Deposition of continuous nickel shells on polymer microspheres

Anisotropic conductive adhesives (ACAs) are widely used as interconnect materials in the manufacturing of LCD screens. To be integrated in a broader range of applications, several technical and economical issues still need to be addressed. Encapsulating the polymer particles within continuous, compact, and adhering metallic conductive shells is one of these challenges. This work describes a method for depositing nickel layers with different thickness (30-120nm) onto monosized polymer particles. The novelty of the approach consists in modifying the surface of polymer particles with linear polymeric amines. We show that by increasing amine chain length the structure and adhesion of deposited nickel shell are significantly improved. The effect of key parameters of the electroless Ni plating are discussed and illustrated.