Systematic approach in testing the viability of mechanical partial-cut singulation process towards tin-plateable sidewalls for wettable flank on automotive QFN technology

Satisfying stringent customer requirement of visually detectable solder joint termination for high reliability applications requires the implementation of robust wettable flank strategies. One strategy involves the exposition of the sidewall via partial-cut singulation, where the exposed surface could be made wettable through tin (Sn) electroplating process. Herein, we report our systematic approach in evaluating the viability of mechanical partial-cut singulation process to produce Sn-plateable sidewalls, enabling the wettable flank technology using an automotive QFN package are technology carrier. Optimization DOE produced robust set of parameters showing that mechanical partial cut is a promising solution to produce sidewalls appropriate for Sn electroplating, synergistically yielding excellent wettable flanks.