Fine pitch chip on board (CoB) bonding using B-stage non-conductive film (NCF) for 3D TSV vertical interconnection

In this study, the CoB bonding using NCF was investigated for the 3D-TSV interconnection as a noble way for compensating the former processes such as fluxing and underfill process. The whole processes using NCF were closely investigated. The properties of NCF such as curing behavior, viscosity, modulus, glass transition temperature, and CTE were optimized for CoB bonding. NCFs which have high glass transition temperature and lower thermal expansion coefficient were effective on the enhancing the reliability of CoB structure for 3D-TSV application. As a summary, 3D-TSV vertical interconnection using B-stage wafer-level NCFs was investigated. The CoB bonding using NCFs for 3D-TSV interconnection was successfully investigated with the stable joint interconnection as well as the enhanced reliability.