Go with the probabilities: the most likely thing to have changed is in
processing rather than materials. Without wishing to teach you how to suck
eggs I think it would be helpful to go back to basics and ensure what you
are actually
doing is what you think you are doing / what you have told your
operatives to do. In my experience most problems with adhesives
which used to work and now don't can be tracked down to finger trouble;
usually storage and handling procedures suffer from a standard which slips
in small unnoticed increments and eventually tips you over into trouble. The
"We aren't doing anything different" thing  may not actually be true if you
look back far enough...
Whether this is the case for you or not you still have to establish that you
are following basic ground rules before you can move on to investigate more
esoteric causes, and certainly if you are going to go back to outside
vendors you need the certainty of knowing that your process is not at
fault.

Mike Fenner
BSP, OX15 4JQ, England
T:+44 1295 722 992
F: +44 1295 720 937
-----Original Message-----
From: Cory and Lise Steeby <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: 02 July 1999 18:35
Subject: [TN] adhesive to solder mask adherence issue


>We are using adhesive to place SMD components and are seeing the something
>fail in the adhesive system.  Parts are falling off the board prior to  the
>wave soldering process and the cured adhesive does not pass the "snap"
test.
>
>When parts are snapped off the board the glue remains on the part and the
>PCB is clean.  The problem did not show up in earlier runs of identical
>product.  We have investigated the PCB fabricators process, the adhesive
>curing process and the adhesive.  Does anyone have any advice?
>
>The adhesive is Loctite 3614
>The mask is Hysol SR1010G
>
>
>Thanks in advance,
>
>Cory Steeby
>EBW Electronics, Inc
>701 Commerce CT
>Holland, MI 49424
>[log in to unmask]
>