300mm Large Scale eWLB(embedded Wafer Level BGA) : Cost Effective Solution with Performance
Demand for Wafer Level Package (WLP) is being driven by the need to shrink package size and height, simplify the supply chain and provide a lower overall cost by using the infrastructure of a batch process. The increasing demand for new and more advanced electronic products with smaller form factor, superior functionality and performance is driving the integration of functionality into the third dimension. There are some restrictions in possible applications for fan-in WLPs since global chip trends tend toward smaller chip areas with an increasing number of interconnects. The shrinkage of the pitches and pads at the chip to package interface is happening much faster than the shrinkage at the package to board interface. This interconnection gap requires fan-out packaging, where the package size is larger than the chip size in order to provide a sufficient area to accommodate the 2nd level interconnects. eWLB is a type of fan-out WLP that has the potential to realize any number of interconnects with standard pitches at any shrink stage of the wafer node technology. 200mm eWLB is in HVM from industry last three years and there was need to move 300mm for scaling-up and low-cost solutions. This paper will highlight some of the recent advancements in large scale 300mm eWLB development. Compared to 200mm case, 300mm has more warpage and process issues due to its area increase. Thermo-mechanical simulation shows 100~150% more warpage with 300mm compared to 200mm. So various design parameters were studied to optimized warpage, such as dielectric materials and thickness, molding compound thickness etc. This paper presents study of process optimization for 300mm eWLB and mechanical characterization, reliability data including component/board level, challenges encountered and overcome, and future steps of scalability for higher throughput and manufacturability.