Die-to-wafer Bonding: Comparison of Designing, Processing and Assembling of Different Approaches

Solder bonding and Cu-Cu bonding are studied and compared to see which method is the best packaging solution for 3D IC packaging. By using real memory wafers, a typical 3D IC structure of 4-layer chip stacking are built up by the two bonding methods. The comparison covers design, wafer fabrication, assembly and reliability.