**enable spurious "OUT OF OFFICE AUTOREPLY" rejection
filter**
Howard,
I
expect that this defect is "caused" by the pick and place operation. Many
times the p-n-p turns on vacuum to the pickup nozzle before it contacts the part
in the pocket (as it is traveling "down" to get the part). Small parts
like 0805s may "jump" up to the vacuum nozzle, and some perform a half
gainer on the way up. Others don't move til the nozzle actually contacts
the part and forms a vacuum with it, and are thus picked and placed
"right".
The
sideways parts block enough (if not all) of the vacuum nozzle for the machine to
still think it has a part there, the width vs height of the part isn't enough to
trigger the vision alignment system (if in use) to call out a reject or
unalignable part, and it gets placed into the solder paste.
Hope
this helps,
Hal
**disable spurious "OUT OF OFFICE AUTOREPLY" rejection
filter**
Technetters,
I'm not sure
if others see this situation, but it's a somewhat rare occurrence when we see
some resistors, like 0805's, soldered on their sides. Though it's not a
defect per the conditions of IPC-A-610, I am still curious as to the root
cause. I don't know if they somehow get placed on their side or if they
get pulled up that way during soldering. Our P&P machine is a Mydata
MY15, we use no-clean with reflow in air, HASL boards, 6 mil stencil w/
homeplate apertures.
Any
thoughts?
Howard Watson
SMT
Manufacturing Engineer
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