Advanced Plating Technology for Electronic Devices

Many electronic devices have been requested to downsize with improving their functionality. Improved semiconductor technologies have been main routes to realize these requests. However, the further improvement of semiconductor technologies has become difficult and costly. The next main technologies to be used are the improvement of printed circuit boards (PCBs) and their connection with integrated circuits (ICs), especially bump formation and their connection methods. For these two technologies, both electroplating and electroless plating are employed as the main methods employed. In this paper, primarily PCBs and their connection methods are reviewed. For PCBs, copper plating technologies are mainly reviewed, especially the selection of additives and current waveforms which are most effective for via-filling. For connections, the formation of bumps and their connecting are reviewed. Two new technologies, nickel bump formation on an aluminum pad and, microbump formation by non-cyanide gold electroplating, were mainly demonstrated. Finally, the production of anisotropic conductive particles by electroless nickel plating are demonstrated. The discovery of new plating technologies is necessary for future development, especially the use of new additives and new agitating methods for copper plating as well as new formation methods and their connection technologies for bump formation.