Precision Hotspot Mitigation in Wafer-Level Electroplating with Novel Auxiliary Electrode Design for Advanced Large-Scale Chip Packaging

This study introduces a novel, non-rotationally symmetrical auxiliary electrode design aimed at mitigating localized hotspots and enhancing the deposition uniformity in wafer-level electroplating for advanced large-scale chip packaging. The formation of hotspots and deposition non-uniformity, particularly at the wafer edge and in regions with complex die layouts, presents significant challenges in electroplating processes. To address these issues, the proposed auxiliary electrode incorporates a dynamic angle control mechanism, which facilitates the precise, localized modulation of the current density. This innovative design improves the regulation of current distribution in hotspot-prone regions, without compromising the overall stability and uniformity of the wafer-level electroplating process. Extensive numerical simulations were conducted to assess the electrode’s effectiveness in redistributing current density, resulting in a marked reduction in current density at the wafer edge, thereby mitigating over-deposition and enhancing overall uniformity. The simulation results also demonstrated the electrode’s capability for dynamic current flow regulation, enabling localized adjustments only when necessary and minimizing disruptions to the electroplating process. Experimental validation further corroborated the simulation findings, with repeated trials confirming the electrode’s consistent performance in reducing localized over-deposition in hotspot regions while maintaining uniform plating in unaffected areas. These findings underscore the potential of the auxiliary electrode as a robust solution for addressing hotspot formation and deposition uniformity challenges in electroplating, providing a solid foundation for its industrial implementation in advanced chip packaging and related fields.