New Developments of Copper Plating Technology for Embedded Power Chip Packages Challenges

Copper plating has been extensively employed in the fabrication of embedded packaging to reach high-density, high-speed, high performance electronic products. With through holes (TH) as well as blind via aspect ratios increase, development of a reliable plating technology is very important. When the depth of through hole was over 200um, it is difficult to fill without void by using direct current (DC) electroplating. In order to overcome this problem, organic additives were applied to cause faster copper deposition at the TH center rather than at the opening. Besides of that, the x-shape through hole was also developed due to its particular geometry form, which was beneficial for the copper bridge at the TH center. In this paper, the x-shape through hole with depth of 350 um was fully filled by DC electroplating within 2hrs. This filling ability development enable the embedded chip package design more flexibility.