The failed Condition 2 is high in WOA and ammonia (from the saponifier
) and the residue is conductive and corrosive (Figure 2).
Did you talk to the technical representatives from the new saponifier and cleaning equipment suppliers to be sure the process and equipment setup you are using is fine?
Even more pertinent is the possible incompatibility of the new saponifier with your soldermask, flux and perhaps water temperatures.
Since you did not have the problems before the changes, the most probable explanation is that the new saponifier is incompatible with your flux and soldermask or water temperatures.
Results showed that saponifier #1 and the water-cleaned only paste left high levels of flux residue on the surface of the board-below the BGA component.
Q: What recommendations would you make to increase the ability to remove residues using saponifier #1?
I recommend using lower pressures in the prewash and wash sections, at a slower belt speed, and evaluation of saponifier #2.
Depending on the contamination, these and the saponifier
mixed with them are the ingredients used in the chemistry.
For example, ethanolamine (an organic base) is perhaps the most common saponifier found in these products.
The more volatile components of the cleaner evaporate over time (the base saponifier, an organic alcohol, and some of the water).
Although it would intuitively seem that aqueous saponifiers
(soap and water) are preferable to semi-aqueous cleaners, the latter have a number of advantages over the former, including avoiding the need for waste treatment or disposal of dirt, saponifiers
and detergents and the possibility of closed-loop recycling, as organic soil dissolves in the cleaning agent.
Additionally, the label materials exhibit excellent resistance to harsh fluxes, cleaning agents, saponifiers
and wave solder environments, and resist all commonly used methods of cleaning, according to the company.