QFN with Wettable-flank
QFN is a lead-less pkg. After mounted onto PCB, it is very difficult to do solder wetting quality inspection, because the solder joint will be covered up by QFN molded body. X-ray inspection is an existing inspection method used in the field, but it is costly and human dependent. For automatic visual inspection (AVI), it requires existence of “solder tail” extended beyond the package edge. QFN with wettable-flank feature is a solution. In a more specific description, the wettable-flank feature is that there is a solderable step-cut on QFN I/Os with certain height such that it forms a solder fillet during SMT, and its tail with sufficient size can be identified by AVI. There are different methods to make the wettable-flank or step-cut feature on QFN, either by lead frame maker or assembly house. However, the most economical method is still produced by our deep-groove etching technology.
Product & Services
because we know assembly process well.