First of all, FR-4 is the code name of a flame-resistant material grade. It represents a material specification that the resin material must be able to extinguish by itself after burning. It is not a material name, but a material grade. FR4 epoxy board is a kind of substrate with epoxy resin as adhesive and electronic grade glass fiber cloth as reinforcement material.

The FR4 epoxy board is selected for the Transformer Bobbin mainly because of the following characteristics of its material:

FR4 epoxy board has stable electrical insulation performance, good flatness, smooth surface, no pits, and thickness tolerance standards. It is suitable for applications with high-performance electronic insulation requirements, such as FPC reinforcement boards, PCB drilling pads, and fiberglass Meson, potentiometer carbon film printed glass fiber board, precision star gear (wafer grinding), precision test plate, electrical (electrical) equipment insulation support spacer, insulation backing plate, transformer insulation plate, motor insulation, grinding gear, electronics Switch insulation board, etc.

FR4 epoxy board is resistant to aging and has a long service life, and the life cycle of the transformer is generally 20 to 30 years. FR4 epoxy board can meet this requirement. In addition, FR4 epoxy board has higher impact resistance and moisture resistance than paper substrate. Its electrical performance is excellent, the working temperature is relatively high, and its performance is less affected by the environment. In terms of processing technology, it has great advantages over other resin glass fiber cloth substrates.