Metal coated polymer particles for electronic packaging

Abstract

Anisotropic conductive adhesives (ACA) are widely used as interconnect materials in the manufacturing of LCD screens. To be integrated in a broader range of interconnect applications several technical and economic issues still need to be addressed. One significant challenge is to encapsulate polymer particles with well controlled modal diameter and size distribution into continuous, compact, and uniform conductive metallic shells. This presentation describes a method to deposit layers of nickel with different thickness (30 - 120 nm) onto monosized polymer particles ranging in size from 1 to 10 micrometers. The novelty of the approach consists in a pre-treatment of the epoxy functionalized polymer particles with linear polymeric amines. We show that by increasing amine chain length the distribution of the palladium catalyst, and consequently the adhesion and distribution of nickel metal deposited, can be improved dramatically. The effect of several plating parameters is discussed and illustrated. Copyright© (2010) by IMAPS - International Microelectronics & Packaging Society.