摘要
For the advanced 3D-IC or 3D-packaging application, Cu-core solder joint is already a high reliability option for high power device and 3D packaging. However, with the harsher requirement for mechanical and electromigration reliability, it is imperative to further strengthen the solder joints. A method of pressurized bonding is proposed in this study to alter and improve the architecture configuration and grain distribution of the Cu-core solder joints. The correlation of strengthening process and microstructure was revealed by electron microscopy, elemental quantification, and grain analysis. Pressurized bonding results in a refined grain distribution, increased shear strength, and possibly stronger resistance to electromigration.