Polyimide (PI) is a polymer of imide monomers. Polyimides have been in mass production since 1955. With their high heat-resistance, polyimides enjoy diverse applications in roles demanding rugged organic materials, e.g. high temperature fuel cells, displays, and various military roles.
Kapton is a polyimide film developed by DuPont in the late 1960s, which is also called as Kapton Polyimide.
In flexible PCB and rigid-flex PCB, polyimide is used to make the materials of FCCL, coverlay and stiffener.