If this an external layer your looking at, it sounds like the plated copper
is peeling form the base foil.


At 03:57 PM 10/6/99 EDT, you wrote:
>Hi ya'll!
>
>Here's something weird I've never come across, but maybe some of you have. We
>built this Hi-Rel board here that the PCB drawing calls out for 2-ounce
>copper.
>
>The board has this leaded SMT multi-capacitor part (it's like 3 huge ceramic
>capacitors stacked on top of each other) and has 8-leads. After assembly, and
>before we test then conformal coat it, we put the assembly on this vibration
>table to go through some ESS.
>
>There's been a few of these capacitor deals come loose because they're so top
>heavy, but that's a whole 'nuther issue...
>
>What we've been seeing on some of these boards, is that either the pad
>completely lets go from the laminate (it's a polyimide), or sometimes we'll
>see the pad come up in what looks like a layer of copper, yet there's still
>copper down on the PCB...as if the copper has split horizontally in two
>distinct layers? Is this possible? Does 2-ounce copper clad laminate get the
>copper plated an ounce at a time? Is this a defect? I've never seen something
>like this before, and I can take a picture and send it to ya' if you want me
>to....
>
>Thanks!
>
>-Steve Gregory-
>
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Ian A. McMillan
Engineer
Herco Technology
Ph# (619) 679-2800
Fax# (619) 679-7565

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