. Insulation of materials
Because P or n is used to replace the halogen atom, the polarity of the
molecular bond segment of epoxy resin is reduced to a certain extent,
thus improving the insulation resistance and resistance to penetration
of the material.
2. Water absorption of materials
Due to the fact that N and P in n-p-based deoxidizing resin have less
electron to halogen, the probability of hydrogen bond between n-and
P-based deoxidizing resin and hydrogen atom in water is lower than that
of halogen-free material, so the water absorption of halogen-free
material is lower than that of conventional halogen-based flame
retardant material. For sheet metal, low water absorption has a certain
impact on improving the reliability and stability of the material.
3. Thermal stability of materials
The content of nitrogen and phosphorus in Halogen-free plate is higher
than that of halogen in common halogen materials, so the molecular
weight and TG value of monomer are increased. In the case of heating,
the mobility of its molecules will be lower than that of conventional
epoxy resin, so the thermal expansion coefficient of halogen-free
materials is relatively small.
Compared with halogen-containing plates, halogen-free plates have more
advantages, and halogen-free plates replace halogen-containing plates
are also the general trend. At present, there are many kinds of
halogen-free solder resist ink in the world. Its performance is similar
to that of ordinary liquid photosensitive ink, and its specific
operation is basically similar to that of ordinary ink.
