Hi TechNet,

Last year the Class II requirements for solder fillet height on resistors
and capacitors was changed from requiring a fillet 1/4 way up the
termination (or 0.5 mm) to only requiring adequate wetting and evidence of a
good solder joint. As a result we are accepting a lot of solder joints that
were previously rejected and of course this concerns many. In particular
there seems to be the feeling among some that if they touch up a joint that
meets the new requirement but does not have much fillet height, then a
circuit pack can be made to pass test. They are proposing that in high
frequency applications (2.5 gigabits per second and above),  the additional
solder volume is sufficient to improve the signal. Admittedly I am way out
of my league here, but I am skeptical and feel that the handling of the pack
and removal and insertion of fiber optics may be the actual cause of
acceptance. My question to the TechNet is whether it is possible to improve
performance for high speed signals if you add solder volume to a secure
connection? As always the input from this group is appreciated.

Thanks,
Robert Furrow
Printed Wiring Board Engineer
Supply Chain Networks
Lucent Technologies
978-960-3224    [log in to unmask]

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