FR-6 is a type of PCB base material that is composed of matte glass and polyester (PET). However, it is not commonly used in the manufacturing of printed circuit boards. FR-6 is known for its flame-retardant properties, which make it suitable for applications where fire safety is a concern. It is important to note that FR-6 does not contain elements from the halogen group or any other harmful materials, making it an eco-friendly option. Unlike some other PCB materials, FR-6 does not produce toxic substances or gases during operation. While FR-6 may not be widely utilized in the PCB industry, its flame-retardant characteristics and environmental friendliness make it a viable choice for specific applications.