Dear Sir,

We have been coming across the phenomenon exactly as indicated in the IPC 6012 document ( figure included below), where in we have a clear black demarcation in the microsection between the base copper / electroless copper and at times between the electroless and plated copper. We did do an EDX analysis at the points, but are not finding anything else, but copper. We are stuck with this and do not know how to go about. We have consulted, both laminate and chemical manufacturers , but have not got any good inputs so far. Though this is acceptable as per IPC 6012, the same is not acceptable as per the customer requirements. Any input on what are the factors that contribute to it and why is it that this is concluded as acceptable, even for class 3 boards

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Rgds

Pradeep
[Logo]<http://www.micro-pack.com>

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