A novel 3D IC assembly process for ultra-thin chip stacking

A novel assembly process was developed for ultra-thin chip stacking technology where wafer-level-packaging (WLP) was adopted and combined with chip-on-wafer (CoW) technology. By such assembly process, thin chip handling would be unnecessary in this process. After assembly process, chip thickness within the chip stack could be thinned down to a thickness of 30μm or less than 30μm. Sheet-type molding compound (SMC) was used to achieve the assembly of ultra-thin chip stacking module. The feasibility of this novel assembly was demonstrated and some process issues were also discussed in this investigation.