CPI challenges in advanced Si technology nodes

The key chip-package-integration (CPI) challenges and solutions in the packaging and assembly of advanced Si technology nodes are reported. The key challenge of CPI due to the use of fragile extreme low-k (ELK) dielectric materials in the back-end-of-line (BEOL) layer has been resolved by optimizing bump structure and materials set including both the organic substrate and solder materials, along with process improvements for both Pb-free solder and Cu bump in flip chip packages.