Preparation of polystyrene@Ni@Cu core–shell microspheres by pickering emulsion polymerization and their autonomous motion in a magnetic field applied to anisotropic conductive films

Abstract Successfully designed and synthesized PS@Ni@Cu core–shell composite microspheres, which provide efficient electronic transmission for anisotropic conductive films for electronic packaging applications. Herein, a simple method for preparing core–shell composite microspheres using Pickering emulsion polymerization as a template, a dense nano‐nickel shell layer was coated on the surface of polystyrene to obtain PS@Ni microspheres, the microspheres have conductivity and magnetic properties. Then the microspheres were coated with nano‐copper layer by electroless plating to enhance the mobility of electrons in specific media. Finally, the microspheres are laminated in epoxy resin, which can realize directional (horizontal, inclined, and vertical) movement under magnetic field force to form anisotropic conductive film. The conductivity is 171.68 S cm −1 , the adhesiveness and conductivity of the film can be changed by adjusting the content of microspheres. The film has excellent thermal stability, good adhesion, and can be anisotropic conductive. The difference in conductivity between the conductive direction and the insulating direction is about 10 8 orders of magnitude, and it can adapt to strong acids and alkalis and other more extreme environments. It is significance to the development of electronic packaging and is expected to be widely used in the field of electronic devices.