The key points to make as regards the wave creation are shown in Figure 9 and discussed in the related text. At the point of entry, the wave needs to be sufficiently dynamic to force solder into contact with all parts of the assembly being soldered. For this reason a more energetic chip wave (or equivalent) is normally selected for soldering SM components.

The central zone of the wave is one where there is relatively little movement of the solder relative to the board, but solder rises in the holes, and heat is transferred to the board to enable wetting to take place throughout the structure. In the third zone, a key feature is moving the solder smoothly and directly vertically away from the solder joint, to avoid leaving excess solder and bridges between connections.

For a low density mixed technology assembly, a standard single wave would probably be sufficient to give good joints, provided that the surfaces were averagely wettable. However, for higher soldering speeds in cases where wetting is impaired, there might be advantages in using either a preliminary chip wave, or some vibration within the main wave. If possible, the single wave should be used, because the dross build up is less, since the wave turbulence is lower. Fortunately, many wave soldering systems are programmable, so it is possible to experiment with different wave formations.