Hi Guy - well, we used to use electroplated SnPb as a standard printed circuit board finish for years until the modern immersion type finishes took over. However, we always reflowed/fused the electroplated SnPb finishes (typically in peanut oil) as a non-fused electroplated SnPb finish had poor solderability characteristics (i.e. oxidation). There is an "art" to fusing an electrolplated SnPb surface finish uniformly. Perhaps what you are observing is a supplier difference is their fusing process. Dave Hillman Collins Aerospace [log in to unmask] On Fri, Aug 2, 2019 at 3:07 PM Guy Ramsey <[log in to unmask]> wrote: > One of our customers specifies electroplated tin-lead reflowed as a surface > finish. > It yields relatively nice flat pads and a good solderable finish. > One of the drawings did not specify "reflowed". Everything seemed fine. > Then, we had to switch vendors. > The new vendor asked about this odd request for surface finish. > Electroplated Sn-Pb, not reflowed. But, they followed the drawing notes. > Now, we have the boards in hand. They look bad. We are running a test print > on the solder sample but I am dubious. > Have any of you experience with electroplated Sn-Pb as a surface finish? >