▎ 摘　　要

NOVELTY - Low dielectric polyimide film comprises polyimide and double-layer hollow particle, and the double-layer hollow particle is hollow nano-particle coated by fluorine graphene oxide. USE - The low dielectric polyimide film is useful in flexible printed circuit board (claimed). ADVANTAGE - The method: can prepare the hollow nano particles and oxygen fluoride graphene into double-layer structure nano particles, introduces fluorine element and porous structure into the polyimide film, and prepares the low dielectric constant polyimide film with excellent performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the polyimide film, comprising (i) adding the amino silane coupling agent into the hollow nano-particle dispersion, stirring, separating, drying and grinding to obtain aminated hollow nano particles; (ii) adding the aminated hollow nano-particles into the graphene oxide dispersion liquid, dispersing, separating and drying to obtain double-layer hollow nano particles; and (iii) uniformly dispersing the double-layer hollow nano-particles in the polyamic acid solution, coating on the substrate, and performing gradient imidization to obtain the polyimide film.