Hello TechNetters,

        I am trying to improve and automate the soldering process for  a
surface mount optical receiver. Presently it is being soldered by hand and
although the results have recently improved, it would be desirable to
automate to improve consistency. The major impediment to automation (and
hand soldering) is the coplanarity of the leads. Over 60% of the parts have
incoming coplanarity greater than 6 mils with a maximum over 10. Due to
handling, by the time the part is placed onto the board and secured in
place, nearly all the parts have greater than 6 mil coplanarity. Because of
the extremely limited supply and uniqueness of these optical devices, the
supplier(s) have not been as responsive to resolving incoming coplanarity
issues as would normally be expected. I have tried a "point to point"
automated solder system, but with the coplanarity issue, it does not
presently appear a viable option. This seems to be an application where hot
bar soldering might be a better solution. The parts have 6 leads at 50 mil
pitch on both the "north" and "south" sides and 4 leads at 31 mil pitch on
the "east" side of the component, all leads are solder dipped. I am not very
familiar with hot bar soldering and would appreciate any input in regard to
this application. Can all three sides be soldered at once? If hot bar
appears viable, which vendors would you recommend? If other solutions spring
to mind, please provide input. Obviously we will continue to work the
coplanarity issue with the supplier(s) but I sure could use a solution now.
Please respond to me directly or via the TechNet if you think it of value to
the group. Any help is greatly appreciated.


Thanks,
Robert Furrow
SMT Process Engineer
Lucent Technologies
978-960-3224    [log in to unmask]

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