▎ 摘　　要

NOVELTY - Preparation of low dielectric polyimide film involves: 1) performing polymerization reaction on aminated graphene quantum dot powder, diamine monomer and dicarboxylic anhydride monomer in organic solvent, followed by adding a pore-foaming agent, mixing uniformly to form polyamide acid resin mixed solution; 2) defoaming and casting polyamic acid resin mixed solution on a substrate to form a self-supporting film; 3) longitudinally stretching the self-supporting film, performing thermal imidization treatment and transversely stretching the self-supporting film while performing thermal imidization. USE - The polyimide film prepared is used for high-frequency communication electronic equipments. ADVANTAGE - The polyimide film prepared has low dielectric constant, good mechanical property, high glass transition temperature and high thermal stability, DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for low dielectric polyimide film.