Toward ultra-high-rate copper pattern electroplating with simultaneously improved coating properties via simulations and experiments

Abstract

The copper pattern electroplating rate significantly impacts electronic packaging substrate preparation efficiency. The direct current (DC) electroplating technique has great potential in economy and convenience but faces challenges in improving the electroplating rate and coating properties, thus making electroplating additives the most critical parameters for controlling the electroplating process and coating properties. Convection and cathodic polarization are two essential parameters influencing the additives' interactions, but the electrolyte flow field distribution is complicated by the changed pattern size, and most electrolyte formulas cannot withstand such strong cathodic polarization. Therefore, we presented a novel electrolyte formula for ultra-high-rate DC copper pattern electroplating and employed three-dimensional flow field simulation to investigate the flow field distribution throughout the patterns. An ultra-high current density of 8 A/dm² was applied, ensuring a stable electroplating process. The pattern size-stimulated electrolyte flow rate trend was discovered by simulations. The mechanism of simultaneously achieving ultra-high-rate electroplating and coating property improvement was thoroughly investigated. An ultra-high rate of 150 μm/h and the dense, uniform copper pattern coating were achieved synchronously with weak convection and strong cathodic polarization. Utilizing the ultra-high-rate copper electroplating method offers a viable approach to expedite the production of electronic packaging substrate with enhanced efficiency.