A study on the 3DIC interconnection using thermal compression bond with non conductive paste process

Three dimensional (3D) stacking technology has been purposed to meet miniaturization trend, high performance, and multi-function electronic products. Chip stacking with through silicon via (TSV) and high density lead free interconnection are believed to realize 3D stacking package. Due to the narrow dispensing request for multi-chip connection, non-conductive paste (NCP) is one of the solutions to replace capillary underfill. Nevertheless, voidless control and wettability are two critical challenges for large dies size flip chip ball grid array (FCBGA) 3D package. In this paper, fine pitch u-bump for large die size 3D stacking using thermal compression bonding (TCB) with NCP is demonstrated. In order to achieve voidless, bonding parameter was studies in different pre-heat time. The effect of bonding conditions such as force, temperature, and time on wettability has been performed. The results showed that longer pre-heat time could accomplish voidless. The u-bump wettability exhibited relationship between TCB parameters and characteristics of NCP. Finally, reliability test was tested for NCP properties discussion.