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Date: | Fri, 08 Nov 1996 08:54:00 -0500 (EST) |
Content-Type: | TEXT/PLAIN |
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Both J-STD-001B (paragraph 9.2.6.1, Figure 9-4, Note 1) and MIL-STD-2000A
(paragraph 4.23.7.5) allow solder in the upper bend on gull wing leads.
MIL-STD-2000A even goes further by saying "Solder in the stress relief bends
does not constitute elimination of stress relief." (Table I, defect 3). This
changed from MIL-STD-2000 rev - which said "The solder fillet for any lead
shall not extend into the start of the upper bend radius." (paragraph
4.19.5.5).
I'm assuming that the requirement (or lack of) in the J-Standard was copied
from the MIL Standard, rev A. When MIL-STD-2000A was generated, was there test
data which verified that the reliability integrity of gull wing devices wasn't
compromised when solder entered the upper bend radius?
If anyone knows why the requirement changed, or, even better, knows where I can
get the reliability data, this would be great. I would also like to know if
nobody knows why the requirement changed.
Thanks...
Jim Marsico
(516) 595-5879
[log in to unmask]
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