With OSATS and foundries releasing an increasing variety of devices packaged in the fan-out format, the productivity and yield of the various wafer processing technologies becomes a key factor in fan-out’s continuing adoption.
This presentation will discuss solutions for optimizing yield and productivity during physical vapor deposition (PVD) of under-bump and redistribution metal layers. The challenges in PVD processing of FOWLP are varied, such as contamination, particles and wafer warpage. The latest PVD hardware specifically designed for BEOL processing has all the necessary features a UBM/RDL customer requires for this application, such as pre-clean etch hardware designed to increase uptime and in-situ multi-wafer degas technology to significantly improve wafer throughput and lower Rc. Data from systems in production will be presented, demonstrating the efficacy of the technology.