No-Clean Flux-Solder Paste technology is increasingly becoming popular, as it offers several benefits like reduced number of process steps, simpler qualifications without the need to specify cleaning details, and reduced expenses. Yet there are equally important reasons for cleaning a board such as when the PCB requires a conformal coating or when the PCB will be tested with a flying probe. Learn the pros and cons of different cleaning solutions to designate the right option for your PCB project in this paper.