We are having some issues with a new solder paste.  The evaluations came out
extremely well at first.  However, upon using it for some trial runs, we run
into some problems.

In our DEK profolw the prints look very good at about 20 deg C.  Throughout
the day, the temp in our facility climbs to 28 or even 30 deg C.  The prints
then start to bridge and flux bleeds out onto the board.  We can compensate
for it to about 25 deg by reducing the proflow pressure and wiping on every
print, but beyond 25 deg, nothing helps.

By the time the 3rd shift rolls in, the temperature starts to drop again and
the prints become more managable again.

Here's the kicker, we use this same paste on our MPM with squeegee's and the
print works every time.  There is never a print problem vs temperature.

Has anybody ever run into this situation?  How did you solve it?

Thanks in advance.

Henry J. Rekers
Manufacturing Engineer
Power Measurement.

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