> Hi all.
>=20
> I had an idea for a project that will be subjected to some pretty low
> operating temperatures (say down to -20C). I know there are some
> tricks when using through hole components (ie leaving a bit of extra
> lead to act as a flex point when things contract at different rates),
> but I don't know much about using SMT in low temperatures. I would
> guess that using as fat tracks as possible would be good to try to
> avoid them getting broken. Would a metal clad PCB be an asset or
> liability? I can think of arguments both ways. Any other tips? SOIC
> would probably work size-wise (and have the largest leads), but 0603
> resistors have zero flex.
>=20
> Anyway, it's just an idea for the moment, but I'm curious.

For space applications we need to use laminate that has thermal expansion c=
haracteristics that match the components. The biggest hassle is leadless ch=
ip carriers (microchips QFN packages for example). For this purpose we use =
polyimide laminate commonly, or other more expensive options that even bett=
er match the thermal expansion characteristics.


--=20
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--=20
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