Game-Changing Nanosolder Technology: Self-Assembling Adhesives for Sub-10 µm Ultra-Fine Interconnects

초록

A nanosolder-based conductive adhesive (SACA-X) incorporating Sn nanosolder and a hybrid binder matrix was investigated as a material platform for ultra-fine-pitch interconnection in advanced semiconductor packaging. The synthesized nanoparticles exhibited spherical morphology with diameters of 50-70 nm. Bump formation was achieved at 205-210 °C within 5 s on 10 µm-pitch pads. In a preliminary bonding test conducted under low applied pressure at 210-220 °C for 40 s, metallurgical joints with ~1 µm bondline thickness were formed, and uniform bonding was observed across ~40,000 pads. Thermal and rheological analyses indicated low-temperature transitions, suggesting particle rearrangement prior to melting. Cross-sectional SEM and EDS analyses revealed localized metallic connections with limited lateral spreading. Die shear testing demonstrated joint strengths of 20-23 MPa, comparable to those reported for underfill-assisted Cu-pillar interconnections in high-density memory packaging. These results suggest that the proposed material system enables fine-pitch interconnection formation under relatively low-temperature and low-pressure conditions while simultaneously providing an insulating polymer matrix surrounding the joints. This approach may provide a complementary bonding strategy for high-density semiconductor packaging architectures requiring reduced thermal budget and simplified processing.

키워드