Hello all,

I just subscribed to TechNet, and I have to ask about solder beads, particularly mid-chip.  Here is our process:
1. Solder paste: Multicore NC40, no clean, 53-38 um particle size.
2. Vitronics XPM-820 convection reflow oven.
3. Mydata MY-15 pick and place.
4. Dek Infinity 265 screen printer.
5. Stencils are 6 mil (some are still 8), with 10% reduction and homeplate designs for chip components.

Solder beads still are a part of the process, even after some process improvements.  There may be a higher incidence of them in the summer when the humidity is high due to the operation of the swamp coolers, but I haven't been here long enough to validate this assumption.  My question is, do other people live with solder beads?  What is acceptable?

Howard Watson
Manufacturing Engineer
AMETEK/Dixson
Grand Junction, CO

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