AOI post-reflow is the most common use of AOI in an SMT line and is pivotal for quality assurance to prevent defects from passing to the next stage of production. All defects must be detected by AOI inspection at this critical step. Post-reflow AOI inspection allows detection of defects that may be attributed to causes prior to reflow, as discussed in the pre-reflow scenario, but post-reflow AOI provides defect detection for all defects throughout the PCB assembly process, including defects whose causal factors might be attributed to the thermal dynamics to which a PCB and its components are subject during the reflow process.