The polyimide film is not uniform.

Is it normal for polyimide film to be uneven? Normal.

Ordinary polyimide film is definitely amorphous. There are two ways to consider: 1, using thermoplastic polyimide film, the disadvantage is high cost.

2. Coating thermosetting resin on the film, and performing thermal curing through the resin. The disadvantage is that polyimide film itself is used in the field of high temperature resistance, while thermosetting resin is mostly resistant to low temperature.

Domestic polyimide films are generally polymerized from pyromellitic dianhydride (PMDA) and diphenyl ether diamine (ODA) and imidized at high temperature. No solvent can be dissolved, and some strong polar solvents can only swell.