Electroplating apparatus and method considerations for high aspect-ratio through-hole copper electroplating process

As the electronic products become multi-functional and complicated, relatively high-density pattern must be designed to meet these requirements. As a result, multilayer printed circuit boards (PCBs) with high aspect ratio (AR>13) through hole metallization become the main trend in fabrication. That is, how to metalize the PCBs by Copper deposit with high throwing power and reliability becomes a major research. In this topic, a batch system of electroplating equipment designed for the use in the pilot line for acid Copper plating are discussed. It is included a comparison of distance between anodes, anode and cathode, different types of solution agitation, such as air, paddle, and cathode vibration. According to the study results, the throwing power for plate-through hole and microvia plating and deposition distribution could be improved by the adjustment of anode distance (anode/anode or anode/cathode), solution agitation (both air and paddle), and rock vibration, of cathode during plating.