In the area of Methane Sulfonic Acid (MSA), (shift into Elmer Fudd mode)

Be vewy, vewy careful.

(Fudd mode off)

In an increasing number of our field failure analysis projects, we are
tracing corrosion back to MSA used in plating operations.  It is an extremely
aggressive material.  In some of our experiments, MSA was about 1000 times
more corrosive than chloride.  That means that if the material is not FULLY
rinsed or FULLY neutralized, a small amount can result in corrosion.  So far,
the corrosion failures have been primarily on component leads, but we know of
some flux vendors who are selling MSA HASL fluxes (oh the horror, the horror).

Doug Pauls, who has far too much Mountain Dew this morning
Technical Director
CSL