Characterize and Understand Functional Performance of Cleaning QFN Packages on PCB Assemblies

As electronic assemblies grow denser with Bottom Terminated Components (BTCs) like QFNs, the challenge of managing flux residues and ionic contamination becomes critical to long-term reliability. Residues trapped under low standoff gaps can cause leakage currents, dendritic growth, and electrochemical migration, leading to performance failures in harsh environments. This iNEMI research project applied Surface Insulation Resistance (SIR), Ion Chromatography (IC), and localized C3 testing to evaluate contamination risks under BTCs. The study established correlations between solder paste types, cleaning practices, and board design features, ultimately proposing a reference Test Suite and Test Specification for cleanliness.