High Coplanarity and Fine Pitch Copper Pillar Bumps Fabrication Method

摘要

In this paper, we report a novel plating-friendly polishing mechanism for fabrication of high coplanarity and high density lead-free copper pillar bumps for advanced packaging applications. The final experimental results showed that the uniformity in wafer (UIW) could be sharply improved from 4.31% after plating to 2.88% after polishing and even to 2.54% after reftow throughout the entire 4 inch wafer.