Hello Technetters,

Is there anyone out there, still using a dry-film solder mask, such as
Dupont's Vacril.

We have encountered the following problem using the dry-film sm and plating
the tips (computer plug-in cards), by TAB using an acid gold plating bath.

 -The solder mask blisters just at the point where the mask ends and the
tip begins, i.e. a curved discolaration appears and peels upon tape testing
revealing copper beneath.

-We have isolated the blisters to be  occuring within the gold bath and it
intensifies at higher current densities.

-The problem does not appear with any other masks, and only occurs if the
part is plated, i.e. if the boards are run without current but only
solution flow, then no blisters occur.

-The chemistry are all well within operating specs.

If anyone using the dry-film sm has encountered the above problem please
relay your findings.
Any input on possible causes and solutions would be greatly appreciated.

Thanks,
Lenny Kurup
905-475-8000
EMX

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311
################################################################