Facile Amine Modification Synthesis of Core–Shell Polychloromethylstyrene@Ni Microspheres for Anisotropic Conductive Films

Abstract Core–shell microspheres with a supporting polymer core and conductive shell emerge as effective fillers for anisotropic conductive films (ACFs) that are widely used in high‐precision interconnection of miniaturized electronics. Conventional methods for synthesizing such conductive microspheres usually require the use of hazardous sensitizers, which severely hinder their scalable and environmentally friendly production. Herein, an economical strategy is developed to facilely synthesize core–shell conductive microspheres by using bi‐functional amine polychloromethylstyrene (PCMS) as the substrate. The amino groups of PCMS can undergo cross‐linking with ethylenediamine, thereby endowing the microspheres with excellent structural stability in organic solvents. Simultaneously, the strong anchoring effect of the amino groups facilitates the formation of ultrafine Pd nanoparticles on the surface, which serve as catalytic sites for the subsequent electroless deposition of Ni layer with an adjustable thickness (100–400 nm). Due to the uniform size, high electrical conductivity, and robust mechanical stability of PCMS@Ni microspheres, the fabricated ACFs exhibit excellent pressure‐sensitive conductive performance and anisotropic conductivity, enabling high‐resolution display and a wide color gamut in liquid crystal devices. Furthermore, the versatility of this functionalization strategy is demonstrated by extending the deposition to other metals, such as Ag and Au, highlighting its broad applicability in advanced electronic materials.