Polyimide is one of the best organic polymers with high temperature resistance of more than 400 ℃, long-term use of temperature range-200~300℃, no obvious melting point, high insulation performance, 103 khz under dielectric constant 4.0, dielectric loss only 0.004~0.007, belong to F to H.

According to the chemical structure of repeating unit, polyimide can be divided into three kinds of aliphatic, semi aromatic and aromatic polyimide. According to the thermal properties, can be divided into thermoplastic and thermosetting polyimide.