Jet Wave
In wave soldering, a unit-directional hollow wave is labeled a jet wave. The jet wave flows either in the direction of board travel, or against board travel. In the tin/lead wave soldering process, it is used frequently as a pre-solder wave to reliably wet surface mount components (on account of its higher energy, it is able to overcome the shadowing effect). In the lead-free process it is mostly replaced by other wave geometries, since the tangential wetting direction of the solder side is the cause for incomplete wetting.