FPC covering film, also known as insulation resin, generally has the following types in the industry:

1. Phenolic resin;

2. Epoxy resin (EP);

3. Polyphenylene ether resin (PPO);

4. Polyimide resin (PI);

5. Polyester resin (PET);

6. Cyanate ester resin (CE);

7. Polytetrafluoroethylene resin (PTFE);

8. Bismaleimide triazine resin BT; Among them, the most common and commonly used is polyimide resin (PI).