Solutions for today’s and next gen advanced packaging: improving the reliability of copper RDLs and pillars

In one of our recent research work, we looked at the current and next generation advanced packaging technologies with regards to reliability and made some very interesting observations. Based on these results we developed a new ultra-pure Copper deposition process series that overcomes the traditional limitations and supports the reliability of Cu RDL lines for much smaller features. In particular, during this webinar issues upon scaling of RDL lines as well as pillar and bump structures will be discussed. RDL lines are prone to cracking upon scaling the dimensions for current L/S of two to five micrometer. Formation of cracks in lines of these scales may be avoided by proper electrochemical deposition processes. In addition, delamination due to voids at the interface to the seed may also be avoided by proper plating chemistry. While such voids also decrease the reliability of copper pillars and bumps, additional void formation may occur within these structures at the interface to the solder. Based on the learnings of solving reliability issues of current technologies, potential processes for upcoming technologies including RDL structures with one micrometer L/S or even beyond, pillars of more challenging dimensions, and direct bond formation from copper to copper will be proposed.