Halogen-free PCB Introduction

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What is a halogen-free PCB?

According to the JPCA-ES-01-2003 standard, copper clad laminates with chlorine (Cl) and bromine (Br) content less than 0.09% weight ratio are defined as halogen-free copper clad laminates. At the same time, the total amount of Cl + Br should be less than or equal to 0.15% (1500PPM).

Why ban halogen?

Halogen refers to the halogen elements in the periodic table of chemical elements, including fluorine (F), chlorine (Cl), bromine (Br), and iodine. Currently, flame retardant substrates such as FR4 and CEM-3 mostly use brominated epoxy resin as flame retardants. The main flame retardants for copper-clad laminates include tetrabromobisphenol A, polymeric polybrominated biphenyls, polymeric polybrominated diphenyl ethers, and polybrominated diphenyl ethers. These materials are low-cost and compatible with epoxy resins. However, studies have shown that halogen-containing flame-retardant materials emit dioxins (dioxin TCDD), benzofuran, and other toxic substances when they are discarded and burned. This results in a large amount of smoke, an unpleasant smell, highly toxic gases, carcinogenic effects, and environmental hazards. In response, the European Union and the Ministry of Information Industry of China have prohibited using PBB and PBDE as flame retardants in electronic information products.

The EU law prohibits the use of six substances, including PBB and PBDE. PBB and PBDE are no longer used in the copper-clad laminate industry; other bromine flame retardant materials are mostly used. While laws and regulations do not regulate copper-clad laminates containing bromine as a flame retardant, they release a large amount of toxic gas and emit a large amount of smoke during combustion or electrical fire. When the PCB is leveled with hot air and components are soldered, a trace amount of hydrogen bromide is released due to the high temperature. Whether this process also produces dioxins is still under evaluation. Therefore, FR4 sheets containing tetrabromobisphenol A flame retardant are not currently prohibited by law and can still be used, but they cannot be called halogen-free sheets.

Halogen-free PCB Introduction

Principle of halogen-free substrate

Currently, most of the halogen-free materials are mainly phosphorus-based and phosphorus-nitrogen-based. When the phosphorous resin is burned, it decomposes to generate meta-polyphosphoric acid, which forms a carbonized film on the surface of the polymer resin, insulating the burning surface from contact with air, extinguishing the fire, and achieving a flame-retardant effect. The polymer resin containing phosphorus and nitrogen compounds generates incombustible gas when burned, which helps the resin system to be flame-retardant.

Halogen-free PCB boards have low water absorption and meet environmental protection requirements. Additionally, other properties can also meet the quality requirements of PCB boards. As a result, the demand for halogen-free PCB boards is increasing, and major PCB suppliers are investing more in the research and development of halogen-free PCB substrates and halogen-free PP. It is believed that low-priced halogen-free circuit board structures will be put on the market soon.

Why Choose China PCBA Supplier KSPCBA as Your Halogen-free PCB Manufacturer?

– Experienced and skilled team

– State-of-the-art equipment

– Strict quality control

– Excellent customer service

– Competitive price