1. Are the boards you are testing from the same bareboard production lot
that the problem boards are from? ""YES, These are boards the customer
brought back to us for evaluation, they are from the same lot as the
ones causing all the woes.""

Are they from the clients storage or are they boards you have retained
at
your facility? ""We shipped them over a year ago to our customer, they
have been in their storage wharehouse until a month ago.""

2. Was the client doing the assembly seeing this problem on
other/different boards at the time? ""NO, just this particular lot.""

3. Is the problem specific to a certain area of the board or all over
it? ""It appears random across the board.""

4. Is the problem specific to a certain type or style of component?
""All components are through hole leaded, .035" .040" hole dia.""

5. Is it possible to obtain and test a sample of the exact flux that was
used to solder these problem boards ? ""I am requesting some""

>Answering these should help to better direct you to the cause.


>I have seen similar outgassing problems from contaminated wavesolder flux. It would volatize in the solder >wave causing the same "swiss cheese" appearance, although not severe as this one. If you look closely at the
>pictures, especially pic 2, the outgassing does not look like it is originating from the hole wall which >would be the case if it was strictly moisture absorption in the board coming out. Although it is difficult at
>times to determine origin when looking at a two dimensional finite slice of a three dimensional object.


""We had performed the cross-sections in three-axis, on 90's from a few
angles and top-down images observing the same results regardless, i.e.
voids/bubbles within the solder not inter-acting with the hole wall
(copper) at any point.

Thanks for all your input

Franklin

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