Jim,
Depending on the temporary solder mask there is the potential for
corrosion.  Several companies have a policy of not using materials that
do not pass IPC and/or Bellcore (telecommunications industry) SIR and/or
electromigration criteria.  Certainly that is the ways it works here.
You can either test the stuff yourself, hire it out or see if the
material supplier has the info from their own labs or an independent
third party lab.

Rule of thumb: if you smell ammonia in the product be wary.

Regards,
Bev Christian
Nortel

>----------
>From:  Jim Mathis[SMTP:[log in to unmask]]
>Sent:  Monday, February 16, 1998 4:01 PM
>To:    [log in to unmask]
>Subject:       [TN] pre-wave masking
>
>In an effort to reduce soldershorts at SOICs from occuring during our wave-
>soldering process, we apply what we call "pre-wave mask", pretty typical
>process, I believe.  (The SOICs are previously paste-reflowed.)  However, we
>have experienced damage to the leads of the SOICs when we peel the pre-wave
>mask off from the wave-soldered boards.  In order to prevent this from
>occuring, we are contemplating not peeling this mask away and just leaving it
>on for the life of the product.  The big question:
>
>Is there any long-term reliability issues here?  Could the mask being a
>future
>failure location due to contamination growth or some other reason?
>
>(Thanks to all for any help.)
>
>################################################################
>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
>################################################################
>
>

################################################################
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
################################################################