Re: OT 0805 resistor noise

Winfield Hill wrote:

Walter Harley wrote...

On my very small "production line", we hand-assemble in batches of about a dozen. We've been doing SMT, hand-soldered using .015" solder and a fine-tip soldering pencil. It's actually turned out to be slightly faster than through-hole (because one doesn't have to bend and trim leads or flip the board over to solder), but I will say that it's taken some training to get good soldering quality; and that's with SnPb solder. [ snip ]

We've only just started with SMT, though, so reliability issues (e.g.,
is our soldering any good) remain to be seen.



 What about the high residualy stress left in SMT parts from
 soldering first one side, and then the other?


If the PCB is run thru a hot air tunnel for reflow both times, there is no residual stress.
Case 1: parts so small that no adhesive is needed = the liquid solder's surface tension holds them in place at all times, and the cooling dimensional change is so small that it would seem the stress is more theoretical than a practical "problem".
Case 2: larger parts with adhesive = do not move, so zero problem.
.

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