Research and Introduction of the Process Flow of 3D-IC Thermo-Compression Intelligent Collective Bonding Equipment

Three-dimensional integrated (3D IC) technologies have attracted substantial academic interest due to their enhanced performance and reduced interfacial dimensions. Conventional 3D packaging for chips of four layers must be stacked and bonded four and three times, respectively, bringing about the low reliability of bumps and productivity. Additionally, the decreasing size and spacing of solder bumps present challenges for defect detection. This paper proposes a collective intelligent bonding equipment for flip-chip 3D packaging. The equipment includes a bonding head system, downward vision, chip shift table, upward vision, bonding zone, in-situ monitoring system, and substrate movement platform. The bonding head system, downward vision, chip shift table, upward vision, and bonding zone complete the collective bonding. The defect detection is accomplished by the in-situ monitoring system. The chips need to be stacked four times, and the time of bonding is once. Meanwhile, during the bonding process, the defects can be monitored in real-time by the in situ monitoring system based on active infrared technology. Four layers in chips can be simultaneously bonded, and alignment accuracy is ±15μm@3sigma. The breakage, misalignment, and other defects can be monitored during the bonding progress. The introduction of this equipment will enhance productivity while ensuring bump reliability. Moreover, its successful development holds significant importance for the advancement and manufacturing of semiconductor packaging equipment domestically.