What is Halogen Free PCB

Posted by freemexy on January 18th, 2021

Halogen free printed circuit board is called Halogen Free PCB. Halogen free PCB is made of halogen-free copper clad laminate. Halogen elements are extremely life-threatening chlorine, bromine, fluorine, iodine and very. For PCB to be considered “halogen-free”, the content of chlorine or bromine must be less than 900 ppm, and the total amount of halogen materials must be less than 1500 ppm.To get more news about Halogen Free PCB, you can visit pcbmake official website.

In PCB manufacturing, the relevant halogen elements (such as chlorine and bromine) do have some benefits, but these benefits do not exceed the negative effects they may cause in our daily life.

Chlorine is used as a flame retardant to protect components and as an element in PVC coating of wires.Bromine is used as a sterilant. It can also be used as a flame retardant in electronic components.

Despite their advantages, they cannot avoid their negative effects. Exposure to chlorine or bromine can cause coughing, nausea, blurred vision, skin irritation, dyspnea and eye burns. Chlorine compounds can also combine with hydrocarbons to form dioxins, a deadly carcinogen.

It is best to avoid large amounts of chlorine or bromine in PCB. As technology advances, manufacturers are developing effective PCBs that do not use these harmful chemicals.
Performance of Halogen Free PCB

Insulation: due to the substitution of halogen by P or N, the polarity of epoxy resin molecular bond is reduced, thus increasing the insulation resistance and breakdown voltage.
Water absorption: due to the relatively low electrons of N and P in nitrogen phosphorus reducing oxygen resin, the possibility of hydrogen atom bonding in water is lower than that of halogen. The water absorption of halogen free PCB is lower than that of conventional PCB, which affects the reliability to a certain extent.
Thermal stability: the content of nitrogen and phosphorus in Halogen free PCB is higher than that in common PCB, so the monomer molecular weight and TG value increase.
Under heating, the molecular mobility of halogen free PCB is lower than that of conventional epoxy resin board, so halogen free PCB has relatively low coefficient of thermal expansion (CTE).