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Date: | Thu, 19 Dec 96 18:06:57 cst |
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Hi John -
I assume that PLCC is a plastic leadless chip carrier. The reliability
of LCC's as a component type doesn't rank up in the top ten! The
electronics industry as a whole went through quite a bit of testing
for several years with the end result that relying on solder for both
the electrical and mechanical connection was not a good idea. Your 44
pin is a fairly large size and you are putting it on a curve - do a
bunch of testing to assure yourself that the joint reliability meets
your use environment. Werner Engelmeir is a good source for additional
info on the pro's and con's of LCCs - he should be commenting on your
question too. Good Luck.
Dave Hillman
Rockwell Collins
[log in to unmask]
______________________________ Reply Separator _________________________________
Subject: smt / pcb or flex assembly ?
Author: [log in to unmask] at ccmgw1
Date: 12/19/96 1:02 PM
Currently, our design group is considering using SMT parts for
assembly onto an FR4 pcb [one or both sides] with dimensions:
approx 22" x 3". We are confronted with the question as to whether we
can do this reliably since this flat substrate/SMT parts mounted will be
formed [bent] into an arch with a radius of curvature of 36" in the final
assembled
product.
The concern is stress on solder joints even though it is a relatively
small arch. At this point, we only anticipate using 44 pin plcc [50 mil] and
discrete smt r's and c's. If particular packages should or should not be used we
would like to know .
Can anyone recommend an alternative or a source of information regarding the
feasibility of doing this. It would be appreciated. Thanks
__\/__
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