Wafer Bumping and Characterizations of Fine-Pitch Lead-Free Solder Microbumps on 12” (300mm) wafer for 3D IC Integration

摘要

In this study, the wafer bumping and characterization of fine-pitch lead-free solder microbumps on 300mmwafer for 3D IC integration are investigated. Emphasis is placed on the Cu-plating solutions (conformal and bottomup).Also, the amount of Cu and solder (Sn) volumes is examined. Furthermore, characterizations such as shearingtest and aging of the microbumps are provided and cross sections/SEM images of the microbumps before and aftertest are discussed. Finally, the process windows of applying the conventional electroplating wafer bumping methodof the ordinary solder bumps to the microbumps are also presented.