Innovative Solution to Eliminate Sn Flakes Migration at Package Singulation on a QFN Sn Plated Stepped Cut Design

Package Singulation partial cut process of a Quad Flat No Leads (QFN) Package is now well-known at semiconductor manufacturing to enhance the Automatic Optical Inspection (AOI) capability of a finished Integrated Circuit (IC) device when subjected into surface mount on its respective functionality board.  To obtain device units with step cut side wall profile, a QFN package strip must underwent on two (2) package sawing processes; Partial cut -sawing and Full cut sawing process.  Partial cut sawing of a QFN package strip aimed to perform target cut depth on the Lead frame (LF) only that defend on the customer requirements prior the full cut sawing.  After completing the package Partial cut sawing, the package will now able to undergo on a Tin plating process to coat the LF exposed copper material on a QFN package strip prior the full sawing process.  During Package Full sawing process, an optimized com