John--
On all of our assembly drawings that contain thru-hole component leads,
we reference the lead protrusion allowed as a max dimension and allow
"the absence of component lead contour discernibilty in the solder joint
is permissible."(Quote from our drawings). On any design with a total
thickness (pwb + heatsink) above .130, it will contain the note for lead
penetration ""WITOUT PROTRUSION". Since we do only mil work, a WHITE
PAPER was prepared for customer/military approval. We beleive that it is
not a reliability issue based on testing completed in-house. We have many
systems flying without negitive feedback for several years and are very
comfortable with our decision. Feel free to contact me if you have any
questions. Have a good day.
(203) 852-4810 Bob Vanech