Reading some spec sheets and am seeing profiles for reflow and TTW soldering. A Google search tells me that TTW means "through the wave". Am seeing this acronym on LEDs mostly. I have never seen this acronym before. Why not just wave or reflow soldering. Maybe because of selective soldering they call it TTW instead of wave. Seem like there would be a better acronym than TTW through the wave. Is this really what what TTW means?