A polyimide composite material, a manufacturing method thereof, and a display substrate are provided. Inorganic nanoparticles are connected with polyimide structural units by chemical bonds, thus enhancing compatibility of the inorganic nanoparticles and the polyimide structural units. Moreover, because of an enhancement effect of the inorganic nanoparticles, a mechanical property and thermal stability of the polyimide composite material may be effectively improved.

Disclosed are an optical film including a light-transmitting matrix and a filler dispersed in the light-transmitting matrix, the optical film having a creep index of 0.46 or less, and a display device including the optical film.

The present disclosure relates to a polyimide-based polymer film comprising a polyimide-based polymer containing a polyimide repeating unit synthesized by the reaction of an acid anhydride compound having a specific structure and a diamine compound, wherein a glass transition temperature is 400 C. or more, and a thickness direction retardation value at a thickness of 10 m is 150 nm or less, and a substrate for a display device and an optical device using the same.