I sent this message earlier. At the same time, lost contact with Tech  Net.
I'm not sure if this message got through. If it did, I apologize for the
duplication.

We purchase some pc boards with immersion gold over nickel to obtain
flat pads for better stenciling of solder paste. Our spec is 5-8
microinches of immersion gold over 150-200 microinches of electroless
nickel. We have generally been successful. The indications are that
about one year ago when this was first implemented, the gold plating
was coming in per the spec.

At this point, however, we are seeing the gold thickness to be more in
the range of 2-4 microinches. We are still doing OK except for one batch
of boards that came in recently. There are solderability problems with
these boards. This batch is also associated with a solder mask change.
But we also have other immersion gold boards with the same solder
mask change and no solderability problems.

Could it be that 2-4 microinches is at the ragged edge where the gold is
insufficiently robust to withstand further processing at the fabricator and
in assembly?

Does anyone else have similar experiences with immersion gold in the
2-4 microinch range?

Is anyone consistently doing well with about 2-4 microinches of gold?

Thanking you in advance.

Vic Beldavs
414-362-2797
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