An impressive amount of conjecture and qty of 
recommendation here based on an external visual 
indicator and (apparently) an absence of any actual failure analysis.

My $.02, start with x-sectional analysis.


>-----Original Message-----
>From: TechNet [mailto:[log in to unmask]] On Behalf Of Avni Selim Özçukurlu
>Sent: Monday, July 01, 2013 6:36 AM
>To: [log in to unmask]
>Subject: [TN] Moisture in PCB
>
>Hello All,
>
>
>
>
>
>After a wave solder process of a PCB with lots of through-hole components
>on it, I have seen that there are popcorn part near via on that PCB. The
>flatness of the first layer of the PCB is gone after that process. I think
>that moisture remaind inside PCB gets outsite during the wave solder
>process and cause this problem. I didn't put the PCB in a vacuum oven
>before wave solder. Is it possible that the problem is related of this. Is
>there any alternative solution about that problem?
>
>
>
>
>Actually I applied the heat up and vacuum to empty PCB before all process
>of manufacturing. After that vacuum oven process, it has passed about 10
>days to start the wave solder process. During that 10 days, did PCB get
>moisture inside?
>
>
>
>Thank you advance.
>
>
>
>Selim.
>
>
>______________________________________________________________________
>This email has been scanned by the Symantec Email Security.cloud service.
>For more information please contact helpdesk at x2960 or [log in to unmask]
>______________________________________________________________________
>
>______________________________________________________________________
>This email has been scanned by the Symantec Email Security.cloud service.
>For more information please contact helpdesk at x2960 or [log in to unmask]
>______________________________________________________________________
>
>______________________________________________________________________
>This email has been scanned.
>
>______________________________________________________________________
>Aero Engine Controls is part of the Rolls-Royce Group, whose legal entity
>is Rolls-Royce Engine Control Systems Limited which is registered in
>England.
>Registered office at Moor Lane, PO Box 31, Derby, DE24 8BJ. Company number
>6686268, UK VAT number GB 939 396 075
>
>______________________________________________________________________
>This email has been scanned by the Symantec Email Security.cloud service.
>For more information please contact helpdesk at x2960 or [log in to unmask]
>______________________________________________________________________
>
>______________________________________________________________________
>This email has been scanned by the Symantec Email Security.cloud service.
>For more information please contact helpdesk at x2960 or [log in to unmask]
>______________________________________________________________________
>
>______________________________________________________________________
>This email has been scanned.
>
>______________________________________________________________________
>Aero Engine Controls is part of the Rolls-Royce Group, whose legal entity
>is Rolls-Royce Engine Control Systems Limited which is registered in
>England.
>Registered office at Moor Lane, PO Box 31, Derby, DE24 8BJ. Company number
>6686268, UK VAT number GB 939 396 075
>
>______________________________________________________________________
>This email has been scanned by the Symantec Email Security.cloud service.
>For more information please contact helpdesk at x2960 or [log in to unmask]
>______________________________________________________________________
>
>
>
>______________________________________________________________________
>This email has been scanned by the Symantec Email Security.cloud service.
>For more information please contact helpdesk at x2960 or [log in to unmask]
>______________________________________________________________________

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________