Question: What are the critical factors when I'm looking for a new wave flux?
Phil Zarrow: Before we actually evaluate specific materials, we have to have some overall considerations, and these directly relate to how we're processing the board.
The first criteria is, is it going to be a no-clean process or are we going to be cleaning? If, indeed, we are cleaning, what solvent methodology are we using? Is it water, water with saponifier, etcetera. The second consideration is whether we need a VOC-free material or if one with VOCs is acceptable. Again, if we're going to a VOC-free process, remember that your preheat has to be in the area of about 110°C, so that we actively bring the water base to a boiling point. This criteria for selection is germane as to whether you're going to be using it for wave soldering or selective soldering.