Overview of Technical and Environmental Advantages of Halogen-Free FR4 Laminates

I. Environmental & Human Health Advantages

1. Halogen-free FR4 does not emit toxic halogen-containing fumes during combustion. Standard FR4 releases highly corrosive hydrogen bromide (HBr) when burned, which irritates the human respiratory tract and corrodes circuit traces and surrounding components. In contrast, halogen-free FR4 only generates low-toxicity, mildly corrosive smoke.

2. No dioxins form during incineration. Standard FR4 incorporates brominated flame retardants that produce highly toxic persistent pollutants such as dioxins and furans upon burning. Halogen-free laminates adopt phosphorus-based or inorganic mineral flame retardant systems, completely preventing the generation of such hazardous substances.

3. Low smoke emission, ideal for enclosed spaces including subways, coaches, elevators and server rooms. In case of fire, standard FR4 creates dense black smoke that blocks evacuation visibility, while halogen-free laminates produce thin, light smoke during combustion.

II. Excellent High-Temperature Resistance

1. Typical halogen-free FR4 features a glass transition temperature (Tg) of ≥140°C, compared with only 130–135°C for standard FR4.

2. It withstands multiple cycles of lead-free reflow soldering with a peak temperature of 260°C, effectively reducing mass production defects like laminate delamination, bubbling and board rupture.

3. It maintains stable insulation performance under continuous high-temperature operation, making it suitable for power supply boards, server motherboards and automotive control PCBs.

III. Superior Leakage Performance

High-CTI halogen-free FR4 achieves a tracking index equal to or higher than standard FR4. This optimizes creepage distance performance and lowers the risk of arc tracking on high-voltage power circuit boards.

IV. Fire Safety for Public & High-Risk Equipment

Free of harmful halogens, this material minimizes secondary equipment damage caused by short-circuit fires. It is a mandatory preferred material for safety-critical equipment such as rail transit devices, medical instruments, building electrical control cabinets and data center servers.

V. Eco-Friendly End-of-Life Treatment

The halogen-free formula simplifies recycling and waste disposal procedures. Recovered metals from scrapped PCBs are purer without bromine contamination. The material fully complies with the WEEE Directive and circular economy regulations worldwide that restrict brominated additives.

RDS Composite manufactures FR4 glass fabric sheet of various thicknesses, including both conventional and halogen-free type. For inquiries regarding technical specifications, pricing, or sample orders, please contact our sales team at [email protected] or visit www.rdscomposite.com. We look forward to helping you select the right material for your next project.