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Solder Shorts
The example short is likely to have been caused by the excessive pad sizes being used on this component. Reducing the pad size will have made this area of the design more robust from a process point of view. Solder shorts can normally be eliminated with modifications to fluxing and solder contact time. Close examination needs to be undertaken when using low residue flux as the process operating window is much reduced. In the case of difficult designs it may be necessary to consider the use of a hot air knife after the solder wave. The stream of hot air or nitrogen contacts the solder on the joints when still in a liquid state. The solder short is literally blown from the base of the board. This process is available on four machine manufacturers systems.