Physical properties of metal coated polymer particles for Anisotropic Conductive Adhesive

Metalized and monodisperse polymer particles in micron size are increasingly used in developing new electrical packaging technology. In this application, the large deformation is applied to the particles for increasing the contact area and hence achieving a reliable and low resistance connection. Therefore mechanical response of metal coated particles is very important during the bonding process. In this study, a nanoindentation-based flat punch method has been employed to compress individual Ni/Au coated polymer particles. Deformation and fracture of particles have been investigated with a wide range of test conditions. The effect of nanoscale Ni/Au coating on the deformation capacity and fracture process of particles has been analyzed. By compressing particles to different maximum loads, the cracking and delamination of the Ni/Au coating have been followed by SEM. The results provide crucial knowledge for the design of metal coated polymer particles to different applications.