> =A0We are developing a controller board that will be mounted on a
> machine, the machine will vibrate (shake) heavily, but should not
> exceed 3g ... (balance at at end) ...


   BCCs may have useful comment?

I don't know if the following is an issue but it would be worth being sure =
of.

Old memory SIMS with SMD memory ICsmake good key rings (for some
values of good) - different than most and interesting to other people.

Carry such a keyring in your pocket and you find that all the memory
ICs fall off in quite a short time - weeks to months - one day you
look at the board and note that there are no ICs. Thi is from the
forces experienced in a pocket or, perhaps, when dangling from a car
ignition key?

(All?) Non ferrous metals have no fatigue limit and will fail under
vibration at any level given enough cycles. I don't know the mechanism
for the IC debonding mentioned above but forces in a pocket would not
be expected to be large or especially frequent. Perhaps keychain
vibration is the main mechanism?  Loss of ICs invariably seems to
happen. Solder would probably be tinlead as these were older SIMs some
yeas ago. Maybe I should try it with a newer RAM.


    Russell McMahon


> =A0We are developing a controller board that will be mounted on a
> machine, the machine will vibrate (shake) heavily, but should not
> exceed 3g. We have no control which direction it goes, so the circuit
> board need to sustain vibration in all directions. =A0On top of that,
> the environment is moist, we have some modules mounted with heavy
> insulation inside. The insulation also added weight to the modules
> (the modules are about the size of a deck of poker cards. places wide
> side down to circuit.
>
> =A0What are the good ways to secure the modules and circuit board that
> can sustain the vibrations?
>

--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.