FR-4 is a code of a grade of flame-resistant materials, which means a material specification that a resin material must be able to extinguish by itself after burning. It is not a material name, but a material grade. Therefore, general PCB circuit boards, There are many types of FR-4 grade materials used, but most of them are composite materials made of Tera-Function epoxy resin with filler and glass fiber.

FR-4 epoxy glass cloth laminate, according to different users, the industry is generally called: FR-4 Epoxy Glass insulation board, epoxy board, brominated epoxy board, FR-4, Glass fiberboard, FR-4 reinforced board, FPC reinforced board, flexible circuit board reinforced board, FR-4 epoxy board, flame-retardant insulation board, FR-4 laminated board, FR-4 glass fiberboard, epoxy glass cloth board, epoxy glass cloth laminated board, circuit board drilling pad.

The name FR4 comes from the NEMA grading system where the ‘FR’ stands for ‘fire retardant’, compliant with the UL94V-0 standard. The FR4 option is followed by TG130. The TG refers to the transition glass temperature – the temperature at which the glass-reinforced material will start to deform and soften. For Fusion’s standard boards this value is 130°C, which is more than enough for most applications. Special High TG materials can withstand temperatures of 170 – 180°C,such as our items 3250.The FR-5,G11 can withstand temperatures of 155°C.

Most FR4 laminates owe their flame resistance to its bromine content, a non-reactive halogen commonly used in industries for its flame retarding properties. This gives FR4 materials obvious advantages as a stock PCB material in terms of fire safety while in the field. It is also a little reassuring if your soldering skills are not up to standard.

However, bromine is a halogen which are highly toxic chemicals that are released in the environment when the material is incinerated. Even small amounts are sufficient to cause serious harm to humans or even death. To reduce the use of such hazardous substances in our everyday products, halogen-free FR4 laminates are readily available.

Recently we have developed white and black halogen-free FR4 epoxy glassfiber laminate sheets,now it is used as the FPC reinforced board in iphone,heating sheets,and so on.