https://doi.org/10.1351/goldbook.08893
Polymers composed of macromolecules containing cyclic dicarboximide groupings in the backbone:
where \(\ce{R^{1}}\), \(\ce{R^{2}}\), \(\ce{R^{3}}\) and \(\ce{R^{4}}\) are groups with connectivity one, two, three, and four, respectively (structure-based polymer class name).

Note: In electronics, polyimides are mainly used as highly flexible insulating and passivation layers in integrated circuits and microelectronic chips.
Example: 
