Wafer level packaging (WLP) using fan-out technology is an attractive platform for achieving low-cost low-profile package solutions for smart-phones and tablets, which require cost-effective, high-density interconnects in small form-factor packaging.

It was originally introduced by Infineon in the fall of 2007. Called eWLB, or embedded wafer-level ball grid array technology, it enables all operations to be performed highly parallel at wafer level. In August of 2008, STMicroelectronics, STATS ChipPAC, and Infineon signed an agreement to jointly develop the next-generation eWLB, based on Infineon’s first-generation technology.

Assembled directly on a silicon wafer, the approach is unconstrained by die size, providing the design flexibility to accommodate an unlimited number of interconnects between the package and the application board for maximum connection density, finer line/spacing, improved electrical and thermal performance and small package dimensions to meet the relentless form factor requirements and performance demands of the mobile market.

STATS ChipPAC’s eWLB high volume manufacturing process, for example, today includes automated wafer reconstitution (including wafer-level molding), redistribution using thin film technology, solder ball mount, package singulation and testing. Incoming wafers in both 200mm and 300mm diameters can be supported.

According to a recent report from Yole Développement, the fan-out WLP (FOWLP) market will reach almost $200M in 2015, with 30% CAGR in the coming years. Yole analysts say FOWLP started volume commercialization in 2009/2010 and started promisingly, with an initial push by Intel Mobile. However, it was limited to a narrow range of applications, essentially single die packages for cell phone baseband chips. In 2012 big fabless wireless/mobile players started slowly volume production after qualifying the technology.