Question: Viability of manual pot soldering with untrimmed through hole
leads.

I am dealing with a manufacturer afar off who is using a subcontractor who
proposes soldering through-hole, 5mm 2 wire LEDs using a manual solder pot
system.
ie not an automated flow solderer but a physical temperature controlled
solder pot designed for the purpose.
Labour rates may make this competitive with both more and less mechanised
alternatives

Potentially this is an entirely viable system to use if appropriate
precautions are taken.
There is much more that could be said, but this application note does a
reasonable job of summarising the key issues
This targets mainly wave and hand soldering but much in it is relevant.

           http://bit.ly/Avago_AN5334_Soldering_through-hole_LEDs

It is claimed by the manufacturer that the LEDs are soldered with the leads
full length* and that the leads are then trimmed using side-cutters after
soldering.
This is one version of normal  practise for fully hand soldered PCBs.

I consider this claim highly suspect for dip soldering, as the long LED
leads would acquire much waste solder. there is a risk of bridges forming
and the whole process would be generally unwieldy. LED inter-lead spacing i=
n
the package is the standard 0.1 inch.

An advantage if this was in fact being done, and if the LEDs could be
maintained correctly directionally aligned during soldering by whatever
means, is that final trimming could be more rapid than if a manual cinch an=
d
cut tool was used prior to soldering. (I am aware of some people using
 power abrasion  (grindstone or similar) to bulk remove leads after
soldering. Doable with due care.

Question:  What are the chances that the LEDs are being trimmed after
soldering? ie pot soldered with long leads. Has anyone any experience with
pot soldering populated through hole PCBs?


               Russell
--=20
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