Wafer level packages having non-wettable solder collars and methods for the fabrication thereof

摘要

Wafer level packages and methods for producing wafer level packages having non-wettable solder collars are provided. In one embodiment, the method includes forming solder mask openings in a solder mask layer exposing regions of a patterned metal level underlying the solder mask layer. Before or after forming solder mask openings in the solder mask layer, non-wettable solder collars are produced extending partially over the exposed regions of the patterned metal level. Solder balls are deposited onto the non-wettable solder collars and into the solder mask openings such that circumferential clearances are provided around base portions of the solder balls and sidewalls of the solder mask layer defining the solder mask openings.