Sean,

If the oven checks out - profile is OK, etc- be sure to look upstream at
the pick-n-place.  Makre sure there are no nicks on the placement nozzels
etc.  This falls back to the mis-allignment mentioned earlier.

Also, from a board design perspective, check the density of the metal that
the leads feed into.  i.e. 1 oz copper voltage plane and 2 oz copper ground
plan.  If you have a difference like that it can cause temperature
gradients which (especially if combined with mis-registration) can cause
tombstoning.

Douglas Bennett
Sales Engineer
Heraeus Amersil, Inc.
Atlanta, Georgia, USA
[log in to unmask]


At 11:12 AM 1/14/98 EST, you wrote:
>     We have been experiencing problems with tombstoning of 1210 caps.  I
>     have not been able to find any information about parts this large
>     tombstoning.  Is there any way to fix this problem while we are
>     waiting for a design change to the pad layout?
>
>     Any help on this subject will be greatly appreciated.
>
>     Sean Gearin
>     [log in to unmask]
>
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