The banding probably does not come from the pulse plating, banding is often
seen in nickel plating without pulse plating and was quire common in the days
of pyrophoshate copper plating also without pulse plating . Overdosing of some
additive/leveler.brighteners will cause banding even in acid copper plate  The
banding due to bath chemistry is seen most often as 6 to 15 bands in about
1.5 mils. of plating.  It is most prevalent at the corners of the holes and
these corners often crack when subjected solder float testing.  The cause of the
banding is the reneucleation of the plating several times during the plating
process, eah reneucleation cause a new band .  It most often occurs with
overdosing brighteners or by running the bath too long with out treatment or cleanup.


Banding due to pulse plating is often not detectable as it would happen at
about 100-300
bands in the the 1.5 mils of plating.      .

Phil Hinton
Hinton PWB Engineering

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