Technetters,

I have several SMT board styles which give me some trouble with 0306
capacitor tombstones, and through many attempts to reduce the number of
these defects, I have found a condition that I can not seem to attribute
a cause to. I have found that across a board, all the tombstones tend to
lift in the same direction (for components in the same orientation).

I have looked at the build process, but different board styles result in
tombstones in different directions, so I believe the cause to be board
related. I have looked at solder mask registration (misregistration
occurs in various directions), power/ground plane connections by pad
(changes from location to location), and solder bumps due to HASL
(wicked pads have similar results), and nothing has led me to a root
cause.

Any ideas???

Thanks,
Ben Gumpert




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