Physical Properties of Metal Coated Polymer Particles for Anisotropic Conductive Adhesive
Z.L. Zhang, J.Y. He, H. Kristiansen
Norwegian University of Science and Technology, NO
Keywords: Ni/Au coated polymer particles, Nanoindentation-based flat punch method, SEM, Deformation, Fracture
Abstract:Metalized and monodisperse polymer particles with diameter ranging from 0.5 to 30 µm are increasingly used in developing new electrical packaging technology, such as Anisotropic Conductive Adhesives (ACA) in Flat Panel Displays (FPDs). In these applications, the large deformation of the particles is required to achieve a reliable and low resistance connection. Therefore the mechanical characterization of the particles is crucial important to the particle producers and the end users. A nanoindentation-based flat punch technique, where a diamond flat punch of 100 µm in diameter is specially designed instead of a common sharp tip, has been employed to compress individual coated polymer particles. Deformation and fracture of Ni/Au coated polymer particles have been investigated. The effect of nanoscale Ni/Au coating on the deformation capacity and fracture process of particles has been studied. By compressing particles to different maximum loads, the growth of the cracks can be followed SEM. The deformation and fracture process of the tested particles is revealed. These results provide crucial knowledge for the design of metal coated polymer particles to different application.