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Date: | Tue, 29 Oct 1996 19:56:57 -0500 (EST) |
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Vic, I did see your posting of this question and I'm very anxious to hear
responses. The reason is that I had previously asked (with limited response)
HOW one accurately measures 2-4 microinches of Gold. From the tone of your
E-mail it seems that this thickness of gold may be problematic.
Dave Rooke
Circo Craft - Pointe Claire
______ reply separator ______
>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
>[log in to unmask]
>
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