Not a whole lot to go on here, but a few suggestions:

1. No-Clean fluxes are becomming more and more popular because of the
elimination of the CFC's. Therefore, it is unlikely that the mask is
incompatible with the flux used.

2. I would suggest that you ask the assembler to talk to his PWB supplier. It
seems that the boards either had damaged mask when they were shipped to the
assembler or the assembler somehow damaged the mask during assembly.

3. "Holes in the mask" is not very descriptive; however, I interpret this as
mask lifting from the board, probably over the circuits. If this is true,
perhaps the mask was just not applied thick enough, making it vulnerable to
mechanical damage.

Hope this helps some. I'd be happy to discuss this with you further.

Larry Fisher
Dexter Electronic Materials
[log in to unmask]
317-628-7401

***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To unsubscribe from this list at any time, send a message to:           *
* [log in to unmask] with <subject: unsubscribe> and no text.        *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact   *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]      *
***************************************************************************